Compressors different types

FIG. 11-84 Typical power-refrigeration capacity data for different types of compressors during partial, unloaded operation. 

Figure 1-17. Performance characteristics of different types of compressors.

Compressors have numerous forms, the exact configuration being based on the application. For comparison, the different types of compressors can be subdivided into two broad groups based on compression mode. There are two basic modes intermittent and continuous. The intermittent mode of compression is cyclic in nature, in that a specific quantity of gas IS ingested by the compressor, acted upon, and discharged, before the cycle is repeated. The continuous compression mode is one in which the gas is moved into the compressor, is acted upon, moved through the compressor, and discharged without interruption of the tlnv. at any point in the process. 

If the nurse is responsible for administering the medication by nebulization, it is important to place the patient in a location where he can sit comfortably for 10 to 15 minutes. The compressor is plugged in and the medication mixed as directed, or the prepared unit dose vial is emptied into the nebulizer. Different types of medication are not mixed without checking with the physician or the pharmacist. The mask or mouthpiece is assembled and the tubing connected to the compressor. The patient is placed in a comfortable, upright position with the mask over the nose and mouth. The mask must fit properly so that the mist does not flow up into the eyes. If using a mouthpiece instead of a mask, have the patient place the mouthpiece into the mouth. The compressor is turned on and the patient instructed to take slow, deep breaths. If possible, the patient should hold his breath for 10 seconds before slowly exhaling. The treatment is continued until the medication chamber is empty. After treatment, the mask is washed with hot, soapy water, rinsed well, and allowed to air dry. 

For high demand compression duties, the overall compression can be broken down into stages and different types of compressor used in the different casings. For example, a large flowrate with a large pressure differential might use an axial compressor followed by a centrifugal compressor. 

Making Incorrect Assembly Impossible Plants should be designed so that incorrect assembly is difficult or impossible. For example, compressor valves should be designed so that inlet and exit valves cannot be interchanged hose connections of different types or sizes should be used for compressed air and nitrogen. 

Dependable information has been developed for the heat rejector requirements of different types of power equipment air compressors, refrigeration equipment, steam condensers, diesel engines and natural gas engines. Table 5.1 gives information on the heat absorbed by cooling water for this type of power equipment. 

Natural gas pipelines normally operate at elevated pressures. In many instances the gas is available at low pressures so must be pumped or compressed to higher pressure. If the volume of the gas stream is small, reciprocating compressors must be used. For larger gas volumes, rotary compressors of various types are available. Figure 20.910 shows pressure and flow rate ranges in which different types of compressors currently available are used. 

Pumps and compressors. Specify type, power requirement, pressure difference, gravities, viscosities, and working pressures. 

Figures 14-39 through 14-54 give approximate costs for different types of pumps, compressors, blowers, fans, and motors. Although the data from these figures...

The equipment used to compress a gas through a process piping system is different from that used for liquids. At low pressure drops, a simple fan may be adequate. At higher pressure drops, multistage compressors are commonly used. The different types of compressors and guidelines for their selection are discussed in Chapter 10, Section 10.12. Equations for the power consumed in gas compression are given in Section 3.13. 

Costs of Gas-moving Equipment. Figure 6-23 gives installed costs of gas-moving equipment based on rated volumetric input. These costs are for preconstruction cost estimating only. The maintenance cost picture should also be examined when installed costs of several different types of compressors are about equal. For example, centrifugals require less maintenance than reciprocating or rotary machines. 

The mechanical engineers will normally need to advise on power consumption data for rotating machines, e.g. pumps, compressors, fans, conveyors, and cranes. They will also advise the power output options available for the different types and models of prime movers for generators, e.g. gas turbines, diesel engines, gas engines. 

The various machineries for smooth conveying of sohd materials are helt, screw and bucket conveyors, hoists, overhead cranes, and fluid transf equipments such as pumps of various types, air blowers, and compressors. Many different types of processing reactor, filters, agitated vessels, condensers, gas absorbers, etc., are also required. 

Types of Compressor. Many different types of compression machinery are used in chlorine service. Low-pressirre and vacuitm applications are considered elsewhere (Section 9.1.12). For compression of the main process flow, we consider centrifugal, reciprocating, and rotary liquid-ring comfHessors. 

Section 9.1.7.1 on chlorine liquefaction briefly describes the typical mechanical refrigeration cycle. Several different types of compressor appear in water chillers. They include reciprocating, screw, and centrifugal machines. The best choice depends very much on the suitability of a manufacturer s package details. The choice of refrigerant is not constrained by reactivity, as in the case of chlorine compression. 

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