It is convenient and safe to use silicon carbon rod heating
Heating with silicon carbon rods is safe and reliable. It has been widely used in some high-temperature fields such as electronics, magnetic materials, powder metallurgy, ceramics, glass, semiconductor, analytical laboratory, scientific research, etc., and has become tunnel kiln, roller kiln, glass kiln, vacuum furnace, muffle furnace, smelting furnace. And electric heating elements for all types of heating equipment.
Straight Silicon Carbide Heating Elements For Kilns have high temperature, high temperature resistance, oxidation resistance, corrosion resistance, fast heating, long life, low temperature deformation, convenient installation and maintenance, and good chemical stability.
Silicon carbon rod heat dissipation
In order to make the temperature of the liquid material uniform, on the one hand, the cooling hole is reserved in the cooling section, and the opening degree of the cooling hole is adjusted to adjust the heat dissipation in the middle part of the cooling section of the supply channel to make the temperature uniform; on the other hand, special silicon carbon is used. Rod assisted heating is achieved. The SIC Furnace and Kilns Heater are generally evenly arranged above the glass liquid in the feed channel, maintaining a certain distance from the glass liquid, and radiating heat downward. In order to ensure heating on both sides of the feed channel and the middle part is not heated, a special SIC Furnace and Kilns Heater for the glass material industry---five-section rod (ie, double-heat-generating straight silicon carbon rod) is generally used.
The silicon carbide protection tube is made by welding two identical heating elements and three cold ends by special process, that is, the middle and indirect one of the two heating elements, and the total length of the three corresponds to the width of the channel (in Double-threaded silicon carbon rods are used in the design of feed channels imported from abroad. Since the middle part of the silicon carbon rod does not generate heat or generate less heat, and is heated near the side wall portion, and a reasonable design, the temperature of the molten glass can be uniformly lowered in the flow. In the design of the feed channel, some manufacturers also use equal-diameter silicon carbon rods (ie, three-stage straight silicon carbon rods), which are welded by a heating element and two cold ends.
The feeding channel adopts three-stage GD Type Silicon Carbide SIC Heating Elements, which not only heats the glass liquid but also heats the two sides of the wall, thus ensuring the temperature of each section of the feeding channel, and also supplementing the heat dissipation of the side wall, but the homogenization effect is far less than Five-section High Temperature SIC Heating Elements. Regardless of whether a three-segment rod or a five-segment rod is used, the homogenization effect is determined by the heating channel structure and the heating of the silicon carbon rod, and the temperature at which the various sections of the feeding channel end up is controlled by the control system.
For continuous operation of the furnace and the feed channel, the voltage adjustment range is 0.7 to 2.0 V (V is the voltage initially used for the silicon carbon rod element). The life of the silicon carbide component can be extended by boost regulation. After the silicon carbon rod electric heating element is used for a certain period of time, since the resistance value is increased, the voltage needs to be increased to compensate for the loss of the resistance increase, so the transformer has a large voltage adjustment range.
In order to extend the life of the U Shaped SIC Silicon Carbide Heater component and ensure safe use, multiple series connection should be avoided. The wiring method of the silicon carbon rod component can be connected in parallel, series, angle, star and other forms; however, the parallel connection is superior to the series connection, and the parallel connection can adjust the load imbalance factor, and the multiple series connection increases the imbalance. Factors that increase the operating voltage.
The higher the furnace temperature, the smaller the surface load density is allowed; the over-loading causes the silicon carbon rod to decompose and cause the surface of the heat-generating part to fall off and burn out. In order to ensure the life of the components, it is forbidden to use the electric heating elements under overload conditions. Generally, the value is controlled at 3~8W/cm2. The surface load density is reduced by adjusting the electrical load applied to the silicon carbon rod component.
If the load is small and the surface load density is low, the temperature in the kiln can be maintained for a long period of time. This can be adjusted by changing the number of installations of the Type W Silicon Carbide Heating Rod components or changing the specifications of the components. The size of the surface is achieved. The silicon carbide rod electric heating element has a firing temperature of up to 2200 ° C, giving it good heat resistance and oxidation resistance.
In addition to the above two points, the advantages of the Type W Silicon Carbide Heating Rod electric heating element are that the heating ability is good, the expansion coefficient is small, the deformation is not easy under high temperature conditions, the chemical stability is good, and the corrosion resistance is good. Silicon carbon rod electric heating elements have a long service life and are easy to install and easy to maintain. Silicon carbide rod heating elements can be used with automated control systems to achieve precise temperature control and constant temperature. After the silicon carbon rod electric heating element is matched with the control system, the temperature can be arbitrarily adjusted according to the control curve according to the production needs.
During the flow of the glass liquid through the cooling section and the homogenization section, the glass liquid should be uniformly cooled to a temperature suitable for molding. If no measures are taken, the heat dissipation on both sides of the material channel is small, and the heat dissipation in the middle portion is small, which may result in the middle portion of the glass. The temperature gradient on both sides is large, that is, the temperature of the same section of the glass liquid is not uniform, so that the viscosity of the glass liquid is inconsistent, which directly affects the quality of the molding.