Subhot Industrial

Circulation Heater

The heat generated is evenly distributed and the efficiency of the heater is high. Circulation heater (a.k.a inline heaters) is basically an immersion heater covered by an anti-corrosion metallic vessel chamber. It is accompanied by National Pipe Thread (NPT) screw plug or ANSI flange heater assemblies mated with a pressure vessel. The vessel is mainly used to provide insulation to prevent heat loss in the circulation system. An inlet flange transports the fluid into the circulation system,

which is then circulated and heated until the desired temperature is reached. The heating medium will then flow out of the output flange at a fixed flow rate decided by the temperature control mechanism. Since it is a compact heating system, the operation is fast and executed in a short time.
Drain valves are also provided to remove leftover fluids or residues. Temperature sensors can be used with any control to achieve the desired temperature range. To manage the liquid flow rate of the heater, the wattage can be manipulated. When the requirement is such that liquid is to be pumped around anyway, a circulation heater is a logical choice. Circulation heaters provide a ready-made means to install electric heating with a minimal amount of time and labor. This is accomplished by combining heating elements, vessel, insulation, terminal enclosure, mounting brackets and inlet and outlet connections into a complete assembly. Such kinds of heaters are ideal for processing fluid, including hazardous liquids that require intermediate heating while maintaining viscosity and flow rate, waste oil, steam, gases, and liquids like de-ionized water for use in semiconductor and electronics industries. These heaters are specially used to heat up vegetable oils efficiently, for maintaining viscosity during food manufacturing by indirect heating. For maintaining accurate viscosity, lower watt densities are recommended. Also, no additional terminal box is necessary for this application.
Different alloys and materials can be used to suit specific applications. The table below shows working temperatures and watt densities of variety of materials.

Sheath MaterialMaximum operating temperaturesMaximum Watt Density
            °F             °C       W/in2       W/cm2
316 stainless steel120065012018.6