• Indaid Engineers Private Limited

Metallic Recuperators

Indaid Engineers Pvt Ltd offers Metallic Recuperators that are simple and effective devices for reducing energy consumption in fuel fired furnaces. The outgoing flue gases from the furnace are used to preheat the combustion air being supplied to the burner and this results in energy savings. The exact amount of preheat and the percentage of energy saved will vary from installation to installation but on an average 10 to 15 percentage energy saving is easily possible by preheating air to approximately 300°C. The payback period for the recuperator is usually less than one year. Metallic recuperators are of two types: 1. Convection recuperators: these are of shell and tube type construction used for recovering waste heat from flue gases up to a temperature of 1000°C. The heat transfer is predominantly by convection. The material of construction can be SS 310/SS 304/carbon steel or a combination of these depending on the duty conditions. The flue gases flow outside the tube while clean air flows through the tubes. This facilitates easy maintenance. Convection recuperator can be conveniently located in the underground flue ducts by suspending them from floor level with free expansion provision. They can also be located on overhead flue ducts and inside suitably designed recuperator housings. 2. Radiation recuperators:: these are of double shell type construction used where flue gases are generally above 1000°C. Hot flue gases flow through the inner shell while air being preheated passes through the outer shell. Suitably designed fins are welded on the outer surface of the inner shell to improve the radiant heat transfer surface area. Radiation recuperators are convenient for vertical flue ducts and can even form part of the chimney. Advantages: reduced fuel cost by using preheated air in burners; short and attractive payback period; long service life of recuperator; higher flame temperatures; and least maintenance; and custom designed for specific applications. Applications: forge reheating furnaces; billet reheating furnaces; heat treatment furnaces; higher flame temperatures; and ceramic kilns.