Most equipment failures are preceded by temperature rises before the actual failure occurs. This is particularly true in the case of furnace refractory lining failures, where heat leaks to outer refractory linings and the shell, both of which are less tolerant to furnace working temperatures.
As a result, significant reductions in the system’s energy efficiency are observed. With continued exposure, the furnace shell weakens and may eventually fail. Such failures may expose personnel to the hot gasses that could escape from the damaged furnace as well as interfere with the required atmospheric conditions inside the furnace.
An infrared camera is used to map out the thermal status of the entire unit. Teams of experts then analyse the infrared thermography scans and where applicable provide recommendations on the most appropriate repair options.
The inspections allow furnace operators to evaluate the quality of their furnace linings. Emphasis is given to the accurate detection of points with elevated temperature within the system (HOT SPOTS). The presence of such hotspots indicates various degrees of internal system deterioration.
When done regularly, infrared thermography also helps furnace operators to monitor the evolution of damages on refractory lining, estimate its remaining thickness at different parts and timeously plan for any necessary interventions.
In the case of water / oil cooled furnaces, furnace infrared thermography can also indicate anomalies in the cooling system before cooling tubes are extensively damaged.
Generally, Infrared Thermography allows for the following:
Mitigating safety risks to staff
Avoid major damage to the furnace
Minimise adverse impacts on ancillary equipment
Avoiding unplanned stoppages and their associated production losses
Avoid expensive repair costs
Maintaining system energy efficiency at optimal levels, minimising carbon footprint and energy costs
BENEFITS
The benefits of furnace infrared thermography are summarised below:
Compilation of comprehensive records of refractory lining wear.
Reduced unplanned stoppages.
Maximising of furnace equipment availability, increasing yields and reducing operating costs.
Efficient planning for scheduled shutdowns and refractory materials supplies.
Confident budget planning for purchase of very expensive items such as refractories.
Knowledge sharing with plant maintenance staff.
