Electric heater

Abstract

The invention belongs to the technical field of electric heating, and particularly relates to an electric heater. The electric heater comprises a metal outer tube, wherein an electric heating wire isarranged in the metal outer tube, the two ends of the electric heating wire are connected with leading-out rods, the metal outer tube is filled with an insulating heat conduction material; the bendingposition of the metal outer tube is locally pressed, the change value of the sectional area of the electric heating tube before pressing and the sectional area after pressing of the pressing part is8%-25%, and pressing transition section treatment is adopted between the pressing position and the non-pressing position. The sectional area of the pressed electric heating tube is reduced, the heat exchange rate of the internal insulating heat conduction material is improved, the high-voltage resistance and other electrical properties of the product are improved, the product safety performance isimproved, and the service life is prolonged.

Description

technical field [0001] The invention belongs to the technical field of electric heating, and in particular relates to an electric heater. Background technique [0002] At present, the conventional electric heating tubes on the market adopt a circular cross-section, which is processed by rolling and other subsequent processes to form the final straight tube heating tube; or directly bent into the final electric heating tube product; or bent and then wound into a spiral to form The electric heating tube product of the final structure. In order to improve the thermal conductivity of the internal insulating material and prolong the service life, the existing technology only performs compression treatment on the local bending position. However, in the existing pressing process, the density of the insulating and heat-conducting material in the pressed position of the pressed product will still not be significantly improved, so that the heat generated by the internal heating wire ...

AI Technical Summary

Problems solved by technology

However, in the existing pressing process, the density of the insulating and heat-conducting material in the pressed position of the pressed product will still not be significantly improved, so that the heat generated by the internal heating wire cannot be quickly transferred out, causing the internal heating wire to overheat and cause fusing; at the same time, the pressing process If it is not in place, the high-voltage resistance of the product at the pressing position is low, and the product has safety hazards such as large leakage current during operation; at the same time, the pressing treatment is not suitable, and the heat generated by the internal heating wire cannot be transmitted quickly. , the resistance wire inside the electric heating tube may be blown earlier than the temperature control device (such as a thermostat, thermal fuse) outside or around the electric heating tube, or the thermal fuse takes a longer time to fuse, resulting in the inability to quickly protect the product, the product surface temperature The continuous rise will bring safety hazards to the accessories around the product, and cannot meet the product safety performance requirements

[0003] In addition, the pressing treatment of the existing technology is unreasonable, and excessive pressing will occur, causing the outer tube of the electric heating tube to be severely crushed and micro-cracked, which affects the safety performance of the product and produces a large amount of scrap.

Images