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Radiator (heating)
Radiators and convectors are heat exchangers designed to transfer thermal energy from one medium to another for the purpose of space heating. Denison Olmsted of New Haven, Connecticut, appears to have been the earliest person to use the term 'radiator' to mean a heating appliance in an 1834 patent for a stove with a heat exchanger which then radiated heat. In the patent he wrote that his invention was "a peculiar kind of apparatus, which I call a radiator". The heating radiator was invented by Franz San Galli in 1855, a Kingdom of Prussia-born Russian businessman living in St. Petersburg. In the late 1800s, companies, such as the American Radiator Company, promoted cast iron radiators over previous fabricated steel designs in order to lower costs and expand the market. Radiation vs. convection A ''radiator'' is a device that transfers heat to a medium primarily through thermal radiation. In practice, the term radiator is often applied to any number of devices in which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Household Radiator
A household consists of one or more persons who live in the same dwelling. It may be of a single family or another type of person group. The household is the basic unit of analysis in many social, microeconomic and government models, and is important to economics and inheritance. Household models include families, blended families, shared housing, group homes, boarding houses, houses of multiple occupancy (UK), and single room occupancy (US). In feudal societies, the royal household and medieval households of the wealthy included servants and other retainers. Government definitions For statistical purposes in the United Kingdom, a household is defined as "one person or a group of people who have the accommodation as their only or main residence and for a group, either share at least one meal a day or share the living accommodation, that is, a living room or sitting room". The introduction of legislation to control houses of multiple occupations in the UK Housing Act (2004) S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Hammer
Hydraulic shock ( colloquial: water hammer; fluid hammer) is a pressure surge or wave caused when a fluid in motion is forced to stop or change direction suddenly: a momentum change. It is usually observed in a liquid but gases can also be affected. This phenomenon commonly occurs when a valve closes suddenly at an end of a pipeline system and a pressure wave propagates in the pipe. This pressure wave can cause major problems, from noise and vibration to pipe rupture or collapse. It is possible to reduce the effects of the water hammer pulses with accumulators, expansion tanks, surge tanks, blowoff valves, and other features. The effects can be avoided by ensuring that no valves will close too quickly with significant flow, but there are many situations that can cause the effect. Rough calculations can be made using the Zhukovsky (Joukowsky) equation, or more accurate ones using the method of characteristics. History In the 1st century B.C., Marcus Vitruvius Pollio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypocaust
A hypocaust () is a system of central heating in a building that produces and circulates hot air below the floor of a room, and may also warm the walls with a series of pipes through which the hot air passes. This air can warm the upper floors as well. The word derives from Ancient Greek ''hupó'' and ''kaustós'' (compare '' caustic''). The earliest reference to such a system suggests that the Temple of Ephesus in 350 BC was heated in this manner, although Vitruvius attributes its invention to Sergius Orata in c. 80 BC. Its invention improved the hygiene and living conditions of citizens, and was a forerunner of modern central heating. Roman operation Hypocausts were used for heating hot baths and other public buildings in ancient Rome. They were also used in private homes. It was considered proper and necessary by the wealthier merchant class for their villas, throughout the Roman Empire. The ruins of Roman hypocausts have been found throughout Europe (for example in It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fan (mechanical)
A fan is a powered machine that creates airflow. A fan consists of rotating vanes or blades, generally made of wood, plastic, or metal, which act on the air. The rotating assembly of blades and hub is known as an '' impeller'', '' rotor'', or ''runner''. Usually, it is contained within some form of housing, or case. This may direct the airflow, or increase safety by preventing objects from contacting the fan blades. Most fans are powered by electric motors, but other sources of power may be used, including hydraulic motors, handcranks, and internal combustion engines. Mechanically, a fan can be any revolving vane, or vanes used for producing currents of air. Fans produce air flows with high volume and low pressure (although higher than ambient pressure), as opposed to compressors which produce high pressures at a comparatively low volume. A fan blade will often rotate when exposed to an air-fluid stream, and devices that take advantage of this, such as anemometers and win ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermostat
A thermostat is a regulating device component which senses the temperature of a physical system and performs actions so that the system's temperature is maintained near a desired setpoint. Thermostats are used in any device or system that heats or cools to a setpoint temperature. Examples include building heating, central heating, air conditioners, HVAC systems, water heaters, as well as kitchen equipment including ovens and refrigerators and medical and scientific incubators. In scientific literature, these devices are often broadly classified as thermostatically controlled loads (TCLs). Thermostatically controlled loads comprise roughly 50% of the overall electricity demand in the United States. A thermostat operates as a "closed loop" control device, as it seeks to reduce the error between the desired and measured temperatures. Sometimes a thermostat combines both the sensing and control action elements of a controlled system, such as in an automotive thermostat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermostatic Radiator Valve
A thermostatic radiator valve (TRV) is a self-regulating valve fitted to hot water heating system radiator (heating), radiator, to control the temperature of a room by changing the flow of hot water to the radiator. Functioning Conventional wax motor TRV The classic thermostatic radiator valve contains a plug, typically made of wax (forming a wax motor), which expands or contracts with the surrounding temperature. This plug is connected to a pin which in turn is connected to a valve. The valve gradually closes as the temperature of the surrounding area increases, limiting the amount of hot water entering the radiator. This allows a maximum temperature to be set for each room. As the valve works by sensing the temperature of the air surrounding it, it is important to ensure that it is not covered by material (such as curtains). If the controller is removed from the valve, the valve turns on and the radiator will always be hot. Interaction with room thermostats Thermostat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Welding
Welding is a fabrication (metal), fabrication process that joins materials, usually metals or thermoplastics, primarily by using high temperature to melting, melt the parts together and allow them to cool, causing Fusion welding, fusion. Common alternative methods include solvent welding (of thermoplastics) using chemicals to melt materials being bonded without heat, and #Solid-state welding, solid-state welding processes which bond without melting, such as pressure, cold welding, and diffusion bonding. Metal welding is distinct from lower temperature bonding techniques such as brazing and soldering, which do not melt the base metal (parent metal) and instead require flowing a filler metal to solidify their bonds. In addition to melting the base metal in welding, a filler material is typically added to the joint to form a pool of molten material (the weld pool) that cools to form a joint that can be stronger than the base material. Welding also requires a form of shield to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cast Iron
Cast iron is a class of iron–carbon alloys with a carbon content of more than 2% and silicon content around 1–3%. Its usefulness derives from its relatively low melting temperature. The alloying elements determine the form in which its carbon appears: Cast iron#White cast iron, white cast iron has its carbon combined into an iron carbide named cementite, which is very hard, but brittle, as it allows cracks to pass straight through; Grey iron, grey cast iron has graphite flakes which deflect a passing crack and initiate countless new cracks as the material breaks, and Ductile iron, ductile cast iron has spherical graphite "nodules" which stop the crack from further progressing. Carbon (C), ranging from 1.8 to 4 wt%, and silicon (Si), 1–3 wt%, are the main alloying elements of cast iron. Iron alloys with lower carbon content are known as steel. Cast iron tends to be brittle, except for malleable iron, malleable cast irons. With its relatively low melting point, g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Towel Warmer
A towel rails radiator or a heated towel rail is a feature designed to heat towels before using them. For many years, European hotels have used them as combined towel- dryers/racks. The towel warmer is a bathroom heater suitable for both drying and heating towels and the environment. There are two versions: traditional ones that are plumbed like a radiator with water heated from a central boiler, and electric ones where an electrical resistance heats water or oil contained in the unit. Towel rails are typically fitted by plumbers. Composition and functioning Towel dryers can be made from different metals such as, steel, stainless steel, or aluminum. In some types, brass or copper is used. The finish can be in chrome plating, polished steel, or lacquer. Dryers can be heated electrically (heating cartridge or heating cable), or by circulating hot water (connected to the central heating). Often, a combination of the methods is used. In these cases, the dryer is heated by hot wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Hammer
Hydraulic shock ( colloquial: water hammer; fluid hammer) is a pressure surge or wave caused when a fluid in motion is forced to stop or change direction suddenly: a momentum change. It is usually observed in a liquid but gases can also be affected. This phenomenon commonly occurs when a valve closes suddenly at an end of a pipeline system and a pressure wave propagates in the pipe. This pressure wave can cause major problems, from noise and vibration to pipe rupture or collapse. It is possible to reduce the effects of the water hammer pulses with accumulators, expansion tanks, surge tanks, blowoff valves, and other features. The effects can be avoided by ensuring that no valves will close too quickly with significant flow, but there are many situations that can cause the effect. Rough calculations can be made using the Zhukovsky (Joukowsky) equation, or more accurate ones using the method of characteristics. History In the 1st century B.C., Marcus Vitruvius Pollio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Convection
Convection is single or multiphase fluid flow that occurs spontaneously through the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the convection is unspecified, convection due to the effects of thermal expansion and buoyancy can be assumed. Convection may also take place in soft solids or mixtures where particles can flow. Convective flow may be transient (such as when a multiphase mixture of oil and water separates) or steady state (see convection cell). The convection may be due to gravitational, electromagnetic or fictitious body forces. Heat transfer by natural convection plays a role in the structure of Earth's atmosphere, its oceans, and its mantle. Discrete convective cells in the atmosphere can be identified by clouds, with stronger convection resulting in thunderstorms. Natural convection also plays a role in stellar physics. Convection is often cate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
