CN111593152A - A method for rapid leak detection of blast furnace cooling stave damage - Google Patents

Abstract

The invention discloses a method for rapid leak detection of blast furnace cooling stave damage. When the pipeline of the soft water system outside the furnace body leaks, or the cooling stave wall body and the water pipe in the soft water system inside the furnace body are damaged, and water leaks into the furnace, the expansion tank will leak. The liquid level is not stable and continues to drop. When the blast furnace soft water closed circulation cooling system is abnormal, the water quality index of the soft water during this period of time is detected, and the PH value index changes in decreasing trend; when the cooling wall is damaged, the soft water closed circulation cooling system Gas can be detected in the gas tank and expansion tank. In the normal production state of the blast furnace, observe the working status of the flap flow meter installed on each soft water return pipe of the cooling stave: when the water flow in the flap flow meter of the cooling stave return pipe There are obvious bubbles and white turbidity, indicating that the cooling wall water pipe pipeline is abnormal, and the longitudinal series cooling wall containing this cooling water pipeline may be damaged.

Description

A method for rapid leak detection of blast furnace cooling stave damage

technical field

The invention relates to a method for rapid leak detection for damage to a blast furnace cooling wall.

Background technique

Cooling stave is an important cooling equipment in blast furnace production. It works under high temperature and harsh conditions, and it is easy to cause cracking and water leakage under the action of high temperature alternating thermal stress. In order to avoid losses or even accidents caused by a large amount of water entering the blast furnace, it is necessary to quickly judge and detect the damage of the cooling stave, so as to deal with it in a timely and appropriate manner to ensure the safety and normal production of the blast furnace. At present, the main problems of Bayi Iron and Steel Company in the blast furnace cooling stave damage and leak detection technology are as follows: (1) The blast furnace cooling stave damage is not easy to be detected by monitoring, the leak detection takes a long time, and the amount of water leaking into the furnace is large. (2) The judgment and leak detection methods of blast furnace cooling stave damage are not unified.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a rapid leak detection method for blast furnace cooling stave damage, which can conveniently, quickly and accurately judge and detect the cooling stave damage of a blast furnace soft water closed circulation cooling system, and handle it timely and properly to ensure safe blast furnace production.

The technical solution adopted by the present invention to solve the technical problem is as follows: a method for rapid leakage detection of blast furnace cooling stave damage. 1) An abnormality occurs in the blast furnace soft water closed circulation cooling system. In the soft water system, the wall of the cooling wall and the water pipe are damaged. When water leaks into the furnace, the liquid level of the expansion tank cannot be stabilized and continues to drop. After the liquid level is replenished to normal, it continues to decline. The liquid level of the tank fluctuates regularly: when the liquid level drops, the N2 pressure also decreases synchronously due to the increase of the volume; when the liquid level rises in the replenishment water, the N2 pressure also increases synchronously due to the volume compression; 2) Judgment of the change trend of PH value in the soft water quality test index: (1) Under normal circumstances, the PH value index in the blast furnace soft water quality test results is stable in the standard range of 8.0 to 10.0, and the fluctuation is not large; (2) When the blast furnace soft water is closed and circulated for cooling When the system is abnormal, check the water quality index of the soft water during this period, and the change trend of the PH value index will decrease; 3) Detect the gas composition in the degassing tank or expansion tank of the soft water system. Gas can be detected in the degassing tank and expansion tank of the cooling stave. 3) Observe the working status of the flap flowmeter. Under the normal production state of the blast furnace, observe the working status of the flap flowmeter installed on each soft water return pipeline of the cooling stave: When the water flow in the cooling wall return pipe flap flow meter has obvious bubbles and white turbidity, it means that the cooling wall water pipe pipeline is abnormal, and the longitudinal series cooling wall including this cooling water pipeline may be damaged; , to rule out the abnormal cooling of the soft water circulation of the cooling wall water pipe, local overheating, a large amount of soft water vaporization, and the phenomenon of external leakage of water outside the cooling wall water pipe pipeline. In addition, combined with the pressure gauge pressure method and the gas ignition method, a comprehensive judgment is made again. , it can be confirmed that the cooling wall is damaged, and the flow water in the flap flowmeter in other cooling water pipelines is clear and transparent, indicating that it is normal.

The invention judges the mutual influence relationship between the liquid level of the expansion tank and the N2 pressure in the expansion tank in the soft water closed circulation cooling system of the blast furnace, judges the change trend of the pH value in the soft water quality detection index, and detects the gas in the degassing tank or the expansion tank of the soft water system. Determine the composition, observe the working condition of the flap flow meter installed on each soft water return pipe of the cooling wall, and combine the pressure gauge pressing method and the gas ignition method to comprehensively judge to confirm the damaged cooling wall. The invention can quickly judge the damaged position of the blast furnace cooling stave, and deal with it timely and properly, so as to ensure the safe production of the blast furnace, be beneficial to the forward running, stability and longevity of the blast furnace, improve the blast furnace operation rate and reduce the blast furnace production cost.

Detailed ways

The present invention is further described with reference to the embodiments.

1) Judgment of the mutual influence between the liquid level of the expansion tank and the N2 pressure in the expansion tank:

(1) When the blast furnace soft water closed circulation cooling system is normal, the liquid level change of the expansion tank is consistent with the N2 pressure change in the expansion tank. (2) An abnormality occurs in the closed circulation cooling system of the blast furnace soft water. When the pipeline of the soft water system outside the furnace body leaks, or the cooling wall and water pipes in the soft water system inside the furnace body are damaged, and water leaks into the furnace, the liquid level of the expansion tank is unstable. Stay, continue to drop, and continue to drop after the liquid level is replenished to normal. The N2 pressure in the expansion tank also fluctuates regularly with the liquid level of the expansion tank: when the liquid level drops, the N2 pressure also decreases synchronously due to the increase in volume; when the liquid level rises, the N2 pressure also decreases. A corresponding rise in synchronization due to volume compression.

2) Judgment of the change trend of PH value in soft water quality testing indicators:

(1) Under normal circumstances, the PH value index in the blast furnace soft water quality test results is stable within the standard range of 8.0 to 10.0, and the fluctuation is not large.

(2) When an abnormality occurs in the closed circulation cooling system of the blast furnace soft water, the water quality index of the soft water is detected during this period, and the change trend of the PH value index is decreasing. The reason is that when the cooling wall is damaged, the gas in the furnace will flow back into the soft water, and the CO2 in the gas will react with the water to form carbonic acid (H ₂ CO ₃ ), resulting in a gradual decrease in the alkalinity of the soft water.

3) Determine the gas composition in the degassing tank or expansion tank of the soft water system:

When the cooling wall is damaged, gas can be detected in the degassing tank and expansion tank of the soft water closed circulation cooling system. The reason is that when the water pressure in the cooling wall is lower than the gas pressure in the furnace, if there is leakage in the cooling wall, the gas in the furnace will flow back into the soft water, and the gas entering will be collected in the highest part of the soft water system, that is, the soft water system. expansion tank or degassing tank.

4) Observe the working condition of the flap flowmeter, and make a comprehensive judgment in combination with the pressure gauge pressure method and the gas ignition method:

In the normal production state of the blast furnace, observe the working condition of the flap flow meter installed on each soft water return pipe of the cooling stave: when the water flow in the flap flow meter of the cooling stave return pipe has obvious bubbles and white turbidity, it indicates that the The cooling wall water pipe pipeline is abnormal, and the longitudinal series cooling wall containing this cooling water pipeline may be damaged. After investigation and confirmation, it is ruled out that the cooling wall water pipe soft water circulation cooling is abnormal, there is local overheating, a large amount of soft water vaporization, and there is external leakage of water outside the cooling wall water pipe pipeline. In addition, combined with the pressure gauge pressing method and the gas ignition method, it can be confirmed that the cooling wall is damaged. In other cooling water pipelines, the flowing water in the flap flow meter is clear and transparent, indicating that it is normal.

Using the method can conveniently, quickly and accurately judge and detect the damage of the cooling wall of the blast furnace soft water closed circulation cooling system, and deal with it timely and properly, so as to ensure the safe production of the blast furnace, and is beneficial to the smooth running, stability and longevity of the blast furnace.

Claims (1)

1. A method for rapid leak detection of blast furnace cooling stave damage, characterized in that the following steps are gradually adopted to judge: 1) An abnormality occurs in the blast furnace soft water closed circulation cooling system. When the cooling wall and water pipes in the system are damaged and water leaks into the furnace, the liquid level of the expansion tank cannot be stabilized and continues to decrease. After the liquid level is replenished to normal, it continues to decrease, and the N2 pressure in the expansion tank also increases accordingly with the expansion tank. The liquid level fluctuates regularly: when the liquid level drops, the N2 pressure also decreases synchronously due to the increase of the volume; when the liquid level rises, the N2 pressure also increases synchronously due to the volume compression; 2) Soft water Judgment of the change trend of PH value in the water quality testing index: (1) Under normal circumstances, the PH value index in the blast furnace soft water water quality test results is stable in the standard range of 8.0 to 10.0, and the fluctuation is not large; (2) When the blast furnace soft water closed circulation cooling system When there is an abnormality, check the water quality index of the soft water during this period, and the change trend of the PH value index will decrease; 3) Detect the gas composition in the degassing tank or expansion tank of the soft water system. Gas can be detected in the degassing tank and expansion tank. 3) Observe the working condition of the flap flow meter. Under the normal production state of the blast furnace, observe the working condition of the flap flow meter installed on each soft water return pipeline of the cooling wall: when There are obvious bubbles and white turbidity in the water flow in the cooling wall return pipe flap flow meter, indicating that the cooling wall water pipe pipeline is abnormal, and the longitudinal series cooling wall including this cooling water pipeline may be damaged; It is ruled out that the cooling wall water pipe soft water circulation cooling is abnormal, there is local overheating, a large amount of soft water vaporization, and there is external leakage of water outside the cooling wall water pipe pipeline. It can be confirmed that the cooling wall is damaged, and the flow water in the flap flow meter in other cooling water pipelines is clear and transparent, indicating that it is normal.