What should you pay attention to in the safe operation of induction melting furnace ?
1 , precautions before opening the furnace
The induction melting furnace must inspect the electrical equipment, the water cooling system ( closed-loop cooling tower ) , the inductor copper tube, etc. before the furnace is opened .
2 , precautions after opening the furnace
After the induction melting furnace is opened, the charging should be checked during the loading to avoid mixing with flammable and explosive materials. In order to avoid an explosion accident, it is necessary to ensure that there is no water and no obstacles on the site . In the pouring, two people need to cooperate, and the remaining molten steel can only be dumped at a fixed location, and cannot be dumped anywhere.
3 , precautions during maintenance
When the induction melting furnace is used for maintenance, keep the room clean and do not stack flammable and explosive materials. Repair the furnace with excessive melt loss in time, and avoid the incorporation of iron filings and iron oxide in the furnace to ensure the compaction of the crucible.
Reasons for induction melting furnace explosion accidents:
1 . The presence of moist materials in the charge causes a steam explosion.
2 . Temperature sampling or lack of operating skills when adding alloys, causing splashes of molten metal.
3 . Injecting large metal materials into the furnace causes the molten iron to splash.
4 . An unreasonable feeding system led to an explosion .
5 . Failure to escape outside the safety line resulted in injury.
The purpose of induction melting furnace steel
The main raw material for melting is scrap steel and a part of pig iron. The purchased scrap has more rust, muddy sand and other dirt, and the content of sulfur and phosphorus in the steel is also high. The purpose of the steel is to smelt the raw materials of the above conditions into high-quality molten steel with low gas content, high inclusion content, qualified composition and temperature. Specifically, the basic purpose of steel is:
( 1 ) melting solid charge (cast iron, scrap, etc.);
( 2 ) making the elements such as silicon, manganese and carbon in the molten steel reach the specification components;
( 3 ) removing harmful elements such as sulfur and phosphorus and reducing their content below the specified limit;
( 4 ) removing gas and non-metallic inclusions in the molten steel to make the molten steel pure;
( 5 ) adding alloying elements (melted alloy steel) to meet the requirements;
( 6 ) The molten steel is superheated to a certain temperature to ensure the need for pouring;
( 7 ) In order to increase production and reduce costs, it is necessary to rapidly reduce steel;
( 8 ) Casting into a good casting.
Reasons affecting the energy consumption of induction melting furnace
1 , medium frequency power supply
Melting rate determines the level of the intermediate frequency power power induction melting furnace, configuration, high melting fast speed, energy-saving effect. Whether the induction melting furnace can maintain high power and continuously send power to the furnace will affect the energy consumption; the power line of the induction melting furnace is disorderly, which will affect the processing capacity of the power supply, resulting in unstable power and low power conversion efficiency. Affect energy consumption.
2 , the melt
The cleanliness of the surface of the charge, such as 5 % of impurities, will consume 5 % of the electrical energy to melt these impurities, and will affect the life of the lining; the appropriate length of the furnace block will affect the electrical efficiency and melting quality of the induction melting furnace, generally 200 ~ 300mm block is appropriate;
3 , refractory materials
The use of a suitable crucible can increase the melting rate, the quartz crucible is resistant to high temperatures, and is used in conjunction with an induction melting furnace . The metal material in the crucible generates heat by induction heating, which reduces the heat transfer consumption.
Induction melting furnace power saving method
1. Under the premise of ensuring the reasonable operation of the workers, the rationality of the layout , and the overall layout of the induction melting furnace , we should minimize the space layout to shorten the overall connecting line, which will reduce the loss of thermal power and save electricity.
2 , the material used should be as large as possible to ensure a smooth flow of current to prevent the copper row too small, causing the heat to take away part of the power.
3, to be diligent workers, and to continue feeding the auxiliary stirring steel, increase the speed of melting, saving power consumption
4 , the technical content of the induction melting furnace , which is not well determined by the manufacturer. Although the induction melting furnace technology is relatively mature, each family still has its own certain advantages. Therefore, manufacturers are advised to choose large manufacturers to cooperate when purchasing induction melting furnaces . Make sure you save on power consumption.
How to increase the melting speed of the induction melting furnace ?
1. Increase the power of the intermediate frequency induction melting furnace intermediate frequency power supply.
2. Choose a reasonable charge size and the correct feeding method.
3. Appropriate molten iron outlet temperature.
Induction melting furnace water system water stop emergency treatment plan
Induction melting furnace water system water stop
The first step is to start the generator . If the startup fails, then the emergency water turns on.
The second step is to check the water pressure of the emergency pump to close the valve at the inlet and outlet of the furnace body.
The third step is to check the return pipe of the furnace body , the water temperature is too high , the return water temperature , open the furnace body emergency , check the emergency water , the water outlet
, whether the water inlet and outlet valves have water flowing out , check the return pipe of the furnace body , and return water temperature .
Precautions for induction melting furnace emergency water start
A, the first time to observe whether there is water outflow at the outlet of the emergency effluent . If there is no water flowing out of the outlet , it means the water circulation pipe
There is no emergency water to be replenished or the valve on the relevant pipeline is not open . It is necessary to immediately identify the cause and make emergency water supplement in time.
B, . Under the emergency water working state , the on-site personnel should always detect the temperature of the return pipe of each furnace body . If the temperature of each pipeline is found
If the temperature continues to rise and there is no cooling trend, the molten iron in the furnace should be poured out in time .
Routine maintenance of induction melting furnace
1, the furnace body tilt: need to be realized by the handle on the console. Pushing the joystick of the directional control valve to the "up" position, the furnace rises and the liquid metal is poured out of the mouth. If the handle is placed back in the middle "stop" position, the furnace will remain in the original tilt state, so the furnace can stay anywhere between 0-95 °. Push the handle to the "down" position and the furnace body will slowly descend.
2, the furnace lining device: the furnace body is tilted to 90 °, the ejector cylinder is connected with the lower part of the furnace body, the high pressure hose is connected and the speed of the ejector cylinder is adjusted. The old furnace lining can be pushed out by pushing the "furnace lining" handle on the console to the "in" position. Pull the handle to the “retraction” position, remove the cylinder after the cylinder is retracted, reset the furnace body after cleaning the furnace, check the refractory mortar and hoist it into the ejector module to start knotting the new furnace lining.
3. When the induction melting furnace is working, there must be sufficient cooling water in the sensor. Always check that the water temperature of each outlet pipe is normal.
4. The cooling water pipe should be cleaned regularly with compressed air, and the compressed air pipe can be connected to the joint on the water inlet pipe. The water source should be turned off before disassembling the pipe joint.
5. When the furnace is shut down in winter, it should be noted that there should be no residual water in the induction coil. It must be blown off with compressed air to prevent damage to the sensor.
6. When the induction melting furnace is installed with the busbar, the coupling bolts should be tightened and the bolts should be checked frequently after opening.
7. After the induction melting furnace is opened, it is necessary to regularly check whether the joints and fastening bolts are loose. Pay more attention to the bolts that connect the conductive plates.
8. In order to prevent accidents caused by leakage at the bottom of the furnace, a leaking alarm device is installed at the bottom of the furnace. Once the liquid metal leaks, it is connected to the bottom electrode of the stainless steel wire at the bottom of the furnace, and the alarm device is activated.
9. When the wall is eroded, it should be repaired. The repair is divided into two cases: full repair and partial repair.
9.1. Induction melting furnace is fully repaired: it is used when the wall is evenly eroded to a thickness of about 70 mm.
The repair steps are as follows;
9.2. Scrape all the slag attached to the crucible until the white solid layer is leaking.
9.3, put the same die as when building the furnace, set the center and fix it on the upper edge.
9.4. Prepare quartz sand according to the formula and operation method provided in items
9.5. Pour the prepared quartz sand between the crucible and the die and use a φ6 or φ8 round bar.
9.6. After the compaction, add the charge to the crucible and heat it to 1000 ° C. It is best to keep it for 3 hours and then continue to heat up to melt the charge.
9.7, partial patching:
Used when the partial wall thickness is less than 70mm or there is erosion cracking above the induction coil.
The patching steps are as follows:
9.8. Scrape off the slag and deposits at the damage.
9.10. Fix the charge with steel plate, fill in the prepared quartz sand, and compact. Notice Do not let the steel plate move in real time.
If the erosion cracking site is inside the induction coil, a full repair method is still required.
9.11, regularly lubricate the lubricating parts of the induction furnace.
9.12, the hydraulic system uses 20-30cst (50 ° C) hydraulic oil, should keep the oil clean and regular replacement.
9.13, the instrument indication and record of the leak alarm device should be paid attention to during the smelting process.