How to Solve the Discharge of High Voltage Isolation Switchgear in Electric Field

Starting from July 2002, a discharge phenomenon occurred in the electric field high-voltage isolation switchgear of the electric precipitator No. 3 kiln tail of our company's wet process plant. The discharge phenomenon became more severe when it encountered rainy days. Because the highest voltage of the switchgear during operation is 70kv, a strong spark is generated during discharge, and sometimes it is discharged in the indoor control cabinet through the high-voltage isolation switchgear control line. In severe cases, high-pressure porcelain bottles have been damaged, which directly endangered personnel and equipment safety.

Cause Analysis

After stopping the machine, open the door and observe that the discharge part is at the connection between the high-voltage porcelain bottle and the disconnector.

1 We inspect the isolating switch, high-voltage porcelain bottle and its connecting screws in the switch cabinet, tighten the screws, clean up the carbon deposits caused by discharge, and conduct insulation tests.

2 Because the high-voltage isolation switch cabinet is located on the top of the dust collector, it is easy to get wet in rainy days. In addition, this kiln is a wet kiln, the humidity in the electric field is large, the cabinet and the outside and the electric field are not well sealed, so that the humidity in the cabinet increases, the insulation performance of various equipment is reduced, and high voltage discharge occurs. We inspected and replaced the seals around the cabinet. After passing the above checks and treatments, the operation is normal. But over time, the discharge phenomenon became more and more serious, especially in rainy days. Therefore, we believe that the high-voltage isolating switch cabinet is due to the high humidity in the cabinet, which causes the discharge phenomenon to occur.

  problem solved:

1 Strengthen the sealing of the high-voltage isolation switch cabinet, so that its sealing performance is further improved.

2 Inspired by the dehumidification of the electric heater in the electric field of the electrostatic precipitator, the electric heater is installed in the cabinet under the conditions of ensuring the safety and easy installation of the high-voltage switch cabinet. The curved heater has a voltage of 220v and a power of 800w. All external insulation is installed at the bottom of the cabinet. Install a single-pole circuit breaker in the control room to control the on and off of the electric heater, which is convenient for turning on in rainy days and stopping in sunny days. Because the power of this electric heater is small, it has little effect on the operation of the equipment.

Effect

After installing the electric heater for 4 months, the equipment runs normally. Therefore, we also installed the electric heater for electric field 2 electric field and 3 electric field for occasional discharge. Three electric heaters have been running for more than one year, and no discharge occurs, and the effect is very good. The total investment for this transformation was less than 300 yuan. Previously, it only cost more than 3,000 yuan to replace high-voltage porcelain bottles due to high-voltage discharge. At the same time, this transformation solved the safety hazards that endangered equipment and people, and ensured the safe operation of the high-voltage equipment. From a process perspective, increasing this height has little effect.