Gas Heat Exchangers are basically designed for removal of heat from the exhaust gas of engines and then transfer into the water circuit. These Gas Heat Exchangers playa a very significant role in the production process, since, they enable waste heat recovery. They are also used to reduce the exhaust temperature in engines operating in hazardous environments where reduction in temperature of exhaust gas is required. Generally, a Gas Heat Exchanger is made of stainless steel tubes, body and tube plates and comes with a cast iron end cover that allows usage with biogas, diesel gas and natural gas.
The stainless steel tubes, tube plates and shell and cast iron end covers should always should be installed horizontally with the water connections on top so that they are always full of water. It is also important that a thermostatic valve is present, to ensure that there is always a flow of water through the heat.
The industrial application of Gas Heat Exchangers consists of the following:
- Ground Water Systems
- Oil Coolers
- Fluid to Fluid Heat Transfer
- Engine and Transmission Coolers
- Boiler Coolers
- Waste Water Heat Recovery
- Chilled Water System
- In refrigeration Systems (as evaporators and condensers)
In a Gas Heat Exchanger hot exhaust gases pass over parallel tubes containing water. The water than vaporize and gets collected in a steam drum, which is further drawn off for processing or heating.
Exhaust Gas Heat Exchangers
This kind of Heat Exchanger for exhaust gases is of gas-water counter-current flow type. The process involves transfer of thermal energy from the exhaust gases to the hot-water system by the heat exchanger. The exhaust gases leaves the heat exchanger through an exhaust pipe and the subsequent chimney.