Muffle furnace

An Automatic Oil Muffle Furnace, circa 1910. Petroleum is contained in tank A, and is kept under pressure by pumping at intervals with the wooden handle, so that when the valve B is opened, the oil is vaporized by passing through a heating coil at the furnace entrance, and when ignited burns fiercely as a gas flame. This passes into the furnace through the two holes, C, C, and plays under and up around the muffle D, standing on a fireclay slab. The doorway is closed by two fireclay blocks at E.
High temperature muffle-furnace, maximum temperature is 1,473 K (1,200 °C; 2,192 °F).

A muffle furnace or muffle oven (sometimes retort furnace in historical usage) is a furnace in which the subject material is isolated from the fuel and all of the products of combustion, including gases and flying ash.[1] After the development of high-temperature heating elements and widespread electrification in developed countries, new muffle furnaces quickly moved to electric designs.[2]

  1. ^ Bulletin - United States Geological Survey, Issues 47–54, 1889, pp. 180 (834)
  2. ^ Crowley, C.A. (June 1937). "Electric furnace". Popular Mechanics. Vol. 67, no. 6. pp. 941–945.