A sintering metallurgical by-product gas spraying device

Abstract

The application provides a sintering metallurgical by-product gas spraying device, which comprises a gas spraying assembly and a spraying cover body, gas spraying assemblies are arranged on the two side plates of the spraying cover body in the longitudinal direction; the gas spraying assembly comprises a gas main pipe and a spraying box in communication with the gas main pipe, a plurality of spraying boxes are arranged in the longitudinal direction, and at least one group of gas spraying port groups are arranged on the end plate of the middle part of the spraying cover body and face the end plate; each group of gas spraying port groups comprises a plurality of spraying outlets arranged in the vertical direction, and the spraying caliber of each spraying outlet gradually increases from top to bottom. The gas spraying assembly is arranged on the side plates of the spraying cover body in the longitudinal direction, which completely avoids the influence of the pipe row on the material surface in the existing spraying device, the wind resistance of the structure is basically zero, effectively solves the problems of the large pressure resistance of the existing spraying device affecting the air extraction amount of the material layer and the uneven air extraction caused by the dense pipe row, and reduces the adverse effects of the spraying device on the sintering process.

Description

Technical Field

[0001] This invention relates to the field of sintering technology, and more specifically to a metallurgical by-product gas spraying device for sintering. Background Technology

[0002] Metallurgical by-product gas is a general term for by-product gases containing certain combustible components, such as coke oven gas, converter gas, and blast furnace gas, produced in the main metallurgical processes. It generally contains a relatively high amount of impurities such as nitrogen (N2), therefore its calorific value is usually low, typically ranging from 800 to 4000 kcal / Nm³. 3 Meanwhile, because it often contains highly toxic gases such as CO and combustible gases mainly composed of highly reactive gases such as H2, it possesses strong toxicity and explosive properties, posing a significant risk. Due to these characteristics, the utilization of metallurgical by-product gas is severely limited. Currently, it is mainly used for direct combustion heating in sintering ignition and waste heat boiler power generation, utilizing it through combustion heat extraction. However, the energy absorbed by these processes is far less than the amount of gas produced in the metallurgical process, resulting in the direct release of large quantities of metallurgical by-product gas, causing serious resource waste and environmental pollution.

[0003] To improve the steelmaking process's capacity to utilize metallurgical by-product gas and achieve closed-loop circulation of this gas within the steelmaking process, sintering gas injection technology is currently a relatively effective method. This technology sprays the metallurgical by-product gas above the sintering material surface, allowing it to be drawn into the sintering bed and burned for heat within the bed. This reduces the amount of solid fuel used in sintering, thus reducing carbon emissions and achieving resource utilization while simultaneously utilizing and disposing of the by-product gas. However, this technology places high demands on the injection device, mainly in the following aspects: ① The injection device needs to evenly spray the gas into the space above the material surface to avoid areas with high concentrations and excessive heat supply, while other areas have low concentrations and insufficient heat supply; ② The impact of the injection device on the sintering ventilation should be minimized. The sintering ventilation volume directly affects the two core aspects of heat transfer in the sintering bed and fuel combustion. An appropriate ventilation volume is a fundamental and crucial factor in ensuring normal sintering operations. In existing technologies, spray structures with open nozzles for direct spraying are often used. However, the airflow resistance through the nozzles is relatively high and the uniformity of air extraction is poor, which can have a certain negative impact on the sintering process.

[0004] In summary, there is an urgent need for a metallurgical by-product gas spraying device for sintering to solve the problems existing in the current technology. Summary of the Invention

[0005] The purpose of this invention is to provide a metallurgical by-product gas spraying device for sintering, aiming to solve the problems of high air resistance and poor air uniformity in existing spraying structures, which negatively affect the sintering process. The specific technical solution is as follows:

[0006] A metallurgical by-product gas spraying device for sintering includes a gas injection component and a spray hood, wherein the spray hood is provided with a gas injection component on each of its two longitudinal side plates.

[0007] The gas injection assembly includes a gas main pipe and injection boxes connected to the gas main pipe. Multiple injection boxes are arranged longitudinally, and at least one set of gas nozzles is provided on the end plate of the injection box facing the middle of the injection hood. The gas nozzles include multiple nozzles arranged at intervals along the vertical direction, and the nozzle diameter of each nozzle gradually increases from top to bottom.

[0008] In the preferred embodiment of the above technical solution, the interior of the injection box is divided into a pressure stabilizing chamber and a spraying chamber by a pressure stabilizing plate. The pressure stabilizing plate is provided with multiple connecting holes that connect the pressure stabilizing chamber and the spraying chamber. The pressure stabilizing chamber is connected to the gas main pipe, and the injection outlet is connected to the spraying chamber.

[0009] In the preferred embodiment of the above technical solutions, the flow cross-section of the connecting hole is 1 / 3 to 1 / 50 of the flow cross-section of the minimum nozzle.

[0010] In the preferred embodiment of the above technical solutions, the flow cross-section of the connecting hole is 1 / 10 to 1 / 30 of the flow cross-section of the minimum nozzle.

[0011] In the preferred embodiment of the above technical solutions, the connecting hole and the nozzle are offset.

[0012] In the preferred embodiment of the above technical solution, the multiple connecting holes on the voltage regulator plate are evenly distributed, and the flow cross-section of each connecting hole is consistent.

[0013] In the preferred embodiment of the above technical solutions, the blowbox is slidably mounted on the side plate of the blow hood, and each blowbox can be driven to slide individually or together manually or automatically.

[0014] In the preferred embodiment of the above technical solutions, the injection box is connected to the main gas pipe via a distribution pipe, and the distribution pipe is a flexible hose.

[0015] In the preferred embodiment of the above technical solutions, a connecting flange is provided at the inlet of the blow-jet box, and the connecting flange is used to connect to the distribution pipe.

[0016] In the preferred embodiment of the above technical solutions, a sealing element is provided between the two sides of the spray hood and the sintering trolley along the longitudinal direction.

[0017] The application of the technical solution of the present invention has the following beneficial effects:

[0018] This invention arranges the gas injection assembly on the longitudinal side plate of the injection hood, completely avoiding the influence of the pipe array on the air suction of the material surface in the existing spraying device. The wind resistance of the structure is basically zero, effectively solving the problems of high pressure resistance affecting the air suction of the material layer and uneven air suction caused by dense pipe array in the existing spraying device. It reduces the adverse effects of the spraying device on the sintering process and strengthens the positive role of sintering sprayed gas in carbon reduction and emission reduction in sintering.

[0019] The nozzle diameter of each nozzle gradually increases from top to bottom, thus gradually increasing the jet range of the gas. By combining several nozzles with different nozzle diameters (i.e. different jet ranges), a comprehensive and uniform coverage of the material surface is achieved, resulting in a uniform spraying effect. At the same time, the gas jet range at the bottom is set to be greater than that at the top, which ensures that the material layer in the middle also receives sufficient gas, and also prevents the gas at the top from escaping after bouncing off the spraying hood.

[0020] The sliding setting of the injection box allows for flexible adjustment of the starting and ending points of the injection area, as well as the size of the area covered by the gas injection component, preventing the gas density in certain areas of the material surface from being too high or too low, and ensuring the uniformity of gas spraying.

[0021] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0023] Figure 1 This is a schematic diagram of the structure of a metallurgical by-product gas spraying device for sintering in the existing technology;

[0024] Figure 2 This is a schematic diagram of the metallurgical by-product gas spraying device for sintering according to the present invention;

[0025] Figure 3 yes Figure 2 A front view of the gas injection assembly on one side plate of the central injection hood;

[0026] Figure 4 yes Figure 2 Schematic diagram of the structure of the middle jet injection box;

[0027] Among them, 01, spray hood, 02, gas main pipe, 03, distribution pipe, 04, spray box, 041, connecting flange, 042, inlet pipe, 043, pressure stabilizing chamber, 044, pressure stabilizing plate, 045, connecting hole, 046, end plate, 047, spray outlet, 048, spraying chamber, 05, slide rail assembly, 06, sintered material layer, 07, air box, 08, spray pipe row. Detailed Implementation

[0028] To facilitate understanding of the present invention, a more complete description is provided below, along with preferred embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0030] Example:

[0031] Figure 1 This is a schematic diagram of a conventional metallurgical by-product gas spraying device for sintering. It shows that the existing spraying device mainly consists of a spray hood 01 positioned above the sintering material layer 06 and several spray pipe rows 08 arranged parallel to the sintering material layer. The bottom of the spray hood is a sintering trolley that loads the sintering material layer. A seal is provided between the side of the hood and the sintering trolley. A flow straightener may or may not be installed on the top of the spray hood 01. Several spray pipe rows 08 are installed inside the hood, with several spray holes at the bottom. The spray hood creates a space relatively independent from the surrounding environment above the sintering material layer 06. During production, the bottom air box 07 draws air downwards, creating a slight negative pressure of approximately 5–10 Pa above the sintering material layer. Under this negative pressure, air outside the hood is drawn into the spray hood space from the top. The gas is then sprayed out from the spray holes on the spray pipe rows 08 at a certain speed (generally approximately 30–50 m / s). After the gas and air diffuse and mix inside the blower, they are drawn into the sintering material layer and burned inside the material layer to provide heat.

[0032] Combination Figure 1As can be seen, in existing spraying devices, the gas jet directly impacts the upper surface of the sintering material layer after being ejected from the spray pipe array. This device has a simple structure, low equipment cost, and can improve uniformity by increasing the number of pipe arrays, thus becoming one of the most widely used solutions in practical engineering. However, the shortcomings of the existing technology are also obvious. Due to the very limited spraying area of ​​a single pipe array, in order to ensure a certain level of spraying uniformity, the spacing between the spray pipe arrays is usually very small, resulting in the projected area of ​​the spray pipe arrays above the material surface in the spraying area accounting for more than half of the total material surface area. This leads to a significant reduction in the flow cross-section when air passes through the spray pipe array, resulting in high air resistance and affecting the sintering exhaust volume. Production practice shows that after adopting the above-mentioned spraying device, the sintering exhaust pressure resistance increases by about 300-800 Pa, leading to an increase in the power consumption of the main exhaust fan. On the other hand, the spray pipe array above the sintering material layer will affect the uniformity of air distribution on the sintering material layer. The air volume is small in the area directly opposite the spray pipe array, and large in the gaps between the spray pipe array. The segregated distribution of air volume will cause the sintering progress to be inconsistent on the same horizontal plane of the material layer cross section, which will affect the sintering quality.

[0033] To address the problems of high air resistance and poor air uniformity in existing spraying devices, this embodiment provides a novel spraying device for sintering metallurgical by-product gas.

[0034] See Figures 2-4 The sintering metallurgical by-product gas spraying device provided in this embodiment includes a gas injection component and a spray hood 01. The spray hood 01 is used to cover the sintering material layer 06 on the sintering trolley, thereby creating a space above the sintering material layer 06 that is relatively independent from the surrounding environment. The spray hood 01 is provided with gas injection components on both side plates along the longitudinal direction (referring to the movement direction of the sintering trolley). The gas injection components are used to send metallurgical by-product gas (i.e., gas) into the spray hood, thereby enabling the gas to be drawn into the sintering material layer for combustion.

[0035] like Figure 2 As shown, since the gas injection assembly in this embodiment is set on the two side plates along the longitudinal direction of the injection hood 01, there is no problem of pipe row causing resistance to the exhaust and affecting the uniformity of the exhaust directly above the sintering material layer. The layout of the spraying device in this embodiment solves the technical problems existing in the spraying device in the prior art.

[0036] Please continue reading Figures 2-4The gas injection assembly includes a gas main pipe 02 and injection boxes 04 connected to the gas main pipe 02. Multiple injection boxes 04 are arranged longitudinally, and at least one set of gas nozzles is provided on the end plate 046 facing the middle of the injection hood 01. Each gas nozzle set includes multiple nozzles 047 spaced vertically, with the nozzle diameter gradually increasing from top to bottom. Preferably, the nozzles in a set of gas nozzles can be arranged coaxially vertically or staggered. Figure 3 The diagram shows a blower box equipped with two sets of gas nozzles.

[0037] Because the nozzles are designed to gradually increase in size from top to bottom, the jet range of the gas also gradually increases from top to bottom. By combining several nozzles with different nozzle diameters (i.e., different jet ranges), comprehensive and uniform coverage of the material surface can be achieved, resulting in uniform spraying. At the same time, setting the gas jet range at the bottom to be greater than that at the top can prevent the gas at the top from escaping after bouncing off the spray hood.

[0038] It is common knowledge to those skilled in the art that a larger nozzle diameter (i.e., the flow cross-section of the nozzle) results in a greater range. This embodiment provides a simple explanation of this common knowledge as follows:

[0039] According to fluid mechanics, the attenuation law of the axial velocity of a circular jet conforms to the following formula:

[0040]

[0041] In the formula: a is the turbulence structure coefficient, which is equal to 0.07 to 0.08;

[0042] r is the nozzle radius;

[0043] s is the distance from the calculation section to the nozzle;

[0044] v m v0 is the velocity at the cross section, and v0 is the initial velocity of the jet.

[0045] If we define the velocity decay at the cross-section as 10% of the initial jet velocity (i.e.) When the distance between the cross section and the nozzle is S0, the jet range is:

[0046]

[0047] The transformation yields:

[0048]

[0049] That is, the jet range S0 is directly proportional to the nozzle size, with a proportionality coefficient of 9.31 / a; thus, it can be seen that the larger the nozzle size, the greater the jet range. For any points not fully explained in the above general knowledge introduction, please refer to "Tongji University. Combustion and Application of Gas [M]. China Building Industry Press, 2011."

[0050] During the process from the gas entering the injection box 04 to being sprayed out from the injection outlet 047, the pressure drop of the gas fluid is mainly composed of two parts: friction resistance and local resistance. The friction resistance is related to the path length of the fluid. The longer the path, the greater the friction resistance. That is, the closer the gas is to the inlet in the injection box, the smaller the friction resistance, and therefore the greater the pressure. The farther away the gas is from the inlet, the greater the friction resistance, and therefore the smaller the pressure. This results in an uneven pressure at each injection outlet.

[0051] To address the issue of uneven pressure at each nozzle caused by the higher pressure at the top of the injection box compared to the bottom, the injection box 04 in this embodiment is divided into a pressure-stabilizing chamber 043 and a spraying chamber 048 by a pressure-stabilizing plate 044. The pressure-stabilizing plate 044 is provided with multiple connecting holes 045 that connect the pressure-stabilizing chamber 043 and the spraying chamber 048. The pressure-stabilizing chamber 043 is connected to the main gas pipe 02, and the nozzle 047 is connected to the spraying chamber 048. That is, the gas first enters the pressure-stabilizing chamber, then enters the spraying chamber through the connecting holes 045, and finally is sprayed out through the nozzle 047.

[0052] Preferably, the flow cross-section of the connecting hole 045 is 1 / 3 to 1 / 50 of the flow cross-section of the minimum nozzle 047. More preferably, the flow cross-section of the connecting hole 045 is 1 / 10 to 1 / 30 of the flow cross-section of the minimum nozzle 047.

[0053] This embodiment addresses the pressure imbalance at each nozzle outlet by increasing local resistance loss. Those skilled in the art will understand that the magnitude of local resistance loss when fluid flows through a connecting orifice is related to the orifice's diameter; a smaller diameter results in greater local resistance loss. This embodiment, by designing a smaller connecting orifice size, ensures that the local resistance loss when fluid flows through the pressure stabilizing plate is significantly greater than the friction loss and other local resistance losses. This makes the differences caused by friction loss negligible, thereby ensuring equal and relatively high pressure throughout the pressure stabilizing chamber and guaranteeing stable and balanced pressure at each nozzle outlet.

[0054] Preferably, the connecting hole 045 is offset from the spray outlet 047 to prevent the gas from the connecting hole from flowing directly out of the spray outlet, which would prevent the spray chamber 048 from building up a high pressure and thus affect the spray range of each spray outlet 047. More preferably, the multiple connecting holes 045 on the pressure stabilizing plate 044 are evenly distributed, and the flow cross-section of each connecting hole 045 is consistent.

[0055] Please see Figure 2 The blow-jet boxes 04 are slidably mounted on the side plate of the blow-jet hood 01. Each blow-jet box 04 can slide individually or together, either manually or automatically. Specifically, the blow-jet boxes 04 are slidably mounted on the side plate via a slide rail assembly 05. This slide rail assembly typically includes a slide rail and a slider, with the slide rail mounted on the side plate and the slider connected to the blow-jet box. When the blow-jet boxes 04 are slid manually, a locking element (such as a bolt or pin) can be used to lock the position of the blow-jet box after it has been slid to a designated location, preventing free sliding. When the blow-jet boxes are slid automatically, a linear drive element (such as a cylinder, hydraulic cylinder, electric cylinder, or motor with a lead screw) can be used to drive the movement of the blow-jet boxes. Limiting elements can also be added to restrict the extreme positions of the blow-jet box movements. When each blowbox slides individually, each blowbox needs to be mounted on the side plate via slide rail assembly 05. When each blowbox slides together, each blowbox can be mounted on the side plate via slide rail assembly, or they can be mounted together via a single slide rail assembly. At the same time, a rigid connection should be added between each blowbox to ensure that each blowbox moves synchronously.

[0056] By individually adjusting the movement of each spray box, the spraying position of each spray box can be adjusted, preventing excessive overlap between adjacent spray boxes. The sliding setting of the spray boxes allows for flexible adjustment of the starting and ending points of the spraying area, as well as the size of the area covered by the gas spraying components, preventing excessively high or low gas density in certain areas of the material surface and ensuring uniform gas spraying.

[0057] More preferably, the injection box 04 is connected to the main gas pipe 02 via a distribution pipe 03, which is a flexible hose and provides the necessary degrees of freedom for the injection box to move. Of course, in some embodiments, a distribution pipe may not be necessary; after the injection box is connected to the main gas pipe 02, the main gas pipe 02 and the injection box slide together.

[0058] Further preferably, the inlet of the blow-jet box 04 is provided with a connecting flange 041, which is used to connect with the distribution pipe 03. Specifically, in this embodiment, the inlet of the blow-jet box is provided with an inlet pipe 042, which is trumpet-shaped. The large-diameter end of the inlet pipe 042 is connected to the pressure stabilizing chamber, and the small-diameter end of the inlet pipe 042 is provided with a connecting flange 041.

[0059] Further preferably, sealing elements are provided between the blower hood and the sintering trolley on both sides along the longitudinal direction. These sealing elements provide a certain degree of sealing between the blower hood and the sintering trolley without affecting the movement of the sintering trolley. The sealing elements enable the air box 07 to generate a stronger negative pressure effect during operation. The arrangement of these sealing elements is described in the prior art.

[0060] The spraying device in this embodiment sprays gas from the side plate towards the center, solving the problems of existing spraying devices affecting the material layer's air extraction volume and uneven air extraction caused by dense pipe arrays, thus reducing the adverse effects of the spraying device on the sintering process. By using a combination of several spray nozzles with gradually increasing nozzle diameters (i.e., different spray ranges) from top to bottom, comprehensive and uniform coverage of the material surface is achieved, resulting in uniform spraying. By flexibly adjusting the position of the spray box, the starting and ending points of the spraying area are adjusted, as well as the size of the area covered by the gas spraying components, preventing excessively high or low gas density in certain areas of the material surface and ensuring the uniformity of gas spraying.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A sintering metallurgical by-product gas spraying device, characterized in that, It includes a gas injection assembly and an injection hood (01), wherein the injection hood (01) is provided with a gas injection assembly on both side plates along the longitudinal direction; The gas injection assembly includes a gas main pipe (02) and a injection box (04) connected to the gas main pipe (02). Multiple injection boxes (04) are arranged longitudinally, and at least one set of gas nozzles is provided on the end plate (046) of the injection box (04) facing the middle of the injection hood (01). The gas nozzles include multiple nozzles (047) arranged vertically at intervals, and the injection diameter of each nozzle (047) gradually increases from top to bottom.

2. The sintering metallurgical by-product gas spraying device according to claim 1, characterized in that, The interior of the injection box (04) is divided into a pressure stabilizing chamber (043) and a spraying chamber (048) by a pressure stabilizing plate (044). The pressure stabilizing plate (044) is provided with a plurality of connecting holes (045) connecting the pressure stabilizing chamber (043) and the spraying chamber (048). The pressure stabilizing chamber (043) is connected to the gas main pipe (02), and the injection outlet (047) is connected to the spraying chamber (048).

3. The sintering metallurgical by-product gas spraying device according to claim 2, characterized in that, The flow cross section of the connecting hole (045) is 1 / 3 to 1 / 50 of the flow cross section of the minimum nozzle (047).

4. The sintering metallurgical by-product gas spraying device according to claim 3, characterized in that, The flow cross section of the connecting hole (045) is 1 / 10 to 1 / 30 of the flow cross section of the minimum nozzle (047).

5. The sintering metallurgical by-product gas spraying device according to claim 4, characterized in that, The connecting hole (045) is offset from the nozzle (047).

6. The sintering metallurgical by-product gas spraying device according to claim 5, characterized in that, The multiple connecting holes (045) on the voltage regulator plate (044) are evenly distributed, and the flow cross section of each connecting hole (045) is consistent.

7. The sintering metallurgical by-product gas spraying device according to any one of claims 1-6, characterized in that, The blowboxes (04) are slidably mounted on the side plate of the blow hood (01), and each blowbox (04) can be driven to slide individually or together manually or automatically.

8. The sintering metallurgical by-product gas spraying device according to claim 7, characterized in that, The injection box (04) is connected to the gas main pipe (02) through a distribution pipe (03), which is a flexible hose.

9. The sintering metallurgical by-product gas spraying device according to claim 8, characterized in that, The inlet of the blow box (04) is provided with a connecting flange (041), which is used to connect to the distribution pipe (03).

10. The sintering metallurgical by-product gas spraying device according to claim 1, characterized in that, The blow-off cover is provided with sealing elements between its two sides in the longitudinal direction and the sintering trolley.

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