Rotary pumps sliding vane

Figure 3-65C. Sliding vane rotary pump. (By permission, Blackmer Pump, Dover Resources Co.)...

Figure 23. Vacuum plant with nonlubricated sliding vane vacuum pumps to reduce pollution of wastewater a) Reactor b) Precondenser c) Roots vacuum pump d) Intermediate condenser e) Sliding vane rotary pump (two stage) f) Final condenser g) Condensate collection vessel...

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

Figure 8.35. The. sliding vane rotary compressor and vacuum pump...

Positive-displacement compressors, such as rotary lobe, screw type, or sliding-vane types, pump a relatively constant volume of vapor against whatever back pressure (resistance to heat transfer) is developed by the eveporator. The mass flow rate depends upon the inlet vapor density. Rotary lobe compressors are used for compression ratios up to about 2.0, the compression ratio being limited by mechanical and thermal distortion of small clearances inside the machine. The efficiency of positive-displacement compressors is between 60 and 75%. 

Figure 6-39 illustrates a single-stage rotary vane vacuum pump, without external cooling jacket. The sliding vanes (No. 7 in illustration) are oiled by a closed system to aid... 

In much the same manner as pumps, compressors are classified as one of two general classes positive displacement or dynamic (see Figure 3-68) [23]. These two general classes of compressors are the same as that for pumps. The positive displacement class of compressors is an intermittent flow device, which is usually a reciprocating piston compressor or a rotary compressor (e.g., sliding vane, screws, etc.). The dynamic class of compressor is a continuous flow device, which is usually an axial-flow or centrifugal compressor (or mix of the two). 

Figure 7.19. Some rotary positive displacement compressors, (a) A two-lobe blower, (b) Performance of a two-lobe blower (Rools-Connersville Co.), (c) A screw pump with one power and two idle rotors (Kristal and Annett, 1940). (d) Performance of 3.5" screw pump handling oils at 1150 rpm against 325 psig (Kristal and Annett, 1940). (e) Principle of the liquid ring seal compressor (Nash Engineering Co.). (0 A sliding vane blower (Beaeh-Russ Co.).

Related Calculations. Use this procedure for any type of rotary pump—gear, lobe, screw, swinging-vane, sliding-vane, or shuttle-block—handling any clear, viscous liquid. Where the liquid is gas-free, apply only the viscosity correction. Where the liquid viscosity is less than 600 SSU but the liquid contains gas or air, apply the entrained or dissolved gas correction, or both corrections. 

A rotary vane vacuum pump (Figure 5.5) is a rotating type of positive displacement vacuum pump in which an eccentrically suspended impeller slides tangentially past the inside wall of the stator (casing). Two or more vanes with the capability... 

Rotary vane pump A displacement pump where the compression occurs in a non-symmetric chamber being swept by a rotor having an oil-sealed sliding vane. See also Vacuum pump. 

Rotary compressors are positive-displacement machines. Figure iO-7 shows a typical vane compressor. The operation is similar to that of a vane pump shown schematically in Figure 10-10 of Volume 1, 2nd Edition (Figure 10-9 in 1st Edition). A number of vanes, typically from 8 to 20, fit into slots in a rotating shaft. The vanes slide into and out of the slots as the shaft rotates and the volume contained between two adjacent vanes and the wall of the compressor cylinder decreases. Vanes can be cloth impregnated with a phenolic resin, bronze, or aluminum. The more vanes the compressor has, the smaller the pressure differential across the vanes. Thus, high-ratio vane compressors tend to have more vanes than low-ratio compressors. 

The main part of all these pumps—an eccentric rotor—divides the internal pump space into several parts. This is achieved either by contact of the rotating eccentric with the stator surface (a valve pump) or by using movable vanes or plates. The latter may either be secured on the stator, being in sliding contact with the eccentric, (a stator-plate pump), or rotate together with the rotor, sliding over the internal surface of the stator (a rotary-plate pump, for example of the type shown in Fig. 29a). 

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