The immersion electrical heater is chiefly applied in the direct contract mode of fluid heating. It features fast heat exchange and high thermal efficiency. It has the varieties of water heater, oil heater ad gas heater. Its heating element power density, i.e. the power per unit of heating area of the heating element, is an important parameter of the electrical heating element, which has a direct bearing on the performance and working life. The working out of the value is a highly specialized problem, being under the influence of many factors ( media flow rate, tempt, physical and chemical properties and direction in which the medium flows past the element etc ) .
Taking a too-high value will mean overheating and sintering and in serious cases causes damage to the heating element. While taking a too-low value will mean a large volume and a drastic rise of cost. Depending on the different applications electrical heaters adopt different power density. One common thing in terms of structure is that one tubing plate carries a number of heating tubes, at the ends of which is a supporting plate or supporting tube to make all heating tubes an integral whole. That way vibration of single heating tube caused by mediu