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Introduction of quick-frozen food processing equipment-blast freezing equipment

Author:admin

Date:2021-08-17

Quick-frozen foods are popular with consumers because of their convenience and benefits. Quick freezing refers to the use of modern freezing technology to reduce the temperature of the food below the freezing point in a short time, so that the food forms small ice crystals, minimizes the damage to the cell tissue, and preserves the original juice and flavor of the food.

The quick-freezing process is a key step that affects the quality of quick-frozen food. The quick-freezing process of food is developing in the direction of low temperature and rapid freezing, and the form of freezing has also developed from large plate freezing to rapid freezing of monomers. At present, my country's quick freezing devices are mainly divided into blast quick freezing devices, contact quick freezing devices and direct freezing devices. The following Xianji.com will take you to understand the characteristics and applications of various freezing devices.

Blow-type freezing device

The blast freezing technology uses the high-speed flow of low-temperature air to promote the rapid heat transfer of the food, so that the cold air can take away the heat of the food in a short time and achieve the purpose of freezing. The evaporating temperature generally used in the blast freezing device in our country is -35~-50℃, the speed of air passing through the frozen food is 2~10m/s, the temperature of cold airflow is -30~-45℃, and the freezing speed is 0.5~3cm/ h. According to the structure, blast freezing is further divided into: quick freezing machine type quick freezing device, spiral belt quick freezing device, liquefied quick freezing device and air flow up and down impinging blast quick freezing device.

Quick-freezing machine type quick-freezing device

The shape of the quick-freezer-type quick-freezing device is a rectangular quick-freezer, the cold air is circulated in the quick-freezer, and the food is frozen when it passes through the quick-freezer. According to the different ways the food passes through the quick-freezer, it can be divided into: hanging type, hanging basket type, conveyor belt type and so on. The quick-freezing machine type quick-freezing device has a simple structure and a fast freezing speed, which can realize continuous production, but the equipment has a large area. Hanging type quick freezing device is mainly used for freezing large aquatic products and poultry carcass; hanging basket type quick freezing device is mainly used for small and medium-sized aquatic products, fruits and vegetables, adjusted food, etc.; conveyor type quick freezing device is suitable for relatively small shapes and freezing time Relatively short products, such as: vegetables, aquatic products, pasta, cold food, cut meat, etc.

Liquidization (fluidization) quick freezing device

Liquidized quick-freezing device, also called fluidized quick-freezing device, is to put the frozen food on a mesh belt or perforated trough plate with a small opening rate, so that the food particles are blown by the vertical upward high-speed airflow to form a semi-suspension In the state (semi-fluid quick freezing) or fully suspended state (full-fluid quick freezing), suspended food particles are surrounded by low-temperature airflow and are quickly frozen. According to different mechanical transmission methods, it is divided into: belt fluidized freezing device, vibrating fluidized freezing device, chute type fluidized freezing device, etc. Liquid freezing has the advantages of fast freezing speed, no agglomeration of frozen products, less dry consumption, lower energy consumption, etc. It is generally used for small granular, flake, strip or block foods, such as strawberries, French fries, green beans, peas, peppers, chestnuts, garlic sprouts, carrots, mushrooms and more.

Airflow up and down impact quick freezing device

The impact quick freezing device uses the upper and lower air jets to directly impact the frozen food and clear the heat boundary layer around it to achieve rapid freezing. The freezing speed of the impact quick freezing device is much faster than that of the conventional blast freezing device, and the dry consumption is small. It is mainly used for freezing thin flat food or small bulk food, such as fish fillets, shrimps, and mixed foods.