Method for eliminating water beam nodulation in a walking beam furnace

Abstract

The application discloses a method for eliminating water beam nodulation of a walking beam furnace, and comprises the following steps: judging the nodulation generation position; adopting a step mode for the walking beam when the nodulation is generated on a fixed beam and adopting a stop center mode for the walking beam when the nodulation is generated on a movable beam; determining the distance between the nodulation and a furnace door after judging the nodulation generation position; increasing the air excess coefficient of a heating section where the nodulation is generated by 20% to 25% after determining the distance between the nodulation and the furnace door; reducing the gas hand valve of a burner corresponding to the nodulation position by 20% to 30% after increasing the air excess coefficient; and reducing the steel loading interval of a slab after reducing the gas hand valve of the burner. Through the method, the water beam nodulation can be inhibited from increasing in about 3 hours, and the water beam nodulation can be basically eliminated in about 12 hours. The method eliminates the situation that the slab is returned due to long adjustment time caused by the slab walking obliquely, reduces the production cost, and has economic benefits.

Description

Technical Field

[0001] This invention relates to the field of hot rolling production technology, and in particular to a method for eliminating water beam nodules in a walking beam furnace. Background Technology

[0002] Water beam nodules are prone to occur when hot rolling mills produce high-temperature slabs. These nodules gradually increase in size during subsequent production, eventually causing the slab to tilt inside the furnace and preventing it from being automatically tapped due to blockage.

[0003] Manual tapping would slow down the production pace and increase production costs.

[0004] If the adjustment time for the inclined slab is too long, it will cause a large temperature drop in the slab, making it impossible to roll, which will eventually cause the slab to roll back and increase production costs. Summary of the Invention

[0005] To address the aforementioned problems, this application provides a method for eliminating water beam nodules in a walking beam furnace.

[0006] This application provides a method for eliminating nodule formation on the water beam of a walking beam furnace, comprising: determining the location of nodule formation; when holding the furnace under the condition of nodule formation on a fixed beam, the walking beam adopts a stepping mode; when holding the furnace under the condition of nodule formation on a movable beam, the walking beam adopts a stop-mid position mode; after determining the location of nodule formation, determining the distance between the nodule and the furnace door; after determining the distance between the nodule and the furnace door, increasing the excess air coefficient of the heating section where the nodule is located by 20%-25%; after increasing the excess air coefficient, closing the burner gas manual valve corresponding to the nodule location to 20%-30%; and after closing the burner gas manual valve, reducing the slab loading spacing.

[0007] In some implementations, when determining the location of nodule formation: stop the walking beam in the lower position and observe whether there are any protrusions on the slab. If there are protrusions, it indicates that the nodule is on the fixed beam; stop the walking beam in the upper position and observe whether there are any protrusions on the slab. If there are protrusions, it indicates that the nodule is on the movable beam.

[0008] In some implementations, in determining the distance between the nodule and the furnace door, given the known width of the slab inside the furnace and the spacing between adjacent slabs, the number of slabs between the protruding slab and the furnace door is observed, and the distance between the nodule and the furnace door is calculated by summing these numbers.

[0009] In some implementations, the raised slab is observed from both sides of the furnace.

[0010] In some implementations, when the nodule is in the range of small nodules, the excess air coefficient of the heating section where the nodule is located is increased by 20%; when the nodule is in the range of large nodules, the excess air coefficient of the heating section where the nodule is located is increased by 25%.

[0011] In some implementations, when the nodule is within the range of small nodules, the burner gas manual valve corresponding to the nodule location is closed to 30%; when the nodule is within the range of large nodules, the burner gas manual valve corresponding to the nodule location is closed to 20%.

[0012] In some implementations, when the height of the nodule is less than 50 mm, the nodule is considered a small nodule; when the height of the nodule is greater than 80 mm, the nodule is considered a large nodule.

[0013] In some implementations, when closing the burner gas manual valve corresponding to the duct nodule position, the position after closing is determined based on the dial pointer of the gas manual valve.

[0014] In some implementations, after closing the burner gas manual valve, the steel loading spacing of the slab is reduced to 50mm-150mm.

[0015] In some implementations, after closing the burner gas manual valve, the steel loading spacing of the slab is reduced to 100mm.

[0016] The beneficial effects of this application are as follows: It provides a method for eliminating water beam nodules in a walking beam furnace. After water beam nodules are detected in the furnace, the following adjustments are made: First, accurately determine the location of the nodule formation, identifying whether it is on a fixed beam or a movable beam. This determines the handling method: when nodules are on a fixed beam, the walking beam uses a stepping mode during heat preservation; when nodules are on a movable beam, the walking beam uses a stop-mid-position mode during heat preservation. Then, determine the distance of the nodule from the furnace door. Based on the width of the slab inside the furnace, calculate the number of protruding slabs from the furnace door, thereby determining the distance of the nodule from the furnace door, accurately identifying the location of water beam nodules occurring during normal production. Finally, increase the excess air coefficient of the heating section where the nodule is located by 20%-25%, maintaining the heating section in an oxygen-rich environment after the nodule appears. The chemical atmosphere transforms the nodule components into brittle Fe2O3, making them easier to detach. By reducing the gas valve of the burner corresponding to the nodule location to 20%-30%, the heating temperature at the nodule location is lowered. By reducing the slab loading spacing, the upward convective heat transfer from the lower part of the furnace is reduced, and the temperature on both sides of the slab is also lowered. This method can control the formation of nodules in the water beam in a timely manner and cause the nodules to detach, preventing the slab from tilting in the furnace due to nodules and ensuring normal furnace production. This method can inhibit the growth of water beam nodules in about 3 hours and basically eliminate them in about 12 hours. It eliminates the slab tilting and the backing caused by long adjustment time, reduces production costs, and has economic benefits. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention.

[0018] Figure 1 A schematic diagram of the slab on the fixed beam in the method for eliminating water beam nodules in the walking beam furnace provided in this application;

[0019] Figure 2 A schematic diagram of the slab on the movable beam in the method for eliminating water beam nodules in the walking beam furnace provided in this application;

[0020] Figure 3 A schematic diagram showing the location of water beam nodules in the furnace chamber in the method for eliminating water beam nodules in a walking beam furnace provided in this application.

[0021] Attached diagram labels: 100-Fixed beam, 200-Moving beam, 300-Furnace body, 310-Burner, 400-Slab, 500-Water beam nodule, 610-Soaking section, 611-Furnace doorway, 620-Second heating section, 630-First heating section, 640-Preheating section, 650-Heat recovery section. Detailed Implementation

[0022] Please refer to Figure 3 , Figure 3 The basic structure of the water beam in a walking beam furnace is shown, from left to right: soaking section 610, secondary heating section 620, primary heating section 630, preheating section 640, and heat recovery section 650. Figure 3 The image shows the location of furnace door 611 involved in this application.

[0023] After discovering the water beam nodule 500 in the furnace, adjustments were made according to the method for eliminating the water beam nodule 500 in a walking beam furnace provided in this embodiment.

[0024] First, accurately determine the location of the nodule formation. This requires stopping the walking beam in both the lower and upper positions to determine whether the nodule is occurring on the fixed beam 100 or the movable beam 200. For example... Figure 1 As shown, stop the walking beam in the lower position and observe whether there are any protrusions on the slab 400. If there are protrusions, it indicates that the nodule is on the fixed beam 100. Figure 2 As shown, stop the walking beam in the upper position and observe whether there are any protrusions on the slab 400. If there are protrusions, it indicates that the nodule is on the moving beam 200.

[0025] For the nodules on the fixed beam 100, the stepping beam uses a stepping mode during insulation. For the nodules on the movable beam 200, the stepping beam uses a stop-center mode during insulation.

[0026] After determining the location of the nodule formation, the distance between the nodule and the furnace door 611 is determined. In some embodiments, given the width of the slabs 400 inside the furnace and the spacing between adjacent slabs, the distance between the nodule and the furnace door 611 is obtained by observing the number of slabs 400 between the protruding slab 400 and the furnace door 611, and by summing up the total width of the slabs 400 and the total gap size.

[0027] Figure 1 and Figure 2 The illustration shows the furnace body 300 with numerous burners 310. After determining the distance of the nodule from the furnace door, the exact location of the water beam nodule 500 that occurs during normal production was determined before the specific locations of the nodule, the heating section where the nodule is located, and the burners 310 corresponding to the nodule location were determined.

[0028] After determining the distance of the nodule from the furnace door, the excess air coefficient of the heating section where the nodule is located is increased by 20%-25%. This keeps the heating section in an oxidizing atmosphere after the nodule appears, making the nodule components brittle Fe2O3, which is easier to detach.

[0029] After increasing the excess air coefficient, the gas hand valve of burner 310 corresponding to the nodule location is closed to 20%-30%, thereby reducing the heating temperature at the nodule location.

[0030] After closing the gas manual valve of burner 310, the steel loading spacing of slab 400 is reduced, thereby reducing the upward convection heat transfer from the bottom of the heating furnace and lowering the temperature on both sides of slab 400.

[0031] The method for eliminating water beam nodules 500 in a walking beam furnace provided in this embodiment can accurately determine the location of water beam nodules 500 during normal production. After the nodules appear, the heating section where they appear is kept in an oxidizing atmosphere, so that the nodule components become brittle Fe2O3, which is easier to detach. By reducing the opening of the gas manual valve at the nodule location, the heating temperature at the nodule location is reduced. By reducing the steel loading spacing of the slab 400, the upward convective heat transfer from the bottom of the furnace is also reduced, and the temperature on both sides of the slab 400 is also reduced. Thus, the water beam nodules 500 can be controlled in time and the nodules can be detached, preventing the slab 400 from tilting in the furnace due to nodules, and ensuring normal production of the furnace.

[0032] The inventors verified the method in practical applications. The method can suppress the growth of the water beam nodule 500 in about 3 hours and can basically eliminate the water beam nodule 500 in about 12 hours. It also eliminates the slab 400 skewing and the back-back caused by long adjustment time, thus reducing production costs and having economic benefits.

[0033] Assuming that each furnace cycle results in 500mm of water beam nodules causing 20 400mm slabs to become misaligned, resulting in 4 400mm slabs being rolled back, and each adjustment adding 3 minutes to the adjustment time, with an average of two 500mm water beam nodules occurring per month, and calculating that each additional hour of adjustment increases costs by 21,000 yuan, the annual cost reduction is: 21,000 * 2 = 42,000 yuan; and that rolling back one 400mm slab increases costs by 1,800 yuan, the annual cost reduction is: 1,800 * 4 * 12 = 86,400 yuan. The total cost reduction is 42,000 + 86,400 = 128,400 yuan.

[0034] When determining the distance of the nodule from the furnace door 611, the protruding slab 400 is observed from both sides of the furnace, which provides a clearer and more accurate view.

[0035] In this method, a nodule is defined as small if its height is less than 50 mm, and as large if its height is greater than 80 mm. Nodules with a height between 50 mm and 80 mm are considered medium-sized.

[0036] In some implementations, the excess air coefficient of the heating section is determined based on the size of the nodules. When the nodules are small, the excess air coefficient of the heating section containing the nodules is increased by 20%; when the nodules are large, the excess air coefficient of the heating section containing the nodules is increased by 25%.

[0037] In some implementations, the gas manual valve of the corresponding burner 310 is closed according to the size of the nodule. When the nodule is in the small nodule range, the gas manual valve of the burner 310 corresponding to the nodule position is closed to 30%; when the nodule is in the large nodule range, the gas manual valve of the burner 310 corresponding to the nodule position is closed to 20%.

[0038] In some implementations, when closing the gas manual valve of burner 310 corresponding to the duct nodule location, the position after closing is determined according to the dial pointer of the gas manual valve, and the gas manual valve of burner 310 corresponding to the duct nodule location is closed to 20%-30%.

[0039] This method involves reducing the steel loading spacing of slab 400. In some embodiments, after closing the gas manual valve of burner 310, the steel loading spacing of slab 400 is reduced to 50mm-150mm. In actual operation, the inventors tend to reduce the steel loading spacing of slab 400 to 100mm. When water beam nodules (500) occur, the slab spacing is changed to manual setting, and is uniformly changed to 100mm until the nodules are completely eliminated.

[0040] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0041] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for eliminating water beam nodules in a walking beam furnace, characterized in that, include: To determine the location of nodule formation, when insulating under the condition of nodule formation on a fixed beam, the stepping beam adopts the stepping mode; when insulating under the condition of nodule formation on a movable beam, the stepping beam adopts the stop-mid position mode. After determining the location of nodule formation, the distance between the nodule and the furnace door is determined; After determining the distance between the nodule and the furnace door, increase the excess air coefficient of the heating section where the nodule is located by 20%-25%; After increasing the excess air coefficient, reduce the gas hand valve of the burner corresponding to the nodule location to 20%-30%; After closing the gas hand valve of the burner, reduce the steel loading spacing of the slab; Specifically, when the height of the nodule is less than 50 mm, it is considered a small nodule; when the height of the nodule is greater than 80 mm, it is considered a large nodule; and when the height of the nodule is between 50 mm and 80 mm, it is considered a medium-sized nodule.

2. The method for eliminating water beam nodules in a walking beam furnace as described in claim 1, characterized in that, When determining the location of nodule formation: Stop the walking beam in the lower position and observe whether there are any protrusions on the slab. If there are protrusions, it means that the nodule is on the fixed beam. Stop the walking beam in the upper position and observe whether there are any protrusions on the slab. If there are protrusions, it indicates that the nodule is on the moving beam.

3. The method for eliminating water beam nodules in a walking beam furnace as described in claim 1, characterized in that, In determining the distance between the nodule and the furnace door, given the width of the slab inside the furnace and the spacing between adjacent slabs, the number of slabs between the protruding slab and the furnace door is observed and calculated cumulatively to obtain the distance between the nodule and the furnace door.

4. The method for eliminating water beam nodules in a walking beam furnace as described in claim 3, characterized in that, When observing the raised slab, observe from both sides of the furnace.

5. The method for eliminating water beam nodules in a walking beam furnace as described in claim 1, characterized in that, When the nodule is within the range of small nodules, increase the excess air coefficient of the heating section where the nodule is located by 20%; When the nodule is within the range of large nodules, the excess air coefficient of the heating section where the nodule is located is increased by 25%.

6. The method for eliminating water beam nodules in a walking beam furnace as described in claim 1, characterized in that, When the nodule is within the small nodule range, reduce the gas hand valve of the burner corresponding to the nodule location to 30%; When the nodule is large, reduce the gas hand valve of the burner corresponding to the nodule location to 20%.

7. The method for eliminating water beam nodules in a walking beam furnace as described in claim 1, characterized in that, When closing the gas hand valve corresponding to the burner position at the puncture site, determine the position after closing based on the pointer on the gas hand valve dial.

8. The method for eliminating water beam nodules in a walking beam furnace as described in claim 1, characterized in that, After closing the gas hand valve of the burner, reduce the steel loading spacing of the slab to 50mm-150mm.

9. The method for eliminating water beam nodules in a walking beam furnace as described in claim 8, characterized in that, After closing the gas hand valve of the burner, reduce the steel loading spacing of the slab to 100mm.

Images