Electric circulation heaters require proper use, maintenance

Electric circulation heaters are used in a variety of applications. They heat gases such as nitrogen, hydrogen and hydrocarbons and liquids such as water, oils and acids. They are also used in a variety of industries, including oil and gas refining, petrochemical and chemical processing. Refining often requires electric heating systems in ancillary processes such as hydrocarbon and hydrogen gas...

07/15/2007


Electric circulation heaters are used in a variety of applications. They heat gases such as nitrogen, hydrogen and hydrocarbons and liquids such as water, oils and acids. They are also used in a variety of industries, including oil and gas refining, petrochemical and chemical processing.

Refining often requires electric heating systems in ancillary processes such as hydrocarbon and hydrogen gas heating, asphalt heating, steam superheaters and mole sieve regeneration heaters and systems. Chemical processing heating and control requires temperature measurement, process control, tank and vessel heating, duct air heating and storage tank heating.

Electric circulation heaters are frequently used as heat exchangers, which have a similar purpose but different application. Heat exchangers are also controlled using a different method. An electric heater can perform very well or very poorly, depending upon the heater design, as well as the control scheme employed in its application.

Optimization, application considerations

Figure 1 shows the construction of a typical electric circulation heater. There are similarities to a shell and tube heat exchanger that are worth noting. Both house the medium to be heated in a circulation vessel. The difference is that a heat exchanger uses tubes or passages through which a hot (or cold) medium flows. Instead of tube bundles, the circulation heater has an electrical heating element.

The 'shell side’ medium picks up heat from the higher temperature 'tube side.’ The electric heater, on the other hand, uses electric heating elements inserted into the 'shell side’ medium directly to provide the heating effect. Virtually all of the electric heat generated by the electric circulation heater is transferred into the medium. Therefore, an electric heater is virtually 100% efficient.

Maintaining electric heaters

After they are installed, effective maintenance procedures will extend the life of electric circulation heaters: