Sunday, May 24, 2015

5 Common Reasons for Refractory Wear

Refractories are used at elevated temperatures for structural purposes and they are used in many cases to contain a high temperature corrosive environment. In any process environment, refractories are potentially continuously under attack from a number of corrosive processes.

Chemical Corrosion

The corrosion envirenment usually contains materials and byproducts of the process in chemical reactions with the refractory at elevated temperatures resulting in refractory consumption or wear, potentially causing glassing or softening of the refractories. It is usually not immediately obvious, but the oxidation and reduction state of the environment can participate in and influence the chemical reactions that take place. Along with chemical reaction during corrosion, physical changes occur that may be accelerated by the corrosion process.

Erosion

Erosion is another prevalent refractory wear mechanism. Refractories can be worn away over time from the washing action of moving liquids, such as molten metals or slags. Erosion further exposes refractory to destruction by corrosive or abrasive elements.

Mechanical Abrasion

Abrasive media, including fuel, ash, and other particles, can wear away refractories over time, much like sandblasting. Refractory resistance against abrasion is a key issue for many industrial furnace applications.

Mechanical Wear

Moving parts and equipment within a process can wear against the refractory lining, jeopardizing the structural integrity of the refractory lining.

Thermal Cycling

As refractories undergo the heating and cooling cycles of a process, the refractories expands and contracts, eventually weakening and wearing down the lining. If refractories experiences a rapid change in temperature, a.k.a Thermal Shock, the refractories can experience immediate damage.

As a result of the high temperature corrosive environment, refractories will wear down over time, requiring periodic maintenance and eventual replacement. Refractory wear can be mitigated or minimized by selecting the right refractories to withstand the corrosive environments.

Sunrise Refractory offers a wide range of refractories with good wear resistance for high temperature corrosive environments in glass industry.

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