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