A method for extending the service life of blast furnace tuyere sleeve

Abstract

The present application provides a method for extending the service life of a blast furnace tuyere sleeve, wherein the method comprises: preparing protective slag for spraying on the tuyere sleeve; using a spraying device to spray the prepared protective slag on the top of the tuyere sleeve to form a protective layer on the top of the tuyere sleeve, and the protective layer is used to protect the tuyere sleeve. The present application solves the problem that the tuyere sleeve of a blast furnace is easily damaged in the blast furnace, resulting in a short service life. The present application uses a spraying device to spray protective slag on the tuyere sleeve of the blast furnace. The protective slag is sintered on the top of the tuyere sleeve of the blast furnace to form a protective layer, so as to extend the service life of the tuyere sleeve, and also improve the production efficiency of blast furnace ironmaking and increase the iron output of the blast furnace.

Description

Technical Field

[0001] The present application relates to the technical field of ironmaking, and in particular to a method for extending the service life of a blast furnace tuyere sleeve. Background Art

[0002] The tuyere sleeve of a blast furnace is one of the vulnerable parts of the blast furnace. Its working conditions are harsh. It not only has to withstand the thermal stress caused by the high temperature of nearly 2000℃ and the large temperature difference, but also has to withstand the erosion of molten iron dripping, the wear of high-speed rotating coke and the erosion of coal powder. According to statistics, more than 65% of the damage of blast furnaces is caused by the burning of slag iron. In addition, there are also forms of damage such as wear and tear. The damage of the tuyere sleeve of the blast furnace will cause the tuyere to leak into the blast furnace. Long-term leakage will cause malignant accidents such as freezing of the blast furnace hearth. Therefore, the conventional operation is to carry out unplanned parking, maintenance and replacement of the tuyere, which has an adverse effect on the operation of the blast furnace, not only resulting in a loss of iron production, but also causing problems such as increased coke ratio and decreased hearth activity.

[0003] In the prior art, the life of the blast furnace tuyere sleeve is prolonged by improving the tuyere material and manufacturing quality, improving cooling water conditions, optimizing the tuyere structure, and strengthening the tuyere surface. However, the operating cost is too high and the operation is complicated to implement.

[0004] Based on this, how to adopt a simple and effective method to protect the blast furnace tuyere small sleeve to extend the service life of the tuyere small sleeve is a technical problem that needs to be solved urgently. Summary of the invention

[0005] The purpose of the present application is to provide a method for extending the service life of a blast furnace tuyere sleeve. The present application solves the problem that the blast furnace tuyere sleeve is easily damaged in the blast furnace and has a short service life. The present application adopts a spraying device to spray protective slag on the blast furnace tuyere sleeve. The protective slag is sintered above the blast furnace tuyere sleeve to form a protective layer, so as to extend the service life of the tuyere sleeve, improve the production efficiency of blast furnace ironmaking, and increase the iron output of the blast furnace.

[0006] Specifically, this application adopts the following technical solutions:

[0007] According to a first aspect of an embodiment of the present application, a method for extending the life of a blast furnace tuyere sleeve is provided, the method comprising: preparing protective slag for injection onto the tuyere sleeve; using an injection device to inject the prepared protective slag above the tuyere sleeve to form a protective layer above the tuyere sleeve, the protective layer being used to protect the tuyere sleeve.

[0008] In some embodiments of the present application, based on the aforementioned scheme, the injection device includes a pumping device, a U-shaped tube, and a support handle. The pumping device is used to pump the protective slag into the U-shaped tube, the U-shaped tube is used to inject the protective slag above the tuyere sleeve, and the support handle is used to support the U-shaped tube to extend into the blast furnace tuyere.

[0009] In some embodiments of the present application, based on the aforementioned scheme, the use of an injection device to inject the prepared protective slag above the tuyere sleeve includes: using the support handle to support the U-shaped tube to extend into the blast furnace tuyere, and placing the injection end of the U-shaped tube above the tuyere sleeve; the pumping equipment pumps the protective slag into the U-shaped tube, and the protective slag is sprayed from the injection end of the U-shaped tube above the tuyere sleeve.

[0010] In some embodiments of the present application, based on the aforementioned solution, the U-shaped tube includes a stainless steel tube and a metal hose.

[0011] In some embodiments of the present application, based on the aforementioned solution, the inner diameter of the stainless steel tube is 20 mm to 40 mm.

[0012] In some embodiments of the present application, based on the aforementioned scheme, the support handle is in a combined state when supporting the U-shaped tube to extend into the blast furnace tuyere, and the U-shaped tube is in an open state after extending into the blast furnace tuyere, so that the injection end of the U-shaped tube is placed above the tuyere small sleeve.

[0013] In some embodiments of the present application, based on the aforementioned scheme, the injection volume of the injection device is 0.6~1.2t / h.

[0014] In some embodiments of the present application, based on the aforementioned solution, the inner diameter of the tuyere sleeve is 120 mm to 150 mm.

[0015] In some embodiments of the present application, based on the aforementioned scheme, the protective slag includes silicon carbide, aluminum oxide, a binder, and a thickener.

[0016] In some embodiments of the present application, based on the aforementioned scheme, the total content of silicon carbide and aluminum oxide in the protective slag is greater than 80%, the content of aluminum oxide is less than 2%, the content of binder is 10%~30%, and the content of thickener is 0.02%~0.10%.

[0017] It can be seen from the above technical solution that the present application has at least the following advantages and positive effects:

[0018] The solution proposed in the present application solves the problem that the blast furnace tuyere sleeve is easily damaged in the blast furnace and thus has a short service life. The present application adopts a spraying device to spray protective slag on the blast furnace tuyere sleeve. The protective slag is sintered above the blast furnace tuyere sleeve to form a protective layer, so as to extend the service life of the tuyere sleeve, improve the production efficiency of blast furnace ironmaking, and increase the iron output of the blast furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 A flow chart of a method for extending the life of a blast furnace tuyere sleeve in one embodiment of the present application is shown;

[0021] Figure 2 A schematic diagram of spraying protective slag above a tuyere sleeve in one embodiment of the present application is shown;

[0022] Figure 3 A simplified structural diagram of a U-shaped tube in one embodiment of the present application is shown;

[0023] Figure 4 A schematic diagram showing a support handle supporting the folding of a U-shaped tube in one embodiment of the present application is shown;

[0024] Figure 5 A schematic diagram showing a support handle supporting the U-shaped tube to open in one embodiment of the present application is shown.

[0025] The description of the accompanying drawings is as follows:

[0026] DETAILED DESCRIPTION

[0027] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0028] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0029] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the objects used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those shown or described.

[0031] The implementation details of the technical solution of the embodiment of the present application are described in detail below:

[0032] According to a typical embodiment of the present application, a method for extending the life of a blast furnace tuyere sleeve is provided, referring to Figure 1 The method includes the following steps S1 to S2:

[0033] Step S1, preparing protective slag for injection on the tuyere sleeve.

[0034] Step S2, using a spraying device to spray the prepared protective slag above the tuyere sleeve to form a protective layer above the tuyere sleeve, wherein the protective layer is used to protect the tuyere sleeve.

[0035] The tuyere sleeve of a blast furnace is one of the vulnerable parts of the blast furnace. Its working conditions are harsh. It not only has to withstand the thermal stress caused by the high temperature of nearly 2000℃ and the large temperature difference, but also has to withstand the erosion of molten iron dripping, the wear of high-speed rotating coke and the erosion of coal powder. According to statistics, more than 65% of the blast furnace is caused by the burning of slag iron, in addition to wear, cracking and other forms of damage. In order to better protect the blast furnace tuyere sleeve, this application proposes a method for extending the life of the blast furnace tuyere sleeve, which can reduce the damage of the blast furnace tuyere sleeve in the blast furnace and greatly extend the life of the blast furnace tuyere sleeve.

[0036] In the present application, this scheme sprays protective slag above the tuyere sleeve when the blast furnace is shut down for maintenance. When the protective slag is sintered above the tuyere sleeve, a protective layer is formed above the tuyere sleeve, which can reduce the erosion of the tuyere sleeve by dripping molten iron, the wear of the tuyere sleeve by high-speed rotating coke, and the erosion of the tuyere sleeve by coal powder, thereby greatly extending the life of the blast furnace tuyere sleeve and ensuring the iron production of the blast furnace.

[0037] In the present application, the protective slag for injection on the tuyere sleeve can be prepared first. Since the protective slag is composed of a variety of compounds, the protective slag needs to be stirred. A mixer can be used to stir the protective slag (such as Figure 2 The mixer 104 shown in the figure) can also use other methods to stir the protective slag to fully mix the multiple groups of compounds in the protective slag. After the protective slag is prepared, an injection device is used to spray the prepared protective slag on the top of the tuyere sleeve to form a protective layer on the top of the tuyere sleeve. The protective layer is used to protect the tuyere sleeve, reduce the damage rate of the tuyere sleeve in the blast furnace, and extend the life of the tuyere sleeve of the blast furnace.

[0038] In one embodiment of the present application, the injection device may include a pumping device, a U-shaped tube, and a support handle. The pumping device is used to pump the protective slag into the U-shaped tube, the U-shaped tube is used to inject the protective slag above the tuyere sleeve, and the support handle is used to support the U-shaped tube to extend into the blast furnace tuyere.

[0039] In this application, if Figure 2 As shown, the protective slag is injected above the tuyere sleeve using the injection device, and the injection device may include a pumping device 101, a U-shaped tube 102, and a support handle 103. Considering that the protective slag has a certain viscosity, or the preparation site of the protective slag is a certain distance from the blast furnace tuyere, in order to ensure that the protective slag can be smoothly injected above the tuyere sleeve, the pumping device 101 is required to pump the protective slag into the U-shaped tube 102. Since the diameter of the blast furnace is too large and the temperature inside the blast furnace is too high, the support handle 103 is required to support the U-shaped tube 102 to extend into the blast furnace tuyere so that the protective slag can be successfully injected above the tuyere sleeve.

[0040] It should be noted here that if the site for preparing the protective slag is too far away from the blast furnace tuyere or it is convenient to pump the protective slag into the U-shaped tube 102, a certain length of pipe can be connected between the pumping equipment 101 and the U-shaped tube 102. The material of the pipe can be a metal hose 106 or a pipe of other materials. The present application does not impose any special restrictions on this, and the material of the pipe can be selected according to actual use.

[0041] In one embodiment of the present application, the step of using a spraying device to spray the prepared protective slag above the tuyere sleeve comprises:

[0042] The support handle is used to support the U-shaped tube to extend into the blast furnace tuyere, and the injection end of the U-shaped tube is placed above the tuyere small sleeve.

[0043] The pumping device pumps the protective slag into the U-shaped tube, and the protective slag is sprayed from the injection end of the U-shaped tube above the tuyere small sleeve.

[0044] In the present application, after the protective slag is prepared, the feed end of the U-shaped tube is connected to the end of the pumping equipment to ensure that the protective slag can be successfully pumped into the U-shaped tube. When the protective slag can be sprayed into the tuyere sleeve, the support handle is used to support the U-shaped tube and extend it into the blast furnace tuyere. After the injection end of the U-shaped tube is placed above the tuyere sleeve, the pumping equipment is turned on to spray the protective slag from the injection end of the U-shaped tube above the tuyere sleeve, so as to form a protective layer above the tuyere sleeve to reduce the degree of damage to the tuyere sleeve in the blast furnace, thereby achieving the effect of extending the life of the blast furnace tuyere sleeve.

[0045] In one embodiment of the present application, the U-shaped tube may include a stainless steel tube and a metal hose.

[0046] In this application, reference is made to Figure 3 , the U-shaped tube 102 may include a stainless steel tube 105 and a metal hose 106. Because after the U-shaped tube 102 is inserted into the blast furnace tuyere, if the injection end of the U-shaped tube 102 is to be placed above the tuyere sleeve, it is necessary to adjust the angle of the injection end of the U-shaped tube 102. Therefore, the metal hose 106 is used so that the U-shaped tube 102 can be folded and opened, and the protective slag can be accurately injected above the tuyere sleeve. It should be noted here that the material of the stainless steel tube 105 and the metal hose 106 can also be pipes and hoses of other materials. This application does not impose any special restrictions on this, and the material of the U-shaped tube 102 can be selected according to actual use.

[0047] In one embodiment of the present application, the inner diameter of the stainless steel tube may be 20 mm to 40 mm.

[0048] In the present application, since the inner diameter of the blast furnace tuyere small sleeve is generally between 120mm and 150mm, the inner diameter of the stainless steel pipe of the U-shaped tube extending into the blast furnace tuyere can be selected to be between 20mm and 40mm, so as to facilitate the U-shaped tube to extend into the blast furnace tuyere.

[0049] In one embodiment of the present application, the support handle is in a combined state when supporting the U-shaped tube to extend into the blast furnace tuyere, and the U-shaped tube is in an open state after extending into the blast furnace tuyere, so that the injection end of the U-shaped tube is placed above the tuyere small sleeve.

[0050] In this application, reference is made to Figure 4 and Figure 5 The support handle 103 can be opened and closed. When the support handle 103 supports the U-shaped tube 102 to extend into the blast furnace tuyere, the support handle 103 is in a closed state (such as Figure 4 As shown in FIG. 1 ), when the injection end of the U-shaped tube 102 reaches the position of the tuyere sleeve, the support handle 103 supports the U-shaped tube 102 to be in an open state (as shown in FIG. 1 ). Figure 5 As shown), the injection end of the U-shaped tube 102 can reach the top of the tuyere sleeve, so that the protective slag can be injected from the injection end of the U-shaped tube 102 above the tuyere sleeve.

[0051] In one embodiment of the present application, the injection amount of the protective slag injected by the injection device can be 0.6~1.2t / h.

[0052] In one embodiment of the present application, the inner diameter of the tuyere sleeve may be 120 mm to 150 mm.

[0053] In one embodiment of the present application, the protective slag may include silicon carbide, aluminum oxide, a binder, and a thickener.

[0054] In one embodiment of the present application, the total content of silicon carbide and aluminum oxide in the protective slag is greater than 80%, the content of aluminum oxide is less than 2%, the content of binder is 10%~30%, and the content of thickener is 0.02%~0.10%.

[0055] In the present application, the protective slag is artificially formulated, and the protective slag may include silicon carbide, aluminum oxide, a binder, and a thickener. The total content of silicon carbide and aluminum oxide in the protective slag is greater than 80%, the content of aluminum oxide is less than 2%, the content of the binder is 10% to 30%, and the content of the thickener is 0.02% to 0.10%. The binder may be water glass, silica sol, phosphoric acid, phosphate, polyphosphate, etc. The thickener includes polyacrylate copolymer emulsion, polyacrylamide, modified polyurea, etc. The protective slag is sprayed on the tuyere sleeve, and its adhesion is very good, which can protect the tuyere sleeve to a large extent, so as to extend the life of the tuyere sleeve, improve the working efficiency of the blast furnace, and ensure the iron output.

[0056] It should be noted here that since the inner diameter of the small sleeve of the blast furnace tuyere is generally between 120mm and 150mm, and the inner diameter of the stainless steel tube of the U-shaped tube extending into the tuyere is between 20mm and 40mm, in order to avoid clogging of the injected protective slag during injection, the particle size of the protective slag can be controlled to be less than or equal to 3mm.

[0057] The specific implementation methods of the present application are further described below through specific examples, but the specific implementation methods of the application are not limited to the following examples.

[0058] In a specific embodiment of the present application, the specific implementation scheme of the method for extending the life of a blast furnace tuyere sleeve is shown in steps 11 to 16 as follows:

[0059] Taking a 2,650-cubic-meter blast furnace of a certain steel enterprise as an example, the inner diameter of the blast furnace tuyere small sleeve is 130 mm, and the blast furnace has a total of 36 tuyere. During the 24-hour shutdown for maintenance, it is planned to replace 8 tuyere. After the shutdown for maintenance and replacement of the tuyere, the workers will carry out slag spraying.

[0060] Step 11, pour 1 ton of prepared protective slag into the mixer, stir for 5 to 15 minutes and set aside.

[0061] Step 12, when the injection construction is ready, use the support handle to support the U-shaped tube to extend into the first air outlet, and place the injection end of the U-shaped tube on the upper part of the air outlet small sleeve of the first air outlet.

[0062] Step 13, start the pump to spray, the spraying time is about 1 minute, the spraying amount is about 10kg-15kg, and then stop the pump to complete the spraying of the protective slag above the small sleeve of the first tuyere.

[0063] Step 14, insert the U-shaped tube into the second tuyere, perform construction according to the operations of steps 12 to 13, and complete the injection of protective slag above the tuyere sleeves in all remaining tuyere according to this method.

[0064] Step 15, after completing the injection of 36 tuyere, which takes a total of about one hour, continue to wait for the completion of other maintenance projects of the blast furnace. During this period, the injected protective slag is dried and sintered at a temperature of 200℃~500℃.

[0065] Step 16, after all maintenance items of the blast furnace are completed, the blast furnace air supply is overhauled, the temperature above the tuyere sleeve gradually rises to 1200℃~1500℃, sintering is gradually completed, and a protective layer is formed above the tuyere sleeve.

[0066] It can be seen from the above technical solution that the present application has at least the following advantages and positive effects:

[0067] Firstly, by adopting the scheme proposed in the present application, protective slag is sprayed on the tuyere sleeve of the blast furnace using an injection device. The protective slag is sintered above the tuyere sleeve of the blast furnace to form a protective layer. This can reduce the damage to the tuyere sleeve caused by the erosion of the molten iron dripping, the wear of the tuyere sleeve by the high-speed rotating coke, and the erosion of the tuyere sleeve by the coal powder, thereby greatly extending the life of the blast furnace tuyere sleeve.

[0068] Secondly, the scheme proposed in this application is adopted, and the time when the blast furnace is shut down for maintenance is utilized, and a spraying device is used to spray protective slag on the blast furnace tuyere sleeve to extend the service life of the tuyere sleeve, thereby avoiding unplanned shutdown rate of the blast furnace due to damage to the tuyere sleeve and reducing the blast furnace ironmaking cost. The method proposed in this scheme has a short construction time, does not affect the blast furnace maintenance progress and the normal production of the blast furnace, greatly improves the ironmaking efficiency of the blast furnace, and increases the blast furnace iron production.

[0069] Thirdly, the solution proposed in this application can greatly reduce the damage rate of the tuyere sleeve, thus greatly saving resources and maintenance funds.

[0070] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the embodiments disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art that are not disclosed in the present application.

[0071] Although the present application has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present application can be implemented in a variety of forms without departing from the spirit or essence of the application, it should be understood that the above-mentioned embodiments are not limited to any of the aforementioned details, but should be widely interpreted within the spirit and scope defined by the attached claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the attached claims.

Claims

1. A method for extending the service life of a blast furnace tuyere sleeve, characterized in that: The method comprises: Prepare protective slag for injection on the tuyere sleeve; Using a spraying device to spray the prepared protective slag above the tuyere sleeve to form a protective layer above the tuyere sleeve, wherein the protective layer is used to protect the tuyere sleeve; The injection device comprises a pumping device, a U-shaped tube, and a support handle, wherein the pumping device is used to pump the protective slag into the U-shaped tube, the U-shaped tube is used to inject the protective slag above the tuyere sleeve, and the support handle is used to support the U-shaped tube to extend into the tuyere of the blast furnace; The method of using the injection device to inject the prepared protective slag above the tuyere sleeve comprises: using the support handle to support the U-shaped tube to extend into the blast furnace tuyere, and placing the injection end of the U-shaped tube above the tuyere sleeve; the pumping device pumps the protective slag into the U-shaped tube, and the protective slag is injected from the injection end of the U-shaped tube above the tuyere sleeve; the support handle is in a combined state when supporting the U-shaped tube to extend into the blast furnace tuyere, and the U-shaped tube is in an open state after extending into the blast furnace tuyere, so that the injection end of the U-shaped tube is placed above the tuyere sleeve; The protective slag includes silicon carbide, aluminum oxide, a binder, and a thickener; the total content of silicon carbide and aluminum oxide in the protective slag is greater than 80%, the content of aluminum oxide is less than 2%, the content of the binder is 10%-30%, and the content of the thickener is 0.02%-0.10%.

2. The method according to claim 1, characterized in that The U-shaped tube includes a stainless steel tube and a metal hose.

3. The method according to claim 2, characterized in that The inner diameter of the stainless steel tube is 20 mm to 40 mm.

4. The method according to claim 1, characterized in that The injection amount of the injection device is 0.6-1.2 t / h.

5. The method according to claim 1, characterized in that The inner diameter of the tuyere sleeve is 120 mm to 150 mm.

Images