Air compressors

Air is heated whenever it is compressed. The air reaches approximately 100 °C in an oil-lubricated compressor, and 200 °C in an oil-free compressor. The large difference in volume flows between the air and coolant sides means that this application has traditionally been dominated by the naturally asymmetric Shell & Tube technology. Today, however, compact installations using SWEP brazed plate heat exchangers (BPHEs) are available. This easily reduces the outlet temperature to less than 10 °C above the ambient temperature in oil-lubricated screw compressors (oil-free compressors still often use Shell & Tube technology). Oil coolers are used on almost all compressor types (piston, screw, centrifugal) and even for the transmission oil in oil-free compressors. In oil-lubricated screw compressors, which dominate the market, the oil lubricates and cools the moving parts, and cools the air. In a typical two-stage screw compressor, an oil curtain (or oil spray) acts alone as the intercooler for the air from the low-pressure stage. Copper-brazed heat exchangers are suitable for all oil types operating at up to 95 °C.

Our BPHEs are used in oil/air coolers and for heat recovery. Our unique solutions include the B60, B30 and B35T, as well as 100% stainless steel models. There are many reasons for using our 100% stainless steel BPHEs in this application. Maintenance intervals are longer because the compressor oil is not contaminated by copper at high operating temperatures. In installations subject to vibration, their fatigue properties make them superior to nickel-brazed units. Finally, they are ideal for operations in corrosive environments. End-user applications include pneumatic automation, energy storage, air tools, spray painting, PET blow molding, and gas dusters for cleaning electronic components.