Air compressor systems

Compressed air systems should be checked frequently for air leakage, as the loss of air is frequently unnoticed due to the noise of escaping air being masked by other production noises. Modem air compressor systems composed of multi-compressors produce much heat, and it is now possible to recover this for space heating purposes. 

Sometimes equipment that is rented or purchased as a packaged unit allows out-of-spec components to enter a chemical plant. Air compressor systems, refrigeration units, and boiler systems are prime examples of units that, if improperly specified, may allow out-of-spec elements into a refinery or chemical plant. 

Safety standatds for air compressor systems Compnteis Protection of electronic computer/data processii equipment Controls... 

This chemical processing unit had three different air compressor systems operating at three different presstrres (50 psig (345 kPa gauge), 100 psig (690 kPa gauge), and... 

The output of air compressor systems shall be tested for air purity every 6 months by means of samples taken at the connection to the distribution system, except that non-oil lubricated compressors need not be tested for oil mist. 

Compressor systems for respirators should be completely separate from other uses. Air compressors that are designed to produce breathing-quahty air are required. In smaller systems, it may be preferable to use botded air rather than a compressor. The contents of bottles, however, should be analy2ed to ascertain that they do contain air and to assure that the concentrations of any contaminants are acceptably low. 

Dense phase systems are at cost disadvantage when multiple feed points are required, or when incremental compressed air for conveying is not available from existing sources. In the latter instance, the entire investment cost of an air compressor and associated auxiUaries must be allocated to the cost of the conveying system. 

Both air and oxygen processes can be designed to be comparable in the following areas product quaUty, process flexibiUty for operation at reduced rates, and on-stream rehabiUty (97,182). For both processes, an on-stream value of 8000 h/yr is typical (196). The rehabiUty of the oxygen-based system is closely linked to the rehabiUty of the air-separation plant, and in the air process, operation of the multistage air compressor and power recovery from the vent gas is cmcial (97). 

Digital control methodologies similar to the Elliott Digital System program evolved from successful and proven reliable high-speed air compressor management and control approaches. 

Injection Pre.s.sure. The injeetion pressure must be between 75-100 psia (5-7 Bar) above the Compressor Diseharge Pressure. In the ease of the Heated and Humidified Compressed Air injeeted system, the air must be saturated. 

Instrument and Plant Air Systems. A typical setup for a large plant could include three to four 50% instrument air compressors and two 100% plant air compressors, with steam drives for normally operated units and electrical drives for spares. Common practice would provide an interconnection to allow makeup from plant air into instrument air, but not vice versa, and two sets (two 100% driers per set—one on-stream and one regenerating) of 1007c instrument air driers. Two main receivers on instrument air near the compressors with several minutes holdup time and satellite receivers at process trains would be likely and proper for feasibility cost estimating. 

Lubricated cylinders use a separate mechanical lubricator to force feed, in metered droplet form, a very precise amount of lubricant to specified points. This minimizes the amount of lubricant in the cylinder and allows a lubricant most compatible with the gas to be selected without compromising the frame lubrication system. Lubricant is fed to a point or points on the cylinder to service the piston rings and the packing when required. In a few cases, as in air compressors, the packing is lubricated from the crankcase. On some applications involving wet CO7 or H2S m the gas stream, special materials may be avoided if one of the lubrication points IS connected to the suction pulsation dampener. 

In this cycle, approximately 30% of the fuel consumed is available as power output. In addition, approximately 30% is used to drive the air compressors, 30% is contained in the hot exhaust gases, and 10%> is lost to radiation and the lube oil system. 

Figure 16-16 shows the performance characteristic of a split-shaft turbine where the only power output limitation is the maximum allowable temperature at the inlet of the turbine section. In actual practice a torque limit, increased exhaust temperature, loss of turbine efficiency, aud/or a lubrication problem on the driven equipment usually preclude operating at very low power turbine speeds. The useful characteristic of the split-shaft engine is its ability to supply a more or less constant horsepower output over a wide range of power turbine speeds. The air compressor essentially sets a power level and the output shaft attains a speed to pnivide the required torque balance. Compressors, pumps, and various mechanical tinvc systems make very good applications for split-shaft designs. 

Another incident occurred on a plant where the pressure in the instrument air system was maintained with nitrogen when the instrument air compressor failed. Two operators who were required to wear air masks attached them to the instrument air system. Unknown to them, the compressor had broken down, and the system was full of nitrogen. They both died [16]. 

Air compressor (coal pneumatic system) Air compressor (ash pneumatic system) Firefighting equipment Detection Portable Hydrant system Springer system Panel... 

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