Closed type milk coolers
The tank cooler of the closed type are issued from 2.000 lt up to 12.000 lt Such a device is economically beneficial for medium and large farms, since this type of tank has an automatic flushing system, which is indispensable when cooling large volumes of milk. Closed coolers, like open coolers, operate in automatic mode, according to a similar principle. The main difference, besides energy consumption, lies in the tank washing system. Here it is automatic. After emptying the tank, the operator presses the button, after which the electronics, according to a given program, starts the flushing system.
Principle of operation
The refrigeration unit supplies liquid freon under pressure to the evaporator. There, the refrigerant boils and turns into a gaseous state. This is an endothermic process that takes place with the absorption of a large amount of heat. The walls of the tank and the product inside are cooled. Freon gas is then pumped to the condenser. There, its temperature drops due to the fact that heat is released into the atmosphere through the radiator, and the freon returns to a liquid state again. After that, the cycle is repeated until the temperature of the raw material reaches the set value within + 2…4°C. According to the indications of the temperature controller, the unit turns off automatically. It also turns on without the participation of the operator, after the sensor gives a signal about a temperature increase of 1 degree (the temperature delta can be adjusted). For uniform distribution of cold inside the volume, there is a stirrer with a frequency of 25 rpm.
The standard sequence of cycles consists of 5 stages:
- Washing with alkali
- Acid washing
- Final rinse.
It is possible to customize the flushing program based on the operating conditions (for example, change the flushing time of each cycle, remove or add flushing steps, change the amount of alkali, acid, water used, etc.)