Processing refrigeration

Process refrigeration is used at many different temperature levels to condense or cool gases, vapors, or liquids. Refrigeration is necessary when the process requires cooling to a temperature not reliably available from the usual water service or other coolant source, includingjoule-Thompson, or polytropic expansion of natural gas or process system vapors. 

Many pulp and paper facilities operate industrial process refrigeration units such as chillers for chlorine dioxide plants. For those units that utilize ozone-depleting chemicals, such as chlorofluo-rocarbons (CFCs), facilities are required under Title VI to follow leak repair requirements. 

Even in urban areas the foods for sale were chiefly raw, unprocessed, and of local origin. By 1900, America was substantially urbanized, and much of the food sold in the cities was processed— refrigerated, canned, chemically preserved—by large firms doing business on a national scale. With this growing distance between producer and consumer came an increasing opportunity for artifice in the food supply. The unannounced substitution of a cheaper food for a more expensive one and the use of added substances to preserve and color, although practiced since antiquity, became more widespread, and new techniques, such as the use of synthetic colors prepared from coal tar, became common (1). 

Figure 5.28 Simplified flow schemes of (a) a conventional and (b) Mobil Oil s membrane solvent dewaxing processes. Refrigeration economizers are not shown. The first 3 million gallon/day commercial unit was installed at Mobil s Beaumont refinery in 1998. Polyimide membranes in spiral-wound modules were used [41-43]...

Chemicals a wide range of commodity and specialty products such as titanium dioxide, fluorochemicals, and polymer intermediates used in paper, plastics, chemical processing, refrigeration, textile, and environmental management industries... 

Minimally processed is an equivocal term that is applied to such different types of products as precut, prepackaged fresh produce, and mildly cooked or pasteurized foods (meals or meal components) that can be stored under refrigeration for more than 1 week. Some conventional products such as cured meats can be considered as minimally processed but more frequently a new generation of partially processed, refrigerated foods are described with this term. 

Industrial Gases. These are classified by chemical properties customarily used in industrial processes, for welding and cutting, heat treating, chemical processing, refrigeration, water treatment, etc. 

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