A Closer look at Circulation Heaters

Industrial HeaterWattco manufactures and designs circulation heaters for maximum efficiency. As a result, these heaters provide high production value at lower costs. Circulation heaters have a simple design making them easy to install and maintain. That means fewer stoppages in processes and longer lifespan, further improving their efficiency and value.  

Circulation heater design

A flange or screw plug circulation heater is fit securely into a heating tank or chamber. The chamber is of corrosion-resistant material and is insulated to prevent heat loss. The heater consists of inlets and outlets for the passage of the liquid or gas, heating the medium through an in-line operation. This is why circulation heaters are often referred to as in-line heaters.

The in-line operation starts with the medium entering through the inlets. The medium flows through the circulation heater elements. The element converts electrical energy into heat energy. This energy then transfers to the medium. The heated medium exits through the outlets. It continues to circulate through this system, maintaining or increasing temperatures as needed.     Circulation heaters are usually paired with a pumping system. This ensures the continual flow of the liquid through the heater. Add-ons, such as thermostats and temperature controls, maintain a constant transfer of heat. This prevents overheating of both the electrical resistance element and the liquid. They are more compatible with standard industrial pipelines than other thermal fluid heaters. Thus, making circulation heaters a popular choice for industrial heating applications.  

Industrial applications

Circulation heaters are suitable for a wide variety of industrial applications. These heaters are an integral component of various industrial processes. Among the most notable are water and thermal heating. However, they are easily customizable for a range of liquid substances. An example of this customizability is the use of materials. The electric heating element or the protective sheath materials vary widely. The metal is dependant on the properties of the target substance. A corrosive medium, for instance, is likely to use stainless steel – as it resists corrosion.  

Industrial thermal fluid heating

Circulation heaters are most suitable for industrial thermal fluid systems. These processes need to maintain both temperature and the flow of the liquid. In thermal oil systems, circulation heaters maintain the viscosity of the oil to ensure a smooth transmission system. This is a crucial step in the transportation mechanism. It prevents potential processing delays and maintains the purity of the product. Thermal oil heaters are popular in the petroleum industry. The liquids in petrol industries need reliable heating. They are easily damaged if temperatures drop too low. And overheating can pose safety hazards.  Heaters are set to custom wattages and temperature for optimal heating and viscosity.  

Case study: The use of circulation heaters in clean water application

Many industrial processes rely on circulation heaters for clean water heating. In the food and beverages industry, circulation heaters serve a variety of functions. Some of them include:

  • Freeze-protection
  • Steam generation
  • Food washing

Let us consider the example of the use of clean water heating for food washing or steam generation. A circulation heater is an integral part of these systems. Pumping systems transport water from a reservoir to the circulation heater. The water stream then enters through the inlets into the heating chamber. Here, as the water flows from the inlet to the outlet, the elements increase the water temperature. The hot water circulates out of the heating chamber for its use in the desired application. Such as food washing or other rinsing processes.  

The closed loop circulation heating system

In certain thermal fluid systems, circulation heaters are a component of a closed-loop heating arrangement. Typically, elements in a closed loop configuration include:

  • A fluid tank or reservoir
  • A pumping system for transporting the fluid
  • Dedicated return lines to carry the fluid to the heater and prevent the mixing of hot and cold liquids on the way
  • The circulation heater

Closed loop systems are the best incremental heating mechanisms for high volumes of fluids. They heat through continuous re-circulation until achieving the desired temperature. They are preferred for their energy efficiency. The two primary heating mechanisms in a closed-loop configuration are:  

Direct heating

As the name suggests, this mechanism involves the direct application of heat. The electrical resistance elements are immersed in the fluid. They heat the fluid as it passes through the elements. The direct immersion of the heating elements achieves greater energy efficiency. When employing a direct heating mechanism, it is crucial to choose the right wattage. This prevents the chemical breakdown of the fluid. Water and thermal oil heating are common applications for direct heating.  

Indirect heating

In indirect heating processes, the fluid does not come into direct contact with the heating elements. Instead, the fluid circulates through pipes, tubes, or vessel jackets around or inside the storage tanks. One common use for indirect heating is for highly corrosive liquids. These liquids would damage equipment or temperature-sensitive materials in a direct heating process. Wattco manufactures a wide range of high-quality circulation heaters. Get a quote or contact one of our qualified experts today.