Structural design rules for industrial tubular heater.
Tubular heaters are generally divided into civil tubular heaters and industrial tubular heaters. The industrial tubular heaters are non-standard products, and the structures are also various. The structural design is often convenient for the installation of heating equipment or the degree of beauty. Therefore, when designing the structure of tubular heaters, we should pay attention to many of them. The following is based on JB / T 2379-93 Industrial tubular heaters standard ", talk about some rules of tubular heaters structure design, for customers to do reference when selecting type.
1. The influence of thermal expansion and cold contraction, ablation, oxidation and creep should be considered in the design of tubular heaters to avoid failure due to deformation in normal operation.
2. The design of the internal structure of the tubular heaters shall ensure that the material used for manufacturing the tubular heaters will not be damaged under the maximum temperature that may be encountered in the process, and can still work reliably.
3. The welding structure design of tubular heaters shall comply with relevant standards. The welding seam of pressure tubular heaters especially the part inside the vessel, shall be as few as possible, and the setting of welding seam shall be convenient for inspection.
4. The design of heating tube shell and its accessories under pressure must comply with relevant standards.
5. The heating pipe (including the end) must be sealed.
6. The heating pipe used for heating corrosive medium must be corrosion-resistant metal pipe or protective sleeve to ensure the working life of the heating pipe.
7. When the shell of heating pipe is ordinary steel or other alloy material with better performance than ordinary steel, its wall thickness shall not be less than 0.35mm. When the shell is made of copper or copper alloy, it must be able to adapt to the harsh working environment according to the corresponding mechanical strength.
8. The bending radius of the heating pipe shall not be less than 2.5 times of the diameter of the heating pipe.
9. The bending shape of the tubular heaters must ensure that the inner end of the lead-in rod is on the straight-line part of the pipe, and the distance from the bending starting point shall not be less than 10 mm
10. The gap between the two current closure parts with potential difference greater than 40V in the heating pipe, the gap between the current closure part and the shell and the thickness of insulation filler shall not be less than 1mm, and the distance between the exposed outgoing line and the shell shall not be less than 1mm. (Note: if there is an agreement, the above clearance and distance can be less than 1 mm, but it needs to strengthen the design and manufacture carefully to ensure the performance and reliability)
11. The cross-sectional area of heating pipe outlet shall not be less than 7 times of that of electric heating wire.
The above rules are taken from JB / T 2379-93 industrial heating pipe standard for reference only.