How to design explosion-proof immersion heater？
Explosion-proof immersion heater is based on the design principles and design requirements summarized during the production process: Use explosion-proof electric heating elements in petrochemical companies to protect the surroundings of the connecting conductors in the pipe, and have solid terminals for connecting power, so they can fully withstand vibration And mechanical forces such as shock and impact, the production structure must use closed metal.
Tubular electric heating element of immersion heater type:
(1) The distance between the heating element and the connecting conductor in the tube and the metal protective tube should be more than 2mm.
(2) The connection between the conductor in the tube and the heating element is crimped.
(3) The end of the metal pipe should be fully protected against moisture.
(D) The design principles of explosion-proof immersion heater also include experimental conditions:
1. At 1: 1 times the rated voltage and rated power, power on for 1 minute and power off for 4 minutes. As a cycle, repeat the 2000 cycle and then add 1 minute AC voltage, which should be able to withstand a minimum of 1600V.
2. After 5 minutes of energizing at 1: 1 times the rated voltage and rated power, all the components are immersed in water under the power-off state, and 25 minutes as a cycle. After repeating 50 cycles, it can be placed in the atmosphere for 40 minutes. Withstand the AC voltage shown earlier for 1 minute.
(5) The explosion-proof structure of the immersion heater must be one of the following explosion-proof structures in the manufacturing process: 1. Pressure-resistant explosion-proof structure: The metal tubular electric heating element is cast into a closed structure with a shell, and the metal shell has a sufficient thickness and strength. 2. Increased safety explosion-proof structure: The enclosed electric heating element is installed in a protective shell. A part of the shell is made of stamped steel. The mesh must be less than 12mm, but the mesh can be less than 20mm at 100mm away from the conductive part.
(6) Temperature rise limit: The electric heating element of explosion-proof structure may be in contact with explosive gas (the heating element of pressure-proof explosion-proof structure is the temperature rise limit of the surface of the casing).