Types of Immersion Heaters
Electric immersion heaters can be divided into several distinct designs based on how they are inserted into the medium being heated. Several common varieties are used more often than others, but as technology has developed to allow for more innovation, the varieties of industrial immersion heaters have grown. When choosing an industrial immersion heater, note the tank size and design to find the best-suited type for your application. At Heatmax, we carry the following immersion heaters:
- Flanged Heaters: Flanged immersion heaters are suited for use in large containers and tanks that have high pressure. Flanged heaters are bolted to a matching flange on the outer wall of the tank.
- L-Shaped Heaters: L-Shaped immersion heaters are placed over the side of the tank. Commonly, they’re used in high-temperature conditions where there is an increased rate of evaporation present. The L-Shaped design allows for better heat distribution throughout a tank and reduces exposure to open air.
- Over-the-Side Heaters: As the name suggests, over-the-side immersion heaters are placed at the top of the tank to provide heat along the side. Commonly, these immersion heaters are used when you need ample space within the tank.
- Titanium & PTFE Heaters: While titanium and PTFE immersion heaters are in their own category, they each come in various designs. PTFE is a highly resistant plastic that coats the immersion heater, allowing for use in acids, alcohols, detergents and solvents without fear of corrosion. Titanium is suited against a variety of acids, chemicals and seawater.
- Sanitary Flanged Heaters: Sanitary flanged heaters utilize a ferrule clamp to connect a vessel or pipe to the heating element. This allows for quick disconnection for cleaning purposes.
- Screw Plug Heaters: Screw plug immersion heaters are the ideal solution for when you have a smaller, limited space tank. They feature a tubular heating element with a threaded hex plug to screw directly into a threaded opening in the tank wall.
What to Consider When Buying An Immersion Heater
Now that you know what an electric immersion heater is, what they do, how they work and the different varieties you have to choose from, it’s time to get into the specifics that will help your heater work at total efficiency and have a long lifespan. These are some of the most important elements to consider before ordering your industrial immersion heater.
One of the first considerations when looking for your electric immersion heater is sheath material. It’s essential to find the proper sheath material for your application, as unique sheath materials react differently to certain liquids. If you, by chance, use your industrial immersion heater in a medium with the incorrect sheath material, it can lead to a critical failure of the equipment. Nickel-based, corrosion-resistant alloys are the most common due to their superior strength at high temperatures. At Heatmax, we offer sheath materials made from copper, stainless steel, titanium and incoloy. Specialty alloys such as hastelloy, incoloy 600, monel and alloy 20 are also available.
The watt density (watts per square inch) of your industrial immersion heater is determined by the thermal properties of the medium and process temperature. In application, watt density accounts for the electric immersion heater’s operating temperature for a given set of fluid conditions. In general, the more viscous the medium is, the lower the watt density of the electric immersion heater will be. The lower the watt density is, the larger the physical size of the immersion heater will be. To calculate your required watt density, consult a Heatmax sales engineer.
The next factor to consider for your industrial immersion heater is wattage, which will determine its capability to deliver the necessary temperature. Three elements factor into determining the required level of wattage:
- Size of the Tank: A measure of how much material needs to be heated.
- Heat Point and Density of Material: Some liquids require more energy to heat up than others.
- Startup Time: Requiring the most amount of wattage, startup time is dependent on the method of heating and the type of immersion heater.
- Operation: After the electric immersion heater has achieved startup, wattage must remain consistent for a continual flow of heat.
- Heat Loss: Heat loss must be factored into the operation of any heating device. With an industrial immersion heater, the container type, heater design and medium used will factor into the amount of heat lost, which can increase the amount of wattage needed.
At the core of a heating element is a resistance wire, or heater coil, that creates heat as electricity flows through it. The resistance wire is made from a combination of nickel and chrome with refractory metals such as tungsten, molybdenum or tantalum encased in stainless steel or titanium. A majority are then insulated with magnesium to act as a filler between the heating element and sheath. The composition of these heating elements can vary depending on the medium being heated. At Heatmax, we make our elements in-house, allowing for more precise engineering to your specific medium and a faster turnaround time.