Document G6d9JJE0Lzw85EDXYdYEOX0nn

866 CHAPTER 47 1946 Guide The Drying: of Solids* by-T. K. Sherwood (Bulletin Massachusetts Institute'of Technology, Nos. 237, 247 and 258). ................... ............ Air Conditioning and Engineering,"American Blower Co:, .1935. Drying in Industrial Plants, by J. O. Ross. Elements of Chemical Engineering, by Badger and McCabe (McGraw Hill Co., 1931). Fan Engineering, Buffalo Forge Co. Die Trockentechnik, by M. Hirsch (Julius Springer, Berlin, 1932). Drying (Kent's Mechanical Engineers Handbook). Drying, by W. H. Carrier {.Marks' Mechanical lingincers Handbook): . , , Drying {Perris Chemical Engineers Handbook, 1941). Kiln Drying of Lumber, by A. Koehler and R. Thelen, New York, 1926i Kiln Drying of Lumber, by H. D. Tiemann (Lippencott, 1920). , Modern Drying Machinery, by H. B. Grenshaw, London, 1926. " Principles of Chemical Engineering, by Walker, Lewis, McAdams (Chapters on Evaporation, Humidity and Drying, McGraw Hill Co.). CHAPTER 48 CJra.n5porla.tion _/^iV (Conditioning. Railway Passenger Car Ventilation, Method of Air Distri bution, Air Cleaning, Winter and Summer.Air Conditioning, Humidity and Temperature Control, Summer Air Condition ing for Buses and Automobiles, Airplane Air Conditioning THE principles of air conditioning used in connection with stationary applications such as stores, restaurants, hospitals, theaters, and homes are in general applicable to such mobile applications as railway passenger cars, passenger buses, automobiles, and ships. However, the equipment used for these mobile applications, differs from that used for stationary purposes in that it must meet additional requirements. Especially important are the features of compactness with the retention of ready accessibility for quick inspection and servicing, and low weight. Freedom from vibration which could be transmitted to the supporting vehicle and thus to the passengers is essential. (For Air Conditioning of Ships see Chapter 49.) RAILWAY PASSENGER CAR VENTILATION In non-air-conditioned cars, ventilation is accomplished by exhaust fans, roof ventilators, and open doors and windows. This practice provides an ample supply of outside air but does-not. prevent the entrance of smoke, cinders, and other dirt. An average passenger car contains approximately 5000 cu ft of air and may seat as many as 80 passengers. The occupants are continually liberating heat, carbon dioxide, moisture, odors, and some organic matter from their breath, skin and clothing. The heat and moisture can be removed by cooling and dehumidification, but the other constituents can be successfully handled only by proper ventilation and, air cleansing. In the average car from 2000 to 2500 cfm should be circulated by the air conditioning unit. Some of this air may be recirculated, but a portion of it should always be brought in from the: outside. The amount of outside air required depends upon the type of car, number of passengers, air temperature, humidity, odors, and whether or not occupants are smoking, and will vary from 15 to 90 per cent of the total'air circulated. Careful attention must be exercised in specifying the rate of outside airtaken in so as to fit the type of service adequately and yet not to supply more ventilation than is necessary. Conditioning this outside air is a major factor in deterniining the size of both summer and winter con ditioning equipment. With present average ventilation requirements; about 30 per cent of the cooling equipment and sometimes as high as 50 per cent of the heating equipment is necessary to handle only the outside air load. For normal conditions, 10 cfm of outside air per passenger is sufficient. When smoking is permitted, at least 15 cfm should be admitted. In some of the dining cars and de luxe sleeping cars, outside air rates as high as 20 and 30 cfm per occupant are-used. Method of Air Distribution . The fact, that the amount of. space devoted to, railway passengers may be as low as 60 cu ft per person (ranging as high as 190 ciTft per person) and the high air flow rates made necessary by severe ventilation and sun 867