Heaters, electric resistance type elements

The short-wave IR radiation can only be generated by an electric IR heater employing a tungsten heating element. A tungsten filament has small mass as well as low electrical resistance, which allows heavy current flow and very rapid heat up and cool down. The rate of response of various types of radiant heat sources can be an important criterion in the selection of a proper source for coating drying applications. 

The single-storage heater is heated by an electric element embedded in bricks and rated between 6 and 15kW depending upon its thermal capacity. A radiator of this capacity must be supplied on its own circuit, in cable capable of carrying the maximum current demand and protected by a fuse or miniature circuit-breaker (MCB) of 30, 45 or 60 A as appropriate. At the heater position, a DP switch must be installed to terminate the fixed heater wiring. The flexible cables used for the final connection to the heaters must be of the heat-resistant type. 

Calorimetric-type gas flow sensors analyze the temperature distribution built up in the environment around a central heater element [2]. Further explanation of its functionality is discussed in the next section. Using thermal electric circuits, thermal behavior of the sensor s stmcture is determined. A number of resistors and capacitors are used in the circuit to function as heat transfer agents. Flquation 11 is modeled for convective resistance and Eq. 12 for thermal capacitance where A is the heater area. The flow velocity can be obtained from Eq. 12. 

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