Over the years, it has been generally believed and well accepted that the furnace or kiln of any processing plant is the “heart” of that plant.
As such, informed decisions and predictive interventions are critical to successful plant operations and profitability.
Subject to a plant’s location and proximity to refractory suppliers, advance procurement planning may be advisable, however this has to be aligned with the planned refractory replacement cycles. Generally, approaches to refractory replacement differ from plant to plant with some having a standard practice to replace refractory after an agreed plant run period and others going with minimum agreed residue refractory brick thickness.
Below are some of the generalised factors affecting refractory life for furnaces or kilns in various industries:
- Refractory material selection
- Quality and type of refractory installed
- Packaging, bagging and material handling
- Environmental effects on refractory products storage and handling
- Hydration of refractory bricks
- Storage and expiry of refractory products, especially monolithics / castables
- Refractoriness of selected & supplied refractory
- Operating conditions of furnace/kiln such as temperature and speed
- Flame profile or burner settings and condition. Flame projection must never be on refractory surface at any time. This causes premature refractory failure as a result of direct flame impact.
- Mechanical condition of kiln shells for rotary kilns and furnace structures
- Quality and consistency of raw materials being processed (quality fluctuations)
- Quality of refractory installation works
- Observance of Heat-up and Cooling curves procedures. Manufacturers’ or Designer’s heat-up or cooling curves are always important to follow to avoid refractory damage. Failure to do so has immediate or short to long term effect which may be difficult to diagnose.
We shall be discussing the above listed points in detail within the upcoming blog articles.