By AZoM Editors
Table of ContentsIntroductionApplicationThe ProblemThe
EMISSHIELD is a NASA licensed high emissivity ceramic material refined and
patented by Emisshield, Inc in collaboration with Virginia Tech. It has been
designed to save fuel costs and increase productivity in heating-based
industrial applications. Use of Emisshield saves operators up to 15% of the
energy costs by utilizing re-radiated heat. It extends the service life of
equipment as well.
The roof of an electric arc furnace, which was used for melting stainless
steel and operated at 2850-3000°F, was coated with Emisshield STG-2 (US Patent
A water-cooled roof could be typically used to nearly 500 heats of steel
after which it has to be removed and rebuilt. Between rebuilds, a typical roof
requires about two repairs. In the roof of an electric arc furnace that was
cooled with exposed water tubes, signs of scaling and corrosion were observed.
Corrosion was severe around water tubes due to occasional water leaks and the
roof had to be repaired. The temperature of water used for cooling the roof was
measured at entry and exit points. The temperature difference varied from 11 to
Prior to the application of Emisshield STG-2, the roof and water tubes were
shot-blasted for removing slag and scale. Pressure testing of the water tubes
was done, following which the furnace roof was cleaned using DIRL-LUM 603. Four
gallons of Emisshield STG-2 were sprayed. The input and output temperatures of
cooling water were determined. It was observed that the temperature difference
ranged from about 2 to 5°F. When put into service, the roof lasted for 940 heats
before it had to be rebuilt. No water leaks were reported during the service of
the coated roof.
Installing Emisshield STG-2 high emissivity coating increased the time between rebuilds, lowering
rebuild costs by 88%. The coating completely eliminated water leak repairs
usually required during service, resulting in significant downtime and
maintenance savings. The heat energy lost through the roof was reduced, saving 2
MW/h of electric power. The arc time that was required for melt was reduced by
three minutes, thus saving electric costs during the roof’s service life. The
amount of heat energy dissipated to the cooling water was found to be constant,
clearly demonstrating that Emisshield STG-2 was strongly bonded to the roof and
its emissivity properties did not vary with time during service.
Refractories Europe is a member of the ANH Refractories family of companies
headquartered in Pittsburgh, USA.
Refractories Europe is the primary contact for the European and Middle
Eastern markets and is able to supply a comprehensive range of refractories for
variety of applications.
Primary information source, ANH Refractories Europe
For more information on this source please visit ANH Refractories