DGC offers a comprehensive range of Furnace Inspection Services to the metals smelting, mineral processing, thermal energy and industrial furnace industries. The services are offered in alliance with ADI Industrial Services; a Belgium based Service Company that has been performing furnace inspections in different industries for more than 25 years. The Furnace Inspection Services allow for real time furnace diagnostics and assisting operators in assessing the state of furnaces at their working temperatures. The services are mainly based on two techniques; infrared thermography for external inspection and high temperature endoscopy for internal inspection, this article will focus on infrared thermography.
Infrared thermography is aimed at providing accurate images representing the thermal status of a furnace’s shell, its value is derived from the accurate interpretation of the output images in their industrial context. The processed information is integrated into users’ preventive maintenance programs. The technique enables operators to constantly monitor a furnace’s metallic shell status, identify or localise damaged areas (internal/external) as well as to estimate the remaining refractory lining thickness. Regular monitoring helps operators in maintaining production within the optimum operating conditions, at optimum costs, optimized yields, minimal the industrial risks in terms of safety.
The benefits of Infrared Thermography are summarised below:
Compilation of comprehensive records of refractory lining wear.
Reduced unplanned stoppages.
Improved furnace equipment availability.
Efficient planning for scheduled shutdowns and refractory materials supplies.
Knowledge sharing with plant maintenance staff.
Mitigation of major damages to the furnace.
Enhanced energy efficiency of operations.
APPLICATION EXAMPLE: PROCESS VESSELS
In order to correctly interpret the images, they are analysed in consultation with equipment drawings.
On images 1 to 4 we see a warmer surface around the entire circumference of the vessel at the platform’s height (about 5 m above the ground). On images 2 and 4 we see lighter spots, indicating hot spots.
Image 5 indicates the positions of anchors on the shell before the refractory lining was installed.
On image 8 we notice that the hot spots appear to be in the pattern of the anchors, indicating the extent of refractory lining wear.