Milk cooling tanks are essential equipment designed to cool milk immediately after milking. This process is crucial for preventing bacterial growth and preserving the quality of the product.
Materials Used in Manufacturing
Milk cooling tanks are constructed using various materials, including:
- Stainless steel: The most common choice due to its corrosion resistance and ease of cleaning.
- Carbon steel.
- Aluminum.
Types of Tanks
Milk cooling tanks are typically classified as:
- Horizontal tanks.
- Vertical tanks.
Key Features
Stainless steel tanks often include the following essential components:
- Mixer: Ensures uniform distribution of milk within the tank.
- Drain valve: Allows for easy milk drainage.
- Lid: Protects milk from contamination.
Cooling Cycle of the Tank
The cooling process involves several key parts:
- Evaporator: Located in the tank walls, it facilitates direct heat exchange with the milk.
- Compressor.
- Condenser.
- Expansion valve.
- Pressure switches.
- Condenser fan.
- Fan speed control.
- Liquid receiver.
- Filter dryer.
- Sight glass.
- Solenoid valve.
Control and Monitoring Systems
- Temperature sensor: Monitors the milk temperature.
- Control system: Regulates the temperature to maintain optimal conditions.
Classification of Milk Cooling Systems
- Direct Cooling System (Refrigerant-to-Milk):
- The most common system.
- The tank’s bottom acts as the evaporator, transferring heat from the milk to the refrigerant.
- Includes an agitator to continuously mix the milk, preventing uneven temperature layers.
- Indirect Cooling System (Refrigerant-to-Water-to-Milk):
- The evaporator is placed in a water-filled receiver.
- The water absorbs heat from the milk and returns to the receiver to be cooled again.
- System with Pre-Coolers:
- Uses heat exchangers cooled by well water or tap water.
- Partially cools the milk before it enters the tank.
- Allows heat recovery and reduces energy consumption.
Technical Specifications
- Agitator speed: Approximately 36 revolutions per minute.
- Cooling 500 liters of milk: Requires approximately 4.5 kW of electrical power and 0.55 kW for the agitator.
