Evaporative Heat Exchanger Immersed In Water For Brine Cooling For Ice Blocks

Evaporative Heat Exchanger Immersed In Water For Brine Cooling For Ice Blocks

An evaporative heat exchanger immersed in water is a common setup for cooling brine used in ice block production. Here's how it generally works:

Components:

Evaporative Heat Exchanger (Coil or Plate Type): This is the primary component responsible for transferring heat from the brine to the surrounding water through conduction and natural convection. It is designed to have a large surface area for efficient heat transfer.

Brine: Brine is a mixture of water and salt, usually calcium chloride or sodium chloride. By lowering the freezing point of water, it allows the brine to cool below 0°C without freezing. The brine is circulated through the evaporative heat exchanger.

Water Reservoir: The evaporative heat exchanger is immersed in a water reservoir. The water acts as a cooling medium and absorbs heat from the brine as it circulates around the exchanger.

Working Principle:

Circulation of Brine: The brine is pumped through the evaporative heat exchanger. As it flows through the exchanger, it absorbs heat from the surrounding environment, including the items (such as ice molds) that need to be cooled.

Heat Transfer: Heat from the brine is transferred to the water in the reservoir. This heat transfer is facilitated by the temperature difference between the warm brine and the cooler water. The principle of heat exchange ensures that heat moves from the warmer substance (brine) to the cooler substance (water).

Evaporation: The water in the reservoir also benefits from evaporation. As water molecules absorb heat, some of them gain enough energy to transition into the gaseous state (evaporate). This phase change further cools the water.

Continuous Circulation: The circulation of brine and the continuous flow of fresh, cooler water into the reservoir maintains a temperature gradient, ensuring efficient heat transfer.

Maintaining the Brine Temperature: The brine temperature is carefully controlled to achieve the desired level of cooling for the ice blocks. By adjusting the flow rate of brine, the rate of heat exchange can be controlled, allowing for precise temperature regulation.

Efficiency: Evaporative cooling is highly efficient because it utilizes the principles of both sensible and latent heat transfer. Sensible heat transfer occurs as the temperature of the brine decreases, and latent heat transfer occurs during the phase change of water into vapor.