What to do if the water temperature of the medium frequency furnace fails
The inlet temperature of the cooling water of the intermediate frequency furnace should not exceed 35°C, and the return water temperature should not exceed 55°C. The water temperature failure of the intermediate frequency furnace is generally due to high temperature, which will cause blockage and affect production and operation. Check one by one to ensure that the cooling water pipe is unobstructed.
Ⅰ. Reasons for water temperature failure of intermediate frequency furnace
1. Circulating cooling water is overheated
The reason for the overheating of the circulating cooling water of the intermediate frequency furnace is mainly because the induction coil cooled by the water has been around the high temperature furnace for a long time. When the temperature in the furnace rises, the temperature of the circulating water gradually increases. . Solution: Raise the return pipe of the pool appropriately, add a large-area steel plate with a hole drilled under the nozzle, and let the hot water directly rush to the steel plate and flow down the small hole, which is equivalent to increasing the heat dissipation area.
2. Water pipes are blocked
The cooling water temperature of the induction coil does not exceed 55C. Because when the temperature is too high, the salt dissolved in the water will precipitate in a large amount and condense on the pipe wall to form scale, which will block the pipe, which is one of the reasons for the explosion of the intermediate frequency furnace. Particularly, the cooling pipe of the electrical part is more likely to be blocked due to the thin pipe. At the same time, scale will also affect the normal operation of the water cooling system and reduce the heat dissipation effect.
3. Scaling of the cooling water jacket
After checking all the waterways and removing the waterway problems, the intermediate frequency furnace equipment still alarms, it is probably caused by the scaling of the thyristor cooling water jacket, which needs to be descaled. Descaling requires the use of a special descaling agent for the intermediate frequency smelting furnace. You can contact Yuhua Electric Furnace Factory. We have an integrated after-sales service mechanism, open network and physical learning classes, and train maintenance technicians for users.
4. Water temperature relay failure
The water temperature alarm troubleshooting method is relatively simple when the machine is turned on. It must be caused by the failure of the water temperature relay of the intermediate frequency melting furnace. The water temperature relay can be replaced to eliminate the fault.
Ⅱ. the solution to the water temperature failure of the intermediate frequency furnace
1. Clear water pipe blockage
The intermediate frequency heating furnace has a water temperature alarm after running for a short time or a few minutes, but the intermediate frequency furnace can continue to run after it is shut down and restarted, but it will continue to alarm after a short time. When this happens, check the inside of the intermediate frequency power cabinet. Cool the water pipe and check for signs of blockage. In the case of long-term use of the intermediate frequency electric furnace, it is necessary to ensure the cleanness of the cooling water to avoid debris in the water blocking the water pipe and forming a water temperature alarm. Open all the water pipes from the direction of the water outlet inside the intermediate frequency power cabinet, and use an air compressor or other blowing equipment to clear the pipes one by one to ensure that all the water pipes are unblocked.
2. Judge the furnace condition and exclude
When the golden charge in the furnace “shelves”, the impedance of the induction furnace will increase and the power will decrease. At this time, the heat generated by the induction coil itself increases, so that the outlet temperature of the cooling water is increased by about 5°C compared with normal operation. Therefore, when the electric bell alarm is heard, if there are no other abnormalities (such as high water temperature), the operator can immediately determine that the furnace material is “scaffolding” and eliminate it, so that the furnace condition can be turned to normal as soon as possible to reduce power loss .
3. Reduce the water temperature of the circulating pool
The cooling water is recycled for a long time. If the water temperature in the pool (should be controlled at 25~35 C) is too high, the temperature of the cooling water outlet of the induction coil will be higher, and the electric bell will continue to alarm at this time (more common in summer). After the operator hears the alarm signal, he immediately releases the hot water from the outlet, and at the same time injects cold water into the circulating pool to reduce the temperature of the water in the pool. After the alarm stops, it can return to normal working state.
4. Reduce the water pressure of the cooling water
During the smelting process, a part of the heat is transferred to the cooling water through the furnace lining. When the thickness of the furnace lining is constant, the greater the temperature difference between the inside and outside of the furnace lining, the more heat is transferred from the furnace to the cooling water. In order to reduce the heat loss of the cooling water, the water pressure and the cooling water flow should be appropriately reduced during the smelting process to increase the cooling water outlet temperature (not greater than 55°C), thereby reducing the temperature difference between the inside and outside of the furnace lining and the heat loss. Preliminary calculation results show that when the cooling water limit temperature is controlled at 45~55°C, compared with the predetermined lower limit temperature (40~45°C), the heat loss caused by the heat transfer of the furnace lining can be reduced by about 2%.