Working principle of feed counterflow cooler and analysis of fluid uniform distribution technology

1. Countercurrent cooling principle and its advantages
The feed counterflow cooler adopts the countercurrent principle in which the cooling airflow direction is opposite to the material flow direction. This design cleverly utilizes the convection heat transfer principle in thermodynamics. Specifically, the cold air enters from the bottom of the cooler and first contacts with the cold particles that have just entered the cooling bin and have a relatively low temperature. As the cold air flows upward, it gradually absorbs the heat of the material and heats up, while the material cools down due to the release of heat. When the cold air reaches the top of the bin, its temperature is close to or reaches the initial high temperature state of the material. At this time, it conducts the final heat exchange with the hot particles on the top layer of the bin to complete the cooling cycle. This process forms a unique temperature gradient in the bin: the temperature of the material gradually decreases from top to bottom, while the temperature of the air gradually increases from bottom to top.

The advantage of countercurrent cooling is that it maximizes the temperature difference between the cold and hot fluids and improves the heat exchange efficiency. Compared with the downstream or parallel cooling method, countercurrent cooling can achieve a lower material outlet temperature within the same cooling time, or reduce the amount of cooling medium while maintaining the same outlet temperature, thereby saving energy.

2. Importance and implementation strategy of fluid uniform distribution technology
In order to ensure the efficient countercurrent cooling process, the cooling medium (such as cold air) must be evenly and stably distributed in the cooling bin and fully contact the material layer to achieve effective heat exchange. The design of the fluid uniform distribution device is therefore particularly important.

Flow channel design: The internal structure of the cooler, especially the design of the flow channel, is a key factor affecting the uniformity of fluid distribution. Through a reasonable flow channel layout, it can be ensured that the cold air has formed a good flow state before entering the cooling bin, avoiding the formation of local vortices or dead zones, and ensuring that the cold air can evenly cover the entire material layer.
Nozzle layout: In some cooling systems, nozzles are used to spray cold air into the bin in the form of mist or thin streams. This requires that the layout of the nozzles should not only consider the coverage of the sprayed cold air, but also avoid direct impact on the material to cause the material to fly or local overcooling. Reasonable nozzle layout and angle adjustment are the key to achieving uniform cooling.
Bulk feeder structure: Bulk feeders are used to evenly distribute materials in the cooling bin to prevent material accumulation and cooling dead corners. Its design needs to take into account the physical properties of the material (such as particle size, density, fluidity) and cooling requirements. By adjusting the shape, speed and other parameters of the bulk feeder, the thickness of the material layer is ensured to be uniform and the cold air is fully contacted with the material.
Dynamic adjustment system: In order to cope with the changes in cooling requirements under different working conditions, modern feed counterflow coolers are often equipped with intelligent control systems. By monitoring parameters such as material temperature and cooling medium flow, the cold air supply, nozzle working status or bulk feeder speed are automatically adjusted to achieve more precise cooling control.