Gas Movers and Compressors Fans Centrifugal blowers and compressors Rotary blowers and compressors...

download Gas Movers and Compressors Fans Centrifugal blowers and compressors Rotary blowers and compressors Reciprocating compressors Ejectors Discharge pressure.

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Transcript of Gas Movers and Compressors Fans Centrifugal blowers and compressors Rotary blowers and compressors...

  • Gas Movers and CompressorsFansCentrifugal blowers and compressorsRotary blowers and compressorsReciprocating compressorsEjectorsDischarge pressure > 2 bara = compressor

  • Gas Movers and CompressorsWhere are they needed?

  • Gas Movers and CompressorsWhere are they needed?utility air, steamhigh pressure reactor;refrigerationheat pumpsfeed to furnacesQuestion: When is redundancy necessary?

  • FansLow pressure (ca 101 kPa) and low P (1-15 kPa)High volume flow to 500 std m3/sEfficiencies of 65-80%Variety of materialsFour typesCentrifugal Fan

  • Centrifugal CompressorsPressure to 700 atm, 1.2-1.4 compression ratio/stageUp to 8 stages per casingVolume flow to 200 std m3/sEfficiencies of 70-80%Favored choice for P < 15 atm What is the compression ratio?Outlet pressure/inlet pressure

  • Axial CompressorsPressures to 14 atmCompression ratio 1.4 per stage, up to 15 stages/casingHigh volume flow to 300 std m3/sEfficiencies of 80-85%Expensive, inflexible operationBase loads, utilities

  • Rotary CompressorsMedium pressure (to 10 atm) and compression ratio to 4!Low volume flow to 20 std m3/sEfficiencies of 60-80%Good for constant volume deliveryFour types listed in UlrichSliding vane compressor

  • Reciprocating CompressorsPressure to 3000 atm, compression ratio=4/stageUp to 8 stages per casingEfficiencies of 60-80%Expensive, but commonly used for high-pressure applications

  • All of this information is summarized in one table:consider the first half in detail

  • Radial FansAxial FansCentrifugalCompressors

  • Summary:Selection of EquipmentFans are for low P (101 kPa), low P (1-15 kPa)Blowers (centrifugal and rotary) are for moderate pressures, up to 1 MPaCompressors operate at 0.01 to 30 MPa depending on typeTurbo-expanders are like compressors running in reverse for power recovery

  • Summary: SelectionSelect based on:range of applicationlocationcostservice

  • Costing of Fans and CompressorsWhat is the size basis?For fans, the volumetric flow: P is lowFor compressors, power or shaft work: must be considered

  • Fans

  • Blowers and Compressors

  • Motors

  • Compressor CalculationsFluid Powerfor costingShaft Powerfor driverNon-ideal fluids:

  • Compressor Calculations (cont)Ideal Gas:Temperature increases with compression compression ratio p2/p1 < 4 for each stage

  • Example CompressorHydrogen compressor, from 1 MPa at 25 C to 20 MPaFlow rate of 0.123 kg/sWhat is the bare module cost?