How does an intermediate frequency heating furnace work2021-09-15
Intermediate frequency heating furnace is induction heating equipment for the purpose of heating metal forging or tempering heat treatment. It is generally used for heating before forging and the heating temperature is 1200 degrees, while the heating temperature for tempering heating is generally within 1000 degrees. This intermediate frequency heating application determines that the heating principle of an intermediate frequency heating furnace is only for heating purposes and cannot melt metal. Therefore, if the heating furnace in the structure, in principle is different from other forms of heating furnace, next we will talk about if heating furnace principle. 1. The principle of intermediate frequency heating furnace is based on electromagnetic induction heating and follows the electromagnetic effect theory, such as electromagnetic ring effect, skin effect, sharp Angle effect, proximity effect, diathermy effect, conduction effect, etc. 2. intermediate frequency furnace is mainly composed of variable frequency device and induction coil, power frequency 50 Hz alternating current frequency conversion device would turn into intermediate frequency 100 Hz – 10000 Hz of alternating current, the three-phase alternating current into direct current (dc) after rectifying power frequency, and then laid adjustable intermediate frequency electric current, direct current supply by the capacitor and inductor in...
The fault analysis and maintenance process of medium frequency heating furnace.2021-09-14
When the medium frequency heating furnace is started, the given voltage is suddenly applied. Because there is no voltage feedback, the output of the voltage regulator increases rapidly. Due to the drift of control parameters, the current feedback coefficient is reduced. The same if the current is given, the instantaneous current of if the device is relatively large, resulting in impulse current. Only when the voltage loop is overshoot, the output current begins to decrease, which is finally determined by the load. Because of the large reactance in the medium frequency furnace, the system response is slow. With the increase of the given voltage, the impact current is larger, and the impact on the thyristor is also large, which accelerates the degradation of the thyristor, resulting in the fatigue breakdown of the thyristor. With the aging of components and the parameter drift of the analog control system, the lead angle triggered by thyristor in the inverter control circuit becomes larger (42.8 °), and the power factor is low (0.733). Even if the same intermediate frequency voltage and current are output, the active power output of the intermediate frequency heating furnace is not high and the heating effect is poor. Under...
What are the daily maintenance of medium frequency furnaces?2021-09-13
In order to ensure the working effect of the medium frequency furnace and prolong the service life of the medium frequency furnace, the medium frequency furnace should be regularly maintained and inspected. Daily maintenance can be carried out from the following aspects: 1. Check and clean the radiator to maintain a high-efficiency cooling effect, and carry out pickling when necessary; 2, Check whether the water cooling system is blocked and leaking phenomenon, whether the water pressure relay is sensitive, inlet water temperature difference should not be greater than 35 ℃; 3, Check the induction coil insulation and whether there is a water leakage phenomenon; 4, Check whether the wires and switches are damaged; 5, Check and clean the water tank, check the drain valve, and remove certain sewage to prevent scaling; 6. Clean the oil stains and dust of all electrical components and other equipment, and use fans or leather tigers to clean up the dust; 7. Check whether each wiring screw is tightened to ensure good contact. 8. Check thyristor, electrical circuit bus, transformer, and each line segment for overheating.
What energy loss is metal induction heating2021-09-13
Energy losses, during induction heating: 1, The energy loss is caused by the current flowing through the copper wire of the sensor. 2, heat loss from heated blanks and thermal insulation through the sensor; 3, heat loss from the heated blank into the surrounding medium. The energy lost in the first two forms is the main part of all the losses, which is taken away by the cooling water flowing through the sensor copper tube and can be obtained by calculation and test methods. The third form of energy is taken away by the flowing air. Its values are difficult to obtain by calculation and testing methods.
Molding method of furnace lining for MF melting furnace2021-09-10
According to the size of the crucible, the forming method of medium frequency furnace lining crucible can be divided into four kinds: mortar pouring forming method, pressure forming method, furnace forming method, and masonry method. the first two methods are mainly used to make small capacity (below 100 kg) crucible. the latter two methods are suitable for making medium and large capacity crucible. 1、Mortar pouring molding method This crucible forming method is suitable for making special refractory crucible with capacity below 25 kg, such as CaO、BeO、ZrO2、ThO2、Al2O3 crucible. 2、Pressure Molding Method The sand material of the crucible is mixed evenly according to different particle size ratios, then put into the pressure forming mold, and the pressure is applied to make it form. The pressure forming method can be divided into simple pressure forming and isostatic pressing forming. 3、Furnace inside Molding Method The furnace forming method is a widely used crucible forming method. It is suitable for crucible forming with different capacities. The furnace molding method is divided into manual tamping molding method and mechanical vibration molding method. 4、Masonry Method Masonry is the use of special refractory bricks, in the furnace masonry into the crucible. This method is suitable for hot charging...
Three Processes of Medium Frequency Furnace Heating2021-09-09
How does the medium frequency furnace convert electric energy into heat energy to heat metal burden? In short, it includes the following three steps: Alternating current generates alternating magnetic field Induced current generated by alternating magnetic field Induced current is converted into heat energy It can be seen that the whole heating process of the medium frequency furnace is frustrated by the process of energy conversion. First, electric energy is converted into magnetic field energy, then magnetic field energy is converted into electric energy, and most of all-electric energy is converted into heat energy to heat metal. From this point, it can be seen that the heating method of a medium frequency furnace is different from that of an electric arc furnace, plasma furnace, resistance furnace, etc. Many transformations of melancholy energy forms will inevitably lead to losses, so it is called low thermal efficiency. This requires taking measures to compensate from the electrical lines to reduce losses and improve efficiency, thus making medium frequency equipment more energy-saving.