gfdryermachine's Blog

First, the effect of cooling medium temperature. Under the process conditions of IQF Freezing Machine , the lower the temperature of the cooling medium, the faster the product freezes under the same conditions. At present, according to the specific situation in China, most of the ammonia is used as a refrigerant, and the evaporation temperature is generally selected between -35 and -45 °C. Under the IQF process, if a forced air continuous freeze is used, the temperature of the cooling medium is also related to the frosting speed of the evaporator. That is, when the evaporating frost layer reaches a certain thickness, the temperature of the cooling medium is correspondingly increased due to a decrease in the heat transfer effect. Therefore, in order to ensure the quality of the frozen, it should be done in time to defrost.

Second, the effect of air flow rate

Under the IQF Freezing process, the air flow rate is the main factor affecting the value of the exothermic coefficient. Therefore, an appropriate increase in the air flow rate can increase the degree of freezing end. For example, the common green beans freeze in the static air of -30°C, which takes about 2 hours. At the same temperature, the air flow rate increases to 4.5-5 m/s, and the freezing time is only 10 minutes.

Under certain conditions, the change between the freezing speed and the air flow rate is not linear, so the air flow rate should be comprehensively determined from an economic point of view.

Third, the effect of freezing termination temperature

The freezing termination temperature is lower than the storage temperature (-18 ° C), which is beneficial to maintain the structure under rapid freezing. If the freezing termination temperature is higher than -18 °C, the unfrozen water inside the vegetable tissue will generate large ice crystals, which will result in the destruction of the tissue structure and the increase of juice loss during thawing, which will affect the nutritional value and flavor of the product.

Zhejiang Guanfeng Food Machinery Co.,Ltd. is one of the leading enterprises in China, specialized in Vegetable Processing Machine and IQF Freezing. Company with modern manufacturing facility and professional team. We are looking forward to establishing relationships with you in the near future, contact us:

Company: Zhejiang Guanfeng Food Machinery Co.,Ltd.

Add : South industrial park of Dongguan, Shangyu District, Shaoxing City, Zhejiang Province, China 312352

IQF Freezing : https://www.gf-machine.com/solution/frozen-solution/iqf-quick-freezing-production-line.html

GuanFeng Freeze Dry Machine consists of a refrigeration system, a vacuum system, a heating system, and an electrical instrument control system. The main components of the Freeze Dry Machine are divided into drying ovens, condensers, refrigeration units, vacuum pumps, heating/cooling devices, etc.

The amount of water vapor in the compressed air is depended on the temperature of the compressed air: Under the condition that the compressed air pressure is basically invariable, reducing the temperature of the compressed air will reduce the amount of water vapor in the compressed air, and the excess water vapor will condense into a liquid. The Freeze Dry Machine uses refrigeration technology to dry compressed air.

The refrigeration system of the Freeze Dry Machine is a compression type refrigeration system consisting of four basic components: a refrigeration compressor, a condenser, an evaporator, and an expansion valve, which connected by a pipe connection to form a closed system in which the refrigerant circulates continuously in the system, undergoes a state change and exchanges heat with the compressed air and the cooling medium.

The refrigeration compressor draws the low-pressure (low-temperature) refrigerant in the evaporator into the cylinder of the compressor, and the refrigerant vapor is compressed, and the pressure and temperature are simultaneously increased; the high-pressure and high-temperature refrigerant vapor is pressed to the condenser. In the condenser, the higher temperature refrigerant vapor exchanges heat with the cooler water or air, so the heat of the refrigerant is taken away by water or air to condense, and the refrigerant vapor becomes a liquid.

This part of the liquid is sent to the expansion valve, which is throttled into a low-temperature and low-pressure liquid through the expansion valve and enters the evaporator; in the evaporator, the low-temperature, low-pressure refrigerant liquid absorbs the heat of the compressed air and vaporizes (commonly called "evaporation") The compressed air is cooled to condense a large amount of liquid water; the refrigerant vapor in the evaporator is sucked away by the compressor, so that the refrigerant undergoes four processes of compression, condensation, throttling, and evaporation in the system, completing a loop.

GuanFeng as a professiona freeze dry machine manufacturer, we also offer high-quality Quick Freezing Equipment , if you intereste in learn more information, please contact us by click https://www.gf-machine.com/product/quick-freezing-equipment/