Step-by-step pressurization self-cooling type air injection gun and use method thereof

Abstract

The invention relates to a step-by-step pressurization self-cooling type air injection gun and a using method thereof. An air inlet pipe is connected with an air outlet pipe through a supporting pipe, an air squeezing pipe is arranged in the supporting pipe, and a gap is formed between the supporting pipe and the air squeezing pipe; the refractory material is coated outside the air outlet pipe, and is coated outside at least part of the supporting pipe; the air inlet pipe is communicated with the air outlet pipe through the gap, and the cross sectional area of the air inlet pipe, the cross sectional area of the gap and the cross sectional area of the air outlet pipe are sequentially reduced. Through the design that step-by-step pressurization is matched with self-cooling, the air injection gun is cooled through injection air, the problems that the strength of a steel structure is reduced and a refractory material cracks due to the fact that the temperature of the air injection gun is increased in the using process are solved, and therefore the strength of an internal structural part is improved; therefore, the service life of the step-by-step pressurization self-cooling type air injection gun is prolonged; and the injection gas is preheated in the air injection gun, so that the problem that the injection gas enters the molten iron and is violently expanded to cause splashing is solved, and the effect of stabilizing the injection effect is also achieved.

Description

Technical Field

[0001] The present application relates to the field of gas injection in molten metal in steel production, and in particular to a step-by-step pressurized self-cooling gas injection gun and a method for using the same. Background Art

[0002] In order to achieve rapid slag removal after molten iron desulfurization, a jet gun is inserted at the top of the molten iron tank, and gas is used to push the molten iron from bottom to top, thereby pushing the top slag to the slag removal port for easy slag removal.

[0003] However, the high temperature, scouring and erosion of molten iron greatly shorten the service life of the jet gun, especially when the amount of slag is large and the insertion time is too long, for example, more than 5 minutes. The steel structure of the jet gun will decrease in strength due to heat, and the expansion of the steel structure will be greater than the expansion of the refractory, causing cracks in the refractory or accelerating the tendency of the refractory to crack, thereby shortening the service life of the jet gun.

[0004] A Chinese patent with publication number CN114737018A discloses a self-consumable jet gun for molten iron slag removal, including a jet pipe, the outer circumferential surface of which is wrapped with a refractory layer. The jet gun is a detachable structure and is composed of multiple jet pipes connected end to end; a support arm is provided on one side of the jet gun parallel to the jet gun, and the support arm is connected to the jet gun by a holding assembly, and the holding assembly adjusts the height of the jet gun by sliding on the support arm.

[0005] The Chinese patent with publication number CN101928801A discloses a molten iron pretreatment air blowing and slag removal equipment, which is arranged on the platform of the molten iron ladle slag removal machine, and includes a guide rail, a swivel support, an adjustable support, a guide roller, a guide sprocket, a lifting drive device, a lifting trolley, a blowing rod and a refractory section. The guide rail is tilted above the molten iron ladle, the lifting trolley is arranged on the guide rail, and the lifting drive device drives the lifting trolley to move up and down along the guide rail through the guide sprocket. The swivel support is connected to the upper part of the guide rail, the adjustable support is connected to the middle part of the guide rail, the guide roller is arranged at the lower part of the guide rail, and the swivel support and the adjustable support are fixed on the slag removal machine platform. The blowing rod is arranged on the lifting trolley, and the refractory section is connected to the lower part of the blowing rod. When the slag removal machine is working, the blowing rod is inserted into the molten iron ladle to blow nitrogen. As the slag removal process proceeds, the amount of slag continues to decrease, and the exposed surface of the molten iron continues to expand until the slag is almost completely removed.

[0006] The Chinese patent with publication number CN105296709A discloses a surging molten iron slag removal method, in which two air jets are vertically inserted into the molten iron from the top of the molten iron tank, the distance between the two guns is 1 / 2 of the tank mouth radius, the insertion position is at 1 / 2 radius of the tank mouth, and the insertion depth is 0.5-2.5m; the air supply intensity is controlled to be ≥2NL / (min·t), and the pressure is >0.7MPa; the air supply intensity of the A air jet is controlled at 2NL / (min·t), and the air supply intensity of the B air jet is gradually increased until the exposed surface of the molten iron rolling contacts the wall of the molten iron tank, and then the A gun is adjusted to the same air supply intensity as the B gun, and slag removal is started when the exposed area of ​​the molten iron rolling is larger than 1 / 2 of the molten iron tank mouth; after the slag removal is completed, the air jet is pulled out of the molten iron and continues to spray for more than 30s; the air jet is lifted by a hoist so that the positioning pin is 190-210mm away from the positioning hole, and the hoist is moved horizontally until the distance between the two guns reaches the length of the tank mouth radius and then lowered to make the positioning pin fall into the new positioning hole.

[0007] A Chinese patent with publication number CN204311083U discloses a combined jet gun for molten iron slag removal, which is mainly composed of three parts: a gun body, a gun body protective cover, and a gun head. The gun body is provided with a protective cover, and the gun body and the gun body protective cover are connected by a hook, an iron chain and a connecting bolt. The jet pipe at the upper end of the gun body is softly connected to the air supply pipe, and the jet pipe at the lower end of the gun body is provided with an external thread, which is connected to the gun head through a nut. The detachable gun head design effectively solves the problem of difficulty in replacing the entire jet gun.

[0008] However, the above patent documents and traditional technologies have not been able to solve the problem that the temperature increase during the use of the spray gun leads to a decrease in the strength of the steel structure and cracks in the refractory material, thereby affecting the service life. Summary of the invention

[0009] Based on this, it is necessary to provide a step-by-step pressurized self-cooling type jet gun and a method of using the same.

[0010] One embodiment of the present application is a step-by-step pressurized self-cooling jet gun, which includes a steel structure body and a refractory material;

[0011] The main steel structure includes an air outlet pipe, a support pipe, an air squeeze pipe and an air inlet pipe;

[0012] The air inlet pipe is connected to the air outlet pipe through the support pipe, the squeeze air pipe is arranged in the support pipe, and there is a gap between the support pipe and the squeeze air pipe;

[0013] The refractory material is coated on the outside of the air outlet pipe and at least partially on the outside of the support pipe;

[0014] The air inlet pipe is connected to the air outlet pipe through the gap, and the cross-sectional area of ​​the air inlet pipe, the cross-sectional area of ​​the gap and the cross-sectional area of ​​the air outlet pipe decrease in sequence.

[0015] The above-mentioned step-by-step pressurization self-cooling jet gun, through the step-by-step pressurization combined with the self-cooling design, on the one hand, utilizes the step-by-step pressurization of the sprayed gas to increase the gas flow rate, thereby cooling the jet gun itself, which is beneficial to solving the problem of reduced steel structure strength and cracking of refractory materials caused by increased temperature during the use of the jet gun, thereby improving the strength of internal structural parts, and further increasing the service life of the step-by-step pressurization self-cooling jet gun; on the other hand, while the sprayed gas cools the jet gun itself, the sprayed gas is preheated inside the jet gun, thereby reducing the problem of splashing caused by the violent expansion of the sprayed gas into the molten iron. Therefore, while the service life of the spray gun is increased, the effect of stabilizing the spraying effect is also achieved.

[0016] In some embodiments, the ratio of the cross-sectional area of ​​the air inlet pipe to the cross-sectional area of ​​the gap is greater than or equal to 2; and or,

[0017] The ratio of the cross-sectional area of ​​the gap to the cross-sectional area of ​​the air outlet pipe is greater than or equal to 2.

[0018] In some embodiments, the gap has a circular cross-section, and the difference between the outer diameter and the inner diameter of the circular cross-section is 1 to 6 mm.

[0019] In some of the embodiments, the step-by-step pressurization self-cooling jet gun further includes a lifting chuck, and the air inlet pipe is connected to the support pipe via the lifting chuck.

[0020] In some of the embodiments, the step-by-step pressurization self-cooling jet gun further includes an anchor hook connected to the outer peripheral surface of the air outlet pipe, and the refractory material is coated on the outside of the air outlet pipe and the anchor hook.

[0021] In some embodiments, a cavity is formed at a position where the support tube communicates with the air outlet tube, and the gap is connected to the air outlet tube through the cavity.

[0022] In some embodiments, the squeeze tube includes an integrally arranged squeeze tube body and a squeeze tube cone end;

[0023] There is a gap between the support tube and the extruded air tube body;

[0024] The conical end of the squeeze tube is located between the squeeze tube body and the air inlet pipe to guide the gas input from the air inlet pipe to enter the gap at a high speed.

[0025] In some of the embodiments, the extruded air tube body is fixed in the support tube via support welds.

[0026] In some embodiments, a method for using a step-by-step pressurized self-cooling jet gun is provided, which uses the step-by-step pressurized self-cooling jet gun described in any embodiment, and the method for using the step-by-step pressurized self-cooling jet gun comprises the steps of:

[0027] Turn on the gas source for ventilation;

[0028] Make sure the gas flow rate reaches the set value;

[0029] The step-by-step pressurization self-cooling jet gun is inserted into the molten iron, and the gas flow rate is increased by step-by-step pressurization to cool the step-by-step pressurization self-cooling jet gun.

[0030] In some embodiments, the method for using the step-by-step pressurization self-cooling spray gun further comprises the steps of:

[0031] When the step-by-step pressurized self-cooling jet gun is used for the first time, it is inserted into the molten iron for a first preset period of time and then withdrawn, and allowed to stand in the air for a second preset period of time. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 This is a schematic structural diagram of an embodiment of a step-by-step pressurization self-cooling jet gun described in this application.

[0034] Figure 2 for Figure 1 A schematic structural diagram of the steel structure body of the illustrated embodiment.

[0035] Figure 3 for Figure 1 A schematic diagram of a portion of the structure of the illustrated embodiment.

[0036] Figure 4 for Figure 1 Another partial structural schematic diagram of the embodiment shown.

[0037] Figure 5 for Figure 1 A schematic diagram of another part of the structure of the illustrated embodiment.

[0038] Figure 6 for Figure 1 A schematic cross-sectional view along the AA direction of the illustrated embodiment.

[0039] Figure 7 for Figure 1The BB direction cross-sectional schematic diagram of the embodiment shown.

[0040] Figure 8 This is a schematic diagram of the structural details of another embodiment of the step-by-step pressurization self-cooling spray gun described in this application.

[0041] Fig. 9 This is a schematic diagram of the structural details of another embodiment of the step-by-step pressurization self-cooling jet gun described in this application.

[0042] Fig.10 This is a flow chart of an embodiment of a method for using a step-by-step pressurized self-cooling spray gun described in this application.

[0043] Fig.11 This is a flow chart of another embodiment of the method for using the step-by-step pressurization self-cooling spray gun described in this application.

[0044] Figure numerals: 100, steel structure body, 110, air outlet pipe, 120, anchor hook, 130, support pipe, 140, air squeeze pipe body, 150, gap, 160, cone end of air squeeze pipe, 170, support welding point, 180, lifting chuck, 190, air inlet pipe, 200, refractory material, 300, cavity, 400, gas direction, 900, step-by-step pressurization self-cooling jet gun. DETAILED DESCRIPTION

[0045] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0046] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0048] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are in contact indirectly through an intermediate medium. Moreover, a first feature being “above”, “above”, or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0049] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0050] The present application discloses a step-by-step pressurized self-cooling jet gun and a method for using the same, which include some or all of the technical features of the following embodiments; that is, the step-by-step pressurized self-cooling jet gun and the method for using the same include some or all of the following structures. In one embodiment of the present application, a step-by-step pressurized self-cooling jet gun includes a steel structure body and a refractory material; the steel structure body includes an air outlet pipe, a support pipe, an air squeeze pipe, and an air inlet pipe; the air inlet pipe is connected to the air outlet pipe through the support pipe, the air squeeze pipe is arranged in the support pipe, and there is a gap between the support pipe and the air squeeze pipe; the refractory material is coated on the outside of the air outlet pipe, and is coated on at least part of the outside of the support pipe; the air inlet pipe is connected to the air outlet pipe through the gap, and the cross-sectional area of ​​the air inlet pipe, the cross-sectional area of ​​the gap, and the cross-sectional area of ​​the air outlet pipe are reduced in sequence. The above-mentioned step-by-step pressurization self-cooling jet gun, through the step-by-step pressurization combined with the self-cooling design, on the one hand, utilizes the step-by-step pressurization of the sprayed gas to increase the gas flow rate, thereby cooling the jet gun itself, which is beneficial to solving the problem of reduced steel structure strength and cracking of refractory materials caused by the increase in temperature during the use of the jet gun, thereby improving the strength of internal structural parts, and further increasing the service life of the step-by-step pressurization self-cooling jet gun; on the other hand, while the sprayed gas cools the jet gun itself, the sprayed gas is preheated inside the jet gun, thereby reducing the problem of splashing caused by the violent expansion of the sprayed gas into the molten iron. Therefore, while the service life of the spray gun is increased, the effect of stabilizing the spraying effect is also achieved. The following is combined with Figures 1 to 11 , the step-by-step pressurization self-cooling jet gun and its use method are described in detail.

[0051] In some embodiments, a step-by-step pressurization self-cooling spray gun 900 is as follows: Figure 1 As shown, it includes a steel structure body 100 and a refractory material 200; the steel structure body 100 is used to transport gas into the molten iron, and the refractory material 200 is coated on a portion of the steel structure body 100 to protect the steel structure body 100. As an example, the refractory material 200 is coated on the portion of the steel structure body 100 that enters the molten iron.

[0052] In each embodiment, Figure 2 As shown, the steel structure body 100 includes an air outlet pipe 110, a support pipe 130, an air squeeze pipe and an air inlet pipe 190; the air inlet pipe 190 is connected to the air outlet pipe 110 through the support pipe 130, the air squeeze pipe is arranged in the support pipe 130, and there is a gap 150 between the support pipe 130 and the air squeeze pipe; Figure 3 and Figure 4 , the refractory material 200 is coated on the outside of the air outlet pipe 110, and the refractory material 200 is coated on the outside of the support pipe 130; Figure 1, the refractory material 200 is coated on at least part of the support tube 130. As an example, the refractory material 200 is coated on the part of the support tube 130 entering the molten iron. As an example, the refractory material 200 is a heat-resistant material structural member, such as a ceramic member. Exemplarily, the refractory material 200 includes an inner coating coated on the support tube 130, and also includes an outer cladding coated on the outlet pipe 110 and at least part of the inner coating. Since the expansion coefficient of the refractory material 200 is different from that of the steel structure body 100, the refractory material 200 is prone to cracks if it does not have a self-cooling effect. In the embodiments of the present application, the gas flow rate is increased by step-by-step pressurization of the injected gas, and the gas cooling of the jet gun body, especially the steel structure body 100, is achieved, so that the thermal expansion of the refractory material 200 reaches a certain balance with the thermal expansion of the steel structure body 100, which is beneficial to improve the expansion consistency of the refractory material 200 and the steel structure body 100, and further improves the strength of the internal structural parts, namely the steel structure body 100 and the refractory material 200, thereby improving the service life of the step-by-step pressurization self-cooling jet gun.

[0053] In order to enhance the connection between the refractory material 200 and the outlet pipe 110, in some embodiments, the step-by-step pressurization self-cooling jet gun 900 further includes an anchor hook 120 connected to the outer peripheral surface of the outlet pipe 110, and the refractory material 200 is coated on the outlet pipe 110 and the outside of the anchor hook 120. Exemplarily, the anchor hook 120 is distributed in a circular pattern on the outer peripheral surface of the outlet pipe 110, and forms at least three parallel circles. Such a structural design enables the outlet pipe 110 to be tightly combined with the refractory material 200 wrapped outside through the anchor hook 120, thereby improving the strength of the internal structural parts of the step-by-step pressurization self-cooling jet gun 900, for example, improving the bonding strength between the refractory material 200 and the outlet pipe 110.

[0054] In order to facilitate fixing the step-by-step pressurized self-cooling spray gun 900 in a molten iron environment, in some embodiments, as Figure 1 and Figure 2 As shown, the step-by-step pressurization self-cooling air jet gun 900 further includes a lifting chuck 180, and the air inlet pipe 190 is connected to the support pipe 130 through the lifting chuck 180. Such a structural design is conducive to quickly and stably placing the step-by-step pressurization self-cooling air jet gun 900 through the lifting chuck 180.

[0055] In some embodiments, such as Figure 5 and Figure 7As shown, the squeeze tube body 140 is fixed in the support tube 130 through the support welding point 170. In this way, the positional relationship between the squeeze tube or the squeeze tube body 140 and the support tube 130 can be ensured as much as possible, which is convenient for producing the step-by-step pressurization self-cooling spray gun 900.

[0056] In each embodiment, Figure 6 and Figure 7 As shown, the air inlet pipe 190 is connected to the air outlet pipe 110 through the gap 150, and the cross-sectional area of ​​the air inlet pipe 190, the cross-sectional area of ​​the gap 150 and the cross-sectional area of ​​the air outlet pipe 110 are reduced in sequence. Figure 5 The cross-sectional area, including the cross-sectional area of ​​the inlet pipe 190, the cross-sectional area of ​​the gap 150 and the cross-sectional area of ​​the outlet pipe 110, is the area of ​​the cross section relative to the gas direction 400. For a cylindrical pipe, the gas direction 400 can also be understood as the axial direction of the cylindrical pipe. In each embodiment, the cross-sectional area can also be understood as the passing area of ​​the gas, that is, for the gas entering the step-by-step pressurization self-cooling spray gun 900, the passing area of ​​the inlet pipe 190, the passing area of ​​the gap 150 and the passing area of ​​the outlet pipe 110 are reduced in sequence. Such a structural design increases the gas flow rate by means of step-by-step pressurization, and can utilize the injected gas to cool the jet gun itself, which is beneficial to solving the problem of reduced steel structure strength and cracking of refractory materials caused by increased temperature during the use of the jet gun, thereby improving the strength of internal structural parts, and further increasing the service life of the step-by-step pressurized self-cooling jet gun 900; and because the injected gas cools the jet gun itself while being preheated inside the jet gun, the problem of splashing caused by the violent expansion of the injected gas into the molten iron is reduced, so that while the service life of the spray gun is increased, the effect of stabilizing the spraying effect is also achieved.

[0057] In some embodiments, the ratio of the cross-sectional area of ​​the air inlet pipe 190 to the cross-sectional area of ​​the gap 150 is greater than or equal to 2; in some embodiments, the ratio of the cross-sectional area of ​​the gap 150 to the cross-sectional area of ​​the air outlet pipe 110 is greater than or equal to 2; in some embodiments, the ratio of the cross-sectional area of ​​the air inlet pipe 190 to the cross-sectional area of ​​the gap 150 is greater than or equal to 2; and the ratio of the cross-sectional area of ​​the gap 150 to the cross-sectional area of ​​the air outlet pipe 110 is greater than or equal to 2. The rest of the embodiments are similar and will not be described in detail. As an example, the ratio of the cross-sectional area of ​​the air inlet pipe 190 to the cross-sectional area of ​​the gap 150 is 2, and the ratio of the cross-sectional area of ​​the gap 150 to the cross-sectional area of ​​the air outlet pipe 110 is 2. In other embodiments, the ratio of the cross-sectional area of ​​the air inlet pipe 190 to the cross-sectional area of ​​the gap 150 is 2.5, 3 or 4, etc., and the ratio of the cross-sectional area of ​​the gap 150 to the cross-sectional area of ​​the air outlet pipe 110 is 2.5, 3 or 4, etc. The rest of the embodiments are similar and will not be described in detail. For example, the ratio of the minimum cross-sectional area of ​​the air inlet pipe 190 to the maximum cross-sectional area of ​​the gap 150 is 2, the ratio of the minimum cross-sectional area of ​​the air inlet pipe 190 to the minimum cross-sectional area of ​​the gap 150 is 3, the ratio of the minimum cross-sectional area of ​​the gap 150 to the maximum cross-sectional area of ​​the air outlet pipe 110 is 2, and the ratio of the minimum cross-sectional area of ​​the gap 150 to the minimum cross-sectional area of ​​the air outlet pipe 110 is 3. Such a structural design, on the one hand, as mentioned above, is conducive to increasing the gas flow rate by step-by-step pressurization, so as to realize the cooling of the spray gun itself by the sprayed gas, thereby solving the problem of reduced steel strength and cracking of refractory materials caused by the temperature increase during the use of the spray gun, thereby improving the strength of the internal structural parts, and further improving the service life of the step-by-step pressurization self-cooling spray gun 900; on the other hand, a step-by-step passing area mutation state is formed, so that the gas flow rate of the gas in the step-by-step pressurization self-cooling spray gun 900 is greatly improved, further improving the effect of cooling the spray gun itself.

[0058] Exemplarily, the cross-sectional area of ​​the air inlet pipe 190, the cross-sectional area of ​​the gap 150, and the cross-sectional area of ​​the air outlet pipe 110 decrease linearly in the gas flow direction; that is, in the gas flow direction, all cross-sectional areas are distributed in a linear decreasing manner, forming an inclined straight line on the plane rectangular coordinate system. Exemplarily, the cross-sectional area of ​​the air inlet pipe 190, the cross-sectional area of ​​the gap 150, and the cross-sectional area of ​​the air outlet pipe 110 decrease linearly in a stepwise manner in the gas flow direction, that is, in the gas flow direction, the cross-sectional area of ​​the air inlet pipe 190 decreases linearly, the cross-sectional area of ​​the gap 150 decreases linearly, the cross-sectional area of ​​the air outlet pipe 110 also decreases linearly, and the minimum cross-sectional area of ​​the air inlet pipe 190 is greater than the maximum cross-sectional area of ​​the gap 150, and the minimum cross-sectional area of ​​the gap 150 is greater than the maximum cross-sectional area of ​​the air outlet pipe 110. With such a structural design, the cross-sectional area of ​​the air inlet pipe 190 is larger than the cross-sectional area of ​​the gap 150, and the cross-sectional area of ​​the gap 150 is larger than the cross-sectional area of ​​the air outlet pipe 110; on the one hand, the high-pressure gas is gradually pressurized after entering the step-by-step pressurizing self-cooling jet gun 900, and the cooling gas gradually reduces the cross-sectional area of ​​the step-by-step pressurizing self-cooling jet gun 900 while the flow rate remains constant, thereby gradually increasing the gas flow rate, thereby cooling the internal steel structure body 100, and also having a certain cooling effect on the refractory material 200, which is beneficial to protect the refractory material 200 from microcracks and achieve the purpose of increasing the strength of the step-by-step pressurizing self-cooling jet gun 900; on the other hand, the high-pressure gas is gradually heated and expanded after entering the step-by-step pressurizing self-cooling jet gun 900, so that the volume of the gas is pre-expanded before entering the molten iron, slowing down the violent increase in the explosion when encountering the molten iron during ejection, thereby making the molten iron surge more stable and improving the slag removal efficiency.

[0059] In some embodiments, such as Figure 6 and Figure 7 As shown, the gap 150 has a circular cross section, and the difference between the outer diameter and the inner diameter of the circular cross section is 1 to 6 mm. The outer diameter and the inner diameter of the circular ring are both diameters, the outer diameter is the diameter of the outer circle of the circular ring, and the inner diameter is the diameter of the inner circle of the circular ring. As an example, the difference between the outer diameter and the inner diameter of the circular ring is 1 to 3 mm. Such a structural design allows the injection gas to enter the gap 150 from the air inlet pipe 190, and the area through which it passes changes greatly, so the pressure increases and the gas flow rate is improved, so that the injection gas is used to cool the steel structure main body 100 and the refractory material 200 of the internal structure. At the same time, the injection gas is preheated in the gun body, reducing the splashing caused by the violent expansion of the gas into the molten iron, thereby achieving the purpose of both increasing the service life of the spray gun and stabilizing the injection effect.

[0060] In some embodiments, such as Figure 2 and Figure 5 As shown, the extruded gas tube includes an integrally arranged extruded gas tube body 140 and an extruded gas tube cone end 160; the support tube 130 and the extruded gas tube body 140 have the gap 150; the extruded gas tube cone end 160 is located between the extruded gas tube body 140 and the inlet pipe 190 to guide the gas input from the inlet pipe 190 to enter the gap 150 at high speed. Exemplarily, the extruded gas tube cone end 160 is conical, and the axis of the cone is the same as the axis of the inlet pipe 190, that is, they coincide with each other. Due to factors such as deflection, thermal expansion, and manufacturing, the surface refractory material of the jet gun, i.e., the refractory material 200, is prone to microcracks under the action of comprehensive stress in the conventional technology, which accelerates the erosion of molten iron and shortens the service life of the jet gun. In contrast, in this embodiment, the conical end 160 of the squeeze pipe is conical, which is convenient for the air intake to be distributed around and enter the gap 150 from the air intake pipe 190, thereby achieving a flow guide effect and increasing the gas flow rate. In this way, the high-speed airflow can be used to cool the step-by-step pressurized self-cooling jet gun 900 or its steel structure body 100, and during the cooling process, the high-speed airflow exchanges heat with the steel structure body 100, which is beneficial to the cooling of the refractory material 200 and the steel structure body 100 of the step-by-step pressurized self-cooling jet gun 900, and the thermal expansion of the refractory material 200 and the steel structure body 100. 00's thermal expansion reaches a certain balance, which is beneficial to improving the expansion consistency of the refractory material 200 and the steel structure body 100, thereby improving the strength of the internal structural parts, thereby increasing the service life of the step-by-step pressurized self-cooling jet gun; on the other hand, the spraying gas is preheated inside the jet gun, thereby reducing the problem of splashing caused by the violent expansion of the spraying gas when entering the molten iron, and thus, while increasing the service life of the spray gun, it also achieves a stable spraying effect. Therefore, it can be used as a special spray gun for spraying gas in molten metal, and is particularly suitable for blowing and slag gathering using the step-by-step pressurized self-cooling jet gun 100 after desulfurization of molten iron.

[0061] In some embodiments, such as Figure 8 As shown, the position where the support tube 130 is connected to the outlet pipe 110 forms a cavity 300, and the gap 150 is connected to the outlet pipe 110 through the cavity 300. For the embodiment with the extruded tube body 140 and the extruded tube cone end 160, the end of the extruded tube body 140 away from the extruded tube cone end 160, together with the support tube 130 and the outlet pipe 110, forms the cavity 300. Exemplarily, the cross-sectional area of ​​the cavity 300 is the cross-sectional area of ​​the support tube 130, that is, the passing area, so that the injection gas coming out of the gap 150 is first accumulated in the cavity 300, and then enters the narrower outlet pipe 110, and then is ejected from the outlet pipe 110 into the molten iron with a higher temperature.

[0062] Combination Figures 1 to 9 In some embodiments, the step-by-step pressurization self-cooling spray gun 900 includes a steel structure body 100 and a refractory material 200. The steel structure body 100 includes an outlet pipe 110, an anchor hook 120, a support pipe 130, an extrusion pipe body 140, an extrusion pipe cone end 160, a support welding point 170, a hoisting chuck 180 and an inlet pipe 190, which is tightly combined with the refractory material 200 wrapped outside through the anchor hook 120. The cross-sectional area of ​​the inlet pipe 190, the cross-sectional area of ​​the gap 150 between the extrusion pipe body 140 and the support pipe 130, and the cross-sectional area of ​​the outlet pipe 110 are gradually reduced, and the reduction ratio each time is greater than 2:1. The gas passing through the gap 150 is gathered in the cavity 300 between the support tube 130 and the outlet pipe 110. Since the cross-sectional area of ​​the outlet pipe 110 is less than 1 / 2 of the cross-sectional area of ​​the gap 150 between the extrusion tube body 140 and the support tube 130, the gas is pressurized twice here and finally ejected through the outlet pipe 110.

[0063] As an example, Fig. 9 As shown, the conical end 160 of the squeeze tube is conical, which is convenient for the intake air to be distributed along the circumference. The squeeze tube body 140 is concentrically fixed in the support tube 130 through the support welding point 170, forcing all the intake air to pass through the gap 150 between the squeeze tube body 140 and the support tube 130 at a high speed, and the gap 150 is controlled to be 1mm-3mm. Exemplarily, when all the gas passes through the gap 150 between the squeeze tube body 140 and the support tube 130, it takes away the heat of the inner wall of the support tube 130. In the test, it can basically ensure that the temperature of the support tube 130 is always below 400°C, and the support tube 130 takes away part of the heat of the inner layer of the refractory material 200, thereby improving the strength of the support tube 130 and its bonding with the refractory material 200, thereby achieving an increase in the service life of the step-by-step pressurization self-cooling spray gun 900. At the same time, the gas is also heated to the maximum extent when passing through the step-by-step pressurized self-cooling jet gun 900. The preheated gas volume is pre-expanded in the step-by-step pressurized self-cooling jet gun 900, reducing the degree of sharp increase when encountering molten iron during ejection, thereby reducing the intensity of bubble explosion, making the molten iron surge more stable, that is, while the gas cools the gun body, it is also heated, and the gas volume is pre-expanded in advance, slowing down the sharp increase and explosion when encountering molten iron during ejection, thereby making the molten iron surge more stable, which is conducive to improving the slag removal efficiency. In the test, the step-by-step pressurized self-cooling jet gun 900 was used to spray gas, which significantly improved the slag removal efficiency, reduced iron loss, and significantly suppressed the splashing of molten iron. At the same time, compared with the traditional jet gun, the life of the step-by-step pressurized self-cooling jet gun 900 was increased by more than 50%.

[0064] In some embodiments, a method for using a step-by-step pressurized self-cooling jet gun adopts the step-by-step pressurized self-cooling jet gun 900 described in any embodiment, that is, the method for using the step-by-step pressurized self-cooling jet gun is implemented based on the step-by-step pressurized self-cooling jet gun 900 described in any embodiment. Since the device described in any embodiment is adopted, the method also has the beneficial technical effects of the device, which will not be described in detail here.

[0065] In some embodiments, the method for using the step-by-step pressurized self-cooling jet gun includes the steps of: opening the gas source for ventilation; determining that the gas flow rate reaches a set value; inserting the step-by-step pressurized self-cooling jet gun into the molten iron, and increasing the gas flow rate by step-by-step pressurization to cool the step-by-step pressurized self-cooling jet gun. As an example, the method for using the step-by-step pressurized self-cooling jet gun is as follows: Fig.10 As shown, it includes the steps of: S200, opening the gas source for ventilation; S300, determining that the gas flow rate reaches the set value; S400, inserting the step-by-step pressurization self-cooling jet gun into the molten iron, and increasing the gas flow rate by step-by-step pressurization to cool the step-by-step pressurization self-cooling jet gun. Such a design, through the technical means of step-by-step pressurization combined with self-cooling, on the one hand, uses the step-by-step pressurization of the sprayed gas to increase the gas flow rate, so as to achieve cooling of the jet gun itself, which is conducive to solving the problem of reduced steel structure strength and cracks in refractory materials caused by the increase in temperature during the use of the jet gun, thereby improving the strength of the internal structural parts, and further improving the service life of the step-by-step pressurization self-cooling jet gun; on the other hand, while the sprayed gas realizes cooling of the jet gun itself, the sprayed gas is preheated inside the jet gun, thereby reducing the problem of splashing caused by the violent expansion of the sprayed gas into the molten iron, so that on the premise of improving the service life of the spray gun, the effect of stabilizing the spraying effect is also achieved.

[0066] In some embodiments, the method for using the step-by-step pressurized self-cooling jet gun further includes the following steps: when the step-by-step pressurized self-cooling jet gun is used for the first time, the step-by-step pressurized self-cooling jet gun is inserted into the molten iron for a first preset time period and then withdrawn, and then left to stand in the air for a second preset time period. As an example, the first preset time period is 1 minute to 5 minutes, and the second preset time period is 3 minutes to 15 minutes. As an example, the method for using the step-by-step pressurized self-cooling jet gun is as follows: Fig.11As shown, it includes the following steps: S100, when the step-by-step pressurized self-cooling jet gun is used for the first time, it is inserted into the molten iron for the first preset time period and then raised, and then left to stand in the air for the second preset time period; S200, the gas source is turned on for ventilation; S300, it is determined that the gas flow rate reaches the set value; S400, the step-by-step pressurized self-cooling jet gun is inserted into the molten iron, and the gas flow rate is increased by step-by-step pressurization to cool the step-by-step pressurized self-cooling jet gun. The rest of the embodiments are analogous and will not be described in detail. As an example, when the step-by-step pressurized self-cooling jet gun 900 is used, the gas source is first turned on for ventilation, and then the gas flow rate is inserted into the molten iron when the gas flow rate reaches the set value. When it is used for the first time, it is inserted into the molten iron for 1min-3min and then raised, and left to stand in the air for more than 5min before being put into normal use. In this way, when used for the first time, the step-by-step pressurization self-cooling jet gun 900 stays in the molten iron for a short time, and the heat of the molten iron is used to pre-sinter the refractory material 200, thereby improving the service life to a certain extent; and, by increasing the gas flow rate through the step-by-step pressurization method, the function of cooling the step-by-step pressurization self-cooling jet gun 900 is achieved, thereby improving the service life.

[0067] The following is an example of a molten iron jet slag stripping test in a 500kg medium frequency induction furnace to illustrate the step-by-step pressurized self-cooling jet gun and its use method described in the present application. The step-by-step pressurized self-cooling jet gun 900 includes an outlet pipe 110, an anchor hook 120, a support pipe 130, an extruded pipe body 140, an extruded pipe cone end 160, a support welding point 170, a hoisting chuck 180, an air inlet pipe 190 and a refractory material 200 wrapped outside.

[0068] In this embodiment, the air outlet pipe 110 is a stainless steel seamless pipe with an inner diameter of 6 mm and a wall thickness of 2 mm, the support pipe 130 is a common carbon steel seamless pipe with an inner diameter of 40 mm and a wall thickness of 5 mm, the extrusion pipe body 140 is a common carbon steel welded pipe with an outer diameter of 36 mm and a wall thickness of 1 mm, and the support pipe 130 and the extrusion pipe body 140 form a gap with a thickness of 4 mm. The air inlet pipe 190 is a common carbon steel seamless pipe with an inner diameter of 13 mm and a wall thickness of 3 mm. The air inlet pipe 190 is flexibly connected to the external air supply pipe and is installed on the equipment through a lifting chuck 180.

[0069] When the step-by-step pressurized self-cooling jet gun 900 is used for the first time, the molten iron temperature is 1330°C-1350°C, and the gas flow rate is 10 Nm 3 / h -12Nm 3 / h, pressure is 0.4MPa-0.5MPa, insert into molten iron for 2min, take out, leave vacant for 10min. Then it can start normal injection.

[0070] Compared with the jet gun made by traditional technology, the step-by-step pressurized self-cooling jet gun 900 described in the present application significantly suppresses the splashing of molten iron, the molten iron liquid level is more stable, the slag removal efficiency is improved, and the number of uses of the step-by-step pressurized self-cooling jet gun 900 is increased by 50%.

[0071] It should be noted that other embodiments of the present application also include a step-by-step pressurized self-cooling jet gun and a method of using the same that are implemented by combining the technical features in the above embodiments.

[0072] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of patent protection of the present application shall be subject to the attached claims.

Claims

1. A step-by-step pressurized self-cooling jet gun (900), characterized in that: It comprises a steel structure body (100) and refractory materials (200); The steel structure body (100) comprises an air outlet pipe (110), a support pipe (130), an air squeeze pipe and an air inlet pipe (190); The air inlet pipe (190) is connected to the air outlet pipe (110) via the support pipe (130); the squeeze air pipe is arranged in the support pipe (130), and a gap (150) is provided between the support pipe (130) and the squeeze air pipe; The refractory material (200) is coated on the outside of the gas outlet pipe (110), and is coated on the outside of at least a portion of the support pipe (130); The air inlet pipe (190) is connected to the air outlet pipe (110) through the gap (150), and the cross-sectional area of ​​the air inlet pipe (190), the cross-sectional area of ​​the gap (150), and the cross-sectional area of ​​the air outlet pipe (110) decrease in sequence.

2. The step-by-step pressurized self-cooling spray gun (900) according to claim 1, characterized in that: The ratio of the cross-sectional area of ​​the air intake pipe (190) to the cross-sectional area of ​​the gap (150) is greater than or equal to 2; and or, The ratio of the cross-sectional area of ​​the gap (150) to the cross-sectional area of ​​the air outlet pipe (110) is greater than or equal to 2.

3. The step-by-step pressurized self-cooling spray gun (900) according to claim 1, characterized in that: The gap (150) has a circular cross section, and the difference between the outer diameter and the inner diameter of the circular cross section is 1 to 6 millimeters.

4. The step-by-step pressurized self-cooling spray gun (900) according to claim 1, characterized in that: The step-by-step pressurization self-cooling jet gun (900) further comprises a lifting chuck (180), and the air inlet pipe (190) is connected to the support pipe (130) via the lifting chuck (180).

5. The step-by-step pressurized self-cooling spray gun (900) according to claim 1, characterized in that: The step-by-step pressurized self-cooling jet gun (900) further comprises an anchor hook (120) connected to the outer peripheral surface of the air outlet pipe (110), and the refractory material (200) covers the air outlet pipe (110) and the anchor hook (120).

6. The step-by-step pressurized self-cooling spray gun (900) according to claim 1, characterized in that: A cavity (300) is formed at a position where the support tube (130) is connected to the air outlet tube (110), and the gap (150) is connected to the air outlet tube (110) through the cavity (300).

7. The step-by-step pressurization self-cooling spray gun (900) according to any one of claims 1 to 6, characterized in that: The extruded air tube comprises an extruded air tube body (140) and an extruded air tube cone end (160) which are integrally arranged; The gap (150) is provided between the support tube (130) and the air squeeze tube body (140); The extruded air tube cone end (160) is located between the extruded air tube body (140) and the air inlet pipe (190) to guide the gas input from the air inlet pipe (190) to enter the gap (150) at high speed.

8. The step-by-step pressurized self-cooling spray gun (900) according to claim 7, characterized in that: The extruded air tube body (140) is fixed in the support tube (130) via a support welding point (170).

9. A method for using a step-by-step pressurized self-cooling jet gun (900), characterized in that: The step-by-step pressurizing self-cooling spray gun (900) according to any one of claims 1 to 8 is used, and the method for using the step-by-step pressurizing self-cooling spray gun (900) comprises the steps of: Turn on the gas source for ventilation; Make sure the gas flow rate reaches the set value; The step-by-step pressurization self-cooling jet gun (900) is inserted into the molten iron, and the gas flow rate is increased by step-by-step pressurization to cool the step-by-step pressurization self-cooling jet gun (900).

10. The method for using the step-by-step pressurized self-cooling spray gun (900) according to claim 9, characterized in that: The method for using the step-by-step pressurization self-cooling jet gun (900) further comprises the steps of: When the step-by-step pressurized self-cooling jet gun (900) is used for the first time, it is inserted into the molten iron for a first preset period of time, then withdrawn and left to stand in the air for a second preset period of time.

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