Electrical resistance heating

One of the most versatile and robust heating techniques is the use of electrical resistance heaters. They are used in as varied heating approaches as hot plates, mantles, heat strips, immersion heaters, and even blankets. 

Although some electrical heating units are self-contained with their own electrical controllers (such as hot plates), many require separate controllers. If a heating unit has no apparent built-in mechanism with which to vary temperature, the unit will require a separate controller.  

The controller is nothing more than an electrical rheostat that can vary the amount of electrical current the wires receive. This rheostat in tum also varies the amount of heat the wires can deliver. Some controllers have built-in (or external) thermocouples that enable the controller to maintain a specific temperature, 

Never rotate a spinning bar too fast because it is likely to cause splashing. Likewise, place the center of a flask over the center of the controller. Otherwise the spinning bar is likely to flip around like a wounded fish, causing a lot of splashing. 

Electrical Heating Tapes. These units always require separate controllers. They come in various widths and lengths and are always flexible. Depending on the insulating materials, they have upper heating temperature limits from 260°C to 760°C. Although the insulation may be resistant to chemical spills, the wires within may not. Sloppiness is therefore likely to be hazardous. Some of the insulations available should not be used against metal surfaces, so if you need to heat a stainless steel container, select suitable insulation. 

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Most laminated glass appHcations are concerned with impact strength, and minimum performance levels are required by specification. The impact strength of two pHes of laminated, aimealed glass and various PVB thicknesses are available (4). Aircraft laminates may utilise electrical resistance heating as deicing for vision enhancement. 

Hydrogen sulfide and carbon react at 900°C to give a 70% yield of carbon disulfide (102,103). A process for reaction of coke and hydrogen sulfide or sulfur in an electric-resistance-heated fluidized bed has been demonstrated on a laboratory scale (104). Hydrogen sulfide also forms carbon disulfide in reactions with carbon monoxide at 600—1125°C (105) or carbon dioxide at 350—450°C in the presence of catalysts (106). 

Conventional Sintering Equipment. Like drying furnaces, sintering furnaces (29,76,85) can be periodic or continuous in nature. Periodic kilns offer greater flexibiHty continuous tunnel kilns are more economical. Advanced ceramics are typically siatered in high purity, controUed atmosphere furnaces by electric resistance heating. Ceramic furnaces used to fire traditional ceramic ware are generally heated with inexpensive natural gas, oil, wood, or coal. 

Nonferrous alloys account for only about 2 wt % of the total chromium used ia the United States. Nonetheless, some of these appHcations are unique and constitute a vital role for chromium. Eor example, ia high temperature materials, chromium ia amounts of 15—30 wt % confers corrosion and oxidation resistance on the nickel-base and cobalt-base superaHoys used ia jet engines the familiar electrical resistance heating elements are made of Ni-Cr alloy and a variety of Ee-Ni and Ni-based alloys used ia a diverse array of appHcations, especially for nuclear reactors, depend on chromium for oxidation and corrosion resistance. Evaporated, amorphous, thin-film resistors based on Ni-Cr with A1 additions have the advantageous property of a near-2ero temperature coefficient of resistance (58). 

The most common form of energy deposition used for planar shock wave research has been electrical resistance heating of a metal foil which vaporizes, driving a flyer plate to a high velocity before it impacts a specimen. In a hybrid system incorporation both resistance vaporization and an electromagnetic push, velocities to 18 km/s are reported for kapton flyer plates which are... 

The two accepted methods used for heating platens are both electric resistance heating and induction heating. 

The most advantageous application of the heat pump in the UK at the present time is where air cooling is required in the summer and air heating from the same piece of equipment in the winter. The alternatives will be electric resistance heating, with a higher fuel cost, or the provision of a hot water coil, at extra capital cost. 

Heating Electrical resistance heating within the pgauze Product gas channel width cooling gas channel width 60 pm 90 pm... 

Thermal enhancement of volatilization.19 21 Volatility of contaminants increases greatly with temperature, so several techniques have been developed to raise soil temperature, including the injection of hot air or steam, electrical resistance heating, and radio frequency heating. 

In actual installations these systems have been shown to use about 45 to 50% of the electricity consumed in a similar house with conventional electric resistance heating. It is more efficient than a conventional air-to-air heat pump system, since the heat source is maintained at a constant, known temperature. In moderate cold climates with 6,000 degree-days, an ACEs uses about 25% less electricity than a conventional heat pump with... 

Note 3 If the air bath is of the electric-resistance heated type, it shall be constructed so that all parts of the interior surface are heated uniformly... 

At the end of the washing step, the liquid is drained to the operative tank by the pump, and through the button filter, FB, then the gas-recovery step takes place to recover most of the vapour or gaseous CO2 from the chamber. As the gas-recovery can be assumed to be like an adiabatic process, the fluid in the chamber is pre-heated by an electric resistance heat exchanger, HE2, to contain the reduction in temperature. The CO2 vapour is compressed by the oil-free compressor CV and fed to HE1 to condense before being stored in the operative tank. Finally, the chamber is vented and the door can be opened to recover the cleaned garments. 

Similarly, the source term in the energy equation is sum of the electrical resistance heating, heat of formation of water, electrical work, and heat release due to phase change (condensation of water vapor). 

BASF has obtained European patent 1,110,913, which describes HCN production by the thermolytic reaction of gaseous formamide in the presence of a fine-particle, solid catalyst in a fluidized bed. They claim that the process is more economical and results in less equipment damage. They also received patent DE 10,144,891 for production of HCN from formamide in a flow-type reactor with electric resistance heating. 

A selection of different methods of evaporation is available—including electrical resistance heating, electron beam, induction heating, and sputtering. 

Furnaces for thermal analysis instruments are nearly always electric resistance heated. Wound furnaces consist of a refractory metal wire wrapped around or within4 an alumina or other refractory tube. Nichrome (nickel/chromium alloy) or Kanthal (a trade name for an iron/chromium alloy 72% Fe, 5% Al, 22% Cr,. 5% Co) windings may be used inexpensively for heating to a maximum temperature of 1300°C. More expensive plat-... 

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