MVR BLOWERS
AND SQUEEZE OIL DAMPER BEARING
PILLER MVR BLOWERS
MADE FOR ENERGY SAVING
PILLER was the first company to introduce centrifugal blower
solutions for the process of Mechanical Vapor Recompression
(MVR) as used in Evaporation Units. Patented bearings and
purposely developed high-performance impellers make PILLER
the leading manufacturer of MVR Blowers.
EFFICIENCY THROUGH FLEXIBILITY
PILLER MVR Blowers ensure maximum efficiency, thus cost
savings, and lower life cycle costs. We tailor our MVR Blowers
to suit the individual customer’s needs. Our products are of
high quality and intelligent design along with a high level of
standardization.
directly heated
thermal vapor recompression
A
A
G
F
D
C
E
D
C
CC
C
B
In-house R&D results in continuous development and
invention such as our patented bearing system.
mechanical vapor recompression
A
D
THE EXPERT AT YOUR SIDE
PILLER is the high performance blower specialist. Our
customers have enjoyed the benefits of our MVR Blower
production expertise for more than three decades. Our
German engineering expertise and precision are worldwide
benchmarks.
C
A
B
C
CC
D
E
F
G
Process steam
Concentrate
Vapor
Condensate
Main steam
Electrical energy
Thermocompressor
PILLER MVR Blower
CC
B
B
Fig. 1: Methods for heating evaporators
2
P I L L E R BL O W E RS & COM P R E S S O R S
PERFORMANCE RANGE
10
9
Max ΔT (°C)
8
2558 Series
2869 Series
3669 Series
4077 Series
7
4577 Series
5077 Series
5677 Series
6
5
0
10000
20000
30000
40000
50000
60000
70000
Inlet Mass Flow (kg/hr)
Fig. 2: Product Line Summary at 60° C
12
11
Max ΔT (°C)
10
2558 Series
9
2869 Series
3669 Series
4077 Series
8
4577 Series
5077 Series
5677 Series
7
6
5
0
50000
100000
150000
200000
250000
300000
350000
Inlet Mass Flow (kg/hr)
Fig. 3: Product Line Summary at 100° C
MV R BLO WERS A N D SQ U EE ZE OIL DAMPER BEARING
3
FIELDS OF
APPLICATION
FACTS
PILLER MVR Blowers are designed for system pressures from
0.05 – 5 bar customized according to the process.
–Tip speeds of up to 320 m/s
–Water injection keeps impellers clean and the steam
saturated
–Low wear floating carbon ring labyrinth seals guarantee
longterm tightness
–Our patented squeeze-oil-damping combines the
simplicity of anti-friction bearings with the performance
of hydrodynamic bearings
–For higher temperature rises up to four MVR Blowers
can be used in series
–Suitable for conditions of corrosive environment such as
sulphuric acid vapors
MVR Specifications
4
Medium
Steam
Motor capacity
up to 5 MW
Temperature increase
up to 10 K
single stage
Impeller speed
up to 320 m/s
Efficiency
up to 86 %
Mechanical vapor recompression was initially used almost
exclusively in the milk and dairy industry. The areas of
application have grown since with PILLER MVR Blowers
having proved successful in many different fields.
–Milk/Whey
–Starch
–Sugar
–Yeast
–Alcohols
–Bioethanol
–Gelatine
–Pectins
–Grain Processing
–Vegetable Processing
–Fruit Juices
–Electrolyte Baths
–Saline Water
–Citric Acid and Acetic
–Sulphuric Acid
–Sewage Sludge and
Lacquer Sludge
–Liquid Manure
–Oil Recycling
–Recycling of special metals
–Seawater Desalination
–Wood Drying, Pellets
Drying and Peat Drying
–Paper Drying
–Boiler Feedwater
–Blood Plasma
–Commercialisation of
Meat and Fish
Petrochemical
–PTA
–EPDM
–Butadiene
–Waste water
The PILLER MVR Blowers are advanced design
solutions that have been standardized to a high degree.
There is no other PILLER product that passed through so
many innovations. Our standardized design provide for
cost-effective solutions which can quickly be realized.
P I L L E R BL O W E RS & COM P R E S S O R S
TECHNOLOGY
The PILLER high-performance Blowers reach temperature rises
through impeller peripheral speed of up to 300 m/s, using
special materials even up to 320 m/s. Impeller geometries have
also been optimized for best possible aerodynamic loading and
efficiency.
Shaft seal
SHAFT SEAL
Various shaft seal concepts are available, depending on the
intended use. In general, distinctions are made between the
following operating conditions:
–Process operates in a high vacuum
–Process operates above ambient condition
WATER INJECTION
A specially designed water injection nozzle keeps steam near
saturation point increasing the heat transfer.
INSTRUMENTS
Every PILLER MVR Blower is equipped with control
instrumentation. These instruments are wired to a common
junction box so that customers can bring back these instrument
signals to the plant control system. Typical instruments monitor
the following parameters:
Water injection
– Casing temperature
– Bearing temperatures
– Shaft vibration
–Speed
– Oil temperature
– Oil level
– Oil flow to the blower bearings
– Oil pressure
– Condensate level in the casing
Instruments
MV R BLO WERS A N D SQ U EE ZE OIL DAMPER BEARING
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PILLER’S SQUEEZE OIL DAMPER BEARING
MVR Blower with Squeeze Oil Damper Bearing
The best operating speed of many MVR Blowers is between
3000 and 3600 rpm. As shown in this figure, at this speed
range all three types of fluid film bearings are going to
be influenced by the critical speed and in almost all cases
we cannot maintain the requested separation margin
from critical speed cannot be maintained. For the 2 and 4
segment bearings, the blower operating speed would be
limited to below 2500 rpm which would significantly limit
the blower performance or above 3700 rpm which may
not be possible because of the tip speed limit of the blower
impeller. In any case the influence of critical speeds with
sleeve type fluid film bearings significantly limits operating
speed range and blower selection.
6
Vibration Amplitude for a Rotor on different Types of Fluid Film Bearings
with Critical Speed Separation Margins Shown
0,045
0,04
Shaft Vibration Amplitude
Demands for increased MVR Blower performance has
required higher blower speeds so that most MVR Blowers
now run above their first critical speed. A rotor running
above its first critical speed is known as a super critical rotor.
Traditionally, a super critical rotor required the use of sleeve
type fluid film bearings to provide the damping necessary
to pass through the critical speed on startup or coast down.
For a fluid film supported rotor to run reliably the blower
speed must be selected to be significantly above or below a
critical speed so that the blower vibration during operation
was not influenced by the critical speed. This required
separation margin in turn limits the blower allowable
operating speed range. A minimum standard separation
margin of 20 percent is often specified. Figure 4 below
shows the calculated vibration amplitude of a blower rotor
supported by three common types of fluid film bearings, a
two segment bearing, a four segment bearing and a 5 pad
tilting pad bearing.
0,035
0,03
0,025
0,02
0,015
0,01
0,005
0
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
Shaft Speed in RPM
2 Segment Fluid Film Bearing
4 Segment Fluid Film Bearing
Tilt Pad Fluid Film Bearing
Fig. 4: Vibration Amplitude for a Rotor on different types of Fluid Film
Bearings
To overcome the limited operating ranges of sleeve bearing
systems, PILLER developed a unique and patented Squeeze
Oil Damper Bearing System. It is made up of a static oil
damper that supports a standard antifriction bearing usually a
cylindrical roller bearing at the impeller end of our rotor and
a deep groove ball bearing at the coupling end of the rotor
that acts as both the coupling end radial bearing and thrust
bearing. Our squeeze oil damper not only provides the required
damping to pass through the critical speed but also reduces the
bearing stiffness so that the critical speed is lowered well below
any required blower operating range.
P I L L E R BL O W E RS & COM P R E S S O R S
Squeeze Oil Damper Bearing
Figure 5 shows the calculated vibration amplitude or rotor
response for a rotor on antifriction bearing with and without
the squeeze oil damper. As you can see the amplitude of the
rotor through the critical speed with the squeeze oil damper
is an order of magnitude lower than the amplitude without
the damper. The influence of the critical speed with the
squeeze oil damper is actually negligible. Further the critical
speed with the squeeze oil damper was lowered from 2900
rpm to 900 rpm allowing this rotor design to operate without
any significant influence of a critical speed from 0 to 4900
rpm.
Vibration Amplitude for PILLER's Squeeze Oil Dampered
Anti-Friction Bearing vs Conventional Anti-Friction Bearings
with Critical Speed Separation Margins Shown
Shaft Vibration Amplitude
0,6
0,5
0,4
0,3
0,2
0,1
0
0
500
1000
1500
2000
2500
3000
3500
4000
4500
Shaft Speed in RPM
with PILLER‘s Squeeze Oil Dampered Anti-Friction Bearings
with Conventional Roller Bearings
5000
The PILLER Squeeze Oil Damper Bearing design also has the
following advantages:
–
–
The antifriction bearings used are available off the shelf
from almost any bearing supply house
The oil lubrication system is a smaller and simpler system
than those supplied with fluid film bearings
- T he total oil flow to our Squeeze Oil Damper Bearings is
less than one liter per min
- In most cases we do not need an oil cooler or heater
as the oil viscosity is not as important for antifriction
bearings. As long as we can spray oil on the bearing our
system is good. With fluid film bearings oil needs to be
controlled to a certain temperature to maintain a design
oil viscosity to get the proper bearing performance
- T he oil in the antifriction bearings is sufficient for coast
down so there is no need for added pumps fed from
uninterruptable power or run down tanks to keep the
bearings from being damaged on loss of oil during
shutdown
– Our vibration monitoring is simpler, there is no need for X
and Y probes as we do not have an orbit. A single
proximity probe is all we recommend
PILLER standard bearings are a roller and ball bearing, simple,
very effective, low in cost and available everywhere.
with Conventional Ball Bearings
Fig. 5: Vibration Amplitude for PILLER’s Squeeze Oil Damper Anti-Friction
Bearings vs. Conventionally Mounted Ball and Roller Bearings
MV R BLO WERS A N D SQ U EE ZE OIL DAMPER BEARING
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Piller Blowers & Compressors GmbH
Sunteco Limited
Piller TSC Blower Corporation
Piller BCS Ltd.
Piller Blowers & Compressors GmbH
Nienhagener Straße 6
37186 Moringen
Germany
+49 5554 201-0
+49 5554 201-271
info@piller.de
www.piller.de
Piller TSC Blower Corporation
445 Duane Avenue
Schenectady, NY 12304
USA
+1 518 372-2496
+1 518 372-0115
info@piller-tsc.com
www.piller-tsc.com
Piller SEA Pte. Ltd.
25 International Business Park
# 03-56 German Centre
Singapore 609916
+65 6562 955-1
+65 6562 955-2
info@piller.com.sg
www.piller.com.sg
Piller BCS Ltd.
Unit 309, 88 Keyuan Road
Zhangjiang Hi-Tech Park
Pudong
201203 Shanghai
PRC
+86 21 5020 3878
+86 21 5020 3876
info@pillerbcs.com.cn
Sunteco Limited
# 1105 An-yang IT Valley
1027, Ho-gye Dong, Dong-an Gu
An-yang Si
Republic of Korea 431-848
+82 31 343 1456
+82 31 343 1459
sunteco@sunte.co
www.sunte.co
0099010701 · Issue Date: 2015-04
Piller SEA Pte. Ltd.