The manufacturer guarantees the performance of the cartridge heater only if 3 conditions are met. You will need to select a suitable heating element, install it correctly and adhere to the recommended operating conditions.
Calculation part
- The first step is to determine the temperature value of the heating element.
- It is necessary to calculate the power with which the required part can be heated. This will be the total power, i.e. from all cartridge chambers.
- The geometric parameters of the heater are calculated based on the dimensions of the opening.
- Determine how many thermocouples will be needed based on the above figures.
- Calculate the area and specific power using the formula below:
S = 3,14 * Ø * L;
P = S / P (specific power)
- From the largest inner diameter of the hole, the smallest dimension of the outer diameter of the heater is determined.
When the specific gravity does not match the desired density, the number of cartridges is adjusted, the fit is selected to be more tight, and the trigger time range is increased (to reduce the required power of the heaters).
Mounting subtleties of the cartridge heater
The work is carried out with the power supply disconnected.
- Tight insertion of the heater along its entire length, without play. If a part of the working surface remains outside the bore, this will accelerate failure. Exceptions are allowed when the cartridge chamber is not heated along its entire length. The wiring is left outside, since it is not able to withstand high temperatures. When there is a danger of overheating the connectors, ceramic beads with wire are used.
- Fixing in a stationary position is carried out using clamps, brackets, fittings, brackets. The devices must not be fixed by the contact leads.
- The current-carrying conductors must be properly insulated.
- Heaters may not be located next to each other. The distance between them is 0.5-4 cm.
- Expanding heaters are convenient in that they help the cartridges to fully adhere to the walls of the holes, expanding during the thermal process. The difference from conventional models is a single coil. A loose dielectric fills the free space between the case and the core, and also
- In order to quickly trace the drop in power due to the breakdown of the heater, it is desirable to use fusible inserts during installation.
- The housings of all heating elements are grounded
Special features of dismantling
If the cartridge case has been in use for a long time, it can change its initial shape or “stick” to the hollow bore. This makes it difficult to remove. It is more convenient to use a bifurcated cartridge, which will shrink a little after the power supply is cut off. Such TENs do not fall into free sale, they are made to order, with the development of drawings.
To pull out the cartridge, a rod of similar diameter is used. This will prevent the working part of the heater from detaching from the wires.