Manufacturing material of electric heating tube shell

The electric heating tube shell is made of materials: carbon steel, stainless steel (corrosion resistance), copper (good plasticity and thermal conductivity), titanium, etc. In addition, the heating temperature conditions also have a certain influence on the selection of materials. Generally, the heat-resistant temperature of stainless steel 304 is 600C. When the heating temperature reaches 00C, you need to choose stainless steel 316 or 316L. When it reaches 1000 degrees, it is even more necessary. Choose stainless steel 310S to ensure the service life of the electric heating tube. The reason why the electric heating tube can generate heat, the electric heating alloy wire is indispensable, which is the resistance wire we usually understand. The high frequency current flows to the heating coil (usually; made of red copper tube) that is wound into a ring or other shape. As a result, an instantaneously changing strong magnetic beam is generated in the coil. When the heated object such as metal is placed in the coil, the magnetic beam will penetrate the entire heated object, and the inside of the heated object will be in the opposite direction to the heating current. The very large eddy current. Due to the resistance in the heated object, a lot of Joule heat will be generated and the temperature of the object will rise rapidly. To achieve the purpose of heating all metal materials. Convert electrical energy into thermal energy to heat objects. It is a form of electric energy utilization. Compared with general fuel heating, electric heating can achieve higher temperature (such as arc heating, the temperature can reach 3000"C or more), and it is easy to realize automatic temperature control and remote control, and the heated object can be maintained as required. Temperature distribution.

1. The temperature of the electric heating tube is very high when it is heated, so high-strength and high-heat resistance nickel-chromium-aluminum and iron alloys are used.

2. In the detection of electric heating tubes, the environmental requirements are relatively high, so more rigorous exquisiteness is required in terms of material selection and processing technology.

3. The electric heating tube is to put the electric heating element in the metal tube and use the lead rod to export it. The gap part is tightly filled with crystalline magnesium oxide powder with good heat resistance, thermal conductivity and insulation, and the tail is added for fixed installation The electric heating element is made of threaded sleeve and sealed porcelain head, processed by other processes.

4. In the heating medium of the electric heating tube, different media have different characteristics, such as: water (oxidizing), some chemical media (acid|, alkali corrosive), molten salt (chlorine ion corrosive), etc., so There are different requirements for the selection of materials when making the shell of the electric heating tube.

5. A voltage of 1800V needs to be used for breakdown test to ensure uniform wire drawing of the resistance wire and ensure the heating effect of the electric heating tube. After it can be heated, a non-negligible problem arises, insulation.

6. The whole body of the heating tube is basically a conductive body. At this time, magnesium oxide with good thermal conductivity and insulation is required to fill the gap between the resistance wire and the shell to achieve the effect of insulation and heat conduction, and use an insulating porcelain head to match the tail. 704 high temperature glue seal achieves good insulation (insulation degree 2 500MQ) to ensure the safety of the electric heating tube when heating.