In industries such as food, chemical, pharmaceutical, electronics, spraying, printing, papermaking, and chemical fibers, drying equipment is often used to raise the air (fresh air) to a certain temperature, process materials, and use the air as exhaust gas (exhaust) to be discharged. The discharged exhaust gas usually has a high temperature and is directly discharged into the atmosphere, causing significant energy waste. Adding a heat exchanger in the exhaust emission system can achieve the recovery and reuse of waste heat. The main component of the heat exchange box is the BXB plate heat exchanger, which is mainly made of aluminum foil (or stainless steel foil). Two streams of air separated by aluminum foil and flowing in opposite directions will transfer heat when there is a temperature difference, achieving energy recovery. By using BXB plate heat exchanger, the heat in the exhaust can be utilized to preheat the fresh air, thereby achieving the goal of energy conservation.