Home 

Ref-Wiki.com -

Technical information Food refrigeration and freezing Humidity And Air Motion

Humidity And Movement Of Air,

Loss of product moisture is one of the main reasons for the deterioration without packaging of fresh foods. Thus, the optimum storage of all perishable foods in their natural state (without packaging) requires careful monitoring of temperature and humidity in memory. Internal moisture transfers on the surface of the meat, poultry, fish, fruit, vegetables, cheese and eggs, evaporating into the surrounding air. This process is known as dehydration. Dehydration is accompanied shrink and wither as the product is subjected to a considerable loss in body weight and content of vitamins. Fruits and vegetables are particularly vulnerable to dehydration. Dehydration causes discoloration, shrinkage and heavy cut-off of losses in meat and cheeses, increasing the rate of oxidation. Eggs lose moisture through their porous membranes, causing weight loss and deterioration of the product.

Dehydration occurs whenever dies vapour pressure of the product more than the vapor pressure of the surrounding air. Speed moisture loss is directly proportional to the difference in pressure and volume of exposed surface area of the product.

The difference in pressure steam between the product and the air is primarily a function of relative humidity in memory. In General, the lower the relative humidity in the storage room, the more die steam pressure. Consequently, the rate of loss of moisture from the product.

The speed of the air flow over the entire surface of the product, also affects the speed of removal of moisture from the food storage. The higher the speed of air flow through the contaminated product surface, the greater the percentage of the loss of moisture from the food. Thus, reduces the loss of moisture in the air humidity in the storage space is maintained above 85% for most products, while the speed of the air in die amount of storage is kept low. In other words, ski storage with 95% relative humidity and stagnant air has ideal conditions to prevent dehydration is stored fruits and vegetables. Unfortunately, good circulation of air die inside of premises for storage and around the product necessaiy to maintain adequate heat transfer.

Ideal environmental conditions for fruits and vegetables may lead to a rapid growth of mold and education bacterial slime on the meat. In these applications, die temperature, humidity, air velocity and packaging methods varied to optimize the storage life of the product. Improved packaging also the methods of solution of certain products to be stored for long periods in places with less than optimum humidity and air velocity conditions. For example, dried fruits, as a rule, hygroscopic, that is, they absorb moisture from the surrounding environment and therefore require storage at low levels of relative humidity. When diis product type, which is stored in vaporproof container space, humidity and air velocity is not as critical...

 
Thanks ->



Ammonia pipe sizing Csr compressor wiring diagram Expansion valve calculation Function of evaporator Laws of refrigeration P. H. diagram Plate and shell heat exchanger Pressure limiting txv R600a refrigerant pressure temperature chart Refrigerant oil types Refrigeration load Rsir compressor Surge receiver
Copyright @ 2009 - 2022, "www.ref-wiki.com"