Vacuum cooling device contains rotary vane vacuum pumps, vacuum precooling system can also be equipped with the roots vacuum pump, also called a vacuum booster pump , and this rotary pump is used as backing pump , rotary vane vacuum pump application in the industry of mainly pumping suction air and water vapor, the vacuum precooling system are mainly used for preservation of fresh fruits and vegetables.
The basic principle of vacuum cooling: under normal atmospheric pressure (101.325 kPa), evaporate water at 100 ℃, if the atmospheric pressure is 610 pa, water evaporation in 0 ℃, the boiling point of water as the reduce of environmental atmosphere.Boiling is quickly evaporate, can rapidly absorb heat.Fresh fruits and vegetables in the airtight container, quickly take out air and water vapour, with continuous reduce pressure, fruits and vegetables because of continuously, quickly evaporates water and cooling.Vacuum cooling water loss is in commonly 3%, won’t cause Withers softly, loss of fresh fruits and vegetables.Due to the pressure difference inside and outside the organization of fruit and vegetable, harmful gases and heat within the organization has been pumped out, can delay step variant respiration peak arrival.So, under the condition of vacuum cooling, cooling from the organization to outside surface simultaneously, namely uniform cooling, it is unique in the vacuum cooling, any other cooling method gradually from the surface to the organization “penetration” cooling, thus keeping fresh time long.
Vacuum precooling equipment is a kind of cooling processing equipment, not refrigeration equipment.Its purpose is for fruits and vegetables quickly cooled to set temperature, and then out from the equipment items, or in the air, or directly, or put into cold storage.For fruits and vegetables in a dormant state, the vitality of the recovery will take time to process, this process is the last period.
Special note: vacuum precooling can go to water surface of rainy days harvest the fruits and vegetables, can make the small wounds on the surface of the fruit and vegetable “healing” opportunity to reduce microbial invasion, there is no other treatment methods, only the vacuum precooling equipment unique!
Vacuum precooling system based on mechanical oil sealed rotary vane vacuum pump unit gas suction pump, reduce the pressure of the vacuum groove, using low temperature cold trap to fruit and vegetable surface evaporation of water vapor capture, so that the fruits and vegetables own cooling vacuum equipment.
Features are: vacuum precooling system can be in high compression ratio and high pressure difference under the condition of normal work, low consumption, low power consumption power.System of drainage time is short and can obtain a lower drainage pressure, make the precooling time of the vegetables, reduce the energy consumption of equipment.