Document gbgx00dQa8k8RK2zkw8xNaB59

906 CHAPTER 43 1930 Guide are.-givenvin,Chapter 34 but should always be verified locally. In lieu of this tedious work, the average gallons per minute per: ton may be taken as 80 per. cent, of design gallons per minute.per ton with reasonable accuracy, for the condition of variable temperature of entering water obtained from rivers-and lakes. . ' - When cooling towers or evaporative condensers are used, the windage and evaporation losses are usually between 3 per cent and 5 per cent of the water circulated. Heating The method of estimating fuel consumption to balance the building heat loss is given in Chapter 17. It is important to include the fuel required to heat^ventilation air as used in ventilating and air conditioning systems. In estimating fuel consumption for. ventilation air, the tendency of the conventional control systems to use less than the estimated quantity of out side-air in cold weather should be considered in-its effect in lowering fuel consumption. In.addition, the heat required to accomplish winter.humi difying must not be neglected, when this feature is included in the equipment. -, BIBLIOGRAPHY - Modern Air Conditioning, Heating and Ventilating, by W. H. Carrier, R. -E. Cheme, and W. A. Grant--Chapter IV (Pitman Publithing Corp., 1940).- " Predicting Operating Hours of Refrigeration Equipment Used in Air Conditioning, by W. A. Grant (Refrigerating Engineering, July, 1941). Cost of Operation of Refrigeration Used for Air Conditioning, by R. E. Cheme (Refrigerating Engineering, December, 1943). CHAPTER 44 INDUSTRIAL AIR CONDITIONING General Requirements for Manufacture, Processing and Preservation; Classifi- , cation of Problems; Moisture. Content and Regain; Conditioning and ' Drying; Chemical and Biochemical Reactions; Crystallization; Control for Machining, Polishing, and for Static Electric ity Elimination; Laboratory Conditions; Calcula tions; Safeguarding Health and Maintaining Safety; Contaminant Control; Dilution Systems for Contaminants; Heat Storage; Radiation; Odors INDUSTRIAL air conditioning is concerned with (1) the manufacture, processing and preservation of material, equipment and commodities, and (2) the atmospheric conditions required for maintaining the health, safety and efficiency of workers. The material in this chapter is treated under these two divisions. GENERAL REQUIREMENTS FOR MANUFACTURE, PROCESSING AND PRESERVATION Table 1 lists the temperatures and relative humidities required for storage of certain commodities, and for manufacturing and processing of others. The desirable relative humidity may range from a low of 5 per cent in certain industrial applications, such as insulation winding proc esses, up to a' condition approaching saturation, as in processes relating to textile, tobacco and baking industries. .... The most favorable temperature and relative humidity will vary accord ing to the specific material and particular process. In some cases the temperatures and relative humidities listed in Table 1 have no direct in fluence upon the product itself, but do affect the efficiency of employees, and in turn affect workmanship, uniformity and the cost of production. Sometimes, a compromise between the known optimum condition-for processing and that required for worker- comfort is unavoidable. In many processes, the optimum air conditions are variable according to the stage and progress of the processing cycle from the raw material to the finished product. Some materials, such, as cotton textiles, begin with a low relative humidity in the carding and picking rooms;-and after passing through the various intermediate steps with a gradual increase of relative humidity, are subjected to relative humidities of from 70 to 85 per cent in the final stage of weaving. Other processes encountered require the re versed procedure, starting with a high relative humidity and finishing with a low relative humidity, as in the manufacture of glue and gelatinous materials, and in making various types, of gelatine capsules. _ In order to apply air conditioning to industrial processes, the air condi tioning engineer must have a thorough understanding of the processing problems involved. Individual processes and machines are changing-rap idly, and air conditions must be revised constantly to meet the new conditions. Air conditioning for industrial processes is so extensive, and 907 ' '