Method for accurately judging whether small sleeve in tuyere leaks water

Abstract

The application relates to a method for accurately judging whether a small tuyere bush leaks or not, wherein the water inlet flow of the small tuyere bush is P1, the water outlet flow is P2, the inlet and outlet water flow curves are stable, the difference between the inlet and outlet water flows is Delta P12; the inlet and outlet water flows do not change after burning leakage, at this time, the curve does not change; the water inlet of the small tuyere bush valve is closed, the water inlet amount and water inlet pressure are reduced; the water inlet pressure after water control is smaller than the hot blast pressure in the blast furnace; the small tuyere bush water inlet valve is continuously controlled; the water inlet flow of the small tuyere bush after water control is Pcontrol1, and the water outlet flow is Pcontrol2. The method can quickly and accurately judge whether the small tuyere bush of the blast furnace leaks or not without increasing any equipment and procedures, and the accuracy is improved through three confirmations, so that a large amount of cooling water is prevented from flowing into the blast furnace, the fuel ratio is reduced, and the safety, stability and smooth operation of the blast furnace are guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of detection technology, and in particular to a method for accurately judging whether a small sleeve in an air vent is leaking. Background Art

[0002] The tuyere sleeve is located above the furnace hearth, extending approximately 300-400 mm into the furnace. It is typically made of copper and cooled by water. During blast furnace operation, the sleeve is subject to immense heat loads, and over time, cracks and fissures develop at its front end. High-temperature slag or molten iron dripping onto the tuyere surface can damage or melt the sleeve. A damaged sleeve, containing high-pressure cooling water, can flow into the blast furnace, directly increasing the fuel ratio and disrupting stable and smooth operation. Currently, conventional blast furnaces use a differential flow rate alarm to detect leaks in the tuyere sleeve. This alarm is triggered by a flow difference exceeding a set value. This mechanism involves installing an electromagnetic flowmeter at each cooling water inlet and outlet. This differential flow rate alarm determines if the sleeve is leaking. However, in practice, this does not trigger an alarm when the sleeve is leaking, posing a significant risk to the safety, stability, and smooth operation of the blast furnace. Summary of the Invention

[0003] The purpose of the present invention is to address the shortcomings and defects in the existing technology and provide a method for accurately judging whether the small sleeve in the tuyere is leaking. This method can use the existing equipment and procedures of the blast furnace without adding any equipment and procedures, and can quickly and accurately judge whether the small sleeve in the tuyere is leaking, which does not cause an alarm in the existing program. The accuracy is improved through three confirmations, thereby avoiding a large amount of cooling water from flowing into the furnace, reducing the fuel ratio, and providing a strong guarantee for the safety, stability and smooth operation of the blast furnace.

[0004] To achieve the above object, the present invention adopts the following technical solution: a method for accurately judging whether the small and medium-sized sleeves of the tuyere are leaking, which comprises the following specific method steps: the water inlet flow of the small and medium-sized sleeves is P1, the water outlet flow is P2, the inlet and outlet water flow curves are stable, and the inlet and outlet water flow difference is △P12; the water inlet valves of the small and medium-sized sleeves are closed to reduce the water inlet volume and water inlet pressure; after water control, the water inlet pressure is less than the hot air pressure in the blast furnace; the water inlet valves of the small and medium-sized sleeves are kept closed; after water control of the small and medium-sized sleeves, the water inlet flow is P control 1, and the water outlet flow is P control 2; when △P control 12-△P12≤-1t / h , then it is determined that the small and medium-sized sleeves of the tuyere are leaking; at the same time, observe at the water outlet of the small and medium-sized sleeves of the tuyere. When the water inlet decreases to a certain level and the pressure in the blast furnace is greater than the cooling water pressure by 200~300Kpa, if white water head gasping and "white line" phenomenon appear in the return water, it is determined for the second time that the small and medium-sized sleeves of the tuyere are leaking; after it is determined that the small and medium-sized sleeves are leaking, in order to avoid a large amount of cooling water leaking into the furnace, the small and medium-sized sleeves take water control measures, and the water control standard is △P control 12<△P12. Observe whether the water marks on the contact surfaces of the tuyere sleeves are completely dry. If the water marks on the contact surfaces of the tuyere sleeves are completely dry, it is determined for the third time that the small and medium-sized sleeves of the tuyere are leaking.

[0005] As a more specific description of the present invention: the continuous control of the water inlet valves of the small and medium sets is specifically: the water control volume needs to be maintained at about 30% of the original water inlet, and the water supply to the small and medium sets cannot be cut off.

[0006] After adopting the above technical solution, the beneficial effect of the present invention is: this method can use the existing equipment and procedures of the blast furnace without adding any equipment and procedures, and can quickly and accurately determine whether the small sleeves in the tuyere that do not alarm in the existing procedures are leaking, and improve the accuracy through three confirmations, thereby avoiding a large amount of cooling water from flowing into the furnace, reducing the fuel ratio, and providing a strong guarantee for the safety, stability and smooth operation of the blast furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0008] Figure 1 This is a schematic diagram of data 1 before water control and leak detection in the present invention.

[0009] Figure 2 This is a schematic diagram of the water control and leak detection of Data 1 in the present invention.

[0010] Figure 3 This is a schematic diagram of data 2 before water control and leak detection in the present invention.

[0011] Figure 4This is a schematic diagram of the water control and leak detection of Data 2 in the present invention. DETAILED DESCRIPTION

[0012] The technical solution adopted in this specific embodiment is: it includes the following specific method steps:

[0013] S1, the inlet flow of the small and medium sets is P1, the outlet flow is P2, the inlet and outlet flow curves are stable, and the inlet and outlet flow difference is △P12;

[0014] S2, close the water inlet valves of small and medium sets to reduce the water inlet volume and pressure;

[0015] S3, after water control, the water inlet pressure should be less than the hot air pressure in the blast furnace;

[0016] S4, keep the water inlet valves of the small and medium sets closed;

[0017] S5: After the water is controlled in the small and medium sets, the inlet flow is P control 1, and the outlet flow is P control 2. Specifically, the controlled water volume must be maintained at 30% of the original inlet water, and the water supply to the small and medium sets cannot be cut off.

[0018] S6, when △P control 12-△P12≤-1t / h, it is determined that the small sleeve in the tuyere is leaking;

[0019] S7, while observing the outlet of the small sleeve in the tuyere, when the water inflow decreases to a certain level and the pressure in the blast furnace is 200~300KPa higher than the cooling water pressure, if white water head gasping and "white line" phenomenon appear in the return water, it is determined that the small sleeve in the tuyere is leaking;

[0020] S8. After it is determined that the small and medium-sized sleeves are leaking, in order to prevent a large amount of cooling water from leaking into the furnace, the small and medium-sized sleeves take water control measures. The water control standard is △P control 12<△P12. Observe whether the water marks on the contact surfaces of each tuyere sleeve are completely dry. If the water marks on the contact surfaces of the tuyere sleeves are completely dry, it is determined three times that the small and medium-sized sleeves of the tuyere are leaking.

[0021] In order to better explain this embodiment, the following relevant experimental data are provided:

[0022] Data 1

[0023] The water inlet flow rate of blast furnace No. 2 small set is 34.23t / h, and the water outlet flow rate is 33.85t / h. After inspection of the air vent, water traces were found. After the water traces were found in the small set, the water inlet flow rate was 34.23t / h, and the water outlet flow rate was 33.85t / h. The operators were immediately organized to control the water, and the water was controlled by 70%-80% to 10.4t / h of water inlet and 11.48t / h of water outlet. The curve water outlet was greater than 1.08t / h of water inlet, satisfying △P control 12-△P12≤-1t / h, and △P control 12<△P12, and it was determined that the small set was leaking.

[0024] Observe the return water head. White gasping and "white line" phenomena appear in the water head, and it is determined that the small set is leaking.

[0025] In order to prevent a large amount of cooling water from flowing into the furnace, water control measures were taken. After water control, the water inlet flow rate was 23.01t / h, the water outlet flow rate was 22.92t / h, and △P was controlled at 12<△P12. After 30 minutes, the water marks on the contact surfaces of each set of tuyere were completely dry. It was determined three times that the tuyere small set was leaking. After the small set was pulled out during the later period of wind shutdown, it was found that the small set was indeed damaged and leaking.

[0026] See Figure 1-Figure 2 , Figure 1 This is a schematic diagram before water control and leak detection in this data; Figure 2 Schematic diagram after water control and leak detection in this data.

[0027] Data 2

[0028] The water inlet flow rate of the blast furnace 20# small set is 30.17t / h, and the water outlet flow rate is 29.53t / h. After the inspection of the air vent, water traces were found. After the water traces were found in the small set, the water inlet flow rate was 30.17t / h, and the water outlet flow rate was 29.53t / h. The operators were immediately organized to control the water, and the water was controlled by 70%-80% to 8.29t / h of water inlet and 9.59t / h of water outlet. The curve water outlet was 1.3t / h greater than the water inlet, satisfying △P control 12-△P12≤-1t / h, and △P control 12<△P12, and it was determined that the small set was leaking.

[0029] Observe the return water head. White gasping and "white line" phenomena appear in the water head, and it is determined that the small set is leaking.

[0030] To prevent excessive cooling water from flowing into the furnace, water control measures were implemented. After this control, the inlet flow rate was 19.22 t / h, and the outlet flow rate was 18.85 t / h. ΔP was controlled to 12 < ΔP12. After 20 minutes, the water on the contact surfaces of the tuyere sleeves dried completely. The tuyere sleeve was identified as leaking three times. Later, when the sleeve was removed during a shutdown, it was confirmed to be damaged and leaking.

[0031] See Figure 3-Figure 4 , Figure 3 This is a schematic diagram before water control and leak detection in this data; Figure 4 Schematic diagram after water control and leak detection in this data.

[0032] The above description is only used to illustrate the technical solution of the present invention and is not intended to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in this field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for accurately judging whether a small sleeve in a tuyere is leaking, characterized by: It includes the following specific steps: S1, the inlet flow of the small and medium sets is P1, the outlet flow is P2, the inlet and outlet flow curves are stable, and the inlet and outlet flow difference is △P12; S2, close the water inlet valves of small and medium sets to reduce the water inlet volume and pressure; S3, after water control, the water inlet pressure should be less than the hot air pressure in the blast furnace; S4, keep the water inlet valves of the small and medium sets closed; S5, after the small and medium sets are controlled, the inlet flow rate is P control 1, and the outlet flow rate is P control 2; S6, when △P control 12-△P12≤-1t / h, it is determined that the small sleeve in the tuyere is leaking; S7. Simultaneously observe the outlet of the small sleeve in the tuyere. When the water inflow decreases to a certain level and the pressure in the blast furnace is 200-300 kPa higher than the cooling water pressure, if white gasping and "white lines" appear in the return water, it is determined that the small sleeve in the tuyere is leaking. S8. After it is determined that the small and medium-sized sleeves are leaking, in order to prevent a large amount of cooling water from leaking into the furnace, the small and medium-sized sleeves take water control measures. The water control standard is △P control 12<△P12. Observe whether the water marks on the contact surfaces of each tuyere sleeve are completely dry. If the water marks on the contact surfaces of the tuyere sleeves are completely dry, it is determined three times that the small and medium-sized sleeves of the tuyere are leaking.

2. A method for accurately judging whether a small sleeve in a tuyere is leaking according to claim 1, characterized in that: The specific purpose of S5 is: the water volume must be maintained at 30% of the original water inlet, and the small and medium sets cannot be cut off from water.

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