RECIPROCATING COMPRESSORS

Reciprocating Compressors and Their Faults

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CHAPTER 2: LITERATURE REVIEW

Reciprocating compressors are among the few of the most common machines that are used for compressing and processing of gas inside the industry. The designing and manufacturing principles of these compressors are extremely true and tired, which is the reason of the high level of reliability of these compressors. However, these compressors possess the ability of increasing its reliability; the reliability

of these compressors can be improved

through condition monitoring. Condition monitoring slows down these machines enabling them to operate at their full potential. Condition monitoring also shows that if it would be beneficial for the compressor to change the defective part instantly or wait for a certain period of time. One of the foremost components of a reciprocating compressor is the valve; there are basically two types of valves in a reciprocating compressor suction and discharge valve. Both of these valves account for almost forty percent of the cases where the valves are required to be shutdown, and these valves account for almost more than fifty percent of the cases where they are the total cost of repair (Yang et.al, 2005, pp. 371-390). Both of these facts serve as the driving reason for making improvements in the process of condition monitoring, for predicting that the valve failure will occur and how severe the failure will be. It is used in oil refineries, gas transportation (pipelines), chemical plants, and refrigeration plants. It is also used in the manufacturing and blow molding, of glass, plastic (polyethylene terephthalate or PET), for liquids.

In most reciprocating compressor gaskets are used between the parts together to ensure leak proof conditions because most of the surfaces are not machined finely enough to give a metal-tight body. Mainly, gaskets are used between the cylinder head and the valve plate, between the valve plate and the compressor housing, between the compressor body and the bottom plate, if any, and also between the outer valves service and mounting bases. When the contact parts are tightly secured, shape and contour printed on the material, which generally is soft and resilient enough to take printing and thereby seal any oil or gas will possibly escape to the atmosphere, and prevent penetration of atmospheric air.

2.1. Working of a Reciprocating Compressor

A reciprocating piston uses the reciprocating action of a piston inside the cylinder for compressing the refrigerant. The process begins with the downward movement of the piston, which results in the creation of vacuum inside the cylinder. During this process the pressure in the above the intake and the pressure in the lower intake falls cower, due to this rise in pressure in the intake valve is forced to open and once the valve of the intake opens up the refrigerant is then sucked inside the cylinder. Once the

piston reaches its bottom piston it then starts to move

in upward direction (Heinz, and John, 1996). Afterwards the intake valve then closes, leaving the refrigerant trapped inside the cylinder, and once the refrigerant trapped inside ...