Integrated flame control system in closed furnace using PLC

Abstract

Furnaces are used throughout varied industries like Glass, Ceramics, Iron and Steel, Chemicals etc., for generation of heat by combustion of fuels. They consist of an insulated, refractory lined chamber containing tubes, which carry the process fluid to be heated. They are designed to ensure that the fluid receives the correct amount of heat and has sufficient resistance time within hot zone. While at the same time excess temperature is to be avoided. This excess temperature can lead to degradation of the product or damage of the furnace. Tube temperatures in some plant may be as high as 900 °C, and combinations of high pressure (e.g., 200 atm) and relatively high temperatures (e.g., 450 °C) are not uncommon. In this system, we control the initial start-up and subsequent heating of the furnace in order to maintain adequate temperature inside the furnace by incorporating PLC system and flame sensors and temperature sensing elements.