How the Evaporator Works in IQF?

How the Evaporator Works in IQF?

The evaporator is an important part of the freezing equipment in the IQF (Individual Quick Freezing) process. The function of the evaporator is to convert the liquid freezing medium (usually ammonia or carbon dioxide) into a gaseous state, thus absorbing heat from the food and freezing it.

The evaporator usually consists of the following main components:

Freezing medium inlet: the liquid freezing medium enters the evaporator through the inlet.

Freezing medium distributor: the freezing medium passes through the distributor and is evenly distributed into the multiple tubes or nozzles of the evaporator.

Food heat transfer surfaces: Inside the evaporator there are a large number of heat transfer surfaces, usually tubes, plates or nozzles. These surfaces are in direct contact with the foodstuff and transfer heat from the foodstuff to the freezing medium by conduction and convection heat transfer.

Freezing medium outlet: The freezing medium absorbs heat from the food during the heat transfer process and gradually transforms into a gaseous state. The gaseous freezing medium is discharged from the evaporator through the outlet.

The working principle of the evaporator is as follows:

The freezing medium enters the evaporator: the liquid freezing medium enters the evaporator through the inlet, usually under high pressure.

Distribution of the freezing medium and heat transfer: The freezing medium passes through the distributor and is evenly distributed to the heat transfer surfaces in the evaporator. As the freezing medium flows over the heat transfer surfaces, it absorbs heat from the foodstuff, resulting in a rapid drop in the temperature of the foodstuff.

Evaporation of the freezing medium: During the heat transfer process, the freezing medium gradually evaporates, changing from a liquid to a gaseous state. The heat absorbed in this process is mainly from the food.

Freezing medium discharge: freezing medium in the process of heat transfer absorbed in the food, and gradually transformed into a gaseous state. The gaseous freezing medium is discharged from the evaporator through the outlet and enters the condenser or recovery system for reuse.

Through the above working process, the evaporator can effectively transfer the heat in the food to the freezing medium and realise the rapid freezing of the food. This can maintain the quality and taste of the food and improve the production efficiency at the same time.