Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 1
Thomas Broadbent and Sons Limited
OPERATING MANUAL
1 x SPV1425 CONTINUOUS
SUGAR CENTRIFUGE
Serial Number
H95702
Gai Lai Sugar Mill
Vietnam
Thomas Broadbent & Sons Ltd
Queen Street South
Huddersfield
HD1 3EA
ENGLAND
©
2015 Thomas Broadbent & Sons Ltd
Operating Manual for SPV1425 Continuous Centrifuge H95702
Written/Modified
Mechanical
©
Page 2
Checked
By
Date
By
Date
KK
11.08.15
GH
12.08.15
2015 Thomas Broadbent & Sons Ltd
Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 3
IMPORTANT INFORMATION
This instruction manual must be studied carefully before attempting to Install, Operate or
Maintain the equipment. Particular attention is drawn to the installation, monitoring, and
protection requirements together with start-up and shut-down procedures.
It should be noted that Thomas Broadbent & Sons Ltd will not accept liability for direct or
consequential damage, loss or injury that may arise from any failure to comply strictly to the
instructions contained in this manual and good engineering practice as covered by the
Standards, Regulations and Codes of Practice referenced in this manual or applicable in the
country of installation.
It is recommended that the installer and user consider the employment of the experienced
Service Personnel of Broadbent Ltd to assist with the installation, commissioning and
maintenance of the equipment. A member of our Service Department will be pleased to
discuss your requirements in this respect. Contact details are given below.
The provisions of the equipment, process or other guarantees may be invalidated if the
equipment is not installed, started, stopped, operated and maintained strictly in accordance
with this manual using trained and qualified personnel. It is a condition of the guarantee that
formal records are maintained by the installer and user detailing:
1)Tests or checks carried out on the equipment and its associated
monitoring and protection systems during installation and commissioning.
2)Maintenance undertaken during the life of the equipment.
3)Tests and checks carried out on the equipment and its associated
monitoring and protection systems during the operational life of the
equipment to ensure their correct functioning.
4)Any defects encountered in the operation, installation or maintenance of
the equipment.
5)Training of personnel operating and maintaining the equipment.
These records must be made available to Broadbent Ltd upon request.
If in doubt regarding any aspect of these instructions or if requiring additional information
assistance should be sought from Broadbent Ltd before operating the equipment. In all
communications please state the equipment serial number detailed on the equipment
nameplate.
Contact details:
Thomas Broadbent & Sons Ltd
Broadbent Incorporated
Queen Street South
2509 Gravel Drive
Huddersfield
PO Box 185249
West Yorkshire
Fort Worth, Texas 76118
UK
USA
Tel: +44 (0) 1484 422111
Tel: +1 (817) 595 2411
Fax: +44 (0) 1484 423159
Fax: +1 (817) 595 0415
E-mail: sugar@broadbent.co.uk
E-mail: broadbent.inc@att.net
©
2015 Thomas Broadbent & Sons Ltd
Operating Manual for SPV1425 Continuous Centrifuge H95702
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2015 Thomas Broadbent & Sons Ltd
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Operating Manual for SPV1425 Continuous Centrifuge H95702
CONTENTS
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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CONTENTS
INTRODUCTION
SAFETY
CENTRIFUGE
1 DESCRIPTION
2 TECHNICAL DATA
3 SITE REQUIREMENTS
4 INSTALLATION
5 OPERATION
6 MAINTENANCE
7 FAULT DIAGNOSIS
8 PART LISTS
FEED CONTROL VALVE - MetalWork (Thailand)
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INTRODUCTION
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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INTRODUCTION
This manual applies to the Broadbent SPV1425 Vertical Axis Conical Basket Self
Discharging Continuous Centrifuge, supplied to Gai Lai Sugar Mill, Vietnam. Which is to be
used for processing Cane ‘C’ Sugar Massecuite.
This manual details the technical features, installation, maintenance and operation of the basic
centrifuge as supplied by Broadbent. It also specifies the requirements for the supporting
structure, process connections, and power supply.
NOTE: ILLUSTRATIONS IN THIS MANUAL MAY DIFFER IN DETAIL
FROM THE EQUIPMENT SUPPLIED. ALWAYS REFER TO THE
REFERENCE DRAWINGS LISTED IN SECTION 2 AS THE DEFINITIVE
VERSION.
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SAFETY
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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SAFETY
A safety information plate is attached to the centrifuge casing. It contains important advice
essential to the safe installation and use of the machine. The notice in English, is reproduced
below for information.
DANGER
IMPORTANT SAFETY INFORMATION
For SAFE and RELIABLE OPERATION, this equipment MUST be installed, operated and
maintained by trained personnel in accordance with safe engineering practice and the
current edition of the instruction manual issued by Thomas Broadbent & Sons Ltd.
The equipment should only be used for purposes agreed at the time of sale and notified at
such time to Thomas Broadbent & Sons Ltd. It must NOT be used for any other purpose
without the written approval of Thomas Broadbent & Sons Ltd or otherwise authorised and
qualified personnel.
Guards and Interlocks are designed and fitted in the interests of safety and UNDER NO
CIRCUMSTANCES should the equipment be operated with Guards removed or Interlock
switches overridden.
In the event of MALFUNCTION the equipment should be SWITCHED OFF and (where
appropriate) disconnected. It should then be inspected and repaired by a suitably qualified
technician before attempting to use the equipment.
FAILURE TO COMPLY WITH THIS PROCEDURE COULD RESULT IN SEVERE OR
FATAL INJURIES.
In case of doubt or continuing difficulty concerning the installation or operation of this
equipment, contact
BROADBENT CUSTOMER SERVICES LTD
Huddersfield, HD1 3EA, England
Telephone: 01484 477200 Telex: 51515 TBS G Fax: 01484 516142
Outside Normal Office Hours: Telephone 01484 424660
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Operating Manual for SPV1425 Continuous Centrifuge H95702
1 DESCRIPTION
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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1 DESCRIPTION
1.1 PRINCIPLES OF OPERATION
1.2 MONITOR CASING
1.3 BASKET ASSEMBLY
1.4 SPINDLE ASSEMBLY
1.5 DRIVE AND TRANSMISSION ASSEMBLY
1.6 SUSPENSION SYSTEM
1.7 PROCESS FITMENTS AND CONTROLS
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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1 DESCRIPTION
The SPV1425 continuous centrifuge is designed to separate sugar crystals from the mother
liquor in low grade massecuites. The whole process is carried out within a single free
standing unit.
1.1 PRINCIPLES OF OPERATION
Massecuite is fed at a carefully controlled rate into a central feed inlet cone on the top
of the centrifuge. This feed cone has facilities to add steam to reheat and improve the
fluidity of the massecuite, and to add water to lubricate the flow. The massecuite then
flows into an unperforated inverted cone, which accelerates and distributes the flow,
ready for uniform feeding into the base of the basket.
Centrifugal forces cause the massecuite to flow up the conical basket, and also separate
the mother liquor from the crystals. The mother liquor passes through the filtering
screens and basket perforations, and is collected in the inner chamber of the casing, and
discharged via a pipe beneath. A spray bar allows the crystals to be washed with water
as they move up the basket. The crystals are eventually expelled off the top rim of the
basket, and fall down the outer annulus of the casing into a discharge chute, leading to
a conveyor running beneath the centrifuge.
1.2 MONITOR CASING
The monitor casing is a heavy duty fabrication, comprising an open topped inner
chamber, supported concentrically within an outer casing by means of a number of
radial spokes. The inner chamber houses the rotating basket and spindle assemblies, and
serves to collect the molasses passing through the basket filtering screens, which
subsequently drain away down a pipe in the floor. The annulus between the inner and
outer casings collects the sugar crystals expelled from the top of the basket
The mounting points for the centrifuge supports, and for the drive motor are attached to
the outer casing. An open bottomed channel spans the annular space between the inner
and outer casings, and partially encloses the belt drive.
The top of the outer casing is flanged for attaching the casing cover, which supports
many of the process fitments. The whole cover or a triangular panel can be removed for
maintenance on the interior of the centrifuge. In addition, a small hinged inspection
hatch with protective grill can be opened for observations during operation.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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Figure 1.1 General Arrangement of Centrifuge
Lubrication Water
Connection
Steam
Reheat
Connection
Massecuite
Feed
Cone
Support
Pedestals
Vibration
Isolator
Monitor
Casing
Main Drive
Motor
Inspection
Covers
Sugar
Sampler
Inspection
Hatch
Molasses
Outlet
Free Standing
Water / Steam
Control
Manifold
Flexible
Hoses
Screen Wash
Connection
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2015 Thomas Broadbent & Sons Ltd
Vibration
Isolator
Outer
Casing
Sugar
Discharge
Molasses
Baffle
Inner (Molasses) Spindle
Chamber
Assembly
Basket
Assembly
Feed
Cone
Driven
Pulley
Basket Wash
Spray Pipe
Drive
Belts
Molasses
Outlet
Casing
Wash Ring
Driving
Pulley
Main Drive
Motor
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Figure 1.2 Sectional Arrangement of Centrifuge
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2015 Thomas Broadbent & Sons Ltd
Seal Collar
Lower Bearing
Cap and Seal
Angular Contact
Ball Bearing
Cylindrical
Roller Bearing
Distance
Piece
Spindle
Cylindrical
Roller Bearing
Upper
Bearing Cap
Bearing
Housing
Clamping
Ring
Basket
Hub
30° Conical
Perforated
Basket
Accelerator
Cone
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Figure 1.3 Sectional Arrangement of Rotating Assembly
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1.3 BASKET ASSEMBLY
The basket is an open topped conical dish mounted on a central cylindrical hub, which
encloses the spindle assembly. The basket is perforated by a spiral pattern of holes,
designed to give unrestricted exit of the molasses. A deep groove around the top of the
basket ensures that molasses cannot run up over the basket lip.
A unique three element screen is fitted. This comprises a coarse backing mesh, a finer
intermediate mesh and a finely slotted front filtering screen. This system allows easy
dispersion of the mother liquor whilst providing uniform support for the front screen
and thereby ensuring a long working life. The backing mesh is tack welded directly to
the basket. The intermediate mesh is retained at the bottom edge by a circlip ring fitted
into a groove in the basket, and the top edge is folded back under the backing mesh.
The filtering screen, in 5 segments, rests on the inner surface of the cone. A clamping
ring screwed into the base of the basket clamps the bottom edges of the segments, and 5
clips screwed to the top rim of the basket locate the top edges.
The extended top flange of the basket has a deep rib on its underside. In conjunction
with a baffle ring attached to the wall of the monitor casing inner chamber. This
produces an effective labyrinth seal, preventing any overspill of mother liquor into the
sugar compartment.
Figure 1.4 Screen Fixing Details (Typical Only)
Screen
Retaining
Clip
BASKET
TOP
Slotted
Working
Screen
Intermediate
Mesh
Intermediate
Mesh
Grooved and
Perforated
Conical Basket
Backing
Mesh
Slotted
Working
Screen
Backing
Mesh
Slotted
Working
Screen
Intermediate
Mesh
Circlip Ring
Screen
Clamping
Ring
BASKET
BASE
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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1.4 SPINDLE ASSEMBLY
The hub of the basket is flange and spigot mounted on a vertical spindle. The spindle
rotates in a rigid bearing housing, which is in turn spigot mounted to the thick floor of
the monitor casing inner chamber. The spindle is located radially by fixed cylindrical
roller bearings at the bottom and top. The weight of the rotating assembly is carried by a
4 point angular contact ball bearing at the bottom. All bearings are continuously rated
and lubricated with special high temperature grease, via flexible tubes leading to
nipples at the front of the casing. The bearing assembly is sealed at both ends by special
lip seals in each bearing cap.
1.5 DRIVE AND TRANSMISSION ASSEMBLY
The electric motor drive and belt transmission are integral with the centrifuge, to ensure
constant drive centres under all dynamic conditions, and thus to maximise belt life.
The lower end of the spindle carries a pulley, which is driven through a matched set of
5 wedge belts by a totally enclosed fan ventilated electric motor. The motor is mounted
shaft downwards on an adapter plate, attached to the monitor casing by 4 large studs,
which allow adjustment of the drive belt tension. The drive belts and pulleys are
accessible by removal of light guard covers attached to the underside of the monitor
casing transmission tunnel.
1.6 SUSPENSION SYSTEM
The whole centrifuge is supported on 3 pedestals around the outside of the monitor
casing via metal spring vibration mounts. These isolate the supporting structure from
any out of balance forces in the basket. This arrangement has several advantages. The
vibration isolators are readily accessible for adjustment. There is no relative motion
between the basket rim and the casing baffle, so an effective molasses seal is obtained
without the need for flexible molasses seals, which may be subject to deterioration.
There is no relative movement between the driving and driven pulleys thus maximising
belt life.
The external vibration isolation arrangement means that out of balance in the basket
will cause small amplitude motion of the whole monitor casing. It is therefore essential
that there are no rigid connections between the casing and fixed equipment. In
particular, all pipework connections must incorporate gaps or flexible sections to permit
slight movement of the casing.
1.7 PROCESS FITMENTS AND CONTROLS
Figure 1.5 is a process and instrumentation diagram showing the various process flows
into and out of the centrifuge, together with various options for control equipment and
instrumentation. A precise specification of the extent of supply by Broadbent on this
particular contract is given in section 2.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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Figure 1.5 Schematic Process and Instrumentation Diagram
Massecuite
Crystalliser
or Manifold
Feed
Lubrication
Water
F3
V3
V1
A1
Feed
Reheat
Steam
P4
V4
Wash
Water
F5
V5
V2
Monitor
Casing
Steamout
A2 P2
V6
LS1
VT1
Sugar Crystal
Discharge
Mother Liquor Molasses
Discharge
1.7.1 Massecuite Feed System
To prevent massecuite being trapped and setting in the feeding line, an isolation
valve V1 will be installed as close as possible to the feeding vessel or manifold.
V1 is a 250mm (10”) NB Butterfly Valve (* MetalWork, Supply), with double
acting pneumatic cylinder A1, fitted with a 110V AC solenoid valve for open/shut
operation from the Control Panel.
The flow of massecuite into the centrifuge is modulated by a flow control feed
valve V2. This is a 200mm NB butterfly valve, and is operated by a double acting
pneumatic actuator A2, controlled by an electro-pneumatic positioner P2. The
positioner/actuator works in a feedback loop, using the drive motor current as a
setpoint. Since the drive motor current is proportional to massecuite throughput,
the valve automatically opens or closes to maintain a constant throughput, even if
the massecuite head or viscosity varies. * Note - The feed system should be as
shown on General Arrangement drawing (Section 2.2), NOT as shown above,
therefore LS1 is not required.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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1.7.2 Water and Steam Systems
Lubrication water can be sprayed onto the massecuite rope as it enters the
centrifuge from a ring around the inside of the centrifuge feed cone. This flow is
controlled manually using a hand valve V3 and visually reading flowmeter F3
mounted on the manifold.
Wash water can be applied onto the sugar crystals as they move up the basket
from a spraying bar inside the centrifuge. This flow is controlled manually using a
hand valve V5 and visually reading flowmeter F5.
Reheat steam can be added to the massecuite as it enters the centrifuge from the
perforated jacket surrounding the feed cone. This flow is controlled manually
using a hand valve V4 and visually reading pressure gauge P4.
The casing can be cleaned by introducing steam into a spray ring installed in the
top of the monitor casing outer chamber. This Casing Steamout flow is
controlled manually using a hand valve V6.
All the above valves and gauges are mounted on a manifold, which is free
standing next to the outer casing, and forms the termination point to the client’s
water and steam supplies. The water and steam flows are carried from the
manifold to the various points on the centrifuge by braided flexible hoses.
1.7.3 Control System
The control system is used to start, stop and protect the centrifuge drive motor. It
also provides automatic control of the massecuite feed valve, based on the
centrifuge motor current. The control system comprises a Starter Panel and a PLC
controlled Operator Panel.
The Starter Panel is a large, wall mounted unit which is connected to the client's
3 phase electrical supply. It houses the main isolator switch and the star-delta
motor starter contactors with an adjustable delay timer. A thermistor relay
provides protection against overloading the motor. A transformer provides the
supplies for the relays and for the Operator Panel. An anti-condensation heater is
fitted.
The Operator Panel is a smaller box which can be mounted on a post close to the
centrifuge. It houses the main PLC controller, operator two line display interface,
start and stop pushbuttons and a running light, which are wired back to the Starter
Panel. The PLC controller takes a 4-20mA analogue input from a motor current
transducer in the Starter Panel. The PLC controller then produces a 4-20 mA
analogue output reference current, which is used as the input to the positioner on
the massecuite feed control valve P2 .
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Operating Manual for SPV1425 Continuous Centrifuge H95702
2 TECHNICAL DATA
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2 CENTRIFUGE TECHNICAL DATA
2.1 GENERAL
2.2 REFERENCE DRAWINGS
2.3 CENTRIFUGE
2.4 OPTIONAL ANCILLARY EQUIPMENT
2.5 PERFORMANCE
2.6 NOISE AND VIBRATION
2.7 WEIGHTS
2.8 TIGHTENING TORQUES
2.9 VIBRATION ISOLATOR SETTINGS
2.10 CONVERSION FACTORS
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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2 CENTRIFUGE TECHNICAL DATA
1 x SPV1425 Continuous Centrifuge
Serial Number H95702
Gai Lai Sugar Mill, Vietnam.
2.1 GENERAL
Broadbent Designation
Broadbent SPV1425/30-F6-110-(F)
Continuous Sugar Centrifuge
Design and Construction Standards
Generally in accordance with the
requirements of:
European Standard BS EN 12547
Type
Vertical axis conical basket self
discharging continuous centrifuge
Product Processed
Sugar Massecuite only
Maximum specific gravity SG 1.5
2.2 MECHANICAL REFERENCE DRAWINGS
General Arrangement of Centrifuge
5131-2002
Sectional Arrangement of Centrifuge (* 1750 RPM)
5035-2014
Rotating Assembly Arrangement
5953-2033
Spindle and Bearing Housing Arrangement
5500-2025
Centrifuge Water and Steam Arrangement (* Platon)
5553-2006
Screen Wash Spray Pipe Arrangement
55530-080
Typical Split Hopper SPV1425
59531-009
Intermediate Screen Fitting Ring SPV1425
59531-005
FOR ELECTRICAL DRAWINGS REFER TO SEPARATE MANUAL
SUPPLIED WITH THE STARTER PANEL AND OPERATOR PANEL.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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2.3 CENTRIFUGE
Monitor Casing
Carbon steel inner chamber.
Carbon steel outer casing and spokes.
Carbon steel outer casing steamout ring.
Carbon steel casing top and covers.
Austenitic stainless steel single molasses baffle.
Suspension
3 point external supports around outer casing.
Steel coil spring vibration isolators.
Carbon steel support pedestals.
Basket
30o conical basket, fabricated construction.
Duplex stainless steel top flange with single molasses baffle.
Duplex stainless steel cone, spiral perforated.
Austenitic stainless steel base.
Screens
Chromium plated nickel slotted sheet 5 segment working screen.
Austenitic Stainless Steel No16 Intermediate Mesh.
Austenitic Stainless Steel 5mm sq aperture Backing Mesh.
Austenitic Stainless Steel clamping ring.
Basket Hub
Carbon steel fabricated ‘top hat’
Spindle Assembly Cast iron bearing housing.
Fine grained forged carbon steel spindle.
Cylindrical roller upper radial bearing.
Cylindrical roller lower radial bearing.
4 point angular contact ball thrust bearing.
Lubrication by high temperature mineral oil/lithium soap grease
Mobilith SHC 220.
Drive Motor
Hascom (* MRP Supplied) squirrel cage induction motor 280M
TEFV.
Vertically mounted, shaft end down on carbon steel support plate
which is in turn supported by 4 studs off the outer casing.
3 phase 380 - 415 V 50 Hz.
110kW at 1485 rpm (4 pole).
205 A full load current.
45 A (approx) with centrifuge running empty.
Transmission
Matched set of 5 wedge belts between pulleys on centrifuge
spindle and motor shaft.
Tension adjustment by 4 studs supporting motor plate off casing.
Feed System
Austenitic stainless steel central feed cone attached to casing top
with facilities for steam reheat and lubrication water addition.
Austenitic stainless steel integral distributor pot and imperforate
accelerator cone attached to basket hub.
Wash System
Austenitic stainless steel spray bar with V jet nozzles mounted on
casing top.
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2.4 PROCESS AND CONTROL EQUIPMENT
Refer to section 1.7 and Figure 1.5.
Massecuite Feed
200mm (8’’) butterfly feed control valve V2 with double acting
pneumatic actuator A2 and 4-20mA positioner P2.
See Appendix A
Centering cone to suit feed control valve, plus a clear shroud and
ducting to form a totally enclosed feed system.
250mm (10”) butterfly isolating valve V1 with doubling acting
pneumatic cylinder A1, fitted with a 110V AC solenoid valve. See
Table 8.1 for Recommended Spares. Feed pipework to be supplied
by client (See Sections 1 and 3).
Water and Steam Manifold complete with manual valves V3 to V6, visually reading
flowmeters F3, F5 and visually reading pressure gauge P4.
Braided flexible hoses from manifold to connections on centrifuge.
Water and steam supplies together with any pressure regulators
and/or filters necessary to meet the conditions specified in
section 2.5 to be supplied by client (see section 3).
Sugar Discharge
Conical Split Hopper (See 59531-009 for Info), discharge chute to
be supplied by client.
Starter Panel
110kW star-delta starter panel complete with contactors and
protection relays. (CPT Drives, Thailand supply).
All wiring from supply and between panels and centrifuge to be
supplied by client.
Operator Panel
Operator panel with PLC and two line display giving automatic
control of feed valve, pushbuttons, indicator lamps and switches.
(CPT Drives, Thailand supply).
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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2.5 PERFORMANCE
Basket Cone Angle
30o
Basket Major Diameter (nominal)
1425 mm (56 inch)
Working Screen Surface Area
2.5 m2 (26.9 ft2)
Maximum Design and Test Speed
1800 rpm
Separating Effect at Maximum Speed
2580 G
Compressed Air - Must be supplied clean (filtered), dry, unlubricated, between 4
bar g to 6 bar g (60 psi to 90 psi), 5.5 bar g optimum, at ambient temperature.
(see section 3.2.3).
The following table summarises the estimated process performance for these particular
applications.
Serial Number
H95702 for ‘C’ Massecuite
Massecuite
1750 RPM - ‘C’ Massecuite
Separating Effect
2440 G at 1750 RPM
Working Screens
0.06mm x 2.80mm slots, (10% open area)
Lubrication Water Clean water, strained to remove debris, sand, rust etc.
3 to 5 bar g mandatory
70oC to 95oC mandatory
Up to 10 litre/minute
Wash Water
Clean water, strained to remove debris, sand, rust etc.
3 to 5 bar g mandatory
70oC to 95oC mandatory
Up to 10 litre/minute
Steam
Clean dry or wet steam, strained to remove debris, sand,
rust etc.
2 to 3 bar g mandatory
120oC to 140oC recommended Up to 500 kg/hour
Water and steam must be supplied at the conditions indicated above. Any departure
from this may require different size nozzles to be fitted.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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2.6 NOISE AND VIBRATION
Since the whole centrifuge is suspended on external spring isolators, any out of balance
in the basket will cause the whole casing to move slightly at the centrifuge shaft rate.
The amplitude of this shaft rate vibration is proportional to the size of the out of balance
and therefore gives an indication of loads and stresses in the rotating assembly.
Vibration levels should be measured using a probe radially on the outside of the outer
casing. The levels quoted below are at shaft rate frequency so the vibration equipment
should be used either with a spectrum analyser to give the shaft rate spike or with a low
pass filter to remove frequencies above 50 Hz.
Typical Levels during operation will depend on the quality, throughput and uniformity
of the massecuite being processed.
Typical Noise Intensity when Running
85 dBA at 1 metre from casing
Typical Vibration Level when Running
2 to 7 mm/s RMS
(0.04 to 0.15 'G' RMS)
To ensure long bearing and shaft life, the following limits on vibration levels are
recommended during operation. Refer to section 6.
Warning Level
Stop massecuite feed immediately. If
vibration does not decrease, stop
centrifuge and carry out Fault Diagnosis
before further extended running
Trip Level
Stop massecuite feed and stop centrifuge
immediately. Carry out Fault Diagnosis
before running again.
0.30 ‘G’ RMS for over 15 seconds
(16 mm/s RMS for over 15 seconds)
0.60 ‘G’ RMS for over 5 seconds
(30 mm/s RMS for over 5 seconds)
2.7 WEIGHTS
Centrifuge Total (excluding pedestals and discharge pipework)
4300 kg
Monitor Casing and Molasses Baffle
2350 kg
Monitor Casing Covers
130 kg
Basket and Hub
420 kg
Spindle Assembly and Driven Pulley
265 kg
Drive Motor
660 kg
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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2.8 FASTENER TIGHTENING TORQUES
WARNING: For safe and reliable operation of the centrifuge,
fasteners on the rotating assembly must be torque tightened and
locked as specified on Figure 2.1
Fasteners should be cleaned and smeared with fresh thread locking compound before
reassembly. Where several fasteners are fitted, they should be tightened evenly in
diagonal pattern to the torques specified.
A
C
B
D
E
F
G
H
J
K
Figure 2.1 Fastener Tightening Torques
Ref
Location
Type
No off
Torque
A
Working Screen Clip to Basket
M8 Socket Head Capscrew SS
10
15 Nm
B
Basket Hub to Spindle Flange
M16 Socket Head Capscrew HTS
6
250 Nm
C
Accelerator Cone to Basket Hub
M12 Hexagonal Head Screw SS
6
65 Nm
D
Top Bearing Cap to Bearing Housing
M12 Hexagonal Head Screw HTS
6
100 Nm
E
Accelerator Centering Screws
M10 Hexagonal Head Screw SS
6
30 Nm
F
Clamping Ring to Basket
M12 Socket Head Capscrew SS
8
78 Nm
G
Basket to Basket Hub
M16 Socket Head Capscrew SS
8
196 Nm
H
Bearing Housing to Monitor Casing
M20 Socket Head Capscrew HTS
12
380 Nm
J
Bottom Bearing Cap to Bearing Housing
M12 Hexagonal Head Screw HTS
6
100 Nm
K
Driven Pulley to Spindle
M20 Hexagon Head Screw HTS
1
380 Nm
NOTE
SS indicates stainless steel and HTS indicates high tensile steel fasteners
IMPORTANT All Fasteners to be locked using Loctite Nutlock 242 or Permabond Threadlock A130
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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2.9 VIBRATION ISOLATOR SETTINGS
Important - Ensure the isolators are fitted in the correct positions.
Front Column - Type ODL D30A
(Part No 22200-045)
Rear Columns - Type ODL D40
(Part No 22200-038)
Refer to section 6 for procedure for adjusting vibration isolators. The following settings
are applicable,
Setting screw size
M24
Setting screw length ‘Y’
100 mm
Recommended initial setting ‘X’ for all isolators
54 mm
Minimum allowable ‘X’ for front isolator
43 mm
Minimum allowable ‘X’ for rear isolators
46 mm
2.10 CONVERSION FACTORS
All data in this operating manual is given in metric units. Figure 2.2 gives conversion
factors to other common units.
Figure 2.2 Selected Conversion Factors
Length
1 m (metre) = 1000 mm (millimetre) = 39.4" (inch) = 3.28 ft (foot)
1 mm (millimetre) = 0.001 m (metre) = 0.0394" (inch)
1" (inch) = 0.0833 ft (foot) = 0.0254 m (metre) = 25.4 mm (millimetre)
1 ft (foot) = 12" (inch) = 0.3048 m (metre) = 304.8 mm (millimetre)
Velocity
1 m/s (metre/sec) = 3.6 kmph (kilometre/hour) = 3.28 fps (foot/sec) = 2.24 mph (mile/hour)
1 fps (foot/second) = 0.3048 m/s (metre/second)
Acceleration 1 G (acceleration due to gravity) = 9.81 m/s2 (metre/second2) = 32.2 ft/s2 (foot/sec2)
1 m/s2 (metre/sec2) = 3.28 ft/s2 (foot/sec2) = 0.102 G
1 ft/s2 (foot/sec2) = 0.3048 m/s2 (metre/sec2) = 0.0311 G
Volume
1 m3 (cubic metre) = 1000 litre = 220 Imperial gallon = 264 US gallon = 35.3 ft3 (cubic foot)
1 litre = 1000 cm3 (cubic centimetre) = 0.0353 cuft (cubic foot) = 35.2 floz (fluid ounce)
1 cm3 = 0.061 in3 = 0.0352 floz (fluid ounce)
1 Imperial gallon = 1.20 US gallon = 4.546 litre = 4546 cm3 (cubic centimetre)
1 US gallon = 0.833 Imperial gallon = 3.785 litre = 3785 cm3 (cubic centimetre)
Mass
1 Te (metric tonne) = 1000 kg (kilogram) = 0.984 ton = 2205 lb (pound)
1 kg (kilogram) = 1000 gm (gram) = 2.205 lb (pound)
1 lb (pound) = 0.4536 kg (kilogram) = 453.6 gm (gram)
Force
1 kgf (kilogram-force) = 9.81 N (newton) = 2.205 lbf (pound-force)
1 N (newton) = 0.102 kgf (kilogram-force) = 0.225 lbf (pound-force)
1 lbf (pound-force) = 0.4536 kgf (kilogram-force) = 4.448 N (newton)
Pressure
1 bar = 0.1 MPa (megapascal) = 14.50 psi (pounds/inch2)
1 psi = 0.06895 bar = 6895 Pa (pascal)
Torque
1 Nm (newton-metre) = 0.737 lbft (pound-foot)
1 lbft (pound-foot) = 1.356 Nm (newton-metre)
Power
1 kW (kilowatt) =1000 Nm/s (Newton-metre/sec) = 1.341 hp (horsepower)
1 hp (horsepower) = 0.746 kW (kilowatt) = 746 Nm/s (Newton-metre/sec)
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3 SITE REQUIREMENTS
Refer to the sections
IMPORTANT INFORMATION and SAFETY
at the start of this Operating Manual
©
2015 Thomas Broadbent & Sons Ltd
Operating Manual for SPV1425 Continuous Centrifuge H95702
3 SITE REQUIREMENTS
3.1 SUPPORTING STRUCTURE
3.2 PROCESS HARDWARE
3.2.1 Massecuite Feed System
3.2.2 Water and Steam Systems
3.2.3 Compressed Air Supply
3.2.4 Discharge Systems
3.2.5 Electrical System
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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3 SITE REQUIREMENTS
Several items of ancillary equipment are necessary to allow the basic centrifuges to be used,
most of which can be provided by Broadbent. In some cases, the client decides to supply this
ancillary equipment. A precise specification of the extent of supply by Broadbent on this
particular contract is given in section 2.
This section gives guidance on the design and selection of ancillary equipment to be provided
by the client.
3.1 SUPPORTING STRUCTURE
The centrifuge can be supported on a concrete floor or, more usually, on a structural
steel framework. All the dimensions and loadings necessary to design the structure are
given on the relevant arrangement drawing specified in section 2.
(a) Attachment points must be provided to suit the bases of the centrifuge's
three support pedestals. These three anchoring pads should be as level as
possible.
(b) There must be a clear opening through the steelwork directly beneath
the casing to allow a sugar discharge chute to be fitted.
(c) There must be clear headroom above the centrifuge to allow access for a
crane to lift out the basket and the motor.
(d) The whole centrifuge moves slightly on its anti-vibration mounts so all
steelwork must be at least 10 mm clear of the centrifuge and any
equipment rigidly attached to the centrifuge (e.g. The discharge chute).
Due to out of balance loads in the centrifuge, dynamically varying loads will be
transmitted to the support structure. Support structures for centrifuges must usually be
significantly more substantial than structures carrying purely static equipment such as
tanks or vessels. There are two design criteria,
The STRENGTH of the structure must be sufficient to carry the static loads of
the centrifuge plus the static weights of any other equipment (vessels, process
equipment etc) all multiplied by a vibration factor of 3. A suitable national or
international standard for structural design should be used.
The STIFFNESS of the structure must be high enough that resonant frequencies
of the equipment on the structure are at least 30% above the maximum running
speed of the centrifuge (i.e. above 43 Hz). The structure will be sufficiently rigid
if the average of the deflections at each load attachment point due to simple
static weight of the centrifuge plus other equipment (without factor of 3 applied)
does not exceed 0.14 mm
Structures which are too flexible will give an uncomfortable working environment, and
in extreme cases may cause premature failure due to fatigue.
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3.2 PROCESS HARDWARE
Refer to the schematic process and instrumentation diagram shown in Figure 1.5.
NOTE The entire centrifuge must be free to move slightly on its external
vibration isolators. To avoid stresses, no pipework should be rigidly
connected to the centrifuge. All pipework must contain flexible sections,
gaps, or loose sleeve features to allow for up to +/-10 mm movement in
any direction.
3.2.1 Massecuite Feed System
To prevent massecuite being trapped and setting in the feeding line, the 250mm
(10”) isolation valve V1 should be installed as close as possible to the feeding
vessel or manifold. V1 is a butterfly type valve which is capable of dislodging any
'plugs' of massecuite setting in the short stub pipe upstream As an additional
precaution, this stub should incorporate a screwed port to allow a steaming out
line to be connected.
Figure 3.1 (Typical) Massecuite Feeding System
Steamout
Connection
Steamout
Connection
Isolating Valve
V1-A1
Disconnection Flange to
allow withdrawal of Feed
Cone and Basket
Feed Control Valve
V2-A2-P2
Centering
Cone
Transparent
Shroud
Massecuite
'Rope'
Conduction
Switch
Lubrication
Water
Reheat
Steam
Centrifuge
Feed Cone
©
Massecuite
Crystalliser or
Manifold
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A joint is required in the feeding line to allow the lower portion of the feeding
system to be removed, to allow the basket to be lifted out of the centrifuge casing.
A further refinement to reduce maintenance times is to mount the lower portion of
the feeding system on a hinged support, so all the equipment below the joint can
be swung away as a single unit, rather than dismantled and lifted away in pieces.
The 200mm (8”) NB flow control feed valve V2 should be attached to the lower
end of the feed pipe. The feed valve should be located high enough above the
centrifuge that it does not have to be disturbed to withdraw the centrifuge feed
cone.
The Centering cone should be attached to the underside of the feed valve, to
ensure the massecuite 'rope' enters the centrifuge feed cone centrally.
* Note - The feed system should be as shown on General Arrangement drawing
(Section 2.2), NOT as shown above.
3.2.2 Water and Steam Systems
The required pressures and temperatures for the water, liquor, and steam services
into the centrifuge are specified in section 2, together with estimated ranges of
flowrate. The actual water and steam flowrates required depend on the quality and
actual throughput of massecuite. Further guidance is given in section 5.
The client’s water and steam supplies should be connected to the manifold which
is floor mounted next to the centrifuge.
3.2.3 Compressed Air Supply
Must be supplied clean (filtered), dry, unlubricated, between 4 bar g to 6 bar g
(60 psi to 90 psi), 5.5 bar g optimum, at ambient temperature. Quality class 3.4.4
(taken from ISO standard 8573.1) is adequate. This implies 5 micron maximum
particle size, 3°C dew point maximum, and 5mg per cubic metre maximum oil
content.
Mean consumption of compressed air for pneumatic actuator on feed valve is 10
litres/minute of free air.
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3.2.4 Discharge Systems
Sugar is discharged from the outer annulus of the monitor casing. A sugar
discharge chute attached around the bottom edge of the casing is required to
direct the sugar onto a conveyor running side to side beneath the centrifuge.The
sides of this chute should be inclined at least 60o from horizontal and, given the
width of the conveyor, this determines the height required between the base of the
centrifuge and the top of the conveyor. To allow free movement of the centrifuge
on its anti-vibration mounts, the bottom of the discharge chute must not be rigidly
attached to the conveyor.
Molasses is discharged from a large bore tube at the back of the monitor casing. A
suitable flange must be welded to the end of this pipe for connection to the
molasses discharge pipework. It is important that this pipework contains a gap or
flexible section to allow free movement of the centrifuge on its vibration
isolators.
3.2.5 Electrical System
The starter panel should be mounted on a load bearing wall or support structure
at a convenient working height suitable for cables to enter via the gland plate on
its base.
The operator panel should be mounted at a convenient height on a stanchion or
post near the centrifuge. It must not be attached direct to the centrifuge casing
where it would be damaged by vibration. It is good safety practice that it should
not be possible to start any potentially dangerous machinery without an operator
being in a position to check visually that personnel are clear and there are no
obstructions or missing equipment.
The hook-up drawing specified (* See CPT Drives (Thailand) supplied Electrical
Operating Manual), details the cabling required between the supply, the panels,
and the centrifuge.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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4 INSTALLATION
Refer to the sections
IMPORTANT INFORMATION and SAFETY
at the start of this Operating Manual
©
2015 Thomas Broadbent & Sons Ltd
Operating Manual for SPV1425 Continuous Centrifuge H95702
4 INSTALLATION
4.1 INSTALLATION PROCEDURE
4.2 COMMISSIONING PROCEDURE
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4 INSTALLATION
4.1 INSTALLATION PROCEDURE SPV1425
(a) Open the packaging and check all items against the advice note. Report
any damage or deficiencies to the manufacturer.
(b) Assemble the 3 support pedestals to the support structure and assemble
the vibration isolators to the tops of the pedestals with the intermediate
adjusting plates and rubber backings in place. Remove the setting
screws from the vibration isolators.
Important - Ensure the isolators are fitted in the correct positions.
Front Column - Type ODL D30A
Rear Columns - Type ODL D40
(Part No 22200-045)
(Part No 22200-038)
(c) Lower the centrifuge so the bottom edge of the monitor casing rests on
temporary blocks placed on the support frame. The undersides of the
centrifuge support brackets should be about 25mm clear of the upper
surfaces of the vibration isolators. Remove the casing cover and place
protection covers over the basket screens. Use wedges and jacks to
adjust the temporary support blocks until a spirit level placed across the
top flange of the basket shows the centrifuge is level.
(d) Move the adjusting plates relative to the tops of the pedestals so that the
holes through the centrifuge support pads line up with the tapped holes
in the tops of the vibration isolators. If further adjustment is necessary,
reposition the pedestals by elongating the holes in their bases.
WARNING: THE SUPPORT PEDESTALS MUST BE AT LEAST 10mm
CLEAR OF THE SIDES OF THE OUTER CASING.
(e) Measure the gaps between the undersides of the centrifuge support pads
and the tops of the isolators. If necessary, fit shims between the
adjusting plates and the pedestals such that these gaps are each parallel
and do not differ from one to another by more than 0.75mm.
(f) Remove the temporary supports and lower the centrifuge onto the
vibration isolators. Check the screwed lengths of the adjusting screws
‘Y’ and adjust the ‘X’ settings as described in section 6.3.6.
WARNING : DO NOT USE THE VIBRATION ISOLATOR ADJUSTMENT
SCREWS TO LEVEL THE CENTRIFUGE.
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(g) Ensure any packings or wedges between the basket and casing are
removed. Rotate the basket by hand to ensure freedom of movement.
Remove any loose items from within the centrifuge. Fit the casing
cover.
IMPORTANT : TENSION DRIVE BELTS BEFORE RUNNING
CENTRIFUGE.
(h) Adjust the belt transmission tension as detailed in section 6.3.1.
(i) Fit the discharge chute and molasses discharge pipework.
WARNING: IF USING AN ELECTRIC ARC WELDER, CONNECT THE
EARTHING CLAMP TO THE OUTER CASING CLOSE TO THE
WELDING AREA TO ENSURE CURRENTS DO NOT PASS THROUGH
THE SPINDLE OR MOTOR BEARINGS.
(j) Ensure that the feed tank and lines are clear of loose object and debris
and install the massecuite feed valves and pipework.
(k) Connect the water, steam and air supplies to the centrifuge.
(l) Install the starter panel, operator panel and electrical wiring.
(m) DO NOT START THE CENTRIFUGE.
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4.2 COMMISSIONING PROCEDURE
WARNING : THE OPERATING CONTROLS AND PROCEDURES
DETAILED IN SECTION 5 AND THE FAULT DIAGNOSIS
PROCEDURES DETAILED IN SECTION 7 MUST BE STUDIED
BEFORE ATTEMPTING TO COMMISSION THE CENTRIFUGE.
(a) Check all wiring for continuity and correct termination.
(b) Check the star-delta timer in the starter panel is set to between 80 and
120 seconds.
(c) Disconnect the lubricating lines from the grease nipples on the front of
the outer casing, to allow excess grease to be expelled.
(d) Jog start the centrifuge to ensure the direction of rotation is correct. The
basket should rotate clockwise when viewed from above.
(e) Start the centrifuge and allow to run up to speed . There may be some
transitory movement or vibration while running through critical speeds
but the centrifuge should run smoothly at operating speed. Allow the
centrifuge to run for at least 4 hours. Stop the centrifuge and allow it to
completely come to rest.
WARNING : IF SEVERE NOISE OR VIBRATION ARE EXPERIENCED,
SHUT DOWN THE CENTRIFUGE IMMEDIATELY AND REFER TO
SECTION 7.
(f) Check and if necessary readjust the belt transmission tension as detailed
in Section 6.3.1. Examine the centrifuge interior and check that the
working screens have seated correctly.
(g) Refit the lubrication lines to the grease nipples on the front of the outer
casing.
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5 OPERATION
Refer to the sections
IMPORTANT INFORMATION and SAFETY
at the start of this Operating Manual
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5 OPERATION
5.1 MANDATORY LIMITATIONS
5.2 OPERATING PROCEDURE
5.2.1 Starting Procedure
5.2.2 Running Routine
5.2.3 Stopping Procedure
5.2.4 Cleaning Procedure
5.2.5 Off Crop Routines
5.3 PROCESS PARAMETERS
5.3.1 Principles of Centrifugal Separation
5.3.2 Massecuite Consistency and Throughput
5.3.3 Centrifuge Speed
5.3.4 Filtering Screens
5.3.5 Water Addition
5.3.6 Steam Addition
5.3.7 Recommended Initial Settings
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5 OPERATION
5.1 MANDATORY LIMITATIONS
The centrifuge is designed to operate within the parameter ranges specified in section 2.
To ensure the safety of operating personnel and to avoid premature failure of the
centrifuge, the following restrictions must be observed,
w Operation of the centrifuge should only be undertaken by personnel
specifically trained in its use.
w The centrifuge must not be run with the monitor casing covers or
drive belt guards removed.
w Non-permeable materials or materials with a density greater than
that specified must not be allowed to enter the basket.
w The rotational speed of the basket must not be allowed to exceed
the 1800 RPM specified ‘maximum’ design speed.
w The massecuite feed rate must not exceed that at which the
specified full load current of the drive motor is reached.
w If unusual noise or vibration are experienced, the centrifuge must be
stopped immediately.
w The centrifuge must be maintained in accordance with the schedule
given in section 6.
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5.2 OPERATING PROCEDURES
5.2.1 Starting Procedure
(a) Close the massecuite isolation valve.
(b) Open any isolating valves on the air, water and steam service supplies.
(c) Switch On the main power supply isolator using the handle on the
outside of the starter panel.
(d) Press the Start button on the operator panel. The Running indicator
lamp illuminates later after the timer has switched the motor
connections from star to delta and the centrifuge is close to running
speed.
(e) Partially open the steam and water valves and allow at least 20 minutes
for temperatures to stabilise.
(f) Open the massecuite isolation valve and allow massecuite to flow down
to the feed valve. Set the feed valve opening to a small value (approx.
20%) on the operator interface whilst in manual control mode.
SEE SEPARATE MANUAL FOR MORE DETAILED
OPERATION OF THE OPERATOR INTERFACE.
(* CPT Drives, Thailand supply).
5.2.2 Running Routine
(a) Adjust the motor current preset on the operator interface display until
the desired throughput is obtained.
(b) Adjust the lubrication water, wash water, and reheat steam flows at the
Manifold Valves until the desired sugar quality is obtained. Sugar can be
examined using the Sampler on the side of the casing. Guidance on
optimising throughput and sugar quality is given in section 5.3.
5.2.3 Stopping Procedure
(a) Close the massecuite isolation valve and wait for the Motor Current to
fall to the no load value showing that massecuite has ceased to flow.
(b) Continue to run the centrifuge for 10 minutes before closing the water
and steam valves.
(c) Press the Stop button and allow the centrifuge to come completely to
rest.
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(d) Switch Off the main power supply isolator using the handle on the
outside of the starter panel.
(e) Close any isolating valves on the air, water and steam service supplies.
5.2.4 Cleaning Procedure
The centrifuge interior should be cleaned if the working screens are becoming
blocked and reducing purging efficiency, if sugar is building up in the casing or if
the centrifuge is to be stopped for more than a few hours. Cleaning should only be
carried out with the centrifuge running.
WARNING: DO NOT STEAMOUT OR WATER WASH THE
CENTRIFUGE WHEN STATIONARY SINCE THIS CAN
FORCE WATER PAST THE SHAFT SEAL / LABYRINTH
INTO THE BEARING LUBRICANT.
(a) With the centrifuge running, close the massecuite isolation valve and
wait for the Motor Current Indicator to fall to the no load current value
showing that massecuite has ceased to flow.
(b) Leave the lubrication water, wash water, and reheat steam on for 10 to
20 minutes to clean the accelerator, basket and screens. This procedure
will remove soluble deposits but in some cases it will be necessary to
stop the centrifuge and remove the working screens e.g. To remove
bagasse fibres caught in the backing meshes or to remove scale blocking
the working screen perforations using acid. See section 6.3.3.5.
(c) To clean sugar deposits from the casing, open the Steamout Valve on the
manifold to admit steam to the spray ring around the top of the casing.
Continue to run the centrifuge until the casing is clean. This can be
checked by turning off the steamout flow and removing one of the small
covers near the outside of the top of the casing.
WARNING: DO NOT REMOVE THE CASING INSPECTION
COVERS IF THE STEAMOUT FLOW IS ON.
5.2.5 Off-Crop Routine
When the centrifuge is to be shut down and left idle for 2 or more weeks, the
following procedures are recommended,
(a) At the end of operations, thoroughly wash out the interior of the
centrifuge with water and steam hoses to remove all traces of
massecuite and molasses. Give particular attention to the bottom of the
basket and hub.
(b) Every week, run the centrifuge dry at full speed for about 20 minutes.
This will prevent condensation in the drive motor and avoid brinnelling
of the bearings.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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5.3 PROCESS PARAMETERS
This section gives an introduction to the principles underlying the process performance
of the centrifuge. Guidance on initial settings for the various process parameters is also
given. By understanding these principles, the quality of the sugar produced can be
optimised by systematically carrying out trial runs at various parameter settings.
5.3.1 Principles of Centrifugal Separation
The separation of the massecuite into its constituent solid crystals and mother
liquor is performed in the conical basket assembly. It is basically a filtration
process assisted by centrifugal force due to rotation. See Figure 5.1.
Massecuite is introduced evenly into the bottom of the basket from the accelerator
cone. The angle of the basket causes the massecuite to flow up the basket and at
the same time the liquor starts to purge through the finely slotted filtering screen.
At the bottom of the basket, the massecuite layer may be several millimetres thick
and still has a high liquor content. At this stage, the process is one of liquor
draining through the crystals,
(Crystal Size) 2 % (Centrifuge G)
Rate of Liquor Purging i
(Liquor Viscosity) % (Layer Thickness)
As the product moves up the basket, the layer thickness decreases to about a
single crystal thickness. This is partly because the circumference of the basket is
increasing and partly because the liquor is purging out. As most of the liquor
purges away, the colour of the product on the screens changes from dark brown to
light brown or white. This is clearly visible and is called the colour line. Above
the colour line, the product mainly comprises crystals with a thin layer of liquor
adhering to the surface. At this stage, the process is one of drying where the
centrifugal force tries to pull these last remnants of liquor off the crystals,
Final Crystal Dryness i
(Crystal Size) 2 % (Centrifuge G)
(Liquor Surface Tension)
In both these relationships, 'Centrifuge G' is the centrifugal acceleration due to
rotation expressed as the number of times natural gravity and is a measure of the
separating effect of the centrifuge design,
Centrifuge G =
©
(Diameter in metres) % (Rotational Speed in rpm) 2
1790
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Low grade massecuites have small crystals and very viscous liquor and are
therefore difficult to purge in batch type centrifuges. Due to their higher 'G' and
thinner product layer thicknesses, conical basket continuous centrifuges are
particularly suitable for separating lower grade massecuites. One disadvantage is
that the crystals tend to be damaged by the action of sliding along the screens and
the impact with the casing after flying off the basket rim. However, the sugar
from lower grade massecuites is usually redissolved for recycling so crystal
breakage is not then a process problem.
Figure 5.1 Schematic of Separation Process
Sugar
Crystals
NOTE
Scale along
basket greatly
contracted
Drying
Purged
Washings
Colour
Line
Centrifugal
Separating
Force due
to Basket
Rotation
Sprayed
Wash
Water
Draining
Purged
Mother
Liquor
Massecuite
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The process performance objectives for a centrifuge are,
(a) Optimise the massecuite throughput to suit the overall process. Usually
this involves maximising the rate that massecuite can be separated so as
to require the minimum number of centrifuges.
(b) Minimise the amount of impurities in or adhering to the sugar crystals.
This can be expressed as purging efficiency which is defined as the
percentage of impurities in the massecuite that end up in the molasses
outlet stream and should be as high as possible.
(c) Minimise the loss of sugar through the filtering screens into the
molasses. Sugar can pass through the filtering screen either as crystal
fragments or as a solution in water. This can be expressed as molasses
purity rise and should be as low as possible.
These 3 performance measures are related to one another and the position of the
colour line is usually a good indicator. A 'high' colour line means that there is a
lot of mother liquor (high throughput) and it is therefore not being purged from
the sugar until close to the top of the basket (low purging efficiency). With a high
throughput, the layer of crystals on the screen will be thicker, and a smaller
proportion will be lost through the screens (low purity rise). The opposites apply
for a 'low' colour line. Generally, the best overall performance will be obtained
with the colour line 25% to 50% up from the base of the basket.
The simple equations above give guidance on the effects of various parameters,
5.3.2 Massecuite Consistency and Throughput
The smaller the crystals, the poorer the purging efficiency. Smaller crystals have
smaller gaps between them so the liquor drains out less easily. Also, smaller
crystals have a larger surface area to volume ratio so more liquor will remain
adhering to their surfaces. Similarly, a 'thick' mother liquor will flow away less
readily, and will adhere more firmly to the crystals. A given centrifuge will
therefore give lower throughputs with low grade 'C' massecuites than intermediate
grade 'B' massecuites.
If the massecuite flow is too small, the purging may be too effective resulting in a
very dry, powdery sugar being produced. This can clog the small clearance
molasses seal between the basket rim and casing. There are therefore minimum as
well as maximum practical throughputs.
5.3.3 Centrifuge Speed
Increasing the centrifuge speed increases the separating effect 'G' which then
improves the purging efficiency and final dryness. To some extent, this can be
used to compensate for poor massecuite properties, but at the cost of causing
more crystal damage. It is therefore usual for centrifuges processing low grade 'C'
massecuites to run at higher speeds, than those processing higher grade 'B'
massecuites.
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2015 Thomas Broadbent & Sons Ltd
Operating Manual for SPV1425 Continuous Centrifuge H95702
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5.3.4 Filtering Screens
The crystals are continually sliding over the screens so the configuration of the
perforations is more important than in batch centrifuges. Continuous centrifuge
screens are usually perforated with fine slots roughly aligned with the direction of
motion of the crystals. A wide range of patterns is available (see section 8) with
slot widths ranging from 0.04 mm to 0.13 mm and open areas ranging from 4% to
25%. Ideally the slots should be narrow to reduce the amount of crystals falling
through (to avoid a high molasses purity rise) but have a large open area (to
increase purging efficiency). Unfortunately, the limitations of the manufacturing
process mean that it is only possible to have both these on screens which are
either very thin which results in a short life or made by a special process which
increases the cost markedly. A screen with a slot width of 0.06 mm and 10% open
area is generally a reasonable compromise for 'B' massecuites (crystal size 0.3 to
0.5 mm) and 'C' massecuites (crystal size 0.2 to 0.4 mm)
The abrasive action of the crystals eventually causes deterioration of the screens,
The slots wear wider and also the screens wear thinner causing them sag into the
gaps between the backing mesh wires which opens out the slots to an oval shape.
Both these effects allow more crystals to pass through. A progressive molasses
purity rise increase of 1% to 2% over a short time indicates a worn screen. To
reduce the 'sagging' effect, Broadbent centrifuges incorporate an additional finer
'intermediate' mesh between the filtering screens and the coarse backing mesh.
This provides better support and thus extends filtering screen life.
5.3.5 Water Addition
Water can be added either as lubrication water to the massecuite as it enters the
feed cone, or sprayed directly as wash water onto the product layer as it moves up
the screens. In both cases, water dilutes the mother liquor and reduces its viscosity
and surface tension, thus improving purging efficiency and paradoxically
increasing the final dryness. On the other hand, too much water dissolves the
sugar, which increases the molasses purity rise. Generally adding about 3% by
weight of water relative to massecuite is a reasonable initial setting.
Washing above the colour line is usually wasteful, as the crystals are widely
dispersed, and the wash does not come into intimate contact with the crystals.
There is also a risk of wash liquor being carried over the basket lip. For this
reason, water addition is usually confined to adding lubrication water and spray
washing below the colour line. For low grade 'C' massecuites with high viscosity
mother liquor, water addition should generally be biassed more to lubrication
rather than spray washing. For intermediate grade 'B' massecuites, spray washing
may be found to be more effective than lubrication water addition.
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2015 Thomas Broadbent & Sons Ltd
Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 58
5.3.6 Steam Addition
The viscosity of the mother liquor in the massecuite roughly halves for every
10oC rise in temperature. A higher massecuite temperature therefore improves
purging efficiency by allowing the liquor to flow out more easily through the gaps
between crystals. Adding feed reheat steam to the massecuite as it passes through
the centrifuge feed cone can therefore be effective since it tends to heat the
mother liquor but does not cause significant dissolving of the crystals. For most
massecuites, adding about 1% to 2% by weight of steam relative to massecuite is
a reasonable initial setting.
5.3.7 Recommended Initial Settings
Based on the above discussions, Figure 5.2 gives recommendations for initial
settings for different grades of massecuite. It is essential that these parameters are
subsequently fine tuned by conducting trials at various settings.
Figure 5.2 Recommended Initial Process Settings for SPV1425
Massecuite Type
High Grade 'A'
45-55% Crystals
91-92 Brix
Intermediate Grade 'B'
35-45% Crystals
93-95 Brix
Low Grade 'C'
28-35% Crystals
96-98 Brix
Mcte Throughput
15-35 Tonne/hour
10-25 Tonne/hour
10-20 Tonne/hour
Centrifuge Speed
1500-1600 rpm
1600-1700 rpm
1700-1800 rpm
Lubrication Water
(at max throughput)
1% w/w mcte
(6 litre/min)
1.5% w/w mcte
(7.5 litre/min)
2% w/w mcte
(8 litre/min)
Wash Water
(at max throughput)
2% w/w mcte
(12 litre/min)
1.5% w/w mcte
(7.5 litre/min)
1% w/w mcte
(4 litre/min)
Reheat Steam
(at max throughput)
1% w/w mcte
(350 kg/hour)
1.5% w/w mcte
(450 kg/hour)
2% w/w mcte
(500 kg/hour)
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2015 Thomas Broadbent & Sons Ltd
Operating Manual for SPV1425 Continuous Centrifuge H95702
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6 MAINTENANCE
Refer to the sections
IMPORTANT INFORMATION and SAFETY
at the start of this Operating Manual
©
2015 Thomas Broadbent & Sons Ltd
Operating Manual for SPV1425 Continuous Centrifuge H95702
6 MAINTENANCE
6.1 SAFETY
6.2 MAINTENANCE SCHEDULES
6.3 MAINTENANCE PROCEDURES
6.3.1 Belt Transmission
6.3.2 Basket
6.3.3 Screens
6.3.4 Spindle Assembly
6.3.5 Drive Motor
6.3.6 Vibration Isolators
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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6 MAINTENANCE
6.1 SAFETY
All maintenance and overhaul activities must be carried out by suitably qualified and
trained personnel. Training courses on operation and maintenance are available - please
contact Broadbent for details. If in doubt, experienced service engineers are available
via Broadbent Customer Services.
Replacement parts used on the centrifuge should be obtained from Broadbent.
Replacement parts not obtained from Broadbent or parts fitted incorrectly may
compromise the safety of the centrifuge. Broadbent does not accept responsibility for
the consequences of using such parts.
If work is to be carried out inside or under the centrifuge,
w Stop the machine and lock the massecuite isolation valve closed.
w Isolate at the mains electrical supply, compressed air supply, water
supply and steam supply. Place suitable warning notices.
w Place protective covers over the conveyor before working under the
machine.
w If possible, position a safety man by the centrifuge
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 62
6.2 MAINTENANCE SCHEDULES
The following schedules are based on continuous usage throughout the operating
season. It is recommended that full maintenance and service records be kept for each
centrifuge. Recorded details should include machine serial number, date and time,
inspections undertaken, procedures carried out, and comments regarding problems
encountered or other observations. Such records will assist troubleshooting and may be
required for evidence in the event of a claim under warranty.
Figure 6.1 Recommended Schedule for Routine Preventative Maintenance
Frequency
Item
Action
Daily
Centrifuge Exterior
Clean, especially casing top
Process Lines
Inspect lines and connections for
leaks and repair if necessary
Spindle Bearings
Lubricate with specified grease
6.3.4
Basket Screens
Steam Clean & Inspect
6.3.3
Feed Valve & Feed Cone
Steam clean
Support Pedestals
Check fastener tightnesses
Steam and Water inlet strainers
Clean & Inspect
Drive Motor Supports
Check fastener tightnesses
Belt Transmission
Check Belt Tension and inspect belt
condition
Spindle Bearings
Check for signs of wear, vibration,
or overheating
Vibration Isolators
Check adjustment
Drive Motor
Lubricate bearings with Shell
Alvania R.A. or equivalent lithium
based grease
Basket and Attachment
to Spindle
Remove and carry out detailed
safety inspection
6.3.3
Complete Centrifuge
Strip and Inspect
6
Basket Screens
Replace
6.3.3
Drive Belts
Replace
6.3.1
Spindle Bearings
Replace
6.3.4
Weekly
Monthly
Annually
As Required or
every 5 years
©
2015 Thomas Broadbent & Sons Ltd
Reference
3.2
6.3.1
6.3.6
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6.3 OVERHAUL PROCEDURES
6.3.1 Belt Transmission
The transmission uses a set of 5 matched wedge profile belts. Belts should be
stored in a dry storeroom well clear of hot pipes and direct sunlight. They should
be allowed to hang untwisted on racks and should not be tied tightly with string or
wire.
6.3.1.1 Removal
(a) Carry out the safety precautions listed in 6.1
(b) Remove the belt drive guards from beneath the centrifuge.
(c) Release the belt tension by evenly winding in the nuts on the large studs
attaching the drive motor to the monitor casing.
(d) Remove the belts.
6.3.1.2 Inspection
(a) Examine the belts for damage
Figure 6.2 Inspection of Drive Belts
Symptom
Causes
Action
Belt Cracked on Flanks and
Base
Excessive Heat
Misalignment of Pulleys
Overtensioning
Replace if damage severe.
Otherwise reset belt tension
Belt swelled or softened
Contamination by oil or solvent
Replace
(b) Clean the pulleys using a suitable solvent and inspect for damage.
Cracked pulleys must be replaced (see section 6.3.4.3 or 6.3.5.1).
6.3.1.3 Replacement
(a) Check that the replacement belts do not differ in pitch line length from
one to another by more than 6 mm.
(b) Fit the belts to the pulleys taking care not to damage the flanks.
(c) Tension the belts as detailed in 6.3.1.4.
(d) Refit the belt drive guards.
(e) Run the centrifuge for 3 hours then readjust the belt tension as detailed
in 6.3.1.4 to take up the effects of bedding in.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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6.3.1.4 Tension Adjustment
(a) Carry out the safety precautions listed in 6.1.
(b) Remove the belt drive guards from beneath the centrifuge
(c) At the midpoint between the pulleys, use a spring balance to apply a
force at right angles to each belt and use a ruler to measure the resultant
deflections. The required settings are,
20 to 25 mm Deflection for 9 kgf Side Force per Belt at Mid Span
(d) Adjust the belt tension by evenly winding in or out the nuts on the large
studs supporting the drive motor. Ensure that the pulleys remain
parallel and aligned. While carrying out the adjustment, rotate the
basket slowly by hand to assist belt seating.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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6.3.2 Basket
6.3.2.1 Removal
NOTE: BEFORE DISASSEMBLY USE AN INDELIBLE PEN TO MARK
THE RELATIVE POSITIONS OF ALL ROTATING PARTS. THIS WILL
ENABLE THE ROTATING ASSEMBLY TO BE REBUILT WITH
MINIMUM CHANGES IN DYNAMIC BALANCE.
(a) Carry out the safety precautions listed in 6.1.
(b) Disconnect the feed, water and steam lines and fit suitable blanking
covers to prevent the ingress of contaminants.
(c) Remove the monitor casing cover.
(d) Steam clean the basket assembly.
(e) Slacken the centering screws and remove the accelerator.
(f) Remove the capscrews attaching the basket hub to the spindle and fit 3
eye bolts. Using a suitable 3 leg sling, lift the basket assembly out of
the centrifuge and lower onto wooden blocks.
(g) Remove the working screens and backing meshes as detailed in 6.3.3.
6.3.2.2 Inspection
WARNING : IN THE INTERESTS OF SAFETY, THE BASKET
ASSEMBLY MUST BE REGULARLY INSPECTED FOR INTEGRITY AT
INTERVALS NOT EXCEEDING 12 MONTHS.
The examination should be carried out by a person with sufficient practical
and theoretical knowledge and actual experience of the type of machinery to
be examined.
Such persons have to be able to examine the basket in all of the ways
stipulated in order to detect faults and weaknesses and assess their
importance in relation to safe operation of the machinery.
The results of examination are to be recorded by the examiner and then
countersigned and filed by the user.
These results should be used for reference at the next inspection when
defects noted previously can be located and checked.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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All basket assembly components must be subjected to VISUAL
EXAMINATION and LIQUID PENETRANT CRACK DETECTION over
100% of their surface areas together with DIMENSIONAL CHECKS in
certain critical areas. The following type of defect may be present,
w MECHANICAL DAMAGE
In the form of indentation or scoring, this could have a stress
concentration effect which could be particularly dangerous in
highly stressed areas such as the outer extremities of the basket.
w WEAR
Some loss of material due to the combined effects of erosion by the
product and surface corrosion mechanisms is to be expected. While
the wear may be localised, it will be fairly smooth bottomed and
will not produce individual deep pits. The effect of the loss of wall
thickness is to reduce the mechanical strength of the component and
so the acceptable limits, based on dimensional checks, are well
established.
w CRACKS
Cracks may be initiated from microscopic defects in the original
material or by certain corrosion mechanisms. Even cracks which
are so small as to be detectable only by liquid penetrant testing can
grow rapidly due to fatigue and are not acceptable. Cracks which
are large enough to be visible are particularly dangerous since they
could soon lead to complete fracture of the component.
w DEEP PITTING CORROSION
In contrast to general surface type corrosion, some mechanisms
such as chloride or stress corrosion produce pitting which is small
in extent on the surface but very deep and has a detrimental effect
similar to cracking. Even stainless steels are prone to this type of
corrosion. It can be recognised by looking for small rust spots,
which, after cleaning off using fine emery paper, reveal small
pitting marks or cracks visible only using a magnifying glass. This
type of defect is unacceptable.
The basket hub, basket, accelerator cone, and clamping ring should be
systematically examined as follows with reference to the schedule in Figure
6.3.
(a) Visually examine the complete surface of the component looking
particularly for signs of corrosion or cracking. Use a magnifying glass
to check suspect areas. Any components containing cracks or deep
pitting must be removed from service
.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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Figure 6.3 Basket Inspection Schedule
Item
Method
Result
Action
All
components
100% Visual and Liquid
Penetrant examination of
all surfaces and welds
Scores or Indentations
Seek manufacturer's advice
Any signs of Cracking
Remove from service
Any signs of Deep Pitting Corrosion
Remove from service
Thickness in any one position less
than 80% of original thickness
Remove from service
Thickness at several positions
between 80% and 85% of original
thickness
Remove from service
Thickness at any position between
85% and 95% of original thickness
Record measurements and
monitor at regular intervals
Thickness in any one position less
than 80% of original thickness
Remove from service
Thickness at several positions
between 80% and 85% of original
thickness
Remove from service
Thickness at any position between
85% and 95% of original thickness
Record measurements and
monitor at regular intervals
Enlargement or elongation of any
one hole exceeds 120% of original
diameter
Remove from service
Enlargement or elongation of several
holes between 115% and 120% of
original diameter
Remove from service
Enlargement or elongation of any
holes between 105% and 115% of
original diameter
Record measurements and
monitor at regular intervals
Thickness measurements
every 150mm along the
flinger rib under the top
flange
Thickness at any one position less
than 95% of original thickness
Remove from service and seek
manufacturer's advice
Concentricity check
using dial gauge on outer
rim of top flange
Total indicated reading exceeds
2mm TIR (i.e. more than 1mm
eccentric)
Remove from service and seek
manufacturer's advice
Wall thickness
measurements every
75mm along and around
the cone
Thickness at any one position less
than 1.5mm
Remove from service
Concentricity check
using dial gauge on
outside of cone
Total indicated reading exceeds
2mm TIR (i.e. more than 1mm
eccentric)
Remove from service and seek
manufacturer's advice
Dimensional checks on
cross section every
150mm along ring
Dimension at any one position less
than 80% of original size
Seek manufacturer's advice
Basket
Hub
Basket
Wall thickness
measurements every
100mm along and
around the cylinder
and flanges
Wall thickness
measurements every
150mm along and
around the shell
Visual and Dimensional
examination of all
perforations
Accelerator
Cone
Bottom
Clamping
Ring
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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(b) Thoroughly clean the component using fine emery paper to remove
corrosion deposits and repeat the visual examination using a magnifying
glass to check suspect areas. Any components containing cracks or
deep pitting must be removed from service.
(c) Liquid penetrant test the complete surface of the component using a
technique, materials, and interpretation procedures complying with an
accepted national or international standard (e.g. as used for examining
pressure vessels). Components containing cracks must be removed
from service.
(d) Assess the degree of wear due to corrosion/erosion by carrying out the
appropriate dimensional checks listed in Figure 6.3.
WARNING : IF IN DOUBT, REMOVE THE COMPONENT FROM
SERVICE AND SEEK THE MANUFACTURERS RECOMMENDATIONS.
6.3.2.3 Inspection of Attachment to Spindle
Before replacing the basket an in-situ safety inspection of the attachment to
the spindle must be carried out,
(a) Visually examine and liquid penetrant test all the exposed surfaces of
the flange at the top of the spindle, paying particular attention to the
fillet radius on the underside of the flange. If there are any signs of
cracking or pitting, the spindle must be removed from service
immediately and replaced as described in section 6.3.4.
(b) Visually examine all the fasteners used for attaching the basket to the
spindle flange. Reject any fasteners with damaged threads or which are
suspect in any way.
6.3.2.4 Replacement
Basket replacement is an exact reversal of section 6.3.2.1. Use the marks
made during stripping to ensure that all components are reassembled in the
same circumferential positions relative to one another. This will avoid
unwanted changes in dynamic balance which could lead to vibration.
Tighten all fasteners to the torque values specified in section 2.7 and use
thread locking compound.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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6.3.3 Screens
The screen system comprises finely perforated chromium nickel Working
Screens, a No 16 stainless steel fine Intermediate Mesh, and a No 5 stainless steel
coarse Backing Mesh. See Figure 1.4.
WARNING : WEAR PROTECTIVE GLOVES TO PREVENT INJURY BY
SHARP EDGES
6.3.3.1 Working Screen Removal
(a) Remove the 5 retaining clips from the top flange of the basket.
(b) Unscrew the fasteners securing the clamping ring to the basket hub.
Remove the blanking capscrews in the clamping ring and jack off using
M8 screws.
(c) Remove the 5 working screen segments
6.3.3.2 Intermediate Mesh Removal
It should not be necessary to routinely remove the intermediate mesh. Over
time, the fine intermediate mesh may become clogged by bagasse fibres or
scale. These can often be removed by washing in place in the basket, by
gently peeling back the working screens from the top edge of the basket and
using a high pressure water jet.
(a) Unfold the top edge of the intermediate mesh out from behind the
backing mesh.
(b) Use a fine screwdriver to lever out the spacer, and then the circlip ring
from the groove in the basket base.
(c) Lift out the intermediate mesh.
6.3.3.3 Backing Mesh Removal
The backing mesh should not require removal or replacement except in the
case of it being damaged by debris, or objects accidentally falling into the
basket.
(a) Mark the position of the seam on the basket top flange using an
indelible pen.
(b) Use a small hand held grinding tool to grind off the tack welds between
the backing mesh and basket. Remove all traces of the weld and
remnants of the mesh. Avoid reducing the basket wall thickness and
ensure a smooth surface results, free of crevices and undercuts.
(c) Lift out the backing mesh and discard.
©
2015 Thomas Broadbent & Sons Ltd
TIG TACK WELD BACKING
MESH TO BASKET SHELL
8 ROWS OF 24 TACK WELDS
PER ROW IN POSITIONS
SHOWN
FITTING OF
BACKING MESH
INTERMEDIATE MESH
FORMING TOOL
©
INTERMEDIATE MESH
FOLDED BACK UNDER
BACKING MESH
\P15 TO 25mm
CIRCLIP SPACER
INTERMEDIATE MESH
RETAINING CIRCLIP RING
SET BACKING MESH
\P2 TO 4mm
FROM EDGE OF
RECESS IN BASKET
EDGE OFINTERMEDIATE MESH
MUST NOT EMERGE OUT OF
GROOVE. TRIM AS NECESSARY
SET BACKING MESH
\P2 TO 4mm
FROM EDGE OF
RECESS IN BASKET
CIRCLIP FITTING
TOOL
SCREEN
SETTING RING
FITTING OF
INTERMEDIATE MESH
Operating Manual for SPV1425 Continuous Centrifuge H95702
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Page 70
Figure 6.4 Fitting of Backing and Intermediate Meshes
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6.3.3.4 Backing Mesh Replacement.
(a) Check that the replacement backing mesh is the correct type i.e. Flat on
one side and tightly crimped at all intersections, so that the wire strands
cannot move relative to one another.
(b) Place the replacement backing mesh in the basket, press against the
basket shell, and hold in position using the setting ring and stainless
steel wire ties through the basket perforations. See Figure 6.4.
w The ‘flat top’ side of the mesh must face away from the basket wall
to provide a smooth support for the working screens.
w The top and bottom edges of the mesh must be within 2 to 4 mm of
the edges of the recess in the basket.
w The seam in the mesh must be located in the position marked on the
basket rim during removal. The joining seam must be flush fitting.
The screen is supplied overlong for trimming during fitting to give
a minimum gap when installed. A gap in the backing screen when
fitted, would leave the working screens unsupported and may
lead to premature screen failure.
(c) Attach the mesh to basket shell with 10 rows of tack welds located
between the bottom 10 rows of perforations, with about 24 equally
spaced tack welds per row. See Figure 6.4. Avoid placing the new tacks
exactly where the old tacks were removed. Start welding diametrically
opposite the joint and work alternately on either side towards the seam.
The recommended technique is to Tungsten Inert Gas (TIG) weld using
a duplex stainless steel filler. Start by melting the basket shell in
between wires, and use filler to run the wires into the pool. It is strongly
recommended that the welding procedure is practiced on pieces of
scrap mesh before welding on the basket.
(d) Dress off any welds that protrude above the flat surface of the mesh.
6.3.3.5 Intermediate Mesh Replacement
(a) Place the intermediate mesh in the basket over the backing screen and
press back and retain using the setting ring. See Figure 6.4.
w The seam in the mesh must be diametrically opposite the seam in
the backing screen. The joining seam must be flush fitting. The
joint must not overlap, but a gap up to 3 mm wide is acceptable.
(b) Using the round ended forming tool, gradually work the bottom of the
intermediate mesh into the groove in the base of the basket.
(c) Fit the circlip fitting tool over the basket centre, with the jacking screws
retracted sufficiently to allow fitting of the circlip. Place the circlip ring
in
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2015 Thomas Broadbent & Sons Ltd
Operating Manual for SPV1425 Continuous Centrifuge H95702
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the groove. Start by engaging one end of the ring diametrically opposite
the seam in the intermediate mesh. Using the nuts on the circlip fitting
ring (see Figure 6.4), push the circlip back into the groove until the
whole circlip ring is fully engaged.
(d) Measure the gap between the ends of the circlip ring, file the spacer to
the correct length, and drive into place. Remove the fitting tool by
turning the nuts in the opposite direction, until the jacking screws are
clear of the basket.
(e) Trim the bottom edge of the intermediate mesh as necessary, to ensure
that no part of the mesh emerges from the bottom of the circlip groove
where it could interfere with fitting of the working screen.
(f) Fold the excess material on the top edge of the intermediate mesh back
between the backing mesh and the basket.
6.3.3.6 Working Screen Replacement
(a) To reduce the possibility of screen segments overlapping in the
clamping area (see (c) below), use scissors or shears to enlarge the notch
in the bottom right hand corner of each screen segment. To assist with
setting the segments in the basket (see (c) below), mark an intermittent
line 20 mm parallel to the right hand edge of each segment with a pen or
pencil. See Figure 6.5.
Figure 6.5 Preparation of Working Screen Segments
20 mm
Mark line on face
of screen with
pencil or pen
Cut notch wider
from 15 mm to
20 mm
Working Screen
Segment
20 mm
(b) Check that the clamping areas of the clamping ring are clean and free
from scoring or burrs. Remove the four M8 x 12 long blanking
capscrews from the jacking holes in the clamping ring and fit four long
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M8 jacking screws and adjust them so that they will support the
clamping ring above the hub, as shown in Figure 6.7. Place the
clamping ring in the basket, ensuring that the fooling pin in the hub
lines up with the hole in the clamping ring.
Figure 6.6 Fitting of Working Screens - Plan View
ROTATION
Trailing Edge
of Top Screen
Leading Edge
of Top Screen
Segment
Top Screen Segment
Edges are not Radial
but Slope Forward in
the Direction of
Rotation. The Leading
Edge of each Segment
must lie under the
Trailing Edge of the
adjacent Segment
Screen
Retaining
Clips
(c) Place the 5 segments of the replacement working screen in the basket as
follows. Refer to Figures 6.6 and 6.7. They can be held in place using
the setting ring provided, and by using strips of tape across the overlaps
between segments, and between the segments and the basket upper rim,
w The identified working faces must be uppermost.
w The bottom edges of the segments must touch the outside of the
clamping ring. See Figure 6.7.
w The overlaps between segments must be located at the pairs of
holes in the basket top rim where the screen retaining clips will fit.
See Figure 6.6.
w When viewed from above, the anticlockwise (trailing) edge of each
segment must overlap on top of the clockwise (leading) edge of the
adjacent segment by about 13mm. Use the lines marked in (a)
above to get the overlaps even. Refer to Figure 6.6.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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w The segments must not overlap at all where the clamping ring sits
(see (a) above). This ensures that the clamping is even right around
the ring, and not just at points where the segments overlap.
WARNING : THE TRAILING EDGES MUST LIE ON TOP OF THE LEADING
EDGES OF THE WORKING SCREEN SEGMENTS TO PREVENT THEM BEING
LIFTED AND EJECTED BY WINDAGE EFFECTS DURING CLOCKWISE
ROTATION.
(d) Gradually lower the clamping ring by unscrewing the four jacking
screws evenly. Remove the jacking screws. Fit the clamping screws and
tighten them evenly to slowly pull down the clampring and form the
bottom edge of the screen segments into the corner in the basket.
Tighten the clamping screws to the specified torque.
Figure 6.7 Fitting of Working Screens - Clamping Details
Screen
Retaining
Clip
BASKET
TOP
Slotted
Working
Screen
Intermediate
Mesh
Intermediate
Mesh
Grooved and
Perforated
Conical Basket
Backing
Mesh
Slotted
Working
Screen
Backing
Mesh
Intermediate
Mesh
Slotted
Working
Screen
Circlip Ring
Screen
Clamping
Ring
BASKET
BASE
(e) Fit the M8 blanking capscrews in the jacking holes in the clampring.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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(f) Fit the 5 clips holding the top edges of the working screens to the basket
top flange and tighten the caphead screws to the specified torque.
(g) Remove the setting ring and retaining tape. Check that the screens lie
flat over the full surface.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 76
6.3.3.7 Working Screen Cleaning
The screens should be thoroughly cleaned and inspected whenever there is a
reduction in sugar quality, or when the normal massecuite throughput
cannot be reached. This is normally due to settlement of scale or bagasse
behind the screen, choking the perforations.
(a) Prepare a cleaning solution. Suitable alternatives are,
w Dilute sulphuric acid 10% by volume at 40oC minimum, 60o C
maximum
w Dilute phosphoric acid 15% by volume at 40oC minimum, 60oC
maximum.
Provided they are stored in a suitable container, these dilute acid solutions
may be used several times.
WARNING : USE PROTECTIVE CLOTHING, GLOVES, AND FACE
MASKS WHEN HANDLING, MIXING, OR HEATING ACID SOLUTIONS.
(b) Remove the working screen segments from the basket as detailed in
6.3.3.1.
(c) Soak the screen segments in the cleaning solution for 2 hours, rinse
immediately under clean running water, brush on both sides, and dry
using compressed air.
(d) Soak the screen segments in the cleaning solution for 30 minutes then
rinse immediately under clean running water. Repeat this short soak
procedure as necessary until the perforations are clear.
(e) Steam clean the basket and backing/intermediate mesh assembly, then
refit the working screen segments as detailed in 6.3.3.4.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 77
6.3.4 Spindle Assembly
The spindle and bearing assembly is a single unit, incorporating two cylindrical
roller radial bearings and a 4 point angular contact thrust bearing. All bearings are
continuously rated and lubricated with special high temperature grease via
flexible hoses leading to nipples on the front of the casing.
Figure 6.8 Spindle and Bearing Assembly SPV1425 Mk3B
* Use Assembly Drawing 5500-2025 (Specified - Section 2.2)
D
Spindle
E
Upper Bearing Cap
Abutment Ring
Lip Seal
C
A
Top Cylindrical
Roller Bearing
Upper Grease Cup
Spacer Sleeve
Lower Grease Cup
Bottom Cylindrical
Roller Bearing
Bearing Housing
Angular Contact
Ball Thrust Bearing
B
Driven Pulley
Pulley Washer
.
Lower Bearing Cap
Lip Seal
Seal Collar
* A Axial float of Bottom Roller Bearing outer race
* See Drg 5500-2025
* B Gap between Lower Bearing Cap and Bearing Housing
* See Drg 5500-2025
C
Gap between Upper Bearing Cap and Bearing Housing
0.6 to 1.2 mm
D
Axial runout of Spindle Flange
0.05 mm TIR
E
Radial Runout of Spindle Flange spigot
0.08 mm TIR
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 78
6.3.4.1. Bearing Lubrication
Lubricate the bearings weekly using the grease specified in section 2. Using
the hook on grease gun provided, give all three nipples, (near the front of
the casing), 5 full turns (equivalent to 5 cm3).
WARNING: USE ONLY THE SPECIFIED HIGH TEMPERATURE
GREASE. ORDINARY MEDIUM DUTY GREASES WILL NOT MIX AND
WILL RESULT IN RAPID BEARING FAILURE. DO NOT OVERCHARGE
THE BEARINGS WITH GREASE AS CHURNING WILL GENERATE
HEAT AND REDUCE BEARING LIFE
The bearing housing is designed to accommodate the recommended
injections of grease, by allowing overspill into the central housing cavity.
This excess grease should be removed during scheduled dismantling of the
spindle assembly, as described in the remaining sections of 6.3.4.
6.3.4.2 Removal
(a) Carry out the safety precautions listed in Section 6.1.
(b) Remove the basket, as detailed in Section 6.3.2.1.
(c) Remove the belt transmission, as detailed in Section 6.3.1.1.
(d) Disconnect the grease lubrication hoses from the underside of the
spindle bearing housing.
(e) Remove the fasteners securing the bearing housing to the base of the
monitor casing, and lift the complete spindle assembly out of the
centrifuge, using an eyebolt in the top flange of the spindle.
6.3.4.3 Stripping
(a) Remove the pulley centre screw and washer.
(b) Fit a hexagon screw into the tapped hole in the end of the spindle, and
attach drawplate 'A' to the pulley
(c) Use the 180mm long draw stud to jack off the pulley, as shown in
Figure 6.9.
(d) Release the fasteners securing the upper bearing cap.
(e) Remove the lower bearing cap (* complete with seal, anti-rotation pins,
shim(s) and collar).
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Operating Manual for SPV1425 Continuous Centrifuge H95702
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Figure 6.9 Removal of Driven Pulley from Spindle
M20x40
Setscrew
Drawplate
'A'
M12x60
Bolts
Short
Drawstud
(f) Attach drawplate 'B' to the bearing housing, in place of the lower
bearing cap. Screw the three 180mm long draw studs into drawplate 'B',
and fit drawplate 'C', with lugs projecting downwards over the studs.
Tighten the drawstuds evenly, to jack the spindle through the housing,
until the top bearing is clear of the housing, and the bottom bearing is
clear of the spindle. See Figure 6.10.
Figure 6.10 Removal of Spindle from Housing
Drawing Plate
'B'
3 off Short
Drawstuds
Drawing Plate
'C'
3 off M16
Nuts and
Washers
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 80
Figure 6.11 Removal of Top Bearing from Spindle
3 off Short
Drawstuds
Spindle
Flange
Upper
Bearing Cap
Top Bearing
Inner Race
Abutment
Ring
(g) Lift the spindle clear, using an eyebolt in the top flange of the spindle.
(h) Fit the three 180mm long drawstuds through alternate holes in the
spindle top flange, and tighten evenly, to jack the bearing inner race and
abutment ring off the spindle. See Figure 6.11.
(i) Position drawplate 'D' against the inboard face of the lower grease cup.
Screw the 250mm long drawstud into drawplate 'D', and fit drawplate 'C'
over the stud, with the lugs projecting against the bearing housing.
Tighten the nut on the drawstud, to pull out the bottom bearing outer
race and lower grease cup. See Figure 6.12.
Figure 6.12 Removal of Bottom Bearing from Housing
Drawplate
'D'
Lower
Grease
Cup
Drawplate
'C'
Long
Drawstud
M16 Nut
and Washer
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 81
(j) Clean and degrease all components
(k) Visually inspect and liquid penetrant test all over the spindle, giving
particular attention to the basket mounting flange and bearing seating
diameters. Spindles showing any signs of cracking must be rejected.
(l) Visually inspect the remaining components for damage or wear. Reject
any doubtful components.
(m)Wipe over the cleaned parts with clean, new lubricating oil, to prevent
corrosion, and store in a dust free environment.
6.3.4.4 Bearing Handling - General Guidance
WARNING : ABSOLUTE CLEANLINESS MUST BE MAINTAINED AT
ALL TIMES WHEN HANDLING BEARINGS SINCE EVEN SMALL
PARTICLES CAN DAMAGE THE ROLLING SURFACES.
(a) It is recommended that new replacement bearings be fitted when
possible. Use only bearings provided by Broadbent. These have
carefully specified cage materials, internal clearances and dynamic load
ratings. Simply using bearings of similar external dimensions could
result in seriously reduced bearing life. The bearing will be supplied
preserved in anti-corrosive oil, which need not be removed, except for
the Cylindrical Roller Bearings ‘Outer Race’, see note below.
(b) Bearings should only be re-used where there is no doubt about their
condition. All traces of old grease should be removed, by cleaning in
petroleum based solvent. Examine the raceways, cage and rolling
elements for scratches, marks, cracks, discolourations etc. Spin the
bearing, and check that it runs evenly, without abnormally large
clearance. Soak the bearing in clean, new lubricating oil, ready for
assembly.
(c) The bearing inner races are normally an interference fit on the spindle,
and should be heated to between 80oC and 100oC, to ease mounting.
The heating must be uniform, and the temperature must be accurately
controlled. Alternative recommended heating methods are,
w Place the bearing in a thermostatically controlled oil bath, with the
bearing supported clear of the bottom, to prevent local overheating
or contamination by settled solids.
w Use a proprietary, thermostatically controlled induction heater.
WARNING : BEARINGS MUST NOT BE HEATED ABOVE 120oC.
(d) Bearings must be removed or fitted using the tools provided, so as to
avoid applying abnormal loads to the rolling surfaces. * Hammering or
shock must be avoided.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 82
6.3.4.5 Rebuilding
(a) Using a grease gun charged with the grease specified in section 2, purge
the grease galleries in the bearing housing, until only new grease is
expelled. Press the upper grease cup into the upper end of the housing,
with the cupped side facing upwards (towards the bearing). Clean the
bearing ‘Outer Race’ and matching ‘bore’ of the bearing housing with a
suitable cleaning solvent, then allow to dry.
(b) Apply ‘Permabond Retainer A1046’ or ‘Loctite 640’, as shown on drg
5500-2025, then quickly fit the top bearing ‘Outer Race’ into the
housing. Use a spatula to charge the top bearing rollers and cavity,
between ¼ and ½ full with the specified grease. Do not overcharge with
grease.
(c) Fit a new lip seal into the upper bearing cap, with the spring side facing
‘away’ from the bearings, smear clean lubricating oil onto the seal edge,
Slide the upper bearing cap, followed by the abutment ring, onto the
spindle, so that the abutment ring is hard against the locating shoulder
on the spindle. Heat the top bearing ‘Inner Race’, and fit to the spindle,
then fit the long spacer sleeve. Heat the bottom bearing ‘Inner Race’
and fit to the spindle, ensuring that the spacer sleeve is trapped between
the top and bottom bearings.
(d) After cooling, set the bearing housing upright and lower in the spindle,
using an eyebolt fitted in the top flange. Ensure the top bearing ‘Inner
Race’ is guided into its rollers, and press the spindle in, until the upper
bearing cap is home. Torque tighten the bearing cap fasteners, and then
wire lock in pairs, using 1.2mm dia annealed stainless steel wire.
WIRE LOCK IN
PAIRS AS SHOWN
(e) Turn the assembly over. Press the lower grease cup into the housing,
(with the castellated side towards the bearing). Clean the bearing ‘Outer
Race’ and matching ‘bore’ of the bearing housing with a suitable
cleaning solvent, then allow to dry.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 83
(f) Apply ‘Permabond Retainer A1046’ or ‘Loctite 640’, as shown on drg
5500-2025, then quickly set the ‘Outer Race’ of the bottom bearing, in
position shown on the arrangement drawing. Use a spatula to charge the
bottom bearing rollers and cavity between ¼ and ½ full with the
specified grease. Do not overcharge with grease.
(g) Heat the thrust bearing and fit to the spindle, ensure that the two slots
on the outer race are towards you. Apply some of the specified grease.
Fit the seal collar
(h) Fit a new lip seal into the lower bearing cap, with the spring side facing
‘towards’ the bearings. Smear clean lubricating oil onto the seal edge,
then fit the cap to the bearing housing, ensuring that the thrust bearing
anti-rotation pins are in place, and locate in the bearing slots.
(i) Use ‘Shims’ as required (* See drawing 5500-2025 - ‘Enlarged’ View Dimension ‘X’). Torque tighten the bearing cap fasteners, and then wire
lock in pairs, using 1.2mm dia annealed stainless steel wire (* as top
bearing cap). Check the upper bearing cap to bearing housing gap
(References ‘C’ in Figure 6.8).
(j) Warm the pulley to 60-80oC and fit onto the spindle, ensuring the key is
correctly located. Fit and torque tighten the pulley centre screw and
washer.
(k) Check that the assembly rotates freely. With the assembly sat vertically,
attach a dial gauge to the bearing housing, and check the runouts on the
spindle flange face (Reference ‘D’ and ‘E’ in Figure 6.8).
6.3.4.6 Refitting
(a) Clean the location face in the base of the inner chamber of the monitor
casing. Using an eyebolt screwed into the top flange of the spindle, lift
the spindle assembly into position. Ensure the grease connections are in
the correct angular position. Fit and torque tighten the retaining
fasteners.
(b) Purge the grease supply hoses until they are full of fresh grease, and
reconnect to the underside of the spindle bearing housing.
(c) Refit and adjust the belt transmission, as detailed in Section 6.3.1 and
refit the discharge chute.
(d) Refit the basket as detailed in Section 6.3.2
(e) Recommission the centrifuge, as detailed in section 3.3
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 84
6.3.5 Drive Motor
6.3.5.1 Drive Pulley Removal
(a) Carry out the safety precautions listed in Section 6.1
(b) Remove the belt transmission as detailed in Section 6.3.1.
(c) Use an indelible pen to mark the positions of the grub screws around the
taper-lock hub, which secures the drive pulley to the motor shaft.
Slacken all the grub screws and remove all but one or two.
(d) Fit the removed grub screws in the (unmarked) tapped jacking holes and
tighten alternately and evenly until the bush is loosened in the pulley.
The complete assembly can then be removed from the motor shaft.
6.3.5.2 Drive Pulley Replacement
(a) Clean the pulley, taper-lock bush and motor shaft and re-oil the grub
screws. Fit the key to the motor shaft.
(b) Insert the taper-lock bush in the pulley so that the holes line up. Fit the
grub screws loosely in the marked holes.
(c) Fit the bush and pulley onto the motor shaft in the desired axial position.
Note that the bush will nip the shaft first, and then the pulley will be
drawn slightly onto the bush.
(d) Tighten the grub screws and then hammer against the large end of the
bush, using a block to prevent damage. This ensures that the bush is
seated squarely in the bore. Repeat this alternate hammering and screw
tightening twice. Fill the empty holes in the taper-lock bush with grease
to exclude dirt.
(e) Refit and adjust the belt transmission as detailed in Section 6.3.1.
6.3.5.3 Drive Motor Removal and Replacement
(a) Carry out the safety precautions listed in Section 6.1.
(b) Disconnect the electrical cables at the motor terminal box.
(c) Remove the belt transmission as detailed in Section 6.3.1.
(d) Attach suitable slings to support the weight of the motor, remove the
nuts and bolts, securing the motor to the adapter plate, and lift the motor
away.
(e) Replacement is an exact reversal of this procedure.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 85
6.3.6 Vibration Isolators
Important - Ensure the isolators are fitted in the correct positions.
Front Column - Type ODL D30A
(Part No 22200-045)
Rear Columns - Type ODL D40
(Part No 22200-038)
The 3 vibration isolators are fitted between the support pedestals and the brackets
welded to the outer casing. These isolators incorporate coil springs, whose
stiffnesses are tuned to minimise transmission of vibration from the centrifuge to
the floor. The centrifuge can therefore ‘float’ on the springs, but felt damper pads
are incorporated to prevent excessive movement. Transmission of high frequency
vibration is minimised by means of rubber seating pads.
Figure 6.13 Vibration Isolator
SETTING
DIMENSION 'X'
Felt Damper
Pad
Suspension
Spring
ADJUSTING
SCREW
LENGTH 'Y'
Centrifuge
Casing
Bracket
Seating
Pad
Support
Pedestal
The long central adjusting screw determines how hard the felt damper pads are
gripped between the moving and fixed parts of the isolator, and therefore the
amount of vibration isolation and damping,
Increasing the ‘X’ dimension by screwing out the adjuster reduces the grip
on the damper pads, which reduces the transmission of vibration to the floor
but allows increased movement of the centrifuge.
Decreasing the ‘X’ dimension by screwing in the adjuster increases the grip
on the damper pads, which increases the transmission of vibration to the
floor, but decreases movement of the centrifuge. Screwing the adjuster in
too much will lock the isolator solid.
The required length of the adjusting screw ‘Y’ and recommended initial settings
‘X’ are given in section 2. Adjustments from these initial settings to try and get
better performance should be carried out gradually, by turning each adjusting
screw no more than one turn at a time. Do not tighten the adjusters to less than
the minimum permitted value for ‘X’ given in section 2. On completion of
adjustments, tighten the locknut. If adjustments to ‘X’ do not improve
performance, replace the damper pads and seating pads.
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7 FAULT DIAGNOSIS
Refer to the sections
IMPORTANT INFORMATION and SAFETY
at the start of this Operating Manual
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Operating Manual for SPV1425 Continuous Centrifuge H95702
©
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Page 88
Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 89
7 FAULT DIAGNOSIS
Broadbent continuous centrifuges are of simple robust construction, and provided that the
recommended maintenance schedules in section 6 are followed, they should give trouble free
service. However faults may occur from time to time, and Figure 7.1 can be used to diagnose
and solve any problems that may occur.
Figure 7.1 Fault Diagnosis
Fault
Possible Causes
Action
Inadequate process
performance
Refer to section 5 for guidance on causes
and possible parameter changes
Persistent high vibration
levels
Refer to Figure 7.2
Excessively short
centrifuge bearing life
High vibration
Refer to Figure 7.2
Drive belt tension too high
Adjust drive belt tension in
accordance with section 6.3.1
Grease in bearing housing
contaminated by water and/or
sugar
Replace seals. Avoid steam
cleaning if centrifuge not
running. Add vapour vents in
outlet pipework and off sugar
discharge chute/conveyor.
Inadequate lubrication or wrong Strip spindle assembly, clean
and fill with correct grease. See
type of grease
section 6.3.4
Excessively short
centrifuge drive belt life
Incorrect Bearings Fitted
Obtain correct bearings from
Broadbent. See section 8
Drive belt tension too high
Adjust drive belt tension in
accordance with section 6.3.1
Pulleys not aligned
Adjust position of taperlock
pulley along motor shaft
Drive belts overheated by steam
cleaning
Improve ventilation under
centrifuge
Drive belts contaminated by
sugar or hardened liquor
Clean underneath centrifuge
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2015 Thomas Broadbent & Sons Ltd
Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 90
Figure 7.2 Fault Diagnosis of Excessive Vibration
CENTRIFUGE VIBRATES EXCESSIVELY AT OPERATING SPEED
NO
Is the Massecuite
quality acceptable?
Steam clean the
basket and screens
Test run without massecuite
Does vibration persist?
YES
YES
Examine screens for
damage or blockage
and replace or clean
as necessary. Check
basket components
for damage or loose
fasteners and rectify
Is sugar quality YES
or throughput
deteriorating?
NO
Is there excessive
movement at the
mounting pedestals
and anti vibration
mountings?
Test run without massecuite
Does vibration persist?
YES
Tighten the securing
bolts and re-adjust
the anti-vibration
mountings
Test run without massecuite
Does vibration persist?
Reshim beneath the
pedestals and
investigate reasons
for movement
Test run without massecuite
Does vibration persist?
Tighten mounting
studs and locknuts
Test run without massecuite
Does vibration persist?
YES
NO
Is the centrifuge NO
level?
YES
Is the main drive NO
motor secure?
YES
YES
YES
Is belt transmission NO
correctly tensioned,
aligned and secure?
Adjust as necessary
Test run without massecuite
Does vibration persist?
YES
YES
Repair or replace
main drive motor
YES
Is main drive
motor damaged?
Test run without massecuite
Does vibration persist?
YES
NO
Is there excessive
movement of the YES
rotating assembly
in its bearings?
Strip the spindle
assembly and
replace the bearings
Test run without massecuite
Does vibration persist?
YES
REMOVE CENTRIFUGE FROM SERVICE AND CONSULT MANUFACTURER
©
2015 Thomas Broadbent & Sons Ltd
Operating Manual for SPV1425 Continuous Centrifuge H95702
8 PART LISTS
©
2015 Thomas Broadbent & Sons Ltd
Page 91
Operating Manual for SPV1425 Continuous Centrifuge H95702
8 PART LISTS
8.1 SPARES
8.2 TOOLS
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 93
8 PART LISTS
8.1 SPARES
WARNING : MANY OF THE COMPONENTS IN CENTRIFUGES ARE
HIGHLY STRESSED SO ONLY GENUINE BROADBENT PARTS
SHOULD BE USED. THE USE OF SUBSTANDARD COMPONENTS
COULD RESULT IN INJURY TO PERSONNEL, DAMAGE TO THE
CENTRIFUGE OR INVALIDATE ANY WARRANTY AGREEMENT.
Tables 8.1 and 8.2 list only those items which may need to be replaced during the life of
the centrifuge. Part numbers for other components such as the monitor casing,
discharge chutes etc can be obtained from the appended reference drawings.
The 'spares factors' given in the Tables indicate the probability that a particular part will
be needed over a 5 year period of operation. Items with a spares factor of 1 or greater
are parts which will be needed for the planned, preventative maintenance schedules
given in Section 6.2. Items with a spares factor less than 1 are contingency spares for
items which may need to be replaced due to wear, damage, or loss.
The recommended spares holding of an item for any number of centrifuges over any
desired period is calculated from the spares factor as follows,
S=NxMxFxY/5
Where, S = Recommended spares holding
N = Number of centrifuges
M = Number of items per centrifuge
F = Spares factor
Y = Number of years spares are to cover
S should be rounded to the nearest whole number. If S is less than 0.5 the probability of
the item being required is low and the user must decide whether the possible loss of
availability while a replacement is ordered justifies the cost of holding a spare item in
stock.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 94
Table 8.1 Recommended Mechanical Spares SPV1425/30-F6
Item
Part Number
Number per
Centrifuge
M
Spares
Factor
F
Comment
Working Screen
3903-2038
1 set of 5
5
Slotted 0.06x2.80mm 10% OA
Backing Mesh
39030-554
1
1
SPV1425-F5
Intermediate Mesh
39030-555
1
1
SPV1425-F5
Circlip
33900-618
1
0.1
SPV
Circlip Spacer
35860-012
1
1
SPV
Screen Retaining Clip
36430-028
5
0.2
SPV-F5
Screen Bottom Clamping Ring
3285-2027
1
0.1
SPV1425/30-F6
Basket
4665-2001
1
0.1
SPV1425/30-F6
Basket Centre
40110-015
1
0.1
SPV1425
Feed Cone
46780-064
1
0.1
SPV1425-1.25
Accelerator Cone
40030-044
1
0.1
SPV1425 one piece fabricated
Top Cylindrical Roller Bearing
24150-031
1
1
SPV1425
Bottom Cylindrical Roller Bearing
24150-056
1
1
SPV1425
Angular Contact Ball Bearing ‘C3’
2410-2034
1
1
SPV1425
Vibration Isolator
22200-045
22200-038
1
2
0.2
0.2
Front
Rear
Top Lip Seal
25841-055
1
1
SPV1425
Bottom Lip Seal
25840-188
1
1
SPV1425
Anti-rotation Pin
33711-003
2
1
SPV1425
Drive Belt
24420-147
1 set of 5
1
Quattro QXPC 4250
250mm Isolating Valve (MetalWork)
22361-070
1
0.2
Includes D/A Cylinder & Valve
Feed Cone Shroud (Clear)
32251-001
1
0.2
Flexible Clear Bellows 250mm long
25161-001
1
0.2
200mm Jubilee Clip
28101-001
2
0.2
High Temperature Grease
10551-011/
10551-012
Special Feed System - See
Appendix A for Feed Valve Details
Thread Locking Compound
(Ordered in 1 metre lengths)
Mobilith SHC 220.
Loctite 242 or Permabond A130
The centrifuge is supplied with the working screen listed above. Depending on the
quality of the massecuite, throughput and required purities, there may be a benefit in
using working screens with different perforation patterns. The perforation patterns
available are given in table 8.2.
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 95
Table 8.2 Working Screens for SPV1425/30 Centrifuges
Part Number
Slot Size
Open Area %
39030-544
0.06 mm x 2.20 mm
7.5 %
39030-550
0.04 mm x 2.20 mm (Veco)
10.0 %
39030-556
0.06 mm x 2.65 mm
9.0 %
39030-557
0.05 mm x 2.75 mm
8.5 %
39031-060
0.09 mm x 2.65 mm
9.0 %
39031-063
0.09 mm x 2.14 mm
9.6 %
3903-2033
0.04 mm x 2.63 mm
6.0 %
3903-2038
0.06 mm x 2.80 mm
10.0 %
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Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 96
8.2 TOOLS
Maintenance work requires a set of standard hand tools as listed in Table 8.3
Table 8.3 Standard Tools
Item
Sizes
Square Drive Ratchet Wrench
Square Drive Torque Wrench
0-400 Nm
Metric Open Ended Spanner
10 13 17 19 24 32 55 mm A/F
Metric Hexagon Square Drive Sockets
10 13 17 19 24 32 mm A/F
Metric Allen Key Square Drive Sockets
6 8 10 14 mm A/F
Imperial Allen Key Square Drive Sockets
3/8 inch A/F
Screwdrivers
Various Blade Widths
Soft Faced Mallet
Hide or Copper Anvils
Spring Balance
0-10 kgf
A set of special tools and fixtures, listed in Table 8.4, is provided to assist with work on
the basket and spindle assemblies.
Table 8.4 Special Tools
Item
Part Number
No off
Used for
Screwdown Grease Gun
28780-003
1
Bearing Lubrication
Screen Setting Ring
38830-004
1
Circlip Ring Fabrication SPV1425
49311-002
1
Circlip Fitting Screw
49011-001
10
Intermediate Mesh Forming Tool
35930-039
1
Fitting Wedge SPV1425
35930-047
5
Tommy Bar and Accessories
28760-029
1
19mm A/F Socket
28760-009
1
Drawplate 'A'
34550-006
1
Drawplate 'B'
31800-049
1
Drawplate 'C'
49310-002
1
Drawplate 'D'
34110-020
1
Short Drawstud M16
40540-004
3
Long Drawstud M16
40540-005
1
M16 Large Pattern Plain Washer
27140-035
15
M16 Full Nut
27800-018
3
M12 x 60 Hexagon Head Bolt
27500-058
2
M20 x 40 Hexagon Head Screw
27500-037
1
M12 Collared Eyebolt
24880-006
3
M20 Collared Eyebolt
24880-021
1
©
2015 Thomas Broadbent & Sons Ltd
Basket Screens
Basket Removal
Dismantling
Spindle
Assembly
Various
Operating Manual for SPV1425 Continuous Centrifuge H95702
Page 97
FEED CONTROL VALVE - MetalWork
MetalWork, Thailand Supply
* See separate manual (Part No 22361-069) for setting and
operating the Feed Valve.
Loading of the centrifuge is via a 200mm NB butterfly valve,
operated by a double acting pneumatic actuator with positioner.
©
2015 Thomas Broadbent & Sons Ltd