Masonry oven India, tandoors are traditional clay ovens, although these days modern electrically fired tandoors are available. The open-topped tandoor is a transitional design between the earth oven and the Roman-plan masonry oven. In the precolumbian Americas, similar ovens were often made of clay or adobe and are now referred to by the Spanish term "horno" (meaning "oven"). Horns are also traditional in the American Southwest. The traditional direct-fired masonry design is often called a "Roman" or "black" oven and dates in Western culture to at least the Roman Republic. It is known as a black oven because the fire generates soot
Vacuum ceramic filter the system without further treatment. Filtrate is used to flush the disc during back flow washing to clean the micro-porous structure and remove any residual cake. One improvement over the standard design of ceramic vacuum filter is to use serialized pore size distributions of non-fibrous porous ceramic filters. The porosity of this type of ceramic can be varied from 20% to 60% by volume, which allows a low-pressure drop of liquid and gas flow. Custom sizes from 1 mm diameter/0.5 mm bore of porous ceramic filters are available for a range of designs. A non-fibrous porous ceramic filter is more