An Introduction to Immersion Heaters
An immersion heater is a heating device that can be immersed in the liquid or gas to be heated. These heaters are preferred due to their ability to produce rapid heating of a process. They can be used either for warming a particular substance, or for heating it to high temperatures. They can be employed for heating a number of different liquids such as water, oils, chemical solutions, milk, and so on.
Typically, immersion heaters are directly placed in the substance that needs to be heated. The heat loss during such a process is very minimal and leads to greater energy savings. Such heaters are considered most efficient when immediate heating is required.
Operation of immersion heaters
Most heaters that are immersed work on the principle of convection. The heaters convert electrical energy into thermal energy. This heat spreads through the molecules of the substance in which the heater has been immersed. A convection wave gradually spreads throughout the entire substance, heating it evenly.
Industrial use of immersion heaters
There are a myriad of applications where such heaters might be used in the industrial sector. Designs range from very small heaters that can be placed in a sample well to large heaters that are placed in tanks. There are hundreds of different heater sizes available for meeting the heating requirements of a process. While household heaters don’t generally have tight tolerance temperature controls, this isn’t the case with industrial heaters. For industrial heating applications, exact temperature control is essential. Such precision heaters are capable of heating process water, solvents, viscous liquids, gases of varying densities, oils, and more—the list is very extensive.
There are a number of immersion heaters manufacturers that offer a large selection of standard heater models. However, for unique applications, custom heaters can be designed and manufactured. These custom designs might cost slightly more than the standard products, but they add immense value to your process as they are entirely tailor-made. For instance, if you need heaters that can withstand high pressure conditions, or need anti-explosive electrical housings; you could make these requirements known to your chosen distributor or manufacturer.
Mounting styles of an immersion heater
The ‘mounting style’ essentially refers to the fashion in which the heater is attached to the desired heating application. Immersion heaters are available in three different varieties based on their mounting styles
- Flanged immersion heaters: These heaters comprise tubular heating elements that protrude out from a metal flange body. The flanges can be of different sizes and sheath materials. They are often bolted to the side of the container.
- Screw plug immersion heaters: These tubular heating elements are brazed or welded to a screw plug. They are screwed to a threaded opening in the wall of the container or tank.
- Over-the-side immersion heaters: Such heaters are installed at the upper edge of the tank. The heating elements hang down and can be directly immersed into the liquid to be heated. Such heaters can be easily immersed and removed without a major modification to the fluid container.