Steam under pressure can clean laboratory utensils {autoclave}|.
Gas ovens {gas oven}| have burners underneath, holes in oven-chamber bottom front to let air in, and flue in oven top leading to chimney in back. Chimney has several turns, to trap grease vapors. Gas burners have gas-jet rows or rings, with small flames {pilot light} at gas-inlet tubes.
Pads {heating pad}| can have molded rubber around insulated wires. Wires are Nichrome.
Heavy cookers {pressure cooker}| have sealed tops, to double pressure of boiled water inside. Pressure cookers boil at 120 C and can cook in shorter time. Safety valves let off excess steam. Remove top only after cooling, after normal pressure returns.
Ore can melt, so impurities float on top and pure metal sinks to bottom {smelter}|.
Furnaces {Bessemer converter} {open-hearth furnace} can use air to burn impurities out of iron ore to make steel {steel making}|. Steel-making furnaces can use pure oxygen gas, instead of air, to burn impurities out of iron ore {L-D process} {basic oxygen process}.
A log holder {andiron} allows air to flow from under logs up through chimney {fireplace}|. Just above fireplace is chimney throat, which contains a hinged metal plate, to open or close throat {damper}. Behind damper is space {smoke box} to collect smoke, in case of temporary downdraft. A passageway {flue} goes up chimney. A glass fire screen is desirable. Chimney should be at least 12 meters high, extend above roof by 60 centimeters, and be at least 400 square centimeters in area. There should be masonry firebox.
Heaters {forced air heater}| can use a fan to blow hot air.
Stoves {Franklin stove}| can be a free-standing fireplace, raised off floor, in room middle, with exhaust pipe leading straight up to ceiling.
Heaters {furnace, heater} {hot air heating} can heat air by electricity or by burning oil, natural gas, or coal carried into furnace by pipe or conveyor {stoker, furnace}. Air blows through ducts to rooms. Screened openings {register, furnace} in floor or walls have louvers to direct airflow. Air returns to furnace through main duct.
Natural gas from jets burns, warms air, causes air to rise, and pulls in more air from below {gas heater}|.
Heat pumps {heat pump}| can transfer heat from underground water to house. They work like air conditioners in reverse.
Heaters {space heater}| can have no blower. Convection moves air.
Melting together by acetylene torch {welding, metal}| can connect two metals.
Welding can use no metal melting {sintering}|.
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Date Modified: 2022.0225