What is Surface Heating?

Surface heating can be described as the application of heat to the surface of any vessel, container or apparatus for the processing, storage or conveyance of any product or substance at a predetermined temperature.

In general terms, surface heating falls into two categories :-

A.    Freeze Protection, where a vessel, container or pipework is maintained at a temperature which will prevent the enclosed product from freezing at low ambient temperatures. Typical applications include the frost protection of water services and the freeze prevention of caustic soda solutions.

B.    Process Heating, where the enclosed product or material has to be maintained at an elevated temperature to permit handling, transportation or processing. Typical applications include the temperature maintenance of pipework carrying heavy grade fuel oil, various chemical products, glues, resins, etc and products used in the food industry such as glucose, chocolate, fats, etc.

Surface Heating may also be used for the prevention of condensation, for example when handling dust or powder products in storage hoppers .

Generally surface heating is required to compensate for the heat losses which would otherwise occur due to the temperature differential between the required product temperature and the minimum ambient air temperature. However in certain limited circumstances, surface heating may also be used to raise the temperature of the product to that necessary for subsequent processing operations.

Surface heating replaces the heat where it is being lost and compared with other heating methods (such as immersion heaters) it can be easily installed without the necessity of breaking into pipework or vessels. For certain applications, for example the heating of long lengths of pipework, surface heating may be the only practicable method of providing the required heat output .

It is true to say that surface heating can be found in all industrial areas including :

--- general engineering
--- chemicals and petrochemicals
--- oil processing
--- electricity generation
--- food industry
--- refrigeration

The term "surface heating" also includes so-called "trace heating"which is derived from the practice of running a heat source along the length of a pipeline (thus tracing the pipeline).