Vacuum pumps rotary blower

The most used mechanical vacuum pumps or compressors are reciprocating, liquid-ring, rotary-vane, rotary blower, rotary piston, and diaphragm. 

Rotary blower—liquid ring vacuum pump... 

Rotary Two-ImpeUer (Lobe) Blowers and Vacuum Pumps... 

Sliding vane, rotary blowers and compressors 346 --------- vacuum pumps 365... 

Vacuum blowers (vacuum pumps) are used to draw waste nitrogen, carbon dioxide, and water vapor from the adsorber vessels during the evacuation step. There are two rotary-lobe blowers operating in series. They are positive displacement machines. A timing gear arrangement maintains the close tolerances that are essential for ef cient operation. 

Dry Vacuum Pumps (DVPs) These use the operating principles of rotary-lobe roots blowers, claw compressors or screw compressors, and hence require electrical power. They run dry and hence at very high temperature due to the heat of compression. Usually,... 

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. 

Positive displacement blowers Positive displacement blowers are probably the most commonly used type of compressor for dilute phase conveying systems. They provide an ideal match, in terms of pressure capability, with the conventional low pressure rotary valve, and are a typical working combination on many plants. They can be used as vacuum pumps, or exhausters, as well as blowers. The principle of operation is illustrated in Figure 4.26. Twin rotors are mounted on parallel shafts within a casing, and they rotate in opposite directions. As the rotors turn, air is drawn into the spaces between the rotors and the casing wall, and is transported from the inlet to the outlet without compression. As the outlet port is reached, compression takes place when the air in the delivery pressure pipe flows back and meets the trapped air. 

Vacuum capacities and operating ranges, table, 344, 355 Ejectors, 344, 357 Integrated systems, 344 Liquid ring pumps, 344 Rotary lobe blowers, 344 Rotary piston pumps, 344 Rotary vane pumps, 344 Vacuum equipment, 343 Applications diagram, 352 ASME Code, 344 Pumps, 382 Steam jets, 357 Vacuum flow,... 

Figure 5.6. Components of pneumatic conveying systems, (a) Rotary positive displacement blower for pressure or vacuum, (b) A rotary airlock feeder for fine materials (Detroit Stoker Co.), (c) A four-compartment receiver-filter (Fuller Co., Bethlehem, PA), (d) A two-stage cyclone receiver, (e) The Fuller-Kinyon pump for cement and other fine powders. Powder is fed into the aeration chamber with a screw and is fluidized with compressed air (Fuller Co., Bethlehem, PA).

Vacuum systems (Fig. 21-12 ) are characterized by material moving in an air stream of pressure less than ambient. The advantages of this type are that all the pumping energy is used to move the product and that material can be sucked into the conveyor line without the need of a rotary feeder or similar seal between the storage vessel and the conveyor. Material remains suspended in the air stream until it reaches a receiver. Here, a cyclone separator or filter (Fig. 21-12c) separates the material from the air, the air passing through the separator and into the suction side of the positive-displacement blower or some other power source. 

Figure 7.12 shows a typical combination negative-positive pressure vacuum system. Vacuum from the pump draws material into either a cyclone separator or filter receiver. The pellets are passed through a rotary airlock and enter the blower discharge airstream, which is at positive pressure. The air/material mixture is transferred to the silos via stainless-steel flex-hose and fill lines. Combination units tend to be high-capacity systems used primarily with multiple silo systems. One advantage is that they require no equipment whatsoever on top of the silo, only a simple fill line. All maintenance is performed at ground level. 

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