High-reliable electric heating pipe sealing structure and method

Abstract

A high-reliable electric heating pipe sealing structure and method are disclosed. A lead rod is arranged in an electric heating tube body. A space between the lead rod and the tube body is filled withmagnesium oxide powders. An insulation sealing device is disposed at the sealing port of the electric heating tube body and is composed of an upper opening, a middle channel, a lower channel, and a lower opening. The lead rod penetrates through the middle channel of a sealing port device. A sealant is arranged between the insulation sealing device and the electric heating pipe body. The outer diameter of the upper part of the insulation sealing device is larger than the diameter of the outer wall of the sealing port of the electric heating pipe body, and the outer diameter of the lower part of the insulation sealing device is smaller than the diameter of the inner wall of the electric heating pipe body. The diameter of the upper opening gradually decreases toward the middle of the sealingport device. The diameter of the lower channel gradually decreases toward the middle of the insulation sealing device. The lower opening is located below the lower channel. The diameter of the loweropening gradually decreases toward the lower channel. The smallest diameter of the lower opening is equal to the largest diameter of the lower channel. The high-reliable electric heating pipe sealingstructure has the advantages of good bonding during the curing process of the sealant and improving the insulation withstand voltage.

Description

technical field [0001] The invention relates to the technical field of electric heating, in particular to a high-reliability electric heating tube sealing structure and method. Background technique [0002] During the use of traditional electric heaters, the insulation resistance of the electric heating tube may decrease, resulting in damage or unusability of the electric heater. Once the above situation occurs, it will cause serious safety and quality problems. An important requirement of the electric heating tube is that there should be no moisture inside the electric heating tube. The general treatment method is to place the electric heating tube in an oven and heat it at 180-280°C for several hours to more than 10 hours, so that the moisture absorbed by the magnesium oxide powder in the electric heating tube can be fully removed. Then use RTV silica gel or epoxy resin (hereinafter collectively referred to as sealant) to seal the nozzle. [0003] Such as figure 1 As sh...

AI Technical Summary

Problems solved by technology

[0004] In actual production, if the amount of sealant 4' added during the packaging process is not enough, it is easy to create a gap between the sealing cap 3' and the sealant 4'; if the amount of glue is just right, but because the bottom of the sealing cap 3' is flat , during the pressing process of the sealing cap 3', it is easy to "hold air", and a small part of the air is "stuffed" between the sealing cap 3' and the sealant 4'; if the sealant 4' is excessively added, the sealant 4' It will overflow from the nozzle of the electric heating tube 1', causing the outer wall of the tube to be polluted; even if the above factors do not exist, due to the shrinkage of the sealant 4' during curing (general shrinkage is between 2-5%), it may also be in the sealant. There are gaps and pinholes at the interface between 4' and sealing cap 3'

The above situations will cause unqualified insulation withstand voltage, which greatly affects the service life and quality of the electric heater.

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