Hold tank temperature effect

Table III. Effect of Hold Tank Temperature on the Adipic Acid Degradation Rate...

Heat-Resistant Lipases. The heat-resistant lipases and proteinases and their effects on the quality of dairy products have been reviewed (Cogan 1977, 1980). Several reports have linked the lipases from bacteria with the off-flavor development of market milk (Richter 1981 Shipe et al. 1980A Barnard 1979B). The microflora developing in holding tanks at 4°C [and presumably in market milk stored at 40°F (Richter 1981)] may produce exocellular lipases and proteases that may survive ordinary pasteurization and sterilization temperatures. Rancidity of the cheese and gelation of UHT milk appear to be the major defects caused by the heat-resistant enzymes. 

Storage tank and in the circulation loop at ambient temperature most of the time (this requires an extra heat exchanger with cooling water on the shell side). To achieve microbial control, such system (or any system that includes ambient loop) needs to be periodically sanitized by heating up its contents to about 80° C and holding the temperature for at least 1 hr. The sanitization frequency can vary from once a day to once a week or less the lower the frequency is, the more attention to the studies proving the effectiveness of the microbial control shall be expected. 

Many of the design principles of a hydride tank also hold for a hydride compressor. It must be an effective heat exchanger. The more effective the heat exchange, the shorter is the cycle time and consequently the smaller the hydride inventory required. Ideally, the hydride should have a high slope to the Van t Hoff plot to produce maximum compression with minimum temperature excursion. Beds of different hydrides can be coupled in series to provide staged compression and thus achieve very high overall compression ratios with modest temperatures. The ability to tailor hydrides, as shown earlier, is very helpful to compressor optimization for specific applications (i.e., available heat sources, H2 input pressure, and desired output pressure). 

The feed tank is mounted on the ceiling using chains and a weighing cell. Continuous weighing of the feed vessel stands for an exact mass balance not influenced by pulsation of the feed pump, volumetric or viscosity effects. To ensure that the connected feed pipes do not block with solidifying liquid they are equipped with an explosionproof electric heating wire which holds an adjustable temperature. 

The main objectives of the test program were the determination of insulation performance under ground-hold compressive loads and external pressures less than 1 atm. The effect of reduced compressive loads on the insulation was investigated over a range of external pressures from 1 to 10" atm, since this appeared to have a strong influence on the thermal conductivity. All tests were conducted at ambient outside temperature, ranging from 40 to 80°F. To achieve these objectives, tests were carried out at the NASA Plum Brook test facility near Sandusky, Ohio. The test tank was suspended by the neck tube in a... 

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