What are the differences in lifespan between embedded heating and exposed air dry heating?

The most obvious difference between dry heating in air and open-air heating is the superior heat transfer efficiency. So, what's the difference in lifespan between embedded heating and dry heating in open air?

Firstly, because the heating element in embedded heating fits tightly to the mold hole, the surface temperature of the heating element is quickly absorbed by the module, preventing the surface temperature from becoming too high and burning out.

Generally, the gap between the heating element diameter and the module hole diameter is recommended to be within 0.1-0.2mm. If the gap is too large, heat transfer is hindered, affecting heat dissipation from the heating element's surface. In this case, the embedded heating element is prone to burning out. However, if the gap is too small, the heating element will expand due to heat, making it difficult to remove later for replacement.

Exposed-air dry-burning heating elements have poor heat transfer due to the air's resistance to heat conduction. The surface temperature of an exposed-air dry-burning heating element is typically 100-150 degrees Celsius higher than its operating temperature. Therefore, careful selection of the heating element material is crucial. The appropriate material must be chosen based on the surface temperature. For example, if the operating temperature is 400 degrees Celsius, the surface temperature of the heating element will be around 500 degrees Celsius. In this case, 310s stainless steel is recommended. Many people choose 304 stainless steel for cost reasons, but this will inevitably shorten the heating element's lifespan, as 304 stainless steel is known to have a temperature resistance below 300 degrees Celsius.

So, what is the difference in lifespan between embedded dry-burning and exposed-air dry-burning heating?

The heating element designs differ. Due to differences in heat transfer efficiency, the surface load (power) design of the electric heating element differs. The surface load design of the electric heating element in embedded heating is higher than that in exposed-air dry-burning heating.

The lifespan of electric heating elements differs depending on the operating environment. Recessed heating elements generally have a longer lifespan than those exposed to dry air, but there's no precise figure; the actual lifespan depends on the specific size and power.

The above content explains the difference in lifespan between recessed heating and exposed dry air heating. Those who are unfamiliar with this can learn more.