Gas Fired Furnaces, Kilns and Lehrs
Gas fired furnaces and kilns can be operated with natural gas, propane or butane, although details of the design may differ with different fuel gases. We build these furnaces either with direct or indirect gas firing.
Selecting a gas fired furnace versus an electrically heated kiln or furnace depends on both economic and process considerations. Firing costs for similarly sized kilns can be significantly different depending upon cycle times and peak process temperature. For example, our calculations indicate that a fuel gas fired bottom drop furnace for solution heat treatment of aluminum and magnesium alloys can save four times the energy cost.
Generally speaking, gas fired (direct and indirect) furnaces and kilns can be used for sizes bigger than 15 cubic feet as long as the application parameters allow it. Application considerations such as sensitivity to the products of fuel combustion (water vapor, carbon dioxide, NOx) may require an electrically heated kiln or the use of muffles or retorts (examples: ALCLAD, bright annealing). Gas fired furnaces and kilns requires a different employee skill sets not always readily available. However, today’s burner and control technologies are sophisticated compared to those available in the past, making this technology practical for even smaller companies.
Typical applications for fuel gas fired furnaces and kilns include dinnerware, garden pottery, sanitary ware (first-fire and re-fire), electrical porcelain, tile, technical ceramics, brick, clay pipe, technical ceramics and refractories. Rising energy costs (and despite increased AQMD regulations like Rule 1147 + rule 219), fuel gas fired furnaces are in demand. Some aerospace process specification don't allow any by-products of combustion in the hot zone, but an indirect fired furnace does meet this requirement.
Keith Company commonly combines an electric fired kiln with a gas fired thermal oxidizer for abatement of potentially toxic gases.
Keith Company’s lineup includes gas fired bogie hearth furnaces, gas fired deco kilns, and much more. Contact us to order the gas fired thermal processing equipment you need, or for more information on any of our products.