A furnace is a device used for high temperature heating. This name is derived from the Latin fornax , which means the oven. Heat energy for furnace fuel can be fed directly by fuel combustion, by electricity such as an electric arc furnace, or by induction heating in an induction furnace.
In American English and use of Canadian English, the term "furnace" refers to a household heating system based on a central furnace, otherwise known as a boiler, or heater in English English. Furnaces may also be synonymous for kilns, a tool used in the production of ceramics.
In English English, the furnace is an industrial furnace used for many things, such as the extraction of metals from ore (smelting) or in oil refineries and other chemical plants, for example as a heat source for fractional distillation columns. The term "furnace" may also refer to a direct fired heater, used in boiler applications in the chemical industry or to provide heat for chemical reactions to processes such as cracks, and is part of the standard English name for many metallurgical furnaces in the whole world.
Video Furnace
Kategori
Furnaces can be classified into four general categories, based on efficiency and design.
Natural design
The first category of furnace is a natural concept, an atmospheric furnace. These furnaces consist of cast iron or a fixed steel heat exchanger built inside the outer shell of brick, masonry, or steel. The heat exchanger is released through a brick or brick chimney. Air circulation depends on a large, wooden or metal pipe. The pipes will deliver warm air to the floor or the walls of the vents inside the house. This heating method works because the warm air rises.
The system is simple, has multiple controls, one automatic gas valve, and no blower. These stoves can be made to work with any fuel just by adapting the burner area. They have been operated with wood, coke, coal, garbage, paper, natural gas, and fuel oil. Furnaces that use solid fuel require daily maintenance to remove ash and "clinker" that accumulate in the lower burner area. In the following years, the furnace is adapted to an electric blower to aid air distribution and accelerate heat transfer to the home. Fired gas and oil systems are usually controlled by home thermostats, while most of the wood and coal burning stoves have no electrical connection and are controlled by the amount of fuel in the burner and the position of the fresh air damper on the access door stove.
Forced air
The second category of furnace is force-forced atmospheric force burner with cast steel or cast iron heat exchangers. During the 1950s and 1960s, this furnace force was used to replace a large natural design system, and was sometimes installed on existing gravity channel work. The hot air is driven by a belt-driven blower and is designed for various speeds. The stove is still large and large compared to modern furnaces, and has a heavy steel exterior with removable panel bolts. Energy efficiency will range from 50% to more than 65% AFUE. This furnace style still uses a large chimney, brick or brick for the chimney and is ultimately designed to accommodate the air conditioning system.
Forced Concepts
The third category of furnaces is a forced concept, a medium efficiency furnace with steel heat exchangers and a multi-speed blower. This stove is physically much more compact than the previous style. They are equipped with a combustion air blower that will draw air through a heat exchanger which greatly improves fuel efficiency while allowing the heat exchanger to become smaller. This furnace may have a multi-speed blower and is designed to work with a central air-conditioning system.
Conditioning
The fourth category of furnace is a high efficiency furnace, or condensate. High efficiency furnaces can range from 89% to 98% fuel efficiency. These furnace styles include a sealed combustion area, a combustion engine induser and a secondary heat exchanger. Since the heat exchanger removes most of the heat from the exhaust gases, it actually condenses water vapor and other chemicals (which form mild acids) while operating. Ventilation pipes are usually installed with PVC pipes rather than metal vents to prevent corrosion. The draft inducer allows for exhaust piping to be routed vertically or horizontally when out of the structure. The most efficient arrangements for high efficiency furnaces include PVC pipes that bring fresh combustion air from outside the home directly to the furnace. Usually air combustion (fresh air) PVC is directed along the exhaust PVC during installation and pipe out through the side wall of the house in the same location. High efficiency furnaces typically provide 25% up to 35% fuel savings above the 60% AFUE furnace.
Type of furnace
One stage
The single stage furnace has only one stage of operation, either on or off. This means that it's relatively noisy, always running at top speed, and always pumping the hottest air at top speed.
One of the benefits for a one-stage furnace is usually the cost of installation. Single stage furnaces are relatively inexpensive because the technology is rather simple.
Two stages
A two-stage furnace has two stages of operation, full speed and half speed (or reduced). Depending on the heat demanded, they can run at a lower speed most of the time. They can be quieter, move the air at less speed, and better keep the desired temperature at home.
Modulating
The modulation furnace can modulate the heat output and the air speed almost continuously, depending on the requested heat and the outside temperature. This means that it only works as much as necessary and therefore saves energy.
Maps Furnace
Heat distribution
The furnace transfers heat to the building's living space through an intermediary distribution system. If the distribution is through hot water (or other liquids) or through steam, then the furnace is more often called a boiler. One advantage of the boiler is that the furnace can provide hot water for bathing and washing dishes, rather than requiring separate water heaters. One disadvantage for this type of application is when the boiler is damaged, both heating and domestic hot water are available.
Convection heating systems have been in use for more than a century. The older system relies on a passive air circulation system where greater cold density causes it to sink into the furnace area below, through the air registers back on the floor, and lower hot air density causes it to rise in need of airways; two forces that work together to encourage air circulation in a system called 'gravity to eat'. The layout of this 'octopus' stove and their duct system are optimized with a large duct diameter duct diameter.
In comparison, most modern "warm air" furnaces typically use fans to drain air into the home rooms and draw cold air back to the furnace for reheating; this is called forced air heat. Because the fan easily overcomes the obstacles of the airways, channel settings can be much more flexible than the old octopus. In American practice, separate channels collect cold air to be returned to the furnace. In the furnace, cold air enters the furnace, usually through an air filter, through a blower, then through the furnace heat exchanger, from which it is blown all over the building. One of the main advantages of this type of system is that it also allows easy central air conditioning installation, simply by adding a cooling coil at the furnace outlet.
Air is circulated through the airways, which can be made of plastic sheet or "flexible" sheet metal, and is insulated or uninsulated. Unless the duct and plenum are sealed using mastic or foil ducts, the channel may have a high leakage in air-conditioned, possibly into an unconditioned space. Another cause of wasted energy is the installation of drains in areas that are not heated, such as attics and crawl space; or require air ducts from the air conditioning system in the attic in warm climates.
Home furnaces
A home furnace is a primary device permanently installed to provide heat to the interior space through the movement of an intermediate fluid, which may be air, steam, or hot water. Heating appliances that use steam or hot water as a liquid are usually referred to as residential steam boilers or residential hot water boilers. The most common fuel source for modern furnaces in North America and most of Europe is natural gas; Other common fuel sources include LPG (liquefied petroleum gas), fuel oil and in rare cases coal or wood. In some areas electric heating resistance is used, especially when the cost of electricity is low or the main purpose is for air conditioning.
High efficiency modern furnaces can be up to 98% efficient and operate without a chimney, with an ordinary 80% efficient gas furnace. Waste gas and heat are mechanically ventilated through PVC pipes that can be discharged through the sides or roof of the house. Fuel efficiency in a gas furnace is measured in AFUE (Annual Fuel Efficiency Efficiency).
Metallurgical furnaces
In metallurgy, some special furnaces are used. These include:
- Furnaces used in smelters, including:
- Blast furnaces, used to reduce iron ore to coarse iron
- Steelmaking furnace, including:
- Muddy furnace
- Furnace reverberatory
- Bessemer Converter
- Open the hearth furnace
- Basic oxygen furnace
- Electric arc furnace
- Electric induction furnace
- The furnace is used to melt metal in casting.
- The furnace used to reheat and heat the metal for use in:
- Milling plants, including tinplate and milling.
- Forge.
- Vacuum furnace
Industrial oven
An industrial firebox or a fired heater directly, is an apparatus used to provide heat for a process or may serve as a reactor providing a number of reactions. The furnace design varies according to function, heating task, fuel type, and method to introduce combustion air. However, most of the process stoves have some common features.
The fuel flows into the burner and is burned with air provided from the air blower. There can be more than one burner in a certain stove that can be arranged in cells that heat up a certain set of tubes. Burners can also be installed on the floor, mounted on the wall or hanging on the roof depending on the design. The fire heats up the tube, which in turn heats the liquid inside the first part of the furnace known as the glowing part or the fire box. In this room where combustion takes place, heat is transferred mainly by radiation to the tube around the fire in the room.
See also
- Outdoor Wood Furnaces
Note
References
External links
- Furnace, Incinerator, Kiln in Curlie (based on DMOZ)
- https://www.youtube.com/How It Works: Furnace
Source of the article : Wikipedia
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