Maximizing Heater Performance

There are a couple ways to maximize existing heater performance. If these don't solve your issues, you may have to look into redesigning your heating process.

General tips to optimize heater performance:

Avoid heater contamination

Contamination (build-up or scaling on immersion heaters) is the most frequent cause of heater failure because it entraps the heat within the heater and leads to burn-out.

Protect leads and terminations from high temperature

Use standard fiberglas-insulated lead wire up to 500degF. If lead is exposed to higher temperature, high temp lead wire or ceramic insulation should be used. (Or add an additional cold section on the terminal end). In vacuum applications, place the terminals outside the vacuum, if possible. for advise.

Protect leads from excessive movements Specify a lead protection option (examples: clip support, stainless steel braid, right angle headers) for advise.

Proper heater selection and sizing

Wattage should be matched to actual application to limit ON / OFF cycling. A tight fit (for example on cartridge heaters, band heaters) minimizes air gaps and reduces hot spotting. We also recommand the use of if you're stuck with bore size. for advise.

Electrical installation

For safety reason ground all heating equipment. Include power surge protection with the proper sized fuse or circuit breaker.

Prevent excessive heater cycling

Full expansion and full contraction of the heater is detrimental to heater life. Heater selection, location of the temperature sensor relative to the heater, choosing PID temperature controller, using solid state relays (SSR) or silicone controlled rectifiers (SCR) (zero-cross or phase-fired) as power controller can increase heater life. for advise.

Select sheath material and WSI to specs

Check parameters such as process temperature , flow rate, heater to part fit, materials (solid or fluid) Use derated heaters where necessary. for advise.

Ensure tight connections and limit protections

Use process temperature sensors (contact or non-contact) for material and high limit sensors for heating elements. PID controllers are better than simple ON/OFF controls or thermostats.

Maximizing performance of immersion heaters:

  • Watt density ratings and sheath material need to be compatible with the liquid being heated
  • install heaters horizontally near the bottom of the tank to maximize convective circulation. If space limitations require vertical mounting, think about a stirring mechanism.
  • The entire heated length of the heater should be immersed all the times. Install a liquid level control in the tank and a overtemperature limit on the heater.
  • For better accuracy, responsiveness and exchangability, install the temperature sensor in a thermowell.
  • Protect the heater from contamination.
  • Protect the terminals from moisture and/or add a moisture seal if necessary
  • Avoid boiling in restricted area
  • Avoid sludge built up on bottom of tank