How many types of quick freeze machine?
The general trend of food quick freeze process is low temperature, rapid freezing, the form of frozen products developed from the large disk-shaped freezing to Individual Quick Freezing.
At present, quick freeze device can be roughly divided into a strong blowing continuous quick freezing device, tunnel type freezing device, contact type freezing device, direct freezing device.
(1) Strong blowing continuous quick freeze machine:
Strong ventilation Quick freezing device adopts fin tube evaporator. The blower adopts high-pressure centrifugal fan or axial flow fan, and the refrigerant is forcibly circulated by the ammonia pump. Therefore, it has the advantages of high heat transfer efficiency, small area characteristics. In general, in this device, when the air passes through a frozen object at a speed of 3 to 6 m / s and a temperature of -40℃ to -30 ° C, the quick-freezing speed of the air is 2 to 4 times faster than that of a tube rack, You can use mechanical intermittent access or continuous access, greater production capacity.
(2) Tunnel type quick freeze machine
The tunnel type freezing device is equipped with an air cooler and a blower, the frozen goods are loaded on the trolley, and when passing through the tunnel, cold air is blown in to make it freeze. Tunnel type freezing device, because it is not limited by the shape of the food, food delivery on the hanger rail, less labor intensity. Most of the devices use axial fan, high wind speed, freezing speed (but large food dry), the evaporator defrosting using hot ammonia gas and water at the same time, so the defrost time is short, characterise is large air volume, fast freezing speed.
(3) Contact type quick freeze machine
Contact type quick freezing device, also known as flat-panel quick-freezing device, the working procedure is to put food on each floor flat, oil pressed the flat, thermal coefficient, quick freezing time is short, and can be run at room temperature. This device can use freon, salt water, etc. But the disadvantage is that the structure is complex, can not be continuous production, but also the thickness of frozen food has some restrictions.
(4) Direct freeze machine
This method requires direct contact between food (packed or unpackaged) and antifreeze solution. After food is exchanged with antifreeze solution, the food is rapidly cooled and frozen. As the direct contact of foodstuff with antifreeze, there is a limit to antifreeze, especially when it comes in contact with unpackaged foodstuffs.
These restrictions include non-toxic, pure, odorless and exotic gases, no external color and bleach, non-flammable, non-explosive, etc. In addition, after non-freezing liquid contact with food, should not change the original ingredients of food