Freon compressor

Guiding rollers of grinder bands, sealing discs of valves in an industrial Freon compressor, segments of air compressors. .. 

Example 4.7. An insulated, steady-flow, horizontal Freon compressor has the following conditions ... 

Water is not significantly cooled by exchanging sensible heat with cold air. Most of the cooling results from the humidification of the air. If you live in the Central Valley of California, your home is likely cooled with a "swamp cooler," rather than with a freon compressor. The water partially evaporates as it mixes with the dry air. The latent heat of evaporation of water is 1000 Btu/lb. If 2 percent of the water evaporates by contact with the cold air, the water loses 20 Btu/lb. The specific heat of water is one Btu/lb per 1°F. Thus, the water will be cooled by 20°F by evaporation. 

Figure 11.26 shows a component removed from an air-conditioning compressor. Pinhole perforations in this component had allowed cooling water to leak into the freon. Many failures of this type had occurred previously. Examinations of the internal surfaces of both the canister and the tubes entering it revealed evidence of metal loss. Tiny perforations at the bases of deep grooves were noted in the tubes. Deep, general, smooth metal loss surrounded irregular islands of intact surface (Fig. 11.27). The canister walls displayed a similar metal loss and comet-tail-shaped depressions (Fig. 11.2).

At a temperature of 25° C the vapor pressure is approximately 6.5 atm for Freon-12. Thus the compressor must be capable of producing a pressure greater than 6.5 atm. 

As before, the essence of the refrigeration device is a working fluid (such as Freon or other refrigerant ). In this case, the working fluid removes heat qc from the low-temperature chamber tc and expels a larger quantity of heat qh to the external room surroundings th, with input of work w (= qh — qc ) from the compressor motor. 

Let s say we have a centrifugal refrigeration compressor, driven by a motor. The motor is tripping off because of high amperage. Should we open or close the suction throttle valve shown in Fig. 22.2 Answer— close it. Of course, both the evaporator vapor outlet temperature and the process fluid outlet temperature will increase. But that is the price we pay for having too small a motor driver on the compressor. Does this mean that when our home air conditioner gets low on freon, our electric bill drops Correct. But the price we pay is a hot home. 

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