Description

Air compressors power... (1) industrial equipment and (2) construction tools Examples of equipment powered by air compressor pneumatic wrenches, l ifts in auto service stations, paint spray booths Air compressors enable... (1) efficient repair of all types of vehicles; and (2) facilitate their safe operation on public thoroughfares Permit is required for air compressor that compresses air above 100 PSI Types of air compressors (1) reciprocating; (2) centrifugal; (3) solar; and (4) rotary *Difference is the way in which they compress air How do air compressors work take the air in a room and force it into a container UNDER PRESSURE. The more air forced into the container, the greater the pressure. Compressed air can be discharged from the container at a controlled rate. Most common air compressor Reciprocating Air compressors are sometimes called air pumps Air compressors can be powered by: (1) electric motors; (2) internal combustion engines; or (3) steam turbines Explosions & air compressors If there is a build up of flammable gases (ex: in service stations and workshops), those gases are heavier than air and fall to the floor before spreading outward. These gases are easily ignited by sparks and high temperatures--which INCLUDES the heat generated by an air compressor. To avoid explosions w/ air compressors Raise air compressor at LEAST 5 feet above ground level so that no flammable gases are drawn into the compressor. To meet the height requirement you can place compressor on a shelf or bench OR the air receiver tank may be turned and stood on end w/ the air compressor bolted to the top of the tank. Power to air compressor entire unit is driven by an electric motor. Motor activates a series of drive belts. Belts power the moving parts of the unit--like w/ power steering and alternator in automobile Compression Chamber operation Air is compressed in compression chamber which consists of a PISTON inside a CYLINDER. Piston moves up and down. When piston moves down -->draws air into cylinder, through INTAKE VALVE (valve automatically opens when piston moves down). When piston moves up-->air is compressed (intake vale automatically closes to avoid air escaping from cylinder). Air Reciever Operation When air pressure reaches a certain level, it forces open a DISCHARGE VALVE (which is spring loaded). This releases compressed air into air reciever (aka air tank), which is what supplies compressed air when needed. Single Stage Air Compressor with one cylinder and one piston Multi Stage Air Compressor with more than one piston and cylinder. Each cylinder will increase the pressure of the air by taking air from the discharge side of the previous cylinder and increasing the pressure to a new level. Once it reaches the last level, the pressurized air is discharged into the reciever. As air is compressed it becomes heated. This is why in a multi stage air compressor there is an intercooler between stages of compressor. Exception to single stage/multi stage distinction CAVEAT: there are air compressors with multiple pistons and cylinders that are single stage but these are only the ones where each cylinder discharges directly into air receiver (unlike a true multi stage air compressor). Storage containers some systems force the compressed air from the receiver into storage containers allowing it to be used later as needed. System of Connected Air Compressors Air forced from one compressor into another several time to increase pressure each time and ultimately forced into a hose line or storage container. Used when there is a need for air under very high pressure. Unloading Valve safety component. allows air to escape compression chamber when there is a strain on the electrical motor. This usually occurs in the first few cycles when the compressor is first started. Automatic in most systems but it may be manual in older compressors. Follow instruction manual for old compressor.