Document Bvymn84DLLmLxJQaZQJKVV4Yk

Heating Ventilating Air Conditioning Guide 1939 REFERENCES Effect of Air Conditioning upon Munitions, by J. I. Lyle (A.S.H.V.E. Transactions Vol. 23, 1917, p. 383). Air Conditioning for Sausage Manufacturing Plants, by M. G. Harbula (A.S.H.V E Transactions, Vol. 28, 1922, p. 343). Air Conditioning and Refrigerating Large Bakeries, by W. L. Fleisher (Heating Piping and Air. Conditioning, December, 1929, p. 621; January, 1930, p. 24). Air Conditioning for Textile Plants Making and Using Synthetic Yarns, by L. L Lewis {Rayon Textile Monthly, July,. August, September, 1930). Air Conditioning in the Bakery, by W. L. Fleisher (Heating, Piping and Air Con ditioning, February, 1931, p. 158). Air Conditioning in Industrial Processes (Match Factory), by W. L. Fleisher (Heatini Piping and Air Conditioning, March, 1931, p. 196). Air Conditioning of Press Rooms, by I. C. Baker (Heating, Piping and Air Con ditioning, July, 1931, p. 553). Pre-Cooling Fruits and Vegetables with Circulating Air, by C. E. Baker (Heating, Piping and Air Conditioning, January, 1932, p. 42). ; Air Conditioning Maintains Quality of Fruits and Vegetables, by C. E. Baker (Heat ing, Piping and Air Conditioning, August, 1935, p. 369). Air Condition the Bakery Throughout, by W. W. Reece (Heating, Piping and'Air Conditioning, August, 1936, p. 149). Air Conditioning as Applied in Theatres and Film Laboratories, by D. C. Lindsay (Transactions Society of Motion Picture Engineers, April, 1927, Vol. XI, No. 30, p. 335365). Air Conditioning Requirements of Multicolor Offset Printing, by C. G. Weber (Refrigerating Engineering, December, 1936, p. 6). Banana Ripening. Manual, Circular No. 14, Equipment Department, Fruit Dispatch Co., New York, N. Y. The Commercial Storage of Fruits, Vegetables and Florists' Stocks, by D. H. Rose, R. C. Wright and T. M. Whiteman (U. S. Department of Agriculture, Circular No. 278). Reactions of Lithographic Papers to Variations in Humidity and Temperature, by C. G. Weber and L. W. Snyder (V. S. Bureau Standards Journal Research, January, 1934) Relation of Air Conditions to Tobacco Curing, by J. Johnson and W. B. Ogden (Wisconsin Agricultural Research Bureau 110: 1-48,1931). Temperature Studies of Some Tomato Pathogens, by Alice A. Nightingale and G. W. Ramsey (U. S. Department of AgricultureJTechnical Bulletin No. 520, August, 1936). The Treatment of Offset Papers for Optimum Register, by C. G. Weber`and M. N. V. Geib (U. S. Bureau Standards Journal Research, February, 1936). Summary Report of National Bureau of Standards- Research on Preservation of Records, by A. E. Kimberly and B. W. Scribner (U. S. Bureau of Standards Miscel laneous Publication, 154, March 16, 1937). PROBLEMS IN PRACTICE 11 Why is air conditioning required for some industrial processes? To control the physical properties of the materials being processed. Example. In the manufacture of chewing gum, it is rolled.into slabs and scored. The scored slab must then be broken at the score marks to form the sticks. If the slab is too warm, breaking is impossible, if the slab is too cold or too dry, it becomes brittle and shatters, thereby producing much material to be reworked-. 648 Chapter 33. Industrial Air Conditioning 2 0 Why is it necessary to control the physical properties of the material being processed? To permit permanent adjustment of machinery. example. In the manufacture of cigarettes, the amount of tobacco fed upon the paper tape is determined by pressure against springs. When the tobacco is over-moist and. therefore, over-soft, a great excess will go into the finished cigarette; when the tobacco is too dry and, therefore, harsh, too little goes into the finished cigarette. 3 A condition of 75 F dry-bulb temperature and 55 per cent relative humidity Is being maintained in a cigarette manufacturing department. What will be tbe regain and moisture content of the tobacco? The regain, from Table 2 The moisture content = 17.75 X 100 100 + 17.75 17.75 per cent. 15.1 per cent. 4 A 1-lb sample taken from a 100-lb batch of material is found to have a bonedry weight of 0.89 lb. This material is to be processed under atmospheric conditions which should produce a regain of 15 per cent. Compute the finished Weight for each original 100-lb batch. Let W equal the number of pounds of moisture in a finished batch. ' gWg = rega.in .= .15 per c' ent = ^15 W = 13.35 89 + 13.35 = 102.35 lb finished weight. 5 A bundle of sea island cotton is found to have a bone-dry weight of 9*26 lb. What is the proper relative humidity at 75 F to produce a weight of 10 lb at equilibrium? Desired conditioned weight -- 10.00 lb Bone-dry weight = 9.26 lb Weight of moisture required = 0.74 lb 0 74 Regain = Q 26 ^ per cent* From Table 2, the proper relative humidity required is 60 per cent. 6 # Compute the bone-dry weight of 1000 lb of manila rope which has been stored for a considerable period of time in a conditioned room at 75 F dry-bulb temperature and 50 per cent relative humidity. Assuming that this material has come to equilibrium under the atmospheric conditions given, Table 2 shows a regain of 8.5 per cent. Let W equal the total weight of moisture in pounds. 1000 -- W = bone-dry weight in pounds. W -or . 8.5 looo -~W ~ regam =8 S per cent " loo W = 78.3 lb moisture 1000 -- 78.3 = 921.7 lb bone-dry weight. 7 An egg evaporating plant wishes to dry 2000 lb of egg whites (85 per cent water) to crystalline form each 24 hours. The maximum permissible air de livery temperature in the drier is 140 F. What air volume will be required, assuming that outside air is at 95 F dry-bulb and 78 F wet-bulb and that air leaves the drier 70 per cent saturated? Moisture to be removed = 2000 X 0.85 = 1700 lb. Using psychrometric chart and starting at the intersection of the vertical 95 F dry.-bulb temperature line and the 46 per