They are used to temper liquids in a tank. Find out here when they are used, how they work, and what types of tank heating is available.
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What Is Tank Heating?
It is a device for heating or tempering liquids stored in tanks. It ensures that the stored media are kept at a desired temperature to maintain their physical and chemical properties, ensure flowability, or protect them from frost.
What Are Tank Heaters Used For?
They are used in a variety of industrial and commercial applications. Their main functions are:
Frost Protection
Preventing the freezing of water-based liquids, which can lead to damage to the tank and pipes. This is crucial, especially when storing water, but also for other frost-sensitive liquids.
Viscosity Control
Many liquids, such as heavy oils, resins, fats, or even foodstuffs like chocolate, become viscous (highly viscous) at low temperatures. A tank heater keeps them at a temperature at which they remain pumpable and flowable.
Process Control
In some chemical and industrial processes, the starting materials must be brought to a specific temperature to enable or accelerate reactions. The tank heaters are used here for the precise temperature control of the media.
Quality Preservation
For temperature-sensitive substances such as paints, varnishes, or certain chemicals, a temperature that is too low can lead to undesirable effects such as crystallization, flocculation, or phase separation. A tank heater ensures product quality during storage and transport.
How Do Tank Heaters Work?
The function of tank heaters can be divided into two basic principles: direct and indirect heating.
Direct Heating
In direct heating, the heating element is in direct contact with the medium to be heated. The heat is transferred directly to the liquid, which makes this method very efficient (nearly 100% efficiency). Examples of direct heating systems are:
- Immersion Heaters: These are immersed directly into the tank. They consist of one or more heating elements surrounded by a protective tube. The shape can vary (e.g., heating rods, cartridge heaters, flange heaters).
- Circulation Heaters: Here, the liquid is pumped out of the tank, passed through an external heater, and then returned to the tank. This allows for uniform heating of the entire tank contents.
Indirect Heating
In indirect heating, the heat is transferred to the liquid via a transfer medium or the tank wall itself. The advantage of this method is that the heating element does not come into contact with the often aggressive or sensitive medium, and the tank does not have to be emptied for maintenance. Examples of indirect heating systems are:
- Heating Blankets and Heating Mats: Flexible heating elements that are wrapped around the outside of the tank. They are particularly suitable for mobile tanks or for retrofitting existing systems.
- Trace Heating: Electric heating tapes or cables that are attached to the outside of the tank. They ensure uniform heat distribution over a large area.
- Double-Walled Tanks or Heating Coils: Here, a heat transfer medium (e.g., steam, hot water, or thermal oil) is passed through a jacket or through pipe coils installed in the tank, which transfer the heat to the stored medium.
Why Is Tank Heating Needed in Connection with Mobile Heaters?
Mobile heaters are often used on construction sites, at events, or in emergencies. They are usually powered by heating oil or diesel, which is stored in separate tanks. At low outside temperatures, especially in winter, diesel and heating oil can experience what is known as paraffin precipitation. This involves the formation of paraffin crystals that can clog the fuel filter and lines, thus paralyzing the operation of the mobile heater.
To prevent this, tank heating is used. They keep the heating oil in the tank at a temperature where no paraffin precipitation occurs (typically 0 °C). This ensures the operational reliability of the mobile heating system even in severe frost.
What Types of Tank Heaters Are There?
They differ in their design, performance, and application area. The most common types are:
| TYPE | DESCRIPTION |
|---|---|
| IMMERSION HEATERS/SCREW-IN HEATERS | Electric heating elements that are immersed directly into the medium. They are equipped with a thread for easy installation. |
| FLANGE HEATERS | Bundles of heating rods mounted on a flange and inserted into the tank from the side or top. |
| HEATING BLANKETS/JACKETS | Flexible, insulated covers with integrated heating elements that are strapped around the tank. |
| HEATING COILS/TUBE HEAT EXCHANGERS | Pipe systems inside the tank through which a hot medium (steam, water, oil) is passed. |
| BOTTOM HEATING | Heating elements installed at the bottom of the tank to promote natural convection. |
References:
ZIEGLER ENGINEERING. (seen on 10/06/2025). Tankheizung zur Lagerung von Flüssigkeiten.
heatsystems GmbH & Co. KG. (seen on 10/06/2025). Tankheizer.
Ignis Trace. (seen on 10/06/2025). Tank Heating Systems and Application Areas.