Compressor

Compression is the fact of reducing the volume of a gas by reducing the temperature or by increasing pressure. Compressors are used to mechanically increase the pressure of a gas by reducing its volume. They can be of various types. The most used in the industry are piston and screw compressors. Piston compressors make part of the first models, but their principle and functioning are still reliable and their use is still widespread; the piston is pushed into a cylinder thanks to a connecting rod and crankshaft. The piston compressor is used in gas compression (inert gas, nitrogen, etc.), engine starting or PET bottling. The screw compressor is also a volumetric model. In this case, two lobed rotors rotate one into the other reducing the volume between them and the compressor crankcase. The pallet compressor, equipped with a rotor having slots along its length hosting sliding palettes gliding over an oil film, and the stationary compressor for fixed applications complete the subcategory of compressors. BOGE, Compair, Ingersoll, Kaeser, Belair, and Mattei are references in this field. The compression of ambient air used for the pneumatic functions of the machine tools provokes the liquefaction of humidity contained in the air into water. This water causes the oxidation of the metal parts; to avoid this phenomenon, an air dryer is used. The dryer is a device used to lower the humidity of compressed air. This family of machines can be subdivided into three subtypes: the adsorption dryer, equipped with two columns operating in two cycles (drying and regeneration) and allowing the desiccation of water, the refrigerated dryer (cools compressed air to a temperature below its dew point temperature) and the membrane dryer, with which air is compressed and dried by going through the porous and hollow fibers filtering only water molecules. Dryer machines are manufactured by Hamo, Rösler, Ingersoll Rand, BOGE, and Polyservice.