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Article Source：Liquid nitrogen quick freezing, liquid nitrogen quick freezing equipment, quick freezing machine, Keweijiani (Beijing) Technology Co., Ltd editor-in-charge：科威嘉尼—朱向磊 click：124 Publication time：2014-02-24 10:36:48

      Characteristics of liquid nitrogen
      Liquefied nitrogen --- liquid nitrogen gas is colorless and transparent low viscosity , chemically stable, liquid nitrogen boiling point at atmospheric pressure is 77.35K. And poultry food ingredients without chemical reaction, in line with food hygiene requirements , is an ideal quick freezing preservative. Nitrogen content in the air is about 78% , so the atmosphere around the earth , inexhaustible . With the finish.
      Frozen in liquid nitrogen preservation mechanism
      At atmospheric pressure , the liquid nitrogen in the liquid state to the vapor phase- evaporation latent heat per kg of liquid nitrogen to be absorbed is 199.29 kJ, then when the heat rise to 273K 77.35K absorbed 202 kJ . This characteristic is the use of frozen in liquid nitrogen cryogenic endothermic dispersion technology using nitrogen gas is dispersed into the liquid nitrogen directly to the desired poultry body , when the temperature difference of up to 200K or more intense heat exchange can be performed , enabling avian body momentary freeze , usually in about 20 minutes to complete all the freezing process , 30 times faster than conventional freezing method . Due to the freezing time is short, very tiny ice crystals generated freeze faster than the speed of intracellular penetration of steam , while producing ice crystals inside and outside the cells , without damaging cells , so you can maintain the original color , smell, taste and freshly thawed state , is today recognized as the world's leading countries in the product .
      Process and apparatus for quick-frozen in liquid nitrogen
      Quick-frozen poultry, frozen in liquid nitrogen for the device in shape tunnel , by special stainless steel mesh belt transmission, the transmission of avian body placed in stainless steel mesh belt , with the move followed after pre-cooling zone , frozen zone and temperature equalization zone complete freeze from the other end of the freezer after the sending device , placed in liquid nitrogen tank outside the box , is introduced into the device through a dedicated pipeline steel pipe , the device comes with a liquid nitrogen system within the tunnel successor , after absorbing vaporized liquid nitrogen dispersed after overheating nitrogen temperature is still very low, generally around 58K, then the fans will be sent to another device with nitrogen pre-cooling , usually 1 kg of frozen chicken consumes 0.4 kg of liquid nitrogen .
     Tank of liquid nitrogen tank factory processed by a professional standardized products , the internal structure of the metal vacuum laminated , also coated with polyurethane outer insulation material insulation, pressure generally within 8KG, equipped with safety valves, level gauge . Gauges and other safety measures pressure within the system can be adjusted to ensure that does not exceed the specified value, the quantity in the liquid nitrogen tank level gauge how much can be said after the tank filled with liquid nitrogen by adding liquid valve.
      
Characteristics of liquid nitrogen freezer preservation device
      1, high -quality frozen quality
      The main factors affecting the quality of frozen poultry food is the size of the ice crystal formation in their cells , the amount of damage its color, smell , taste and freezing process avian cells in the body have a direct relationship , long plain old freezing method freezing time , form the big ice , make cell deformation and damage , and short of liquid nitrogen to freeze time , with quick-frozen nature , completely avoid this, the formation of ice crystals is very small , it is possible to maintain the original freshness, flavor and color nutritional value , and in cold storage process does not burst noncombustible does not rot, long-term storage ; simple structure, safe and reliable. Analysis, the only moving parts of the entire device and the conveyor belt moving mechanism simple axial fan , a refrigeration system that unlike ordinary complex structure , more mechanical moving parts , thus reducing the possibility of failure , and low system pressure , no high-pressure equipment ; simple operation. It can be seen that the device is a conveyor belt of the way straight continuous operation , the operator need only a simple operation buttons outside the box , and import and export foreign transfers Frozen ; consumes less energy . The device is a phase change cooling by liquid nitrogen and changes in internal energy to achieve the purpose of quick-frozen fresh , unlike ordinary refrigeration system at the time of the freeze that requires large amounts of energy to drive the refrigeration mechanical refrigeration , so from the refrigeration principle , it is no direct consumption of electricity ; hygiene and no environmental pollution , no noise . Freezer box insulation plates assembled by the constitution , and the inner and outer shield of stainless steel, so that both easily removable and easy to clean, reloading quickly , in direct contact with poultry but also for stainless steel conveyor body , cleaning more convenient.
      Because of this freezing process does not require refrigeration system in general fluorine refrigerant , so without damaging the ozone layer , is the trend to develop in the future . Equipment, small footprint , low noise. Simple operation without professional operation.
      2 , economic analysis
We know the cost of the device includes a one-time investment and use of economic costs , which the former is mainly for the purchase of a full set of equipment, the number of decisions by the scale of production , frozen in liquid nitrogen and low cost equipment procurement , environmental protection, low running costs , frozen the products of high quality , long storage time, and the cost of the device to the device using the old general freeze investment, large area, require professional maintenance , human pollution of the atmosphere , it is an investment in the former is more economical. Fee includes : liquid nitrogen costs , depreciation of equipment, labor costs, a small amount of electricity. On poultry, shrimp and high nutritional value of food , are used fresh , then frozen in liquid nitrogen , the demand for liquid nitrogen freezer will be very great.