Inspecting Gas Fired Furnaces Using Infrared Thermography

The natural gas fired furnace is a key component in our process lines. Our two vertical furnaces operate at an internal temperature of 2100° F. These furnaces are used to heat a five foot wide ribbon of steel to 1500° F as it moves through the furnace at speeds up to 600 feet per minute. Unplanned shutdowns of these furnaces can result in production losses as high as $84K. Traditionally, visual inspections have been the preferred method of monitoring wall insulation health. Peeled or blistered paint and a cherry red glow are used as indicators that insulation is breaking down inside the furnace. What isn't apparent is the severity of these breakdowns. IR thermography allows us to identify insulation breakdowns sooner and then map the severity of our finds. IR thermograms are a valuable predictive tool for planning the timing and duration of furnace repairs. Steelscape operates 12 gas fired furnaces. These are used to heat steel strip during the process of turning it into a product used by our customers to make roofing, siding, gutters, garage doors and steel buildings.