1. Low-cost products for high-temperature equipment
Low-end heating tube products may only cost a few dollars, but high-quality products are much more expensive, which is a very normal phenomenon because the materials are different. In the past 30 years, the state has implemented a market economy, and the raw material market has become more and more transparent. We can be sure that expensive products do not necessarily use good materials, but cheap products do not necessarily use good materials. Can you imagine that? A small heating tube requires more than 10 materials, one of which is slightly problematic and can cause the entire batch to be scrapped. Materials are one of the important reasons for the difference in price and service life:
Housing material
At high temperatures, oxidation of the stainless steel shell will cause the surface to fall off and the surface color will darken, which is normal. However, the unsuitable housing material can accelerate the oxidation process and shorten the service life. For example, materials containing a large amount of impurities are used as conventional materials, and low-temperature environmental materials are used in high-temperature equipment. Using the Incoloy 800 at high temperatures would be a better option.
Resistance wire (heating wire)
The resistance wire will face a strong electrical load when operating and withstand high temperatures. Similarly, resistance wires also accelerate oxidation at high temperatures, so it is essential to choose resistance wires that can withstand high temperatures for a longer service life.
magnesium oxide
Magnesium oxide is the core insulation material of the heating tube, which is filled between the sheath and the resistance wire, transferring heat and avoiding a short circuit between the housing and the resistance wire. Especially at high temperatures, high-purity magnesium oxide must be used. High-purity magnesium oxide not only transfers the heat of the resistance wire to the housing more efficiently, but also has good insulation properties.
2. The installation gap between the heating tube and the die hole is not correct
The installation gap is wrong, which is easy to cause damage to the heating pipe. In particular, high-power electric heating pipes have stricter requirements for the size of the mounting holes. Imagine such a wrong use scenario: the heating tube is inserted into a large mold hole, due to the installation gap is too large, most of the surface of the heating tube is in contact with the air, the heat emitted by the heating tube is first transferred to the air, and then transmitted to the mold, the efficiency is greatly reduced, resulting in the heating tube needs to emit twice the heat to meet the use temperature of the mold, which is self-evident for the loss of the heating tube. The diameter tolerance of the heat wave single heating tube can be controlled within ±0.02mm, and the gap between the tube and the mold hole should be less than 0.1mm (that is, within 0.05mm on one side). For example, a heating tube with a diameter of 10mm should be a hole within 10.1mm.
3. The installation depth of the heating tube is not correct
The hole is too shallow to cause the heating part of the heating tube to be exposed, the heat dissipation environment is not good, it will damage the heater, and even cause a fire accident, the hole is too deep to cause the heater to install and seal, the wire part enters a higher use environment, long-term use may lead to a short circuit, understand the heating length of the single heating tube, choose the appropriate installation hole depth, which has great benefits for the heating tube.
4. The ambient humidity is high or the sealing end of the heating tube is not strict
When the air humidity around the heating tube is heavy or the wire sealing end of the heater is not strict, moisture can easily enter the heating tube, and magnesium oxide and water will undergo a chemical reaction, which may cause a short circuit. Sealing magnesium oxide stability is very good, heat wave single heating tube effectively dry moisture before leaving the factory, the use of very sealed materials to seal need attention, storage and use in high humidity environment, will lead to a decrease in insulation resistance, but after the heater water evaporation, the insulation performance will gradually recover. Therefore, if it must be used in a high humidity environment, it is recommended to use a low-pressure start.
5. The power supply voltage and the use of power are incorrect
The power used by the heating tube also has a great influence on its service life. For example, the resistance value of a finished heating tube is fixed. When the rated voltage value is 2 times, the current will also become 2 times, and the output power will also become 4 times (power = voltage * current). At this time, the heating line is subjected to 2 times the current load, and the overall heating core should support 4 times the power output. The higher the power of the product, the better the required heat dissipation environment. When the heat dissipation needs of the heating tube cannot be met, the service life of the heating tube will be shortened because the internal temperature of the heating element will exceed the limit of the heating element.