An immersion heater is a device which is installed in a tank or container to heat a liquid. The installation can be over-the-side, flanged, or threaded. Immersion heaters are relatively inexpensive to purchase and come in a wide range of physical configurations, materials, and temperature ranges and can be used for a wide range of applications.
How does an Immersion Heater Work?
Immersion heaters are made by encasing a resistance heating wire in a ceramic jacket which is then surrounded by a sheath. The sheath can be made of copper, steel, stainless steel, cast iron, incoloy, titanium, or PFA coated. As electricity flows through the heating element, it moves heat at a high rate through the ceramic jacket and sheath. The heat emanating from the sheath quickly heats the water or liquid surrounding it.
What are the Operating Temperatures of an Immersion Heater?
Immersion heaters are available in many temperature ranges. The temperature an immersion heater can output depends on the supply voltage and the resistance (watts = voltage2/resistance). Industrial heaters can typically heat water to around 900°F (482°C) internally. The heat output will remain constant regardless of the environment or application since the heater’s resistance measurement is also constant.
What are the Applications of an Immersion Heater?
Each type of immersion heater is suited for different types of applications. Water, oils, solvent, plating baths, salts, and acids are some of the many liquids and viscous materials commonly heated with immersion heaters.
Below are the most common applications for the different types of immersion heaters:
- Over-the-side immersion heaters are best for applications where ample working area and portability, such as for easy removal for cleaning of tanks and heaters, is important.
- Flanged immersion heaters are excellent heater choice for all tanks, vats, or irregularly shaped vessels due to the wide selection of watt densities, heating outputs, and flange sizes and ratings of these heaters.
- Screw plug immersion heaters are ideal for process water heating and freeze protection. All types of oils and heat transfer solutions can also be heated using these compact and easily controlled units. The direct immersion method is energy efficient and well suited for many applications.