Document 7RQZrgVKEEyrGy6RxgGVGbGX6

682 CHAPTER 50 1959 Guide Table 1 .... Temperatures and Humidities Applicable to Industrial Air Conditioning--(Continued) BAKERY (Continued) vectioa cooling; surfaces for temperature reduction and dehnmiriifying--thereby eliminating objectionable air currents. Proof box and bread cooler conditions vary slightly for dark bread. Cakes are sterilised by ultra-violet rays before wrapping. Procats | Tamp. F | JLH.% Enrobing Procaa Tamp. F CANDY (CHOCOLATE) KH.% BANANAS 40 to 50 60 54 to 56 85 to 90 Forced ripening is accomplished in 4 to 5 days while slow ripening is extended to 7 to 9 days with lower temperatures. The green fruit with a pulp temperature of 66 F is placed in a ripening room at 68 F and 90 to 95 percent relative humidity until itbegins to change color. The temperature is then lowered sharply to 60 F (or slightly less) dependent upon how quickly the fruit is to be moved. Typical refrigeration load for ripening room per carlot, with an 85 F ambient temperature: Insulation and electric load 0.4 ton. Live load = 0.9 ton. Full down load (from 68 F to 60 F) -- 1.6 ton. Minimum carlot--20,000 lb which represents about 300 steins. Since bananas give off minute quantities of ethylene and pos sibly other gases necessary for ripening, ventilation during the early stages of ripening is undesirable. Cooling unit to be sized to provide a complete air change every l}i to 2 min. Provide a heating system with a rated capacity to warm the fruit at a rate of oot less than 2 deg per hr. Specific heat--0.9 Btu per (lb) (F deg). Approximate rate of evolution of heat by bananas when stored at temperatures indicated: Bananas at 54 F * 3,300 Btu (per ton) (24 hr), green at 68 F = 8,360 Btu (per too) (24 hr), turning at 68 F = 9,240 Btu (per ton) (24 hr), ripening at 68 F = 8,360 Btn (per ton) (24 hr). Room BREWING leap. F tH.% * If wooden tankage is used, other wise humidity controlled to prevent condensation on walls and ceiling. 32 to 35 60 max. 7R 7K min 7* min 71 min 75 Wort cooled to 47 F for lager, 54 to 59 F for ale, by evapora tive cooling or use of double pipe or plate type coolers with counterflow of cooling medium. Fermentation produces 250 Btu per lb of sugar fermented. Lager fermented five days at 55 to 60 F, ale at 68 to 75 F, then coded to storage temperature. Bottled beer pasteurised by beating to 140 F in twenty min utes, maintaining temperature for eighteen minutes, then cooling to 80 F in twenty minutes. Canned beer requires onethirdless time. Cold water, brine, direct-expansion ammonia, or propyleneglycol and water solutions may be used as the cooling medium. 65 to 70 40 to 50 Tempering room. = Ventilation only Tunnel discharge room requires a dew point lower temperature of the product leaving the tunnel. the During the summer months the product is usually held in the tempering room for 24 hours prior to shipping. ' Recovery of sugar fly in coating kettle rooms is accomplished by use of cyclone-type dust collecting devices. Supply air to coating kettles is maintained at 85 F dry-bulb ana 61 F wetbulb temperature. Bacteriological control is employed. Load calculations for hand dipping rooms are based on 100 lb of 90 F chocolate per (worker) (hr). Specific beat of chocolate -- 0.30 to 0.56 Btu per (lb) (F deg). Latent heat of fusion 34 to 40 Btu per (lb) (F deg). Freezing point = - Sweet milk chocolate -- 86 F. Dark chocolate =* 90 to 92 F. PrOCMt Tmp. F SM.% CANDY (HARD) 40 to 45 Tempering -- (Ventilation only) 65 to 75 45 to 50 Hot rooms used in the drying of jellies and gums are main tained at 120 to 150 F. A purge system using 100 percent out side air, bypassing the heating coil, is incorporated to produce rapid cooling of both the product and the room. Cold rooms for cooling marshmallows and cast creams are maintained at 75 to 80 F with a relative humidity of 45 to 50 percent. Uniform air distribution is essentiaL Standard starch drying equipment is employed. Filtration of air is required. Process CERAMICS Tamp. f SH.% 80 60 to 70 75 to 80 48 48 Relative humidity has no effect on the manufacture of the products. Temperature and humidity must be controlled in the dec orating shop in the whiteware plants, and the decalcomania production room. Dust control is essential and the dust count must be held down to four million particles per cubic foot due to the danger of silicosis._________________________________________________ Process and Product Air Conditioning 683 Table 1 ... .Temperatures and Humidities Applicable to Industrial Air Conditioning--(Continued) ILH.% AH.% jPackaging................. ............................ 75-80 | 45-50 CITRUS FRUIT * Prior to transcontinental ship ment 84 to 88 86 to 88 Careful consideration must be given to air volumes, air temperatures, humidity, ventilation, and distribution. In regions where end rot is prevalent, it may be necessary to store grapefruit at temperatures of 32 to 34 F for a period not exceeding six weeks. Lemon and grapefruit storage requires an air-conditioning system to (1) maintain a constant temperature, (2) maintain a high relative humidity, (3) ventilate to mainf-ain 0.1% COj content, (4) obtain uniform air distribution, and (5) provide air washing or air filtration. Load calculations include (1) transmission losses, (2) inter nal load-fruit cooling and respiration, cooling fruit boxes, electric load, and people, and (3) outside air load--72 cfm per carlot. Specific heat--Btu per (lb) (F deg): Lemons 0.94, Grapefruit 0.87, Boxes 0.40 Heat or Evolution in Btu Peb (ton) (24 bb) Tamp. Umoos Grepefrwf 32 580 460 40 810 1070 60 2070 2770 80 6200 4180 Approximately 10 percent of the cooling load is considered as latent heat load. In a conventional system the air required is one cfm per storage box or 650 cfm per carload, resulting in a gmafl tem perature rise in the supply air making possible the required high humidities. In a combination system the air required is one cfm per sq ft of floor area or 300 chn per carlot with the addition of auxil iary humidifying nozzles.to maintain the required high hu midities. Installation of metal ducts is required. Ductwork made of insulation board is sometimes preferred. Proceti Tamp. F *H.% DISTILLING Storage: 35 to 40 45 to 60 65 to 72 50 to 60 Mashing done at 150 to 155 F, then cooled to 64 to 68 F. Yeast culture fermented at 170 F, then cooled to 70 to 72 F. Yeast propagated at 150 to 154 F. Mash heated to 165 F and then cooled to 80 F, then pitched with yeast and fermented at maximum temperature of 85 F. Cooling for various distilling processes normally accom plished by use of river or well water depending on tempera tures and availability. Low humidity and dust control important where grains are ground. Viscous filters preferred as mold spores and bacteria are trapped in the viscous film, preventing propagation.________ ELECTRICAL PRODUCTS Electronics and X-Ray: Coil and transformer windinv......... Tube assembly.................................... Electrical Instruments: Manufacture and laboratory............ Thermostat assembly and calibra tion............................................... Humidistat assembly and calibra tion............................................... Small Mechanisms: Close tolerance assembly.............. Meter assembly and test............... Switchgear: Fuse and cutout assembly.............. Capacitor winding.............................. Paper storage...................................... Conductor wrapping with yarn........... Lightning arrestor assembly................ Thermal circuit breakers assembly and test................................ Water wheel generators: Thrust runner lapping Rectifiers: Processing selenium and copper ox ide plates................................... Dust control is essential in these processes 72 68 70 76 76 72 74 to 76 73 73 73 75 68 76 70 74 15 40 50 to 55 50 to 55 40 to 45 60 to 63 50 50 50 65 to 70 20 to 40 30 to 60 30 to 50 30 to 40 FLOOR COVERING Linoleum: Mechanical oxidizing of linseed oil.. 90 to 100 160 to 250 * grains per pound abs. bum. 20 to 28 30 to 50 60 gr* Some operations are stabilized to prevent mold growth. Precise control of.temperature and humidity is required for mechanical oxidizing of linseed oil. The rate of flow and the temperature of cooling water in the jacket surrounding the tank must be controlled. Air filtration is recommended for the storing process. FOUNDRIES Core making............................................ Mold making: Bench work.......................................... Floor work........................................... Pouring..................................................... Shakeout.................................................. Cleaning Room....................................... Winter design temp. 60 to 70 60 to 70 55 to 65 - 40 40 to 50 55 to 65 The charging room is usually unheated. In core making fume-exhaust hoods are required for oven and for cooling areas adjacent to ovens. In mold making provide hoods at transfer points with wet collector dust removal system. Use 600 to 800 cfm per hood. Pouring rooms require two-speed powered roof ventilators. Design for minimum of two cfm per sqft floor area at low speed. Shielding is required to control radiation from hot surfaces. Proper introduction of air will minimize preheat requirements. In shakeout room provide hoods with wet-collector dustremoval system. Exhaust 400 to 500 cfm per sq ft grate area. Roof ventilators are generally not effective. In cleaning room provide hoods for grinders and cleaning equipment with dry cyclones or bag-type collectors. Winter ventilation (preheated) is required to the extent of replacing exhausted `air. Summer ventilation is usually sup plemented by use of pedestal fans. Spot coolers are sometimes used in larger installations.