Static magnetic field assisted liquefied CO2 pulse spouting quick freezing device and pressurized efficient freezing method

Abstract

The invention discloses a static magnetic field assisted liquefied CO2 pulse spouting quick freezing device and a pressurized efficient freezing method, and belongs to the technical field of freezing processing. The quick-freezing device comprises a freezing chamber, a liquid CO2 spraying device, a static magnetic field generating device, a pulse spouting device, a temperature collecting device and a controller, liquefied CO2 is adopted as a freezing medium, the pulse spouting device is matched to enable thick stacked materials to be frozen evenly and quickly, the static magnetic field generating device is matched to assist in freezing, and the size of ice crystals can be reduced. The freezing method comprises the steps of evacuation, precooling, CO2 pressurization, magnetic field-assisted quick freezing and deep freezing. According to the method, CO2 pressurization pretreatment and pulse spouting are combined, the freezing time is remarkably shortened, the ice nucleation process is regulated and controlled, and freezing is uniform. Compared with industrial air blast quick-freezing, the time for the frozen materials to pass through the maximum ice crystal generation zone is shortened by more than 20%, and the ice crystal size of the product is reduced by more than 20%. The juice loss rate of the unfrozen product is reduced by more than 4%.

Description

technical field [0001] The invention relates to the category of freezing processing technology in the technical field of food processing, in particular to a static magnetic field assisted liquefaction CO 2 A pulse jet quick-freezing device and a pressurized high-efficiency freezing method. Background technique [0002] Today, freezing has become an important means of food processing and preservation, especially for long-term storage and transportation, and is considered an ideal choice. Studies have shown that freezing is particularly harmful to food when the freezing speed is slow, because the water molecules gradually migrate to the nuclei and the ice crystals continue to grow. The mechanical damage of ice crystals to frozen food is one of the main reasons for the deterioration of product quality. On the other hand, slow freezing has a concentration effect. During freezing, liquid water gradually turns into solid ice, and the free water content decreases, resulting in a...

AI Technical Summary

Problems solved by technology

However, according to the liquid carbon dioxide food quick-freezing technology disclosed in ZL201910271687.5 and ZL201911029464.4 above, it can be clearly known that the current liquid carbon dioxide spray is sprayed from above to the material, based on the principle of quick-freezing of liquid carbon dioxide, the material accumulation thickness There must be some restrictions, otherwise it is difficult to guarantee the freezing quality of materials. The reason is that for materials with a certain accumulation thickness, the materials at the bottom cannot be covered and penetrated by the spray liquid as quickly as the materials at the upper layer. Therefore, in the same During the freezing time, the materials in the upper layer may have been frozen in place, and the materials in the lower layer may need more freezing time to be frozen in place. On the contrary, when the materials in the lower layer have been quick-frozen in place, the materials in the upper layer must have been frozen. extremely uneven

Therefore, the existing liquid carbon dioxide quick-freezing technology cannot promote the quick-freezing treatment of all materials at the same time for the quick-freezing treatment of thicker materials, that is, when the material is thicker, the quick-freezing quality of the materials cannot be effectively controlled.

Images