Many industries rely on refractory repair service to improve the performance of fired heaters, incinerators, kilns, and reactors.
Not only can the correct refractory lining solution improve production yield and save energy costs, but it can also ensure the consistent performance of a furnace.
In some cases, the life of the refractory lining can last 20 years with the right refractory installation.
Here is what you need to know about refractory failures that need refractory repair service.
Common Causes of Refractory Failure
1. Fallen Fiber Modules from Roof
Usually, it is due to the material, design, or installation. Insufficient stud welding or severe corrosion from the shell are the most common causes of missing modules and support refractory anchors.
If fiber modules are missing but the support anchoring is still intact, there is a high possibility of mechanical abuse. For example, excess weight of water on the fiber which is 90% porous, thus absorbing many times its weight in water.
Hence, check if the fiber has been pulled from the anchoring or for symptoms of water damage. Are there any gaps in the fiber? Is there a hot spot?
Always inspect the design to determine the exact cause before the issue spreads.
2. Failing Refractory Lining
You can determine if refractory linings are the root cause of the failure by closely inspecting them in the event of failure.
Outside the structure, look for hotspots. If the backup lining is damaged, this could suggest a problem with the wall.
Thus, pump hot spot repair materials from the outside of a functioning unit to fill the gaps.
Also, make sure you examine the brick’s surface too. It could have melted or cracked, indicating higher furnace operating temperatures, probable fuel impurities, or an incorrect brick grade.
3. Deformation of Bridge or Tunnel Wall
Commonly, walls lean to some degree, but they can fail if they lean too much, which could be the result of an uneven floor.
Generally, many refractory wall problems are caused by insufficient expansion provisions, especially when conditions are raised to higher temperatures than planned.
As a result, too high temperatures can cause slumping over time.
Hence, it is crucial to investigate both the ambient and hot strength qualities when determining the optimal choice.
Also, focus on reliability rather than costs because the best products for the task aren’t always the cheapest.
4. Cracks in Castable Lining
Refractory castable linings are unique because they are not fully complete when they leave the production factory. This means that the refractory installation determines its final quality.
Before water is removed during the dry-out process, the materials are mixed with clean water of the right temperature, installed, and cured.
However, the castable can explode if a refractory contractor doesn’t do the drying process slowly and carefully.
Although cracking due to shrinkage is normal, if it occurs frequently, it could result in a poor installation or indicate too much water was used.
5. Cracks in Refractory Floor
Floor cracking often occurs when temperatures rise after the original design. Provisions for reversible thermal expansion in the floor should be protected since they can quickly become clogged with debris during operations, restricting the gap’s ability to move.
Hence, to avoid debris build-up, it’s a good idea to vacuum the gaps regularly.
When a refractory installer places different materials, floor cracking can also happen. If you have a floor-fired unit, surround the burner with castable burner blocks of a specific material grade and a distinct floor material.
As a result, cracks are common at the burner block corners if insufficient expansion joints are installed.
6. Corbel Damage in Convection Section
Refractory castables are commonly damaged during the manufacturing and shipping processes. This can be seen in the form of visible cracks that run through the whole thickness.
Pinch spalling may also be visible on the surface which indicates directional mechanical flexure of the steel.
Moreover, corbels which protrude from the base lining, are also vulnerable to damage.
Therefore, fix any visible damage as soon as possible with a refractory casing repair procedure. Also, remove and replace the affected lining piece to avoid damaging the surrounding components.
7. Mismatched Refractory Materials
Different refractory materials are common, particularly for surrounding openings such as doors (fiber and brick), peep sights (IFB, castable, fiber modules), burner blocks, and pressure relief doors.
A homogeneous design can be difficult since different materials have different refractory properties at elevated temperatures.
As a result, hot effluent gases may pass through the damaged refractory lining, causing hotspots on the exterior casing.
Thus, to avoid design failures and to make the best possible seal, use comparable refractory materials around the peep sight as those used around the entrance.
The Best Refractory Contractor for Refractory Repair Service
Even though refractory failure is common, it may result in energy waste, reduced performance, and, in extreme situations, complete shutdown.
Hence, plant managers must collaborate with expert refractory installers to minimize failure and improve material reliability.
We are one of the top refractory installation companies providing industrial refractory services for any refractory application.
So, send us an inquiry for refractory repair services to help you minimize downtime, reduce energy loss, and avoid valuable equipment failure.