Pipeline transformation method for preventing nozzle of heat treatment furnace from being blocked

Abstract

The invention discloses a pipeline transformation method for preventing a nozzle of a heat treatment furnace from being blocked, which comprises the following steps of: adding two sections of pipelines, namely a straight pipeline (2) and a bypass pipeline (3), on a gas pipeline (1) at the front end of a nozzle instrument of the heat treatment furnace; then, corrosion product filtering devices (4) are installed on the straight-through pipeline (2) and the bypass pipeline (3), under the normal condition, the straight-through pipeline (2) is opened, the bypass pipeline (3) is closed, coal gas is input from the straight-through pipeline (2), and powdery and blocky solid corrosion products are filtered through the corrosion product filtering devices (4); during maintenance, the straight-through pipeline (2) is closed, the bypass pipeline (3) is opened, coal gas is input from the bypass pipeline (3), powdery and blocky solid corrosion products are filtered through the corrosion product filtering equipment (4), and at the moment, the straight-through pipeline (2) is maintained. The device has the advantages of effectively preventing the nozzle of the steel mill heat treatment furnace from being blocked, realizing maintenance without shutdown, and improving the heating effect of the steel heat treatment furnace.

Description

Technical Field

[0001] The invention belongs to the technical field of pipeline modification and filtration, and in particular relates to a pipeline modification method for preventing a heat treatment furnace nozzle from being blocked. Background Art

[0002] At present, the domestic steel mills generally use plain carbon steel Q235B or Q345B for gas transportation pipelines. Gas types are divided into blast furnace gas, coke oven gas, converter gas and mixed gas. Gas pipelines connect various equipment in steel mills that need to provide heat, including nozzles for steel heat treatment furnaces. Mixed gas is used in the connected gas pipelines. The main components of mixed gas are CO, N2, CO2, H2, O2, etc. In addition, it also contains a large amount of water and a small amount of H2S, etc. The maximum working temperature is 40~60℃. When the temperature is less than 100℃, H2S, CO2 and other gases dissolve in water, making the condensed water acidic. At the same time, the condensed water contains Cl - and SO4 2 Plasma can cause serious corrosion to pipelines during gas transportation.

[0003] During the maintenance process, it was found that there were a large amount of powdered and blocky ash in the pipes connected to the nozzles of the heat treatment furnace. Inspection found that they were mainly corrosion products of the pipes. The gas pipes connected to the nozzles of the heat treatment furnace were relatively small, and corrosion products often blocked the nozzles, affecting the heating efficiency and thus the heat treatment process of the steel. If the gas corrosion problem is to be completely solved, the use of stainless steel for the pipes can reduce the corrosion problem, but the gas pipelines in the steel plant are complicated and long. If stainless steel is used, the cost investment will increase dramatically, and the cost-effectiveness is extremely low and the feasibility is very poor. The current solution is to regularly inspect the associated gas pipelines, but the inspection will bring higher labor costs. At the same time, the inspection and shutdown will affect the production rhythm and cause huge losses. Summary of the invention

[0004] The purpose of the present invention is to solve the problems that the existing heat treatment nozzle pipeline is easy to be blocked, the cost of replacing materials is high, and the regular maintenance is time-consuming and labor-intensive. A pipeline modification method for preventing the blockage of the heat treatment furnace nozzle is provided, which can effectively prevent the blockage of the steel plant heat treatment furnace nozzle and improve the heating effect of the steel heat treatment furnace.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A pipeline modification method for preventing nozzle blockage in a heat treatment furnace, the specific steps are as follows: (1) Add two new sections of pipelines to the gas pipeline in front of the nozzle instrument of the heat treatment furnace, namely a straight pipeline and a bypass pipeline; (2) A set of corrosion product filtering equipment is respectively installed on the straight pipeline and the bypass pipeline. Under normal circumstances, the straight pipeline is open and the bypass pipeline is closed. The gas is input from the straight pipeline, and the powdery and blocky solid corrosion products are filtered out by the corrosion product filtering equipment; (3) When maintenance is required, the straight pipeline is closed and the bypass pipeline is opened. The gas is input from the bypass pipeline and the powdered and blocky solid corrosion products are filtered out by the corrosion product filtering equipment. At this time, the straight pipeline is maintained.

[0006] Furthermore, in the step (1), the bypass pipeline is a U-shaped structure, and its two ends are respectively connected to a bypass stop valve, and the corrosion product filtering device is arranged on the pipeline between the two bypass stop valves.

[0007] Furthermore, in step (1), both ends of the straight-through pipeline are connected to a straight-through stop valve respectively, a corrosion product filtering device is provided between the inner sides of the two straight-through stop valves, and the connection between the bypass pipeline and the straight-through pipeline is provided on the outer sides of the straight-through stop valves respectively.

[0008] Furthermore, in step (2), the corrosion product filtering device is a filter made of stainless steel, including a straight filter and a bypass filter, both of which adopt two-stage filtration, the first stage filter screen filters the coarser block corrosion product ash, and the second stage filter screen filters the finer powder corrosion product ash.

[0009] Furthermore, in step (2), a coarse slag discharge outlet and a fine slag discharge outlet are provided on the straight filter and the bypass filter. The coarse slag discharge outlet is provided at the front side of the first filter screen, and the fine slag discharge outlet is provided between the first filter screen and the second filter screen. The ash filtered by the first filter screen is discharged through the coarse slag discharge outlet with a larger size, and the ash filtered by the second filter screen is discharged through the fine slag discharge outlet with a smaller size, so as to improve the filtering effect without causing serious filter blockage and frequent maintenance.

[0010] Furthermore, in the step (2), the first filter screen has a 7-mesh size, and the minimum size of the block corrosion product is 3 mm, and the product is discharged through the coarse slag outlet; the second filter screen has a 295-mesh size, and the minimum size of the powder corrosion product is 50 μm, and the product is discharged through the fine slag outlet.

[0011] Furthermore, in step (2), the straight filter or the bypass filter is connected to the straight pipe or the bypass pipe through a flange to facilitate quick disassembly and assembly, thereby saving maintenance time and improving maintenance efficiency.

[0012] Furthermore, in the steps (2) and (3), under normal circumstances, the through stop valve is opened and the bypass stop valve is closed, so that the coal gas enters the nozzle of the heat treatment furnace through the through pipeline.

[0013] Furthermore, in the steps (2) and (3), during maintenance, the through stop valve is closed and the bypass stop valve is opened, so that the coal gas bypasses the bypass pipeline and enters the nozzle of the heat treatment furnace, and maintenance work is carried out on the through pipeline.

[0014] Compared with the prior art, the advantages of the technical solution of the present invention are: (1) The present invention adopts two-stage filtration, which effectively prevents the ash slag produced by the corrosion product of the heat treatment furnace nozzle from clogging the pipeline, reduces the maintenance frequency, and improves the filtration effect; (2) The structure of the present invention is simple and easy to operate, with low cost and convenient maintenance, thus saving the cost and loss caused by maintenance and improving economic benefits; (3) The present invention sets spare pipelines on two sections of pipelines and installs stop valves to control the direction of gas flow, which can achieve the effect of maintenance without stopping the work and does not affect the normal production rhythm; (4) The present invention is not limited to the pipes connecting the nozzles of the heat treatment furnace, but is applicable to similar situations when connecting different equipment, and has strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a structural diagram of a pipeline modification for preventing nozzle blockage in a heat treatment furnace according to the present invention. DETAILED DESCRIPTION Example

[0016] To make the present invention more clear, a pipeline modification method for preventing nozzle blockage in a heat treatment furnace of the present invention is further described below in conjunction with the accompanying drawings. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0017] In this embodiment, the gas pipeline is modified and installed with Figure 1 As shown, it is characterized by: Two sections of pipelines are added to the gas pipeline 1, namely the straight pipeline 2 and the bypass pipeline 3; Two through stop valves 21 are connected to both sides of the through pipe 2, and two bypass stop valves 31 are connected to both sides of the bypass pipe 3; A set of straight-through filter 41 is connected to the pipeline between the two straight-through stop valves 21, and a set of bypass filter 42 is connected to the pipeline between the two bypass stop valves 31. The filters are both cylindrical and connected to the pipelines on both sides through flanges 5; The straight filter 41 is divided into two sections, namely the first filter screen 4a and the second filter screen 4b. The two filter screens are respectively provided with a coarse slag discharge outlet 4c and a fine slag discharge outlet 4d. The structural material of the bypass filter 42 is exactly the same as that of the straight filter 41.

[0018] Under normal circumstances, during the gas input process, the valves on both sides of the straight pipeline 2 are in an open state, and the valves on both sides of the bypass pipeline 3 are in a closed state. The gas is input from the straight pipeline 2, and the block and powder solid corrosion products are filtered through the straight filter 41; during maintenance, the straight stop valve 21 is closed, and the gas is input from the bypass pipeline 3. Installing two sections of pipelines can provide a spare pipeline, and installing a stop valve can facilitate the control of the gas flow direction, which can achieve the effect of maintenance without stopping the work, does not affect the normal production rhythm, and solves the problem of corrosion product ash clogging the nozzle of the heat treatment furnace.

[0019] In this embodiment, the material of the straight pipe 2 and the bypass pipe 3 is consistent with that of the gas pipe 1. Both sides of the straight filter 41 or the bypass filter 42 are connected to the corresponding pipes through flanges 5, which can achieve convenient and quick disassembly and assembly, save maintenance time and improve maintenance efficiency.

[0020] In this embodiment, the material of the straight filter 41 and the bypass filter 42 are both made of stainless steel 304, which can solve the problem of gas corrosion through the filter section. The filter mesh inside the filter is also made of stainless steel 304. The first filter mesh 4a is used to filter relatively coarse block corrosion product ash. According to the minimum size of the block corrosion product of 3 mm, the first filter mesh 4a is 7 meshes, and it is discharged through the larger coarse slag discharge port 4c; the second filter mesh 4b is used to filter relatively fine powder corrosion product ash. According to the minimum size of the powder corrosion product of 50 microns, the second filter mesh 4b is 295 meshes, and it is discharged through the smaller coarse slag discharge port 4d. The two-stage filtration can improve the filtration effect, and at the same time will not cause serious filter blockage problems and frequent maintenance.

[0021] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. A pipeline modification method for preventing nozzle blockage in a heat treatment furnace, characterized in that: Step 1: Add two new pipes to the gas pipe (1) at the front end of the heat treatment furnace nozzle instrument, namely a straight pipe (2) and a bypass pipe (3); Step 2: A set of corrosion product filtering equipment (4) is respectively provided on the straight pipeline (2) and the bypass pipeline (3). Under normal circumstances, the straight pipeline (2) is opened and the bypass pipeline (3) is closed, and coal gas is input from the straight pipeline (2), and powdery and blocky solid corrosion products are filtered through the corrosion product filtering equipment (4); Step 3: When maintenance is required, the straight pipeline (2) is closed and the bypass pipeline (3) is opened. The coal gas is input from the bypass pipeline (3) and the powdery and blocky solid corrosion products are filtered out by the corrosion product filtering device (4). At this time, the straight pipeline (2) is maintained.

2. The pipeline modification method for preventing nozzle blockage in a heat treatment furnace according to claim 1, characterized in that: In step 1, the bypass pipeline (3) is a U-shaped structure, and is connected to a bypass stop valve (31) at both ends, respectively. The corrosion product filtering device (4) is arranged on the pipeline between the two bypass stop valves (31).

3. The pipeline modification method for preventing nozzle blockage in a heat treatment furnace according to claim 2, characterized in that: In step 1, two ends of the straight pipeline (2) are respectively connected to a straight stop valve (21), a corrosion product filtering device (4) is provided between the inner sides of the two straight stop valves (21), and the connection points between the bypass pipeline (3) and the straight pipeline (2) are respectively provided on the outer sides of the straight stop valves (21).

4. The pipeline modification method for preventing nozzle blockage in a heat treatment furnace according to any one of claims 1 to 3, characterized in that: In step 2, the corrosion product filtering device (4) is a filter made of stainless steel, including a straight filter (41) and a bypass filter (42), both of which use two-stage filtering, the first-stage filter (4a) filtering relatively coarse block corrosion product ash, and the second-stage filter (4b) filtering relatively fine powder corrosion product ash.

5. The pipeline modification method for preventing nozzle blockage in a heat treatment furnace according to claim 4, characterized in that: In the step 2, the straight filter (41) and the bypass filter (42) are further provided with a coarse slag discharge outlet (4c) and a fine slag discharge outlet (4d); the coarse slag discharge outlet (4c) is provided at the front side of the first filter screen (4a), and the fine slag discharge outlet (4d) is provided between the first filter screen (4a) and the second filter screen (4b); the ash filtered by the first filter screen (4a) is discharged through the coarse slag discharge outlet (4c) with a larger size, and the ash filtered by the second filter screen (4b) is discharged through the fine slag discharge outlet (4d) with a smaller size.

6. The pipeline modification method for preventing nozzle blockage in a heat treatment furnace according to claim 5, characterized in that: In the step 2, the first filter screen (4a) has a 7-mesh size, and the minimum size of the block corrosion products is 3 mm, and the coarse slag is discharged through the coarse slag discharge port (4c); the second filter screen (4b) has a 295-mesh size, and the minimum size of the powder corrosion products is 50 microns, and the powder corrosion products are discharged through the fine slag discharge port (4d).

7. The pipeline modification method for preventing nozzle blockage in a heat treatment furnace according to claim 4, characterized in that: In the second step, the straight filter (41) or the bypass filter (42) is connected to the straight pipeline (2) or the bypass pipeline (3) via a flange (5).

8. The pipeline modification method for preventing nozzle blockage in a heat treatment furnace according to claim 3, characterized in that: In the steps 2 and 3, under normal circumstances, the through stop valve (21) is opened and the bypass stop valve (31) is closed, so that the coal gas enters the nozzle of the heat treatment furnace through the through pipeline (2).

9. The pipeline modification method for preventing nozzle blockage in a heat treatment furnace according to claim 3, characterized in that: In the steps 2 and 3, during maintenance, the through stop valve (21) is closed and the bypass stop valve (31) is opened, so that the coal gas bypasses the bypass pipe (3) and enters the nozzle of the heat treatment furnace, and maintenance work is performed on the through pipe (2).

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