SPECIFICATIONS
MODEL EHV-6000-96-38-X
VACUUM OIL PURIFIER
ENERVAC CORPORATION
Proposal No. ESA2006-110
1 DEGASSING TECHNOLOGY
This proposal describes the equipment which shall be supplied by ENERVAC for a system for processing
(degassification, dehydration and filtration) transformer insulating fluids.
Removing dissolved vapor and gas from a liquid is a physical process. Vapor or gas molecules randomly
leave the surface of a liquid into surrounding gas, and also randomly leave the gas and enter the liquid.
When the rate of molecules entering the liquid is equal to the rate of molecules leaving an equilibrium is
achieved which is called saturation. Henry's Law states that the mass of gas dissolved in a given volume
of solvent is proportional to the pressure of the gas with which it is in equilibrium. In a vacuum oil purifier
the pressure of the gas is reduced by a vacuum pump and the oil is treated so that equilibrium can be
achieved quickly.
One approach is to extend the surface between liquid and gas and another is to encourage the formation
of bubbles below the surface of the gas. Several approaches can be taken to the removal of dissolved
vapors and gases from liquids as shown below.
TRAYS extend the surface of the liquid, but no means of encouraging the bubbles
to form are included. Trays require a high processing temperature which
results in light ends being permanently removed from the oil.
RINGS extend the surface of the liquid but no means of encouraging the bubbles to
form are included. Rings require a high processing temperature which results
in light ends being permanently removed from the oil.
GLASS FIBER DEGASSING ELEMENTS both extend the oil surface and present
millions of sharp ends to the flow of oil and each creates a "point of release" which
encourages the formation of a bubble. This is similar to the stream of bubbles which
can often be seen in a glass of Coca Cola or beer, the point from which the bubbles
come is a scratch causing a "point of release".
ENERVAC degassing accelerator elements are constructed in a way to maximize
the "point of release" density. The elements not only stimulate the formation of small
bubbles they also help large bubbles to collapse, tests prove that there is much less
tendency to foam than with other degassing methods.
Using this technique, ENERVAC Vacuum Oil Purifiers provide effective degassing at higher pressures
and lower temperatures than other methods. The lower processing temperature assures that light
ends, which preserve low viscosity for good cooling properties, are retained in the oil to perform
exactly as the oil manufacturer intended.
2
ENERVAC CORPORATION
Proposal No. ESA2006-110
2 SCOPE
The scope of supply of this specification shall include the design, fabrication and factory testing of one (1)
ENERVAC Model Number EHV-6000-96-38-X Vacuum Oil Purifier, as shown schematically in Bulletin 610-000, and shall consist of the equipment and components as subsequently described.
The system, when received by the purchaser, shall provide a fully workable unit and shall perform in
accordance with this specification.
ENERVAC shall supply all necessary physical arrangements, mechanical, electrical connection, piping
schematic and all necessary data for use in the operation and maintenance of this system. Prior to
delivery of this system, ENERVAC shall provide three (3) copies of the instruction manual. One (1)
complete copy of the manual shall be included with the shipment. This manual shall contain:
● Detailed Operating Instructions
● Maintenance Information
● Equipment drawings including Physical Arrangement, Electrical Diagram and Flow Diagram
● A Recommended Spare Parts List
3 PERFORMANCE
Clean oil containing 100 PPM total water content and fully saturated with air at 12% by volume shall be
dehydrated and degassified at the full rated capacity of the system, at a minimum oil supply
temperature of 2oC and shall meet the following specifications.
Dielectric strength by ASTM Method D-877 shall not be less than 40 KV with new oil.
Total soluble water content by ASTM Method D-1533-61 or D-1744-64 (Karl Fisher) shall be less than 10
PPM.
Total gas content shall not be greater than 0.25% by ASTM Method D-831-63 or by Doble Gas Content
Analyzer ASTM D-2945-71.
4 CAPACITY
The maximum continuous purification capacity shall be 6,000 litres/hour. The ultimate pressure of the
vacuum pump shall be less than 0.08 mbar. Capacity of the vacuum system shall be 300 m3/hr (50Hz).
The system shall be capable of processing at reduced flow if required.
5 POWER REQUIREMENTS
380 Volts, 3 Phase, 50 Hertz - (110 kW Max.)
3
ENERVAC CORPORATION
Proposal No. ESA2006-110
6 DIMENSIONS AND WEIGHT
The purifying system shall be approximately 1,778 mm Wide x 3,048 mm Long x 1,980 mm High and shall
weigh approximately 3,100 kgs.
7 DESCRIPTION OF COMPONENTS
The purification system shall be fully assembled on a heavy duty steel base, which shall be sufficiently
braced to minimize vibration. A drip lip shall be provided on the base to collect spillage and drippage. The
system shall consist of the following components.
7.1
One (1) Oil Inlet Ball Valve 1-1/2 inch NPT.
7.2
One (1) Strainer, complete with a 30 mesh basket.
7.3
One (1) Inlet Flow Sight Indicator.
7.4
One (1) Positive Displacement, Inlet Pump, with mechanical seal. The pump shall be rated at
10% approximate higher flow than discharge pump. It shall be direct driven by a 1.5 kW, 1800
RPM TEFC electric motor.
7.5
One (1) Inlet Pump Relief Valve.
7.6
One (1) 96 kW Electric Inlet Oil Heater. The heater shall contain six, 16 kW heater elements,
which shall have a watt density not greater than 1.7 W/cm2. The heater shall be capable of
increasing the oil temperature 30oC in a single pass. The heater elements shall be controlled in
two banks by contactors. Fuses shall be used for over current protection of each bank of heater
elements.
7.7.1
One (1) Flow Switch, which shall be interlocked with the heater and shall require flow prior to
energizing heaters.
7.7.2
One (1) Indicating Temperature Controller, which shall be used to control the electric heating
elements to maintain the desired oil temperature. The controller shall be panel mounted. The
temperature controllers, on deviation from the set point, activates the heater contactors through a
series of time delay relays, which energize the required number of heating elements, raising the
oil temperature to the set point. The digital controller set point is adjustable by a single adjusting
button, thereby changing the set point on all elements simultaneously.
The heater controller is designed to drop out the heating load on loss of power or oil flow. On
resumption of power or flow, the controller resumes function and begins to energize banks of
heating elements as required through the time delay relays.
4
ENERVAC CORPORATION
Proposal No. ESA2006-110
The heater element banks are energized individually at timed intervals to prevent an overload on
the power supply to the system.
7.8
One (1) Degassification Chamber. The illuminated chamber shall have a viewing port and a
hinged service door.
7.9
One (1) Float Actuated Level Control Valve. The valve is actuated by a float mechanism in the
degassification chamber to maintain the desired oil level. The level control valve is fully
modulating and will maintain an inlet flow equal to the capacity of the discharge pump.
7.10
One Vacuum Gauge, 0-50 Torr range, to indicate the vacuum in the processing chamber.
7.11
One (1) Pressure Gauge, which is used to monitor pressure drop across the degassification
accelerator elements, thus showing the need to replace the elements.
7.12
One (1) Foam Detector, which shall be activated on the appearance of excessive foam.
7.13
One (1) Solenoid Operated Valve to break vacuum on appearance of foam. The valve shall be
operated by the Foam Detector. The inlet pump shall be stopped on appearance of, or persistent
foaming condition.
7.14
One (1) Degassification Header, which shall contain chemically inert accelerator degassing
elements.
7.15
One (1) High Level Detector. This level switch shall stop the inlet pump to prevent flooding and is
a back-up for the flow control valve Float Actuated Level Control Valve.
7.16
One (1) Low Level Switch shall be interlocked with the discharge pump to prevent it from
operating unless sufficient oil head is present.
7.17
One (1) Positive Displacement Discharge Pump with double mechanical seals. The pump shall
have a rating of 6,000 litres/hour and shall be belt driven by a 1.1 kW, 1200 RPM, TEFC electric
motor.
7.19
One (1) Discharge Pump Relief Valve.
7.20
Two (2) Sampling Cocks shall be provided, one for the incoming oil and one for processed oil, as
shown on the Flow Diagram.
7.21
One (1) Outlet Flow Sight Indicator
7.22
One (1) Discharge Ball Valve 1-1/2 inch NPT.
7.23
One (1) Manual Recirculation Ball Valves.
7.24
One (1) System Relief Valve.
7.25
One (1) Enervac Model E858B-1-EP-718-1/2A2 Oil Filter to be installed after the outlet pump. The
Afterfilter is furnished with replaceable pleated paper elements with a micron selectivity of 0.5
microns and a filtration efficiency of 98%. Standard filter units are of steel construction and
complete with manual drain valve and pressure gauges to monitor differential pressure.
5
ENERVAC CORPORATION
Proposal No. ESA2006-110
7.27
Free displacement of vacuum package 300 m3/hr (50Hz). Ultimate vacuum level: 0.08 mbar.
7.29
All necessary pressure gauges and valves as shown on the Flow Diagram shall be provided to
complete system. Suitable flexible connections shall also be provided in the piping to minimize
vibration.
7.30
A NEMA 12 Control Cabinet shall be provided, which shall contain all necessary control items
required for the system. All motors shall be provided with magnetic starters for full voltage,
across-the-line starting. Each motor shall have sufficient overload protection. Fuses shall be
provided with each motor starter.
7.31
The following instruments shall be mounted on the control box:
● Temperature Controller
All other gauges shall be locally mounted.
7.32
The following conditions shall have audible and visual alarms:
● High Foam/High Level
● Low Oil Level
7.33
Electrical System
All components shall be suitable for 380 Volt, 3 Phase, 50 Hertz power supply. One (1) dry-type
500 VA transformer shall be supplied for control circuits.
7.34
Piping
All piping shall be carbon steel, sized for the designed flow, braced and supported to prevent
vibration. Piping will be welded construction when possible, to minimize leaks. Special vacuum
tight welded 'O' ring unions and pipe flanges shall be provided to allow removal of components for
maintenance, when necessary.
8 OPTIONAL VOLTAGE - (INCLUDED)
Option 38 is included , 380 Volt, 3 Phase, 50 Hertz power supply.
9 PRE-FILTER OPTION – OPTION ‘P’ - (SEE QUOTATION)
The Pre-filter is furnished with replaceable pleated paper elements with a micron selectivity of 5 microns
and a filtration efficiency of 98%. Standard filter units are of steel construction and complete with manual
drain valve and pressure gauges to monitor differential pressure.
10 FLOW METER OPTION – OPTION ‘M’ - (SEE QUOTATION)
One (1) electronic in-line flow totaliser to provide a dependable and accurate totaling. The meter is
furnished with digital menu display, for multi-choice flow units (lpm, Usgpm, IMPgpm), resettable main
totaliser and daily totaliser. This display is registered in a choice of litres in 7 digits, and US Gallons,
Imperial Gallons or cubic meters, all in 6 digits.
6
ENERVAC CORPORATION
Proposal No. ESA2006-110
11 VACUUM BOOSTER – OPTION ‘VB’ - (NOT INCLUDED)
One (1) Roots type vacuum blower, Kinney model KMBD-1600 or equivalent to improve the vacuum pump
down time when vacuuming a transformer. The vacuum booster will have a free air displacement of 2,700
m3/hr.
12 HYGROMETER – OPTION ‘H’ - (SEE QUOTATION)
One (1) Doble Domino Hygrometer can be supplied, digital readout for monitoring water content in the
transformer oil, complete with probe, cable, sampling cell.
Probe locations are as follows:
H1
H2
Discharge or Inlet of Vacuum Oil Purifier
Discharge or Inlet to Vacuum Oil Purifier in addition to H1 above.
13 ELECTRONIC VACUUM CONTROLLER OPTION - OPTION ‘C1’ - (NOT INCLUDED)
C1
C2
C3
Electronic Vacuum Controller with one probe
Electronic Vacuum Controller with two probes
Electronic Vacuum Controller with three probes
14 CASTERS – OPTION ‘W’ - (NOT INCLUDED)
Unit can be mounted on casters for in-plant mobility. Wheels would be 6" diameter polyolefin, 2 swivel, 2
stationary.
15 CIRCUIT BREAKERS – OPTION ‘B’ - (NOT INCLUDED)
Circuit breakers can replace fuses for over current protection.
16 VITON GASKETS - OPTION ‘V’ - (NOT INCLUDED)
Viton gaskets and seals can be incorporated in the vacuum oil purifier replacing Buna-N material.
17 SPECIAL OPTIONS - OPTION ‘X’ - (INCLUDED)
Vacuum Oil Purifier will be mounted in a tag-a-long aluminum enclosed trailer with double open rear
doors, side access doors, interior fluorescent lights, convenience receptacles, pintle hook type hitch.
7