Contact type quick freezing device

The contact type quick freezing device is to place food between different layers of flat plates, and then press the plates tightly. Due to the evaporation of refrigerant in the hollow plates, direct contact quick freezing occurs. This device can use saltwater or other refrigerants. The contact type quick freezing device has the advantages of high heat transfer coefficient, short quick freezing time, operation at room temperature, small footprint, easy installation and operation, and easy mobility. However, its structure is complex and cannot be used for continuous production, and it has certain limitations on the thickness of frozen food. The contact type quick freezing device is suitable for batch freezing of fish paste, meat, fruit puree, shellfish and other foods, and can be used on ships, etc.

Direct freezing device

The direct freezing device is a device that directly contacts and exchanges heat between food and low-temperature refrigerant, rapidly cooling and freezing the food. The commonly used refrigerants include liquid nitrogen, liquid carbon dioxide, saltwater, propylene glycol, etc. According to the contact method, direct freezing devices can be divided into spray type, immersion type, or a combination of both methods. The direct freezing device has the advantages of fast freezing speed and low food drying consumption, but it has disadvantages such as difficult refrigerant recovery, high loss, and high cost. And there are certain restrictions on refrigerants, especially when in contact with unpackaged food. Refrigerants require purity, no odor or unusual gases, no foreign colors or bleaching agents, and are not flammable or explosive.