Document xzD83mDdQ755z7ybj8Rrmj3X0

1016 CHAPTER 45 1956 Guide Table 1. Temperatures and Humidities Applicable to Industrial Air Conditioning* Process Temp. F R.H. % BAKERY Mixer (bread dough).................................................................... Fermenting.................................................................................... Proof box........................................................................................ Bread oven.................................................................................... Cake oven...................................................................................... Bread cooler (room or tunnel) Vacuum 28.6 in.................... Cold room............................................ ........................................ Make up room............................................................................... Cake miring................................................................................. Cake mixing (sponge)................................................................. Crackers and biscuits.................................................................. Wrapping........................................................................................ Dried ingredients, storage......................................................... Freeh ingredients, storage.......................................................... Flour storage................................................................................. Shortening (depending on type), storage............................... Sugar, storage............................................................................... Water, storage............................................................................ Wax paper, storage................................................................... 75-80 75-80 92-96 375-450 300-430 70-75 40-45 75-80 70-75 95-110 60-65 60-65 70 30-45 65-80 45-70 80 32-35 70-80 40-50 70-75 80-85 80-85 65-70 65 50 60-65 55-65 80-85 50-65 55-65 35 40-50 METHODS OF MIXER COOLING 1. 35-40 F water circulated through mixer jacket. 2. 15-25 F brine. 3. Direct expansion, refrigerant circulated through mixer jacket. 4. Cracked ice added to dough in mixer. 5. Cold air introduced into mixer during mixing process. 6. Cooled agitators are used in mixers. MIXER LOAD CALCULATIONS Refrigeration is required to remove: excess ingredient, if any; heat generated by the beating and mixing of dough; excess heat m mixer body; heat of hydration of flour and water; and heat absorbed by mixer from 'atmosphere during mixing process. Additional factors are the design and speed of mixer, consistency, kind and mass of dough. Data Used in Calculations: 1 bbl. flour = 2001b Heat of hydration TM 6.5 Btu per lb of flour Specific heat of flour = 0.42 Btu per lb Water is 65% of weight of flour Flour is 65% of batch ' Sponge is GO% of batch Total motor output is converted to heat in the mixer. In fermenting rooms recent practice is to use direct radiation for heating, atomising sprays for humidify* Ing, and gravity convection cooling surfaces for temperature reduction and dehumidifying thereby eliminat ing objectionable air currents. Proof box and bread cooler conditions vary slightly for dark bread. Cakes are sterilized by ultra-violet rays before wrapping. Process BANANAS Tbmp.F R.H. % Ripening........................................................................................ Storage ............................................................................................ Shipping.................................. :.................................................... 68 60 54 to 56 90 to 95 85 to 90 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 56 F is placed in a ripening room at 68 F and 90 to 95 percent relative humidity until it begins 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 & electric load = 0.4 ton Live load = 0.9 ton Pull down load (from 68 F to 60 F) => 1.6 ton Minimum carlot--20,000 lb which represents about 300 stems. . Since bananas give off minute quantities of ethylene and possibly 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 U to 2 min. Information in Table 1 is drawn from many sources. See bibliography at end of chapter. Industrial Air Conditioning 1017 Table 1. Temperatures and Humidities Applicable to Industrial Air Conditioning--(Continued) BANANAS (Continued) Provide a heating system with a rated capacity to warm the fruit at a .rate of not less than 2 deg per hr Specific heat--0.9 Btu per Qb)(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 ton) (24 hr), turning at 68 F 9,240 Btu (per ton) (24 hr), ripening at 68 F -- 8,360 Btu (per ton) (24 hr). Room BREWING Temp. F R.H. 1 Ale................................................................................................ * If wooden tankage is used, otherwise humidity con trolled to prevent condensation on walls and ceiling. 55 32 to 35 55 to 62 60 max. 75 min.* 75 min.* 75 Wort cooled to 47 F for lager, 54 to 59 F for ale, by evaporative cooling or use of double pipe or plate type coolers with counter flow of cooling medium. Fermentation produces 250 Btu per lb of sugar fermented. L&ger fermented five days at 55 to 60 F, ale at 68 to 75 F, then cooled to storage temperature. _ Bottled beer pasteurized by heating to 140 F in twenty minutes. rrmintiMning temperature for eighteen minutes, then cooling to 80 F in twenty minutes. Canned beer requires one-third !*** time. Cold water, brine, direct expansion ammonia or propylene-glycol and water solutions may be used as the cooling medium. Process Temp. F CANDY (CHOCOLATE) R.H.% Enrobing Tempering room = Ventilation only 80 to 85 60 to 65 80 90 70 40 to 45 65 70 to 75 65 to 70 40 to 50 50 to 55 55 to 60 50 13 40 to 50 55 45 40 to 50 Tunnel discharge room requires a dew point lower than the temperature of the product leaving the tunnel: . During the summer months the product is usually held in the tempering room for 24 hours prior to ship ping. Recovery of sugar fly in coating kettle rooms is accomplished with the use of cyclone type dust collecting devices. Supply air to coating kettles is maintained at 85 F dry-bulb and 61 F wet-bulb temperature. Bacteriological control is employed. Load calculations for hand dipping rooms are baaed on 100 lb of 90 F chocolate per (worker) (hr). Specific heat 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. Process CANDY (HARD) Tunnel ................................................................:*'* i'ackino' Storage.. tempering = (Ventilation only) Temp. F 76 to 80 76 to 80 55 65 to 75 65 to 75 R.H.% 30 to 40 40 to 45 40 to 45 45 to 50