Refrigeration mechanical

In Texas, subterranean sulfate brines are pumped to the surface where the brines are first saturated with NaCl before they are cooled by mechanical refrigeration to form Glauber s salt (7,8). This salt is then separated from its mother Hquor, melted, and dehydrated with mechanical vapor recompression evaporators (9). 

Coefficient of performance of the absorption cycle is defined on the same principle as for the mechanical refrigeration ... 

The minimum design temperature should be the lowest temperature to which the tank will be subjected, taking into consideration the minimum temperature of material entering the tank, the minimum temperature to which the material may be autorefrigerated by rapid evaporation of low-boiling hquids or mechanically refrigerated, and the minimum ambient temperature of the area where the tank is located. API 620 provides for installations in areas where the lowest recorded one-day mean temperature is —50°F. 

The family of short curves in Fig. 29-45 shows the power efficiency of conventional refrigeration systems. The curves for the latter are taken from the Engineering Data Book, Gas Processors Suppliers Association, Tulsa, Oklahoma. The data refer to the evaporator temperature as the point at which refrigeration is removed. If the refrigeration is used to cool a stream over a temperature interval, the efficiency is obviously somewhat less. The short curves in Fig. 29-45 are for several refrigeration-temperature intervals. A comparison of these curves with the expander curve shows that the refrigeration power requirement by expansion compares favorably with mechanical refrigeration below 360° R (—100° F). The expander efficiency is favored by lower temperature at which heat is to be removed. 

Gas can be condensed by (a) mechanically refrigerating it, (b) compressing and expanding it, using turboexpanders, or, (c) pressure effects such as by Joule-Thomson cooling and overcoming the vapor pressure. The liquefaction of methane can involve all three of these effects. These effects can be separately evaluated to show the effectiveness of each in producing liquid. 

Figure 3-1. This example flow scheme for methane liquefaction uses compression, turboexpansion, and mechanical refrigeration.

The process illustrates the use of mechanical refrigeration in its high-efficiency temperature range the maximum use of compression energy because of its high efficiency and the use of turboexpansion at a low temperature—its Carnot efficiency is best at low temperatures, especially because it permits large use of the efficient pressure effect. 

This quick but accurate graph shows the design engineer how much horsepower is required for mechanical refrigeration systems, using the most practical refrigerant for the desired temperature range. 

Ballou, Lyons, and Tacquard, Mechanical, Refrigeration Systems,." Hydrocarbon Processing,]une 1967, p. 127. 

With the introduction of mechanical refrigeration, the term ton was retained. The owner could now buy a system capable of providing the equivalent capacity of hov/ever many tons was needed. Since one pound of ice absorbs 144 Btu when melting, one ton of ice melting over a period of 24 hours has a heat transfer rate equivalent to the following ... 

In the United States, Dr. John Gorrie, unaware of the work of Perkins, proposed that mechanical refrigeration he used for comfort cooling, and he constructed mechanical systems for cooling his patients at his home in Florida in about 1842. 

The perfection of the electric household mechanical refrigerator by the 1930s provided a technology applicable to home air conditioning. This technology... 

Inbreathing requires vacuum relief for the tank. The usual conditions arise from liquid flow out of the tank or from condensation or contraction of the vapors by reduction in temperature of the tank contents caused by atmospheric changes (not by system mechanical refrigeration). 

Figure 11-22. Basic features of mechanical refrigeration cycle.

ANSI/ASHRAE Standard 15-1994, Safety Code for Mechanical Refrigeration, should be studied, examined, and complied with by the design engineer. 

FPN No. 4) For classification of areas involving ammonia atmosphere, see Safety Code for Mechanical Refrigeration, ANSI/ASHRAE 15-1992, and Safety Requirements for the Storage and Handling of Anhydrous Ammonia, ANSI/CCA G2.1-1989. 

In mechanical refrigeration, a multicomponent refrigerant consisting of nitrogen, methane, ethane, and propane is used through a cascade cycle. When these liquids evaporate, the heat required is obtained from... 

In the meat industry, the main applications of mechanical refrigeration are ... 

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