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It is believed that many enterprises make use of heat exchangers such as hot air exchangers; in industries ranging from the food industry to the chemical and pharmaceutical sectors, hot air drying is a very common type of heat exchange equipment. What we would like to recommend today is a hot air exchanger that uses steam as the heat source. It involves the techniques and knowledge needed to maintain the required temperature of the hot air while reducing steam consumption, thereby achieving energy savings. If Haiyou finds any flaws in what has been presented, we earnestly ask for your feedback and guidance. Thank you! A hot air exchanger uses medium to high-pressure steam (at high temperature) to heat the cold air blown in by the induced draft fan or blower, through the finned tubes of the exchanger. Through successive stages of heating, the temperature of the cold air gradually increases, until it reaches the temperature of hot air required for the enterprise’s production processes. The steam, after cooling and exchanging heat in the finned tubes, releases its latent heat of vaporization and condenses into high-temperature condensate water. Since the first set of finned tube exchangers comes into contact with cold air, the temperature difference is greatest there, resulting in the highest amount of condensate water; as one moves toward the hot air outlet, the amount of condensate water decreases. The condensate water needs to be drained through a drain valve installed at the lowest point at the bottom of the hot air exchanger. If a company has its own boiler, the quality of this condensate water is good, and it can be directly collected and sent back to the deaerator or the boiler (in some companies it is sent to the tank used for supplying softened water to the boiler; most of these tanks are open, and hot steam escapes from them. It may seem as though hot water is being recovered, but the high-temperature condensate water returning from the hot air exchanger continues to heat the water in those tanks, causing the tanks used for supplying softened water to boil. This results in heat waste, and we will explain below how to make effective use of this heat ； Some companies do not have their own boilers, and the condensate water generated must either be reused or discharged into sewers. In such cases, a large amount of steam is released at the drainage points, which not only wastes valuable heat resources but also has an adverse impact on the environment. Many enterprises equip their hot air exchangers with drain valves; some install one such valve at the bottom of each set of finned tube bundles in the exchanger. Since a hot air exchanger typically has 5–8 such sets of finned tube bundles, this results in a large number of drain valves at the bottom of the exchanger, which takes up valuable installation space and makes maintenance and replacement tasks much more difficult in the future. Some companies install only one drain valve assembly at the bottom of each hot air exchanger. In many cases, during production, the bypass valve of the drain valve must be kept slightly open to prevent condensate from failing to leave the hot air exchanger, which could affect the quality of product drying. It is not possible to control the opening degree of the bypass valve; it is better to keep it open at a higher degree rather than having it open too little, as this could cause water buildup in the system, affecting heat exchange and leading to defective product quality. All of the above issues are problems associated with heat exchange equipment such as steam-hot air exchangers, as well as energy waste problems. To address such issues, we have developed a steam waste heat recovery and reuse system without a hydrophobic valve. This system can collect the high-temperature condensate generated by each set of finned-tube heat exchangers, as well as the saturated steam that leaks out. Through steam-water separation, the steam and the high-temperature water are separated and then sent back to the heat exchangers for further heat exchange, thereby ensuring that the temperature of the discharged condensate remains below 80°C. This allows for the effective utilization of steam heat energy, reducing the steam consumption per unit of dried product. Based on comprehensive calculations from previous project cases, the steam energy savings rate alone can reach 10%–25%. A single hot air exchanger can be equipped with a steam waste heat recovery system without a drain valve, or multiple exchangers can be paired with such a system; in all cases, there is no more steam emission from the condensate discharge ports. It also completely solves the problems related to labor costs and valve expenses associated with replacing and repairing the steam trap in the future.