Due to the differences at home and abroad, the name of the single-head electric heating tube is also different, (single-head) or (cartridge) electric heating tube). In China's electric heating industry, there is a model called M3 for a long time. In the late 1990s, electric heating tubes were widely used in China, and the shapes of electric heating tubes were also present. In southern China, this kind of one-end electric heating tube for molds is called a single-end electric heating tube, which is very similar. It is called a cartridge heater in foreign countries, and it is also a kind of image name, because the cartridge shell is cylindrical, and one end is blocked. It is ingenious to call it a single-head heating tube in China. Compared with the double-headed electric heating tube, the single-headed electric heating tube is wired out from one end, and generally adopts the star connection method. Single-head electric heating tubes are generally used for mold heating or air dry firing, mainly for mold heating single-head electric heating tubes, which are directly inserted into the drilling holes of the mold, and the outlet ends are fixed with gaskets to prevent the electric heating tubes from moving.
Professional technicians pay special attention to the fact that the production of single-head electric heating tubes should consider the matching of the tube diameter and the aperture of the template. The tube diameter of the electric heating tube is too large, so that the electric heating tube cannot be installed in the hole position, and the expansion factor of the tube after heating is considered. It will bring inconvenience to later maintenance; in addition, the pipe diameter should not be too small, and the space between the hole wall and the hole wall should not be reserved too large, which will affect the heat transfer effect and service life of the electric heating tube. Even more consideration should be given to the power and voltage of the single-head electric heating tube.
The heating tube is a metal tube with a resistance wire, which is the same as an electric furnace wire.
The heating principle of the single-head electric heating tube: the electric current passes through the resistance to generate heat.
According to the law of electric heating: the calorific value is proportional to the product of the square of the current and the resistance.
The principle of current thermal effect: electrons are accelerated in an electric field, gain kinetic energy, have speed, and then collide with other particles (atoms, molecules, atomic groups) to make other particles gain kinetic energy, resulting in an increase in average kinetic energy and temperature.
The heating principle of the single-head electric heating tube is mainly through the internal resistance wire through the current heating, in the case of a fixed voltage, the greater the resistance, the lower the power; the smaller the resistance, the greater the power. Is it possible to use a resistance wire with a small resistance value to save costs and improve thermal efficiency more? The answer is no. Generally, the larger the resistance, the smaller the wire diameter of the resistance wire. When the voltage is fixed, the current through the resistance wire will be greater. When the current passing through exceeds the load of the resistance wire, it is prone to breakage and damage. Therefore, the resistance of the electric heating tube is not as large as possible. The appropriate resistance wire should be selected according to the actual situation and to ensure normal use.