Vacuum pumps Booster

The sliding-vane compressor is widely used as a vacuum pump as well as a compressor, with the largest volume approximately 6,000 cfm. The lower end of the volume range is 50 cfm. A single-stage compressor with atmospheric inlet pressure is limited to a 50 psi discharge pressure. In booster service, the smaller units can be used to approximately 400 psi. 

Booster vacuum pumps are used to shorten the pump-down on evacuation (time) of a vacuum system before switching to the smaller vacuum pump to maintain the system opening vacuum and to handle the air inleakage to the system. 

Devices for compressing gases are used extensively in the chemical industry (see "High Pressure Techniques"), eg, in the manufacture of nitric acid by the ammonia oxidation process Compressors for transferring gases and vapors may be divided into vacuum pumps or exhausters (when the gas is below atmospheric pressure) and into fans, blowers, boosters and ax . I compressors (when the gases are above atmospheric pressure)... 

Following the condensing section, and depending on the utility situation at the plant site, either a liquid ring vacuum pump or a two-stage steam jet with an intercondenser is used. A booster ejector is not required to maintain the vacuum level required for evaporation. 

Vacuum pumps are generally divided into 13 categories according to the working principle, as listed in Table 2.5. They include water jet pump, water ring pump, steam ejector, oil-sealed rotaiy pump, Roots pump, vacuum diffusion pump, oil vapom booster pump, sputtering-ion pump, radial field pump, titanium sublimation pump, sorption pump, molecular pump and cryopump [9],... 

All of the other vacuum pumps listed above can be used as booster pumps. This combination is particularly suitable for continuous processes in which the intake pressure in the recipient must be kept almost constant... 

For most steam ejector applications, direct contact condensers between stages were frequently used. For vacuum steam stripping, use shell and tube condensers with refrigerant at -8 to -12 °C upstream of the booster ejector with interstage dry condensers plus a liquid ring vacuum pump. 

Low vacuum (1 bar-1 mbar) Positive displacement pump Booster diffusion vacuum pump (particularly steam jet pumps) Low vacuum distillation Vacuum circulation evaporator Continuous evaporator with falling or wiped film Rotary evaporator... 

Medium vacuum (1 mbar-0.1 Pa) Pump combination for example positive displacement pump+ booster diffusion pump (oil ejector) Medium vacuum distillation Continuous evaporator with agitated film (film evaporator with fixed or swinging wipers, film evaporator with brushes or rolls) Rotary evaporator... 

In many cases, multistage vacuum pumps consume less energy than single-stage pumps while doing the same job. Power requirements may be reduced as much as 50%. Rotary blowers are often called mechanical booster pumps because they are commonly used as a first stage in a multistage system. 

Q. There are other types of vacuum pumps, seldom found in cleaning machines. A fifth type of pump is a dry pump, which can be a screw, scroll (high speed), or claw design. Booster pumps are also dry and a generally rotary lobe type. 

These Roots vacuum pump combinations serve not only as boosters within the low pressure range where only a small pressure difference needs to be overcome, but also serve in multistage arrangements as a complete pumping unit, compressing from a few millibar abs. directly to atmospheric pressure. 

FIGURE 6.36 (a) Pump-down factor for single-stage and compound vacuum pumps (b) pump-down factor tor mechanical booster and backing pump. (After Kinney Vacuum Division, The New York Air Brake Co., and VanAtta.)... 

Booster pump (vacuum technology) A pump used between the high vacuum pump (particularly the diffusion pump) and the backing pump in order to increase the throughput in the medium vacuum range and decrease the volumetric flow through the backing pump. Example Diffusion pump (DP) exhausts into a Roots blower (booster pump) then into an oil-sealed mechanical pump. See also Vacuum pump. 

Figure 6-48A. Typical performance of high vacuum booster lobe-type high volume draw-down for evacuating vacuum systems before use of higher vacuum (lower absolute pressure) pump. By permission, Roots Division, Dresser Industries, Inc.

Dry pumps can produce very high levels of vacuum in a booster role. Some screw pumps can reach less than 0.1 Torr absolute. 

Vacuum Gas Vacuum Air Phase Booster Water Pump... 

These booster pump stations usually consist of a centrifugal pump (capacities ranging between 0.6 and 4 mVs) with a diesel or electric drive mounted on a skid or trailer for on land applications or on a pontoon when used over water To avoid the development of a vacuum in the pipeline it is imperative that the position of... 

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