The evaporator of a 20kg Per Day Ice Maker Machine plays a crucial role in the ice-making process. It is the key component responsible for freezing the water and turning it into ice cubes. The working principle of the evaporator involves a heat exchange process known as the refrigeration cycle.

The refrigeration cycle in the evaporator can be summarized in the following steps:

1. Expansion Valve: The refrigerant, typically a low-pressure gas, enters the evaporator through an expansion valve. The expansion valve reduces the pressure of the refrigerant, causing it to expand rapidly. This expansion lowers the temperature of the refrigerant, making it colder than the surrounding environment.

2. Absorbing Heat: Inside the evaporator, the cold refrigerant absorbs heat from the water surrounding it. The water is in contact with the evaporator's metal plates or tubes. As the refrigerant absorbs heat from the water, it changes from a low-pressure gas to a low-pressure, low-temperature vapor.

3. Water Freezing: The heat transfer from the water to the refrigerant causes the water to freeze and form ice on the evaporator's surface. This ice buildup continues to grow as more heat is absorbed from the water.

4. Vaporizing Refrigerant: The refrigerant, now in vapor form and carrying the heat it absorbed from the water, exits the evaporator and enters the compressor.

5. Compressor: The compressor is the next stage in the refrigeration cycle. It compresses the refrigerant vapor, increasing its pressure and temperature.

6. Condenser: The high-pressure, high-temperature refrigerant vapor is then sent to the condenser, where it releases the heat it absorbed from the water in the evaporator. The refrigerant condenses into a high-pressure liquid as it releases heat.

7. Expansion Valve (again): The high-pressure liquid refrigerant then goes through the expansion valve again, where it experiences a drop in pressure, returning to a low-pressure, low-temperature state. This prepares the refrigerant to re-enter the evaporator and repeat the refrigeration cycle.

The continuous refrigeration cycle allows the evaporator to maintain a cold temperature, causing the water in contact with it to freeze and form ice cubes. The ice cubes are then released from the evaporator, collected in the ice storage bin, and made available for use.