Recovery heat exchanger

What is the heat recovery unit?

The heat recovery unit, also known as an air dryer, exhaust heat recovery unit, air-to-air heat exchanger, heat recovery exhanger, or heat recovery tank, is a type of heat exchanger used to recover heat from hot exhaust gases such as exhaust gas from chimneys, hot steam from boiler systems, etc. to help heat fresh air or increase the temperature of the water supplied to the factory's production system.

This is an advanced technological solution that helps to utilize excess heat, save costs, reduce the greenhouse effect, protect the environment, and is widely used in factories and enterprises.

There are many types of exhaust heat recovery units, but currently the THOMPSON HEAT TRANSFER exhaust heat recovery unit product line is still installed and operated by many factories

THOMPSON HEAT TRANSFER air dryers are made in the EU, so they are durable and operate very smoothly, and are installed and used by many customers today

Operating principle of exhaust heat recovery units, air dryers

An example problem:

Hot exhaust gas and smoke from the factory has a flow rate of 35m3/h and an exhaust temperature of about 650 to 700 degrees C.

If using the THOMPSON HEAT TRANSFER air dryer, with the following conditions:

• Fresh air is supplied with a flow rate of 35m3/h and a fresh air temperature of about 30 degrees C

• Hot exhaust gas and smoke from the factory has a flow rate of 35m3/h and an exhaust temperature of about 650 to 700 degrees C.

After exchanging heat through the air drying

• Hot air discharged with a flow rate of 35m3/h and an exhaust temperature of 374 degrees C

• Fresh air with a flow rate of 35m3/h supplied to the production system can reach a temperature of 250-300 degrees C

So, compared to not using an air dryer, after installing a THOMPSON HEAT TRANSFER waste heat recovery device, the factory gains the following benefits:

• Reduce the heat of the exhaust gas source, discharged into the environment (previously 650-700 degrees C - now only 374 degrees C. Can be lowered further depending on the design requirements of the factory)
• Increase the temperature of fresh air supplied to the furnace (previously 30 degrees C - now up to 250-300 degrees C) - this greatly reduces the cost of fuel, sometimes up to 30% compared to not using a waste heat recovery device.

To calculate, design and install a waste heat recovery system, it is necessary to pay attention to the following points

1. Excess heat source in the factory

In the industrial production process, factories always have excess heat source from:

• Boiler system - steam - hot steam

• LPG gas (Gas) - Burning oil, coal

• Exhaust smoke (from LPG, coal, oil, ...) has a high temperature of 300 - 1200 degrees C.

If the above excess heat source is not utilized, it will be released into the environment through chimneys, exhaust pipes, leading to environmental pollution. greenhouse effect, making the earth hotter. Waste of resources

So, In developed countries, the above excess heat source is always reused and applied to:

• Heat recovery

• Drying hot fresh air supplied to the furnace

• Drying water, drying oil

• Heating bath water

• Heating water supplied to the boiler.

• Heating the plating tank

• Heating the air supplied to the drying oven, steaming oven, etc.

Collect information on waste heat sources and requirements for heating the input of the production system:

• What is the waste heat source? (LPG gas, exhaust fumes from coal-fired furnaces, exhaust fumes from boilers, hot steam, etc.)

• Size and material of the exhaust pipe

• Temperature of smoke, exhaust gas (does not need to be too precise) - flow (if this parameter is not precise, it needs to be measured or estimated)

• Heating requirements for fresh air or bath water, or water supplied to the production system, or hot air supplied to the drying oven, etc.

• Required inlet and outlet flow and temperature for fresh air, hot water, etc.

2. Benefits from recovering and reusing waste heat energy

Utilizing the above excess waste heat source brings many immeasurable benefits if used for a long time:

• Saving fuel - Usually can be from 20 - 40%/year (a huge number for fuel consumption compared to before installing and using waste heat recovery technology)

• Saving an additional 50 - 70% of the energy needed for reuse (Because if to dry air, dry oil, heat bath water, ... if there is no waste heat, the factory will need a new heat source to do it).

• Saving costs for smoke and wastewater treatment (at high temperatures, smoke must be cooled and chemically treated before being released into the environment).

• Environmental protection

• Reduce energy consumption (electricity, gas, ...)

3. Heat recovery unit - air dryer - air heater - oil dryer - steam and gas heat exchanger THOMPSON HEAT TRANSFER

• Design can be improved according to customer requirements (Inlet, outlet, shape. The technology part is arranged by the company itself)

• Low noise - high pressure resistance - input and output temperature limit according to customer requirements

• Optimal design to increase heat exchange efficiency - no clogging - easy cleaning - maintenance

• Anti-corrosion materials - Carbon steel, Stainless steel, SUS304, SUS316, Titanium, ... or Titanium coating, SMO254 / C276 / Ni201

• Optimize design and operation through simulation with specialized design software.

• Reliable production and quality management

Please contact us to inspect and get suitable design.