Indirect Heating using Cartridge Heaters
Indirect heating systems transfer heat energy from heat sources to targeted material through either conduction, convection, radiation, or in some cases, a combination of these. And in this case, we’ll be focusing on how to set up one involving conduction while using a cartridge heater as the heat source.
But what is a Cartridge Heater? A Cartridge heater is a tube-shaped, heavy-duty, industrial Joule heating element used in the process heating industry. Cartridge heaters can be built according to the parameters set by a customer.
Different customers come with many different requests. So, we often take custom orders, which often involve tweaking the wattage for the cartridge heater. Such tweaks depend on the specifications of the insulated tank plus the derived minimum ambient temperature of its environment. Here, the goal is to ensure that the object, material, or liquid being heated attains and is maintained at a specific temperature.
Remember, the cartridge heater is just part of the system, and the best choice when building an indirect heating system requires a pipe heater assembly which typically consists of:
- a welded pipe at the bottom of a tank or reservoir
- a low-temperature heat source from either an open coil heating element or a tubular heating element to heat the inside the pipe.
- the ability to remove the heater from the pipe without draining the tank.
Pipe Heaters are proven to be a reliable method of heating fluid in tanks. And for this setup, in particular, they are the best option
However, due to the space constraints of this application, a cartridge heater and custom thermowell with the required NPT fitting will be used as the heat source and pipe. The assembly also includes a moisture-resistant terminal box over the electrical termination of the heater and there you have your set up for indirect heating using a Cartridge heater.