During the operation of the cat litter dryer, a large amount of high-temperature exhaust gas (80-120 ℃) is emitted. If directly discharged, it not only wastes heat energy but also increases the operating costs of the enterprise. Using a cross flow air-to-air heat exchanger to recover waste heat from exhaust gas and use it for fresh air preheating can effectively reduce energy consumption, improve drying efficiency, and reduce carbon emissions.

1. Scheme principle
Cross flow air-to-air heat exchanger is an efficient thermal energy recovery device that utilizes the high-temperature exhaust gas discharged from the dryer and cold air (fresh air) for cross flow heat exchange, achieving heat transfer without mixing the two streams of air, ensuring efficient and pollution-free heat exchange.

Workflow:
High temperature exhaust gas enters the heat exchanger: The exhaust gas (80-120 ℃) discharged from the dryer enters the exhaust gas channel of the air-to-air heat exchanger.

Fresh air enters the heat exchanger: Environmental fresh air (0-30 ℃) enters the fresh air channel and forms a cross flow with the exhaust gas.

Heat transfer: Heat is transferred from the exhaust gas to the fresh air through the heat-conducting wall of the heat exchanger, increasing the temperature of the fresh air by 20-50 ℃.

Preheating fresh air enters the dryer: Preheating fresh air enters the dryer to reduce energy consumption and improve drying efficiency.

Exhaust gas emissions after cooling: The temperature of the exhaust gas after heat exchange is reduced to 40-70 ℃ and then discharged into the external environment.

2. Equipment selection
✅ Type of heat exchanger: Adopting a plate fin cross flow air-to-air heat exchanger, suitable for high-temperature dry exhaust gas.
✅ Heat exchange material: High temperature and corrosion-resistant stainless steel or aluminum alloy, ensuring long-term stable operation.
✅ Heat transfer efficiency: up to 50% -75%, depending on specific operating conditions.
✅ Structural design: Compact modular design, easy to install and maintain.

3. Advantages of the plan
✅ Reduce energy consumption: Reduce gas, coal, or electricity consumption by 20-40%, saving operating costs.
✅ Improve drying efficiency: After preheating with fresh air, the drying temperature is more stable, and the drying speed is increased by 10-30%.
✅ Reduce carbon emissions: Reduce direct emissions of high-temperature exhaust gases, minimize heat pollution and carbon emissions.
✅ Air non mixing, hygiene and safety: cross flow heat exchange, no secondary pollution, in compliance with environmental standards.
✅ Low equipment maintenance, reliable operation: no moving parts, long service life, stable operation.

4. Economic benefit analysis
Assuming that the cat litter dryer emits 5000m ³ of exhaust gas per hour, with an exhaust gas temperature of 100 ℃ and a heat exchange efficiency of 60%

Fresh air preheating increases by 30 ℃, reducing fuel or electric heating costs by 25%

Annual fuel or electricity savings of 300000 to 500000 yuan (calculated based on medium-sized dryers)

By using a cross flow air-to-air heat exchanger to recover waste heat from a cat litter dryer, the economic and environmental performance of the drying system can be effectively improved, achieving energy conservation, consumption reduction, and green production.