Do you know what are the resistive heating elements?

1. Tubular heating element
 
It is a technically mature, safe and reliable electric heating element. This kind of element is made by placing a spiral heating wire in a steel pipe or a magnetic pipe, filling the gap with thermally conductive insulating materials such as magnesium oxide, aluminum oxide, etc., and then through the process of end plugging and surface treatment. The end leads out the heating wire for connecting the power supply.
 
 
2. Semi-closed electric heating element
 
This kind of electric heating element is made by winding the electric heating alloy wire on the insulating frame, and it is installed in a special protective cover when in use. The safety performance of the semi-closed electric heating element is good, but the thermal efficiency is low. Such as: electric irons and other appliances are made of this element, which is semi-closed with mica, and the heat from the electric heating element is transmitted to the bottom plate through the mica; the heating element of the electric stove is also made of this element, which is to heat the cover first. The cover is then conducted to the object to be heated, therefore, a part of the thermal energy is lost, resulting in a decrease in thermal efficiency.
 
3. Resistance wire
 
Most of the resistance wires are arranged in a disc-shaped groove made of insulating material, or placed in a spiral shape on an insulating support, and the heat energy it emits is transmitted to the heated object in two ways: radiation and convection. The advantages of this type of electric heating element are simple structure, low cost, fast heating speed, easy installation and maintenance, etc. The disadvantage is that the exposed resistance wire is easy to be oxidized, the service life is short, and the work is unsafe. If objects or fluids fall into the electric heating element, it will cause a partial short circuit and make the electric heating element exceed the rated power. Commonly used resistance wire devices include electric stoves, hair dryers, etc.
 
4. Electric hot plate
 
Electric heating plate is also known as cooking electric plate, electric stove plate, etc. It is a safe and reliable electric heating plate with no open flame on the surface, no electricity, and mainly relies on heat conduction during use. Therefore, it has high thermal efficiency. Various forms, see Figure 2-2. The electric heating plate is mainly composed of electric plate body, insulating filler and spiral heating wire. The electric heating plate body is required to be flat, able to withstand rapid temperature changes without deformation, and the filling material must have high thermal conductivity, good insulation performance and low energy absorption performance.

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Compared with other electric heating elements. The tubular electric heating element has the advantages of simple structure, low cost, long service life and high mechanical strength, and can be bent into various forms such as U shape, single ring shape and W shape to meet different needs. In addition, the surface is not charged when electrified and heated, which ensures the safety in use. Therefore, tubular electric heating elements are widely used in household appliances such as electric stoves, electric ovens, electric frying pans, water heaters, and electric irons.
 
 
 
Materials and properties of resistive heating elements
 
 
1. The main function of the protection component is when the heating temperature of the electric heating appliance exceeds the normal range. Automatically cut off the power supply to prevent overheating and damage to the appliance. Commonly used devices for protection include thermal fuses, thermal fuses, thermal relays, etc.:
 
2. The main function of the temperature control component is to control the temperature, heating power and power-on time of the heating component to meet people's needs. Commonly used temperature control components include bimetal, magnetic, PTC, thermistor, thermocouple, electronics, computer temperature control components, etc.

3. The main function of the heating component is to convert electrical energy into thermal energy, which is composed of various electric heating elements. Commonly there are resistance heating electric heating elements, electric heating wires, electric heating alloy heating plates, resistance heating elements, tubular electric heating elements, PTC electric heating elements, far-infrared radiators, etc.