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960 CHAPTER 45 1953 Guide Table 1. Temperatures and Humidities Applicable to Industbial Aib CoNDITIONING*- Process BAKERY Temp. F R.H..% 75-80 375-450 300-430 70-75 40-45 . 75-80 70-75 95-110 60-65 70 30-45 45-70 80 32-35 70-80 80-85 80-85 65-70 65 50 60-65 55-65 80-85 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. 4t Cracked ice added to dough in mixer. 5. Cold air introduced into mixer during mnHng process. 6. Cooled agitatora are used in mixers. MIXER LOAD CALCULATIONS Refrigeration is required to remove: excess ingredient, if any; heat generated by the beating and miring of dough; excess heat in 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 miter, consistency, kind and mass of dough. Data Used in Calculations: 1 bbl. flour = 200 lb Heat of hydration -- 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 60% 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 Temp. F R.H.% . BANANAS Ripening ................................................................................ 6torage ......... i................................................................... Shipping............................... ............................................... 68 60 54 to 66 90 to 95 ' 85 to 90 85 to 90 Forced ripening is accomplished in 4 to 5 dayB 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 (mange 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 A 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 14 to 2 min. Information in Table 1 is drawn from many sources. See bibliography at end of chapter. Industrial Air Conditioning 961 Table 1. Temperatures and, Humidities Applicable to-Industrial Aib 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 (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. 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 1 BREWING Temp. F-1 - H-H. % Storage: Hops.................................................................. Grain............................................................................. Liquid yeast.................................................................. Lager.............................................................................. Ale........................................ ............... .\................... Fermenting Cellar: Lager................................................ Ale................................................................................. Racking Cellar................................................................. * If wooden tankage is used, otherwise humidity con , trolled to prevent condensation on walls and ceiling. 30 to 32 80 max. 32 to 34 32 to 34 40 to 46 40 to 45 55 32 to 35 55 to 6260 max. 75 min.* 75 min.* 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. Lager 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{ maintaining temperature for eighteen minutes, then cooling to 80 F in twenty minutes. Canned beer requires one-third less 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.% Candy centers for coating..................................................... Enrobing Tempering room -- Ventilation only 80 to 85 60 to 65 75 to 80 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 based on 100 lb of 90 F chocolate per- (worker) (hr). Specific heat of chocolate = 0.30 to 0.56 Btu per (lb)(F deg)l 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........ ................................................................ Tempering = (Ventilation only) Temp. F 75 to 80 75 to 80 55 65 to 75 65 to 75 R.H. % 30 to 40 40 to 45 40 to 45 45 to 50