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 discharge due to reduced resistance and marginally lower cake moisture. Stage 2: Dewatering In rare cases, due to the even structure of the cakes formed, the steady flow profile of the ceramic filter media and the gas free filtrate flow cake, washing has proved to be efficient in ceramic disc filters. The formation of thicker cakes during filtration and higher vacuum level leads to greater removal of solute. Stage 3: Discharge The basic scraper works well when the cakes are relatively thick and non-sticky. The final cakes are discharged by blade or wire scrapers on either side of the discs