Electromagnetic heating often faces the need of high-temperature workplaces. Because the intensity of the electromagnetic field decays rapidly as the distance between the coil and the heating element increases, the distance between the coil and the heating element is theoretically the closer the better, which leads to this demand and There is a contradiction in the insulation effect. When facing a high-temperature heating place, how to achieve a better insulation effect in a relatively small distance (the thickness of the insulation cotton between the coil and the heating element)?
Insulation process selection:
In order to achieve a better insulation effect with a thinner insulation layer, it is important to understand the insulation performance of different materials.
Insulation materials of different materials have huge differences in their temperature resistance grades, thermal conductivity, material compactness, hardness, and construction techniques. Therefore, when choosing insulation materials, we need to follow the following principles:
1. According to the temperature resistance grade of the material, select an insulation material with a temperature resistance of at least 300 degrees higher than the heating temperature of the heating element surface.
2. According to the area of the coil layout and the distance between the coil and the heating element, select the thermal insulation material with appropriate thermal conductivity.
3. According to the requirements of coil forming, choose insulation materials with different density and hardness.
4. According to the construction conditions on site, select suitable insulation materials.
5. An important principle is to ensure that after the above selection, the temperature of the surface of the insulation cotton is as low as possible during the working process. Keep it at least below 100 degrees in high temperature situations.
Inverter heating stove
Take high temperature thermal insulation coating as an example to explain its performance
1. High-temperature thermal insulation coatings are mainly composed of abrasion-resistant, high-temperature thermal insulation ceramic powder and high-molecular inorganic polymer slurry. The thermal insulation efficiency of the high temperature thermal insulation coating can reach about 90%, which can inhibit the heat radiation and heat loss of the object, the thermal conductivity is only 0.03W/m.k, and the high heat resistance can reach 1800℃.
2. The high-temperature thermal insulation coating is fireproof, waterproof, crack-proof, soundproof, flame-retardant, insulating, wear-resistant, acid-base resistant, chloride-resistant, sulfide-resistant, non-toxic and environmentally friendly. Coating on the surface of high-temperature pipelines, high-temperature equipment, furnaces (inside and outside), and high-temperature containers, with high heat insulation efficiency.
3. Brush 8mm thick coating on the surface of the object at 1100℃, and the surface temperature of the object can be reduced to within 100℃.
4. Brush a 6mm thick coating on the inner surface of the furnace chamber. The inner wall of the furnace chamber is flat and smooth without cracks. Due to the low thermal conductivity of the coating and the infrared reflection function of the coating, the flame center temperature is increased by 10-50℃. It can reduce the heat loss by more than 30%, and the energy saving effect is obvious.
5. It has a strong fire prevention effect. It can be continuously calcined in the fire for 365 days, and the material will not be powdered or shaped.
6. Brush the 12mm thick coating on the ladle, the surface temperature before brushing is 1000℃, and the surface temperature after brushing is 80℃. Less heat loss, protection of equipment and personnel safety, and abrasion resistance and impact resistance (coating hardness up to 6H).
7. The chlorine ion content of the coating is zero, which can prevent the air or wet chlorides, sulfides and other media in the process from entering the contact metal surface, which has a good protective effect on the metal, and will not cause the embrittlement of the weld metal weld. .
8. The coating has a high insulation coefficient, and it has an insulating effect at room temperature and high temperature.
9. The product does not have any peculiar smell, does not contain or produce VOC substances, does not contain asbestos and other carcinogens and other harmful polymers, decomposition products and high-temperature reaction by-products.
10. Stable chemical performance, does not react with other substances, and is not affected by corrosive media such as acid and alkali.
What are the advantages of electromagnetic heaters?
The electromagnetic heater is a new type of heating energy-saving product, which is composed of an electromagnetic heating coil and an electromagnetic heating controller. It has significant power saving effect, fast heating speed, high thermal efficiency, lower production environment temperature, maintenance-free and other notable features, and it has no influence or change on the original production process and operating procedures. It has been widely used in plastic processing and similar heating industries-plastic machinery (such as: injection molding machine, extruder, pelletizer, film blowing machine, wire drawing machine in energy-saving transformation).
Compared with the traditional resistance wire heating mode, the electromagnetic heater can save more than 30% of electricity and improve thermal efficiency. With the emergence of electromagnetic heating technology and the practical application in recent years, a large amount of data proves that the production efficiency, product quality, and energy saving of machinery and equipment after electromagnetic heating energy saving are much better than traditional resistance wire heating.
The electromagnetic heating coil itself basically does not generate heat, has a long life, does not need to be overhauled, and has no maintenance and replacement cost; the heating part adopts a ring-shaped cable structure, the cable itself does not generate heat, and can withstand high temperatures above 500°C, with a service life of up to 10 years. No maintenance is required, and there is basically no maintenance cost in the later period.
High-efficiency and energy-saving: Using internal heating method, the molecules inside the heating body directly induce magnetic energy to generate heat. The thermal start is very fast. The average preheating time is shortened by more than 60% compared with the resistance coil heating method. At the same time, the thermal efficiency is as high as 90%. Under the same conditions, Compared with resistance coil heating, it can save 30-70% of electricity, which greatly improves production efficiency.
Electromagnetic heater
Accurate temperature control: the coil itself does not generate heat, the thermal resistance is small, the thermal inertia is low, the temperature of the inner and outer walls of the barrel is the same, the temperature control is real-time and accurate, and the product quality is obviously improved, and the production efficiency is high.
Good insulation: The solenoid coil is made of customized special high-temperature and high-voltage special cable, with good insulation performance, no direct contact with the outer wall of the tank, no leakage, short-circuit failure, and safety.
Improve the working environment: The injection molding machine modified by electromagnetic heating equipment adopts the internal heating method. The heat is concentrated inside the heating body, and there is almost no external heat dissipation. The surface temperature of the equipment can be improved to be touchable by the human body, and the ambient temperature has been reduced from above 100°C when the resistance coil is heated to normal temperature. This greatly improves the working environment of the production site, greatly improves the enthusiasm of the production workers, and reduces the cost of ventilation and cooling in the factory area in summer.