Technical Overview of Dryer Waste Gas Heat Recovery Heat Exchanger

1. Heat exchanger type

• Plate Heat Exchanger
  Compact structure, high heat exchange efficiency, suitable for low exhaust gas temperature (<200°C) and non-severe corrosive scenes. Easy to clean, suitable for small and medium-sized drying equipment.

• Rotary heat exchanger
  Heat is transferred through the rotating wheel, which is suitable for large-flow, low-temperature-difference waste gas recovery. It has high heat exchange efficiency and is suitable for large drying systems, but it occupies a large area.

2. Design points

• Exhaust gas characteristics
  The exhaust gas temperature (usually 80–200°C), flow rate, humidity and dust content need to be evaluated. Corrosive gases require the use of corrosion-resistant materials (such as stainless steel).

• Heat transfer efficiency
  The recovery efficiency is usually 50%–80%, depending on the temperature difference and heat exchange area. It is necessary to balance the efficiency and pressure drop to avoid affecting the exhaust performance.

• Maintenance and cost
  Plate heat exchangers are easy to disassemble and clean, and have low maintenance costs; rotary heat exchangers are suitable for continuous operation, but the initial investment is higher.

3. Application scenarios

• Plate Heat Exchanger：Used in small and medium-sized dryers, such as in the food and textile industries, to recycle low-temperature exhaust gas and preheat fresh air.

• Rotary heat exchanger：Used for large-scale industrial drying, such as papermaking or chemical material drying, and treatment of high-flow exhaust gas.