Waste Heat Recovery Heat Exchanger for Food Drying Tower Exhaust Gas

Waste Heat Recovery Heat Exchanger for Food Drying Tower Exhaust Gas

In a food drying tower, hot air is used to remove moisture from the food to dry it. This process generates a large amount of exhaust gases with temperatures typically around 60 - 120°C. These exhaust gases contain water vapor and volatiles from the food drying process. These exhaust gases contain water vapor and a small amount of organic components volatilized during the drying process of the foodstuffs and have a certain amount of heat.

Heat pipe heat exchanger

Principle: There is a working medium inside the heat pipe, when one end of the heat pipe (evaporation section) comes into contact with the high temperature exhaust gas, the working medium absorbs the heat and evaporates, and the steam flows to the other end of the heat pipe (condensation section) under the action of pressure difference, and releases the heat to the heated medium in the condensation section, and then the working medium comes back to the evaporation section again through the action of capillarity or gravity to form a cycle.

Application Advantage: Heat pipe heat exchanger has high efficient heat transfer performance, which can quickly transfer the heat in the exhaust gas to the heated medium. When dealing with the exhaust gas of food drying tower, the waste heat of the exhaust gas can be effectively utilized, for example, in the drying tower of drying grain, the cold air entering the drying tower is preheated by the heat pipe heat exchanger, so as to improve the efficiency of energy utilization.

Installation and operation of heat exchanger in food drying tower system

Installation position

The heat exchanger should be installed in a reasonable position between the exhaust gas outlet and air inlet of the drying tower in order to maximize the use of exhaust gas waste heat. In general, make sure that the exhaust gas piping is tightly connected to minimize heat dissipation. For example, install the heat exchanger at the side or top of the drying tower, and introduce the exhaust air into the heat exchanger through the piping for heat recovery, and then send the preheated air back to the drying tower.

Operation and Maintenance

Regularly check the working condition of the heat exchanger, including checking whether the pipeline is clogged or not, and whether the heat exchange surface is scaled or not. For inter-wall heat exchanger, if the pipe wall is scaled, it will affect the heat transfer efficiency and needs to be cleaned regularly. For regenerative heat exchangers, it is necessary to check whether the performance of the regenerative body decreases, and for heat pipe heat exchangers, it is necessary to pay attention to whether the heat pipe is damaged. At the same time, it is necessary to ensure that the flow rate and temperature of the exhaust gas and the heated medium are within a reasonable range, and real-time monitoring and control is carried out by installing temperature sensors and flow sensors.