Ceramics/Refractory Applications

Using space age technology licensed from NASA, Wessex Incorporated has created Emisshield™ Coatings. These coatings have many beneficial uses in the Ceramic/Refractory industry that help save time and money. The technology that NASA developed and Emisshield™ uses is based upon the principle of emissivity, but are uniquely different than previous emissive coatings.

Emissivity is defined as a refractory's ability to absorb and subsequently release energy from its surface to a furnace load. Emissivity is rated on a scale of 0.0 (low) to 1.0 (high). While many refractories may report to have a high emissivity value at ambient temperatures, most refractories will steadily lose their ability to reradiate that energy as the temperature increases particularly in the infrared zone of the electromagnetic spectrum where 90% of radiant energy is found. As determined by NASA scientists, Emisshield™ not only has an emissivity value of 0.85 to 0.9 at ambient air, it maintains that level of emissivity even as temperatures increase above 3000°F. At those high temperatures, refractories will only have an emissivity value of 0.2 to 0.5 depending on their type. This demonstrates that Emisshield™, as the concept of emissivity dictates, is a function of temperature. In other words, the higher the temperature, the more energy Emisshield™ reradiates.

Many of the benefits of Emisshield™ are dependent upon the coatings ability to keep the substrate it is protecting cooler. By reradiating energy back to a cooler load (kiln car), Emisshield™ prevents heat transfer (via conduction) through the furnace wall and out the stack. This in turn prolongs the life of the refractory by reducing maintenance down time and quantity of refractory required for service.

Emisshield™ can provide for a lower rated refractory to operate at higher temperatures, under certain conditions, thus potentially reducing costs of more expensive brick.

Slagging and spalling are also major problems in the industrial market. Emisshield™ will impede and even prevent the build up of slag and the effects of spalling by not allowing materials to stick to the refractory and/or metal. By applying an Emisshield™ Coating to refractory or metal, molten materials no longer have a place to bind to the refractory; which will slow slag and spalling considerably.

Emisshield™ Ceramic/Refractory Coatings for metals (Patent Pending) can prolong the life of ladles and molds by forming a heat shield for ladles while acting as a release agent for molds. Emisshield™ Products can also be used on boiler tubes where the reverse of reradiation is observed. Because the cooler load is the liquid product in the tubes the coating acts as conductor and transfers heat to the liquid better then an uncoated tube. This can allow for energy savings or an increase in production.