| MECHANICAL VACUUM BOOSTERS:-Mechanical
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| | process rates and through-puts. The
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| Vacuum Boosters are dry pumps that meet
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| | drawbacks of steam ejector system such as
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| most of the ideal vacuum pump
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| | sensitivity to motive fluid pressures and
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| requirements. They work on positive
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| | discharge pressure are overcome easily by
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| displacement principle and are used to
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| | the Mechanical Boosters, since the
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| boost the performance of water ring /oil
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| | volumetric displacements/pumping speeds
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| ring /rotating vane /piston pumps and
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| | are insensitive to the inlet & outlet
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| steam or water ejectors. They are used in
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| | working pressures.Typical Booster
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| combination with any one of the above
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| | Installation
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| mentioned pumps, to overcome their
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| | (1) Evaporator (2) Gauge (3) Condenser
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| limitations. Vacuum booster pumps offer
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| | (4) Mechanical Booster
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| very desirable characteristics which make
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| | (5) backup PumpEverest .................
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| them the most cost effective and power
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| | Leaders in Vacuum Booster Technology
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| efficient option.The major advantages
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| | Boosters for Vacuum Process © Everest
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| are:-(a) Can be integrated with any
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| | Transmission January, 2005.Calculating the
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| installed vacuum system such as Steam
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| | Pump Capacity: -
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| Ejectors, Water Ring Pumps, Oil Sealed
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| | Based on the fundamental gas laws PV= RT,
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| Pumps, Water Ejectors, etc.(b) The vacuum
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| | an expression can be derived for
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| booster is a Dry Pump as it does not use
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| | Volumetric Flow Rates required for pumping
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| any pumping fluid. It pumps vapor or gases
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| | different vapors/gases. Based on the Mass
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| with equal ease. Small amounts of
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| | flow rates one can estimate the pump
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| condensed fluid can also be pumped.(c)
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| | capacity required.V = R . Tgas / P Q1/M1 +
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| Vacuum boosters are power efficient. Very
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| | Q2/M2 ............. Qn/Mn
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| often a combination of Vacuum Booster and
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| | Where V = Inlet Volume flow rate m3/hr.
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| suitable backup pump results in reduced
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| | R = Universal gas Constant, 83.14 mbar m3
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| power consumption per unit of pumping
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| | Kgmol x ºK
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| speed. They provide high pumping speeds
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| | Tgas = Gas/Vapor abs. Temp, in ºK
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| even at low pressures.(d) Boosters
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| | P = Process Absolute Pressure in mbar
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| increase the working vacuum of the
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| | Q1, Q2, Q3 = Gas / Vapor flow rate, in Kg
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| process, in most cases very essential for
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| | hr.
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| process
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| | M1 , M2 ,M3 = Molar mass, in Kg/mol. of
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| performance and efficiency. Vacuum
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| | gas /vapor.Booster Operation:
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| Booster can be used over a wide working
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| | Power Constraints restrict the total
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| pressure range,
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| | differential pressures across the booster.
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| from 100 Torr down to 0.001 Torr (mm of
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| | This demands to ensure the total
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| mercury), with suitable arrangement of
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| | differential pressure across the Booster
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| backup pumps.Everest
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| | must not exceed the rated limits. This can
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| ...................... Leaders in Vacuum
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| | be ensured by any of the following
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| Booster Technology Boosters for Vacuum
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| | means:-1.) Manual method:- Initially the
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| Process © Everest Transmission January,
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| | fore pump is switched on until the
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| 2005.(e) It has very low pump friction
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| | required cut in pressure is achieved and
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| losses, hence requires relatively low
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| | there-after the booster is switched on.2.)
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| power for high volumetric
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| | Auto method:- Installation of mechanical
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| speeds. Typically, their speeds, at low
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| | By-pass arrangement across the booster or
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| vacuums are 20-30 times higher than
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| | hydro kinematic drive or Variable
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| corresponding vane
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| | Frequency Drive (VFD). In this
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| pumps / ring pumps of equivalent
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| | arrangement, the booster and fore pump can
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| power.(f) Use of electronic control
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| | be started simultaneously from
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| devices such as Variable Frequency Control
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| | atmosphere.Advantages of using Electronic
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| Drive allow to modify
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| | Variable Speed Control Device
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| vacuum boosters operating characteristics
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| | Electronic A.C Variable Frequency Control
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| to conform to the operational requirements
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| | Drives are most preferred devices used to
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| of the prime
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| | regulate the
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| vacuum pumps. Hence they can be easily
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| | Booster speed to match the varying load
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| integrated into all existing pumping set
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| | conditions of the process. These drives
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| up to boost their
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| | enhance the overall performance of the
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| performance.(g) Vacuum boosters don't
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| | Boosters and offer various advantages for
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| have any valves, rings, stuffing box etc.,
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| | the trouble free operation.The major
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| therefore, do not demand regular
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| | advantages are: -
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| maintenance.(h) Due to vapor compression
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| | 1. Booster can be started directly from
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| action by the booster, the pressure at the
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| | atmosphere.
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| discharge of booster (or inlet of backup
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| | Everest ................... Leaders in
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| pump) is maintained high, resulting in
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| | Vacuum Booster Technology
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| advantages such as low back streaming of
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| | Boosters for Vacuum Process © Everest
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| prime pump fluid, effective condensation
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| | Transmission January, 2005.
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| even at higher condenser temperatures and
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| | 2. No need for separate pressure switch,
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| improvement of the backup pump
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| | by pass line or offloading valves.
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| efficiency.The Table below gives a rough
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| | 3. Considerable savings in power.
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| estimate of how the boosters enhance the
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| | 4. Prevents over-heating of Boosters.
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| working vacuums of the processes when
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| | 5. Protects the Booster against overload
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| installed in combination with various
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| | and excessive pressures.
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| types of industrial vacuum pumps currently
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| | 6. Offers complete protection to motor
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| used in the industry. They can effectively
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| | against over voltage, under voltage, over
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| replace multistage steam ejectors,
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| | current,
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| resulting in considerable steam savings
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| | Over-heating, ground fault.
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| and reduced loads on cooling towers.
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| | 7. Eliminates the needs of separate
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| Mechanical Vacuum Boosters are versatile
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| | starter and overload relays for the Motor.
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| machines and their characteristics depend
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| | 8. Automatically adjusts the speed of
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| largely on backing pump. Various types of
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| | Booster between low and high range set
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| backing pump can be used, depending upon
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| | giving high
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| the system requirement and ultimate vacuum
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| | pumping speeds with relatively low input
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| needs.
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| | power.The Electronic Variable Frequency
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| However, the final vacuum is governed by
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| | Control Drive is a microprocessor based
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| the suitable selection of the backing pump
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| | electronic drive which is specially
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| and booster
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| | programmed to meet the demands of the
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| arrangement. The table below gives a
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| | Booster allowing it to operate directly
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| broad range of vacuum achieved with
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| | from atmosphere along with suitable fore
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| various backing pumps combinations.Vacuum
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| | pump. Conventionally, Boosters can be
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| Pump Expected vacuum Vacuum on
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| | started only after achieving fore vacuum
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| installation Range of Booster (single
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| | in the range of 30 - 100 Torr, as they are
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| stage)
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| | not recommended for direct discharge into
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| Single Stage Ejector 150 Torr 15 - 30
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| | the atmosphere. Use of Pressure Switch,
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| Torr
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| | Hydro kinematic drive and by pass valves
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| Water Ejector 100 Torr 10 - 20 Torr
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| | is necessary to prevent the overloading of
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| Water Ring Pump 40 - 60 Torr 5 - 10 Torr
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| | the Booster. However with the installation
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| Liquid Ring Pump 20 - 30 Torr 2 - 5 Torr
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| | of Electronic Variable Frequency Control
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| Piston Pumps 20 - 30 Torr 2 - 5 Torr
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| | Drive all the conventional methods can be
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| Rotary Piston Pumps 0.1 Torr 0.01 Torr
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| | bypassed since the drive is programmed to
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| Rotary Vane Oil Pump 0.01 - 0.001 Torr
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| | regulate the Booster speed automatically,
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| 0.001 - 0.0001 Torr.
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| | keeping the load on motor within
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| Everest ................ Leaders in
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| | permissible limits. This allows the
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| Vacuum Booster Technology Boosters for
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| | Booster to start simultaneously with
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| Vacuum Process © Everest Transmission
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| | backup pump. When the backup-pump and
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| January, 2005.For example, if a process is
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| | Booster are started the drive reduces the
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| using water ring Pump, the estimated
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| | Booster speed to the pre-set levels and as
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| working vacuums would be of the order of
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| | the vacuum is created the Booster speed
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| about 670-710 mmHg gauge (90-50 mmHg
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| | picks up, reaching the final pre-set
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| abs.), largely depending on the water
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| | speed, giving most optimum performance
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| temperature and pump design. When a
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| | over the entire range. Since all the
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| Booster is installed prior to the water
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| | parameters are easily programmable, one
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| ring pump, in series, the vacuum levels of
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| | can adjust the booster pumping speeds to
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| the order of 5-10 Torr can be easily
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| | match the system requirements easily and
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| achieved. In a Multi-Stage booster
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| | quickly. The drive limits the current to
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| installation, vacuum levels of the order
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| | the motor and safeguards the motor against
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| of 0.5 Torr & better can easily be
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| | over voltage, under voltage, electronic
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| expected. Mechanical Boosters offer a
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| | thermal, overheat ground faults. i.e.
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| completely dry pumping solution and do not
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| | protects the motor against all possible
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| add to any vapor load, unlike steam
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| | faults.
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| ejectors, and therefore, do not require
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| | External computer control over all
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| large inter stage condenses. At low
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| | aspects of booster performance is possible
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| vacuums, higher pumping speeds are
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| | via RS485 serial interface built into the
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| required to maintain the through-put,
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| | drive electronics. This enables the
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| since the specific volume increases with
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| | Booster to be integrated into any
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| the increase in vacuum. Vacuum boosters
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| | computer-controlled operating system.To
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| enhance the pumping speeds by about 3-10
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| | know more about this site visit this site:
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| times depending upon the selection by
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| | is author and designer of the guide area
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| virtue of which one can expect higher
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| | of blowers.
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