Electric Process Heaters vs Shell & Tube Heat Exchangers

21 May 2014



In the process industry electric process heaters are designed, simulated and specified similar to shell and tube heat exchangers as they are used in similar applications except that the tube side is replaced by an electric heater bundle made from tubular rod elements and the heat energy is driven by electricity instead of recovered heat. In many process applications, the replacement of the tube side with electric rod element bundles brings a lot of advantages.

Head-to-Head advantages of the two heating methods are as follows:

Electric Process Heaters
  • Small foot print and low weight.
  • Electric heaters offer precise temperature control
  • Due to thyristor control, Electric heaters have 100% turn down capacity
  • In electric heaters, the process side energy is driven by electric power hence these are independent, without any need for process hook up
  • Virtually 100% efficient since almost all electricity is converted to heat.
  • Same kW electric heater can delivery high element temperature heat to achieve process temperature rise
  • Instant cold start facility because electricity is converted to heat.
 Shell and Tube heat exchangers
  • These normally require bigger space due to shell size and are lot more heavier
  • Temperature control is good but not as good as Electric
  • Many restrictions on turndown capacity due to process linked to heat recovery elsewhere
  • Shell and Tube heaters rely on recovering heat from some other source hence they are restricted by heat recovery; process hook up is required
  • Efficiency is far less
  • Dependent on source, if heat source is not able to deliver high temperature recovery then they are not suitable in this service
  • Instant cold start is not possible because heat is recovered from some other application.

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