May 2021 Volume 3

MATERIALS

before and after pictures show nearly a 300 o F difference in the shell temperature. After the refractory repair, the increase in heat retention (lower temperatures on the shell) means greater furnace efficiency and less gas consumed, all while running the same amount of product. Another common failure for refractory is chemical attack. In one example, a client’s steel slag sample was sent to a refractory manufacturer for cup testing.The manufacturer made cubes of six (6) refractory materials they felt would be best for the client’s application. Then, steel slag was placed in each refractory cup and heated in a lab furnace to operating temperature. At the end of the process, slag penetration into the refractory cup was measured. This testing allowed for a refractory material that was inert to the chemical attack of the slag to be chosen for the application. No in-service testing was required at the client’s facility saving costly downtime.

Exhibit 3: Engineered Combination Module Installation

Root Cause Failure Analysis Failures occur. So, how do you and your refractory supplier work together to determine the root cause of the failure? One of the tools that can be used to identify problem areas in a furnace is a thermal imaging camera. These thermal scans examine a refractory lining and the associated heat loss while the equipment is in service allowing time for an outage to be planned. The thermal scan can be completed for the entire furnace system, targeting problem areas such as the roof and the door seal to “see” heat loss and refractory insulation integrity. Problem areas will be immediately visible. The photos provide a starting point for conversations with the business stakeholders on how quickly and where repairs need to take place.

Exhibit 5: Furnace sidewall after reline

Exhibit 6: Slag cup tests of six (6) different refractory materials Choosing the proper refractory material for your specific application is important. Not all refractorymaterials are created equal so partner with a refractory contractor that “has seen a thing or two,” utilizes the proper installation techniques and makes use of technology when evaluating material failures. ■ Patrick Laskey

Exhibit 4: Furnace sidewall before reline Exhibits 4 and 5 are a before and after photos of the same door penetration. A thermal scan was utilized to justify the need for a furnace reline to the business owner. A complete set of photos was presented to the client detailing the minimum and maximum temperatures before and after the furnace was relined. In this case, the

Business Development Manager | Onex Email: patrick.laskey@onexinc.com Phone: 814-440-1494 www.onexinc.com

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FIA MAGAZINE | MAY 2021