How to install and debug the induction melting furnace ?

1. Preparation before installation            

Before installation, it is necessary to check whether all the components of the complete set of equipment, the main components of the furnace and the installation materials are complete, and check their condition. The defects of some parts and materials caused by improper transportation and storage should be repaired to ensure that all equipment, parts, corresponding materials and parts are intact to ensure the smooth progress of future installation and commissioning.

In addition, the inspection and acceptance of various civil engineering facilities related to furnace equipment, such as checking whether the main dimensions in the layout are correct; checking whether the foundations, trenches and embedded parts required for the installation of various electrical equipment and main busbars conform to the design Requirements, whether the furnace foundation, platform elevation, deviation of the vertical and horizontal axes, and the position of the anchor screws are within the specified size range; check whether the construction quality of the base and platform meets the requirements. Only after the above preparations are completed, can the furnace be installed and debugged.

2. Installation and commissioning of furnace and electrical equipment

1 . Furnace installation  

The installation procedures of the furnace body are specified on the drawings. The first is to install the furnace frame on the flat base, and then install the furnace oil tank and furnace body. If there is a weighing device, it should be installed in the specified position according to the requirements of the drawing. The furnace bracket (for the crucible induction melting furnace includes a fixed bracket and a movable bracket) and the furnace body part, during the processing , the thermal deformation caused by the welding construction should be limited to the specified range of the design . Only in this way can it be ensured Future work proceeded smoothly.

2 . Installation and commissioning of water cooling system  

The water-cooling system is an important part of the entire furnace device, and its installation and debugging will affect the normal operation of the furnace in the future. Before installation and commissioning, first check whether the various pipes, hoses and corresponding joint sizes in the system meet the design requirements. It is best to use galvanized welded pipe for the water inlet pipe. If ordinary welded steel pipe is used, the inner wall of the pipe should be pickled before assembling to remove rust and oil stains. The joints in the pipeline that do not need to be disassembled can be connected by welding, and the welding seam is required to be tight, and there should be no leakage during pressure test. The detachable part of the joint in the pipeline should be structured to prevent water leakage and facilitate maintenance.

After the water cooling system is installed, a water pressure test is required. The method is that the water pressure reaches the highest value of the working pressure and keeps it for ten minutes. All welds and joints are qualified if there is no leakage at the joints. Then conduct water and drain tests to observe whether the flow rates of the sensors, water-cooled cables, and other cooling water channels are consistent, and make appropriate adjustments to make them meet the requirements.

The backup water source and its switching system should be completed before the first test furnace.

3 . Installation and commissioning of hydraulic system  

The hydraulic drive device should have the advantages of small size, flexibility and lightness, and convenient control and operation. Most crucible induction melting furnace use hydraulic tilting systems. The design of the oil pump station should consider reliable use and convenient maintenance. There are melting sections with multiple induction melting furnaces . The hydraulic systems of each furnace should be able to borrow each other to reduce the time of forced shutdown due to maintenance of the hydraulic system.

The oil pump station is generally installed on a base with a certain height, which is convenient for draining oil from the oil tank during maintenance, and at the same time, it is conducive to safe production. Even if a serious furnace leakage accident occurs, the oil tank can be protected from molten iron. When installing oil pipelines, we must also proceed from the worst conditions, avoid encountering high-temperature iron liquid at any time to prevent the expansion of the accident.

Eliminating the oil leakage in the hydraulic system is a relatively difficult task. This starts with improving the installation quality. The joints of the oil pipeline that do not need to be disassembled should preferably be connected by welding. The weld should be dense and free of leakage. After welding, clean the inner wall without leaving welding slag and oxide scale. For oil pipeline joints with threaded connections, sealing and leak-proofing should be considered in the structure. When installing, adopt corresponding auxiliary measures, such as adding anti-leakage paint, to reduce the possibility of oil leakage during operation.

After the hydraulic system is installed, the endurance test of the entire system should be carried out. The method is to pass in 1.5 times the working pressure of the oil, keep it for 15 minutes, carefully check every joint, welding and the interface of every component, if there is any leakage, measures should be taken to eliminate one by one.

After the furnace body, water cooling system, and hydraulic system are installed, the furnace body tilting test should be carried out, and the overall inspection of the furnace installation quality, such as whether the hydraulic control system is flexible and reliable, whether each action is correct; whether the furnace body and furnace cover are operating normally ; When the furnace body is tilted to 95 °, whether the limit switch plays an insurance role, and adjusts the pressure and flow of the hydraulic system to make it in a good working condition. While tilting the furnace, check the installation quality of the movable joints of the water-cooling system. No water leaks or hinder the tilting of the furnace body; check the hoses of the hydraulic and water-cooling system, observe whether the length is appropriate when the furnace body is tilted, and make appropriate measures if necessary. Adjust; check whether the drainage system can work normally when the furnace body is tilted. If any deficiencies are found, corresponding measures should be taken.

4 . Installation and debugging of electrical systems, inductors, and magnetic yokes  

The installation of the main power supply line, transformers, capacitors, reactors, various switch cabinets and control cabinets, main bus bars, power lines and control lines of the furnace should be carried out in accordance with the relevant regulations of the national industrial enterprise electrical design and installation, and special attention should be paid Is the following:

( 1 ) The terminal numbers should be marked on both ends of all control wires in the electrical equipment room to facilitate inspection and maintenance. After the wiring is completed, check repeatedly and test the electrical actions to ensure that the actions of all electrical appliances and their interlocking devices are correct.

( 2 ) Before the sensor is connected to the water, the insulation resistance of the sensor should be tested and the withstand voltage test should be done. If the sensor has been watered, you need to use compressed air to dry the water, and then perform the above test. The inductor should be able to withstand an insulation withstand voltage test of 2U n +1000 volts (but not less than 2000 volts) for 1 minute without flashover and breakdown. Un is the rated voltage of the inductor. During the high voltage test, the voltage starts from the specified value of 1/2U n and increases to the maximum value within 10 seconds.

In the inductor, the insulation resistance between the induction coils and between the induction coil and the ground should meet the following requirements: For those with a rated voltage below 1000 volts, use a 1000 volt shaker, and the insulation resistance value should not be less than 1 megohm; the rated voltage is 1000 For those above volts, use a 2500 volt meter with an insulation resistance of 1000 ohms. If the insulation resistance value is found to be lower than the above value, the inductor should be dried, which can be dried with the help of a heater placed in the furnace or blowing hot air. At this time, however, care should be taken to prevent local overheating that is harmful to the insulation.

( 3 ) Whether the yoke top screw is firm and tightened.

The furnace must be confirmed before it is put into operation: all interlocking and signal systems are intact, the tilt limit switch is reliable when the furnace body is tilted to the maximum position, and the power supply, measuring instruments and control and protection systems are in normal conditions, and then the furnace is built, Tests for knotting and sintering the lining.