Maximum Recommended Watt Density

Some materials such as water, vegetable oils and salt baths can tolerate relatively high sheath watt densities. Other materials such as petroleum oils or sugar syrups require lower watt densities. These solutions have high viscosity and poor thermal conductivity. If the watt density is too high, the material will carbonize or overheat, resulting in damage to the heating equipment or material being heated.

Other sections of this catalog provide guidelines and suggestions for sheath materials and recommended watt densities for many common heating problems.

Using the values determined in the selection criteria, choose the type of heater best suited to the application. For instance, water can be heated by direct immersion, circulation heaters or with tubular or strip heaters clamped to tank walls. The final choice of heater type will involve process considerations, appearance, available space both inside and outside, economy, maintenance, etc. The following pages cover the procedures for selecting heaters for clamp-on applications, liquid immersion heating, oil immersion heating, air or gas heating and cartridge or platen heating.

General Recommendations For Liquid Heating Applications
Telelec standard immersion heater ratings match the suggested watt densities for general-purpose immersion heating. Extended heater life will be obtained by using the lowest watt density practical for any given application.

Standard Ratings