Industrial Frequency Induction Furnace Structure

Industrial Frequency Induction Furnace Structure

An industrial frequency induction furnace is generally composed of a set of power supply and electrical control equipment and two furnaces, one for smelting and the other for standby. Each furnace is mainly composed of a furnace body, fixed frame, furnace cover mechanism, water and electricity introduction system, and hydraulic system.

1. Furnace

An assembly unit is composed of frame type (below 5 tons) or simple shell type (above 10 tons) furnace shell, inductor, magnetizer, the crucible, and other main components. It is the "heart" of the furnace. It depends on how this part works. The furnace shell is welded into a whole by steel plate or section steel, which has sufficient strength and rigidity. The inductor is made of a high-quality special-shaped steel pipe, with water cooling in the middle, and a power supply connector, and a water supply connector at the end; the inductor is seated on the furnace bottom coil, centered by the surrounding magnetic yoke and compressed in a radial direction. The upper part is equipped with an elastic axial fastening device to reduce the vibration of the inductor during power transmission and prevent the movement of the induction coil when the furnace is tilted. According to the design needs, there are one group or two or three groups of sensors; according to the requirements of the smelting process, they can be incorporated into the network separately or together.

The magnetic yoke is made of high-quality silicon steel sheets, distributed on the periphery of the inductor, and serves as a framework for supporting the inductor. At the same time, it can restrain the leakage of magnetic flux from the outside of the inductor to prevent the metal components from heating up. Crucible is used as a container for the molten metal solution. It is made by ramming and knotting high-carbon steel, cast iron, copper, aluminum, and other non-ferrous metals and their alloys during the melting process. The furnace body composed of the above-mentioned parts is connected to the fixed frame through the bearings on both sides, and the two plunger cylinders realize the furnace body tilting to pour the metal solution.

2. Fixed Frame

The fixing frame is welded by section steel and is firmly fixed on the concrete foundation with anchor bolts. It bears the entire load of the entire furnace body and plays a supporting role during the tilting of the furnace body.

3. Furnace Cover Mechanism

Industrial frequency induction furnace cover, lifting handle or lifting cylinder. Through manual or hydraulic drive, the furnace cover can be moved up and down and rotated to achieve charging and prevent a large amount of radiant heat loss. Filling refractory materials in the furnace cover ring is also used to reduce heat loss. There is an observation hole on the stove cover, which can be used to monitor the smelting situation at any time during the smelting process. It is also used for temperature measurement and sampling. The maximum opening angle of the furnace cover is 90°.

4. Water and Electricity Introduction System

The system consists of inlet and return water mains, water-cooled cables, branch waterways and their monitoring instruments. Mainly used for water-cooled sensors and water-cooled cables.

The inlet temperature of the cooling water is generally controlled between 5°C and 35°C, and it is best to keep it slightly lower than the ambient temperature. Otherwise, the temperature difference is too large, which will often cause condensation on the outside of the inductor, cables and pipelines, resulting in damage to the insulation and There is a leakage phenomenon. The temperature of the outlet water should be controlled below 55°C to reduce the scale of CaO and MgO deposited on the inner wall of the sensor in the water.

The cooling water enters the main pipe from the water source and is distributed to each branch. One of them is used to cool the sensor and the other is used to cool the cable. Usually, two cables form a cooling water circuit; each branch is equipped with a stop valve, and its flow can be adjusted according to the size of the water outlet. . The water monitoring system adopts the electrical contact pressure gauge installed on the quasi-inlet side main pipe. When the inlet water pressure is less than the minimum pressure, a signal and sound are sent out; the outlet water temperature of each branch on the outlet side is controlled by a bimetallic signal thermometer. When the road water temperature exceeds the adjusted maximum water temperature of 55°C, a signal can be issued, and then the over-temperature branch can be found according to the instructions or measurement, and the cooling water volume of the branch can be manually adjusted.

The cooling water must be clean. The water quality is required: the acidity is in the range of pH 6-9, the hardness is not more than 10 degrees (1 liter of water contains 10 mg of calcium oxide per degree), and the total solid content is not more than 250 mg/liter. The system should be placed at the connection point of the water source The filter is connected to it to prevent large impurities from clogging the waterway. The length of the water delivery hose used in this system should not be less than the design value, so as to avoid electric shock accidents caused by leakage of electricity.

5. Hydraulic System

The two furnace bodies are provided by one or two hydraulic devices to provide pressure oil. The furnace body is tilted or the furnace lid is opened and closed through manual valves and buttons on the console. The hydraulic device is composed of two identical sets of oil pumps, motors, valves, etc. The two sets are spare for each other, the working oil is No. 3 stator oil, and the furnace body has a maximum tilt angle of 95°.

The tilting oil cylinder is installed between the industrial frequency induction furnace body and the fixed frame as the actuator for tilting. The lower oil inlet is equipped with a "pipe rupture safety valve". Once the oil pipe is broken or the hose is disconnected due to some accident, the safety valve Act immediately to close the oil circuit and prevent the furnace body from falling automatically.