Immersion Heaters Explained: Their Function and Applications

Immersion heaters are an essential part of many industrial and commercial heating systems. They are versatile, efficient, and adaptable to a wide range of applications. Under Control Instruments Ltd, a leading supplier of heating elements, provides insights into the inner workings of these indispensable heating devices. For those who are researching, and who require immersion heaters explained, read on to find out more.

What are Immersion Heaters?

Immersion Heaters Explained
Immersion heaters are electrical devices used to heat large quantities of liquid quickly. Installed in hot water tanks or cylinders, they connect to their power supply via a cable. These heaters can be switched on or off as required and serve as both primary or backup heat sources.

At their core, they use insulated electric resistance heaters, such as metal loops or coils, to generate heat. They often come equipped with temperature sensors. To put it simply, think of them as gigantic kettles.

How Do They Work?

When you switch on the heater, an electrical current passes through the resistance heating element, which then heats up due to the resistance it offers to the current’s flow. This heat is then directly transferred to the surrounding liquid, warming it up. The temperature sensor can detect when the liquid has reached the desired temperature and automatically switch off the heater or regulate its output.

This direct method of heating is highly efficient, as almost all the energy consumed by the heater gets transferred to the liquid. It’s also a very fast way of heating, as the heating element is in direct contact with the liquid, providing immediate heat transfer.

Types of Immersion Heaters and Their Applications

Immersion heaters can be installed using over-the-side, flanged, or threaded connection joints, with their specific properties dependent on the tank size and their intended use.

Commercial Immersion Heaters
Generally, these heaters have a copper-sheathed heating element that’s nickel-plated and brazed to a brass flange, which also features a cap for terminal protection. They are used in light-duty boilers, washing machines, geysers, sterilisers, and more.

Industrial Immersion Heaters
Industrial immersion heaters are employed for heavy-duty hot water baths, water-jacketed apparatus, and sidearm circulating process tanks. Like commercial heaters, they’re nickel-plated but are made from two or three copper-sheathed heating elements and fixed to a brass flange with a metallic cap for terminal protection.

Oil Immersion Heaters

A special grade steel tube is used to make these heaters, and it is brazed to a cast iron flange equipped with a thermostat pocket, earthing terminals, and a terminal protection cap. They serve in fuel oil heating, oil circulation, plastic and chemical processes, oil jacketed kettles, and similar equipment.

The Benefits

This type of heating element offers numerous advantages, including high energy efficiency, as they directly heat the liquid without any energy loss. They are also highly reliable and require little maintenance. Their compact size and ease of installation suit them for various applications, and they can be customised to meet specific requirements.