Production method for reducing edge effect of sintering pallet

Abstract

The invention belongs to the technical field of sintering, and relates to a production method for reducing the edge effect of a sintering pallet, which comprises the following steps: laying a grate-layer material and a mixture in sequence, so that the total material layer thickness of the sintering pallet is a first thickness; on the premise that the first thickness is not changed, the thickness ratio of the bedding material to the mixture is adjusted so as to reduce the fringe effect; during material distribution, the bedding material is distributed in a mode that the middle is thick and the two sides are thin, and the mixture is distributed above the bedding material in a mode that multiple openings are distributed at the same time. The method has the beneficial effects that the bedding material and the mixture are distributed in different modes, so that the air permeability of the middle and the edge of a material layer is considered at the same time, the edge effect is effectively reduced, and the quality of sintered ore is improved; and the movable compression roller is arranged, so that the compaction degree of a material layer is ensured, gaps among mixed material particles are reduced, mineral powder particles can be tightly bonded by a liquid phase generated in the sintering process, and meanwhile, the solidification effect among mineral powder is also improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of sintering production, and in particular relates to a production method for reducing the edge effect of a sintering trolley. Background Art

[0002] With the development of sintering technology, the thick-bed sintering technology has increasingly become a key technology for effectively improving the quality of sinter and reducing the sintering cost. As the thickness of the bed increases, the high-temperature holding time of the sintering zone increases, the self-heating capacity of sintering is enhanced, which is beneficial to reducing the consumption of solid fuel and the production cost, and is also beneficial to improving the quality of sinter.

[0003] When increasing the thickness of the bed while keeping the height of the baffle of the original sintering trolley unchanged, the ignition effect at the edge position of the sintering trolley will be poor due to the "edge effect", resulting in unmolten particles and weakly bonded parts in this area, which affects the quality of sinter. If reducing the proportion of sinter with poor surface quality in the bed, the surface sinter will be rapidly cooled and the liquid phase will not have time to crystallize, generating a glass phase, resulting in a reduction in the strength of sinter. The bonding phase in the sinter in the upper part of the bed is mainly fayalite phase, with only a small amount of calcium ferrite, which is likely to cause poor mineralization of sinter and a low ore formation rate of sinter. Therefore, a production method for reducing the edge effect of a sintering trolley is needed to solve the above technical problems. Summary of the Invention

[0004] A production method for reducing the edge effect of a sintering trolley is provided to reduce the edge effect of the sintering trolley, improve the ore formation rate of sinter, and reduce the sintering production cost.

[0005] The technical solution adopted in the embodiment of the present invention is: A production method for reducing the edge effect of a sintering trolley, comprising the following steps: successively laying the bedding material and the mixed material through a distributor so that the total bed thickness of the sintering trolley is a first thickness;

[0006] On the premise that the first thickness remains unchanged, adjusting the thickness ratio of the bedding material and the mixed material to reduce the edge effect;

[0007] During feeding, the bedding material is laid in a way that it is thick in the middle and thin at both sides, and the mixed material is laid above the bedding material by a multi-opening feeding method.

[0008] Further, the first thickness is 950 - 1050 mm.

[0009] Further, the middle thickness of the bedding material is 40 - 50 mm, and the thickness at both side edges is 20 - 30 mm.

[0010] Further, when laying the fabric, the base material is laid through the first fabricator, and a reflector is added along the lower edge of the first fabricator. The cross-section of the reflector is concave, so that the cross-section of the laid base material is convex.

[0011] Further, the mixture is laid through the second fabricator, and the bottom of the second fabricator is configured to form a plurality of discharge ports when the opening is opened.

[0012] Further, the discharge ports include two groups, one group facing the middle position of the base material, and the other group facing the edge position of the base material.

[0013] Further, a discharge gate is movably provided at the discharge port to open or close the discharge port.

[0014] Further, a movable pressing roller is provided between the second fabricator and the ignition chamber to flatten the surface layer of the mixture and control its compaction thickness.

[0015] Further, the movable pressing roller is provided above the mixture, and its length covers the transverse width of the mixture.

[0016] Further, the movable pressing roller is provided on the ignition chamber, and it includes two groups. One group is close to the second fabricator for compacting the middle material layer; the other group is close to the baffle of the sintering trolley for compacting the two side edge material layers.

[0017] The advantages and positive effects of the present invention are as follows: Different fabricating methods are adopted for the base material and the mixture respectively to simultaneously take into account the air permeability in the middle and at the edges of the material layer, effectively reducing the edge effect and being beneficial to improving the quality of sintered ore; the cross-section of the base material at the bottom is convex, and the cross-section of the mixture at the top is concave. By adjusting the thickness ratio between the two, not only can the overall thickness of the material layer be ensured, but also the content of small particle sizes in the sintered ore can be reduced, which helps to improve the strength and yield of the sintered ore; the movable pressing roller is provided to ensure the compaction degree of the material layer, reduce the gap between the mixture particles, facilitate the liquid phase generated during sintering to tightly bond the ore powder particles, improve the bonding force, and at the same time also improve the consolidation effect between the ore powders, thereby achieving the purpose of pressing the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is the process flow in the use of the embodiment provided by the present invention;

[0019] Figure 2 is the positional relationship diagram of the first fabricator and the reflector in the embodiment provided by the present invention;

[0020] Figure 3 is the cross-sectional view of the reflector in the embodiment provided by the present invention;

[0021] Figure 4 Structural schematic diagram of the movable pressing roller in the embodiment provided by the present invention;

[0022] Figure 5 Cross-sectional view of the front view in the embodiment provided by the present invention;

[0023] Figure 6 Cross-sectional view of the left view in the embodiment provided by the present invention;

[0024] Figure 7 Structural schematic diagram of the material layer in the embodiment provided by the present invention.

[0025] In the figure:

[0026] 1. Sintering trolley; 21. First feeder; 22. Second feeder; 23. Reflector; 24.; 3. Ignition chamber; 4. Movable pressing roller; 5. Adjusting bracket; 6. Transition pipe; 7. Arc-shaped pipe. Detailed implementation manners

[0027] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0028] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "thickness", "upper", "lower", "left", "right", "top", "bottom", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0029] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0030] In the present invention, unless otherwise clearly defined and limited, terms such as "installation", "connection", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communication with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In the sintering process, various powdered iron-containing raw materials, fluxes, fuels, and return fines are mixed evenly according to the ratio, granulated, and then spread flat on the sintering machine trolley for suction ignition sintering. At present, the thickness of the material layer on domestic sintering trolleys is mostly between 600 - 700 mm, and there are few cases where the thickness can reach or even exceed 1000 mm. Generally, we call the material layer with a thickness exceeding 600 mm a thick material layer. The total material layer thickness in the technical solution of this application is between 950 and 1050 mm. Usually, the way of distributing the material, the thickness of the material layer, and the quality of pressing the material directly affect the subsequent sintering gas flow distribution, the development process of each sintering zone, the sintering consolidation strength, and the power consumption of the main sintering induced draft fan, etc., and thus affect key indicators such as the yield of sintered ore, sintering consumption, and the physical quality of sintered ore.

[0032] The technical solution of this application is: a production method for reducing the edge effect of a sintering trolley, including the following steps:

[0033] Sequentially distribute the bedding material and the mixed material through a distributor so that the total material layer thickness of the sintering trolley is a first thickness;

[0034] On the premise that the first thickness remains unchanged, adjust the thickness ratio of the bedding material and the mixed material to reduce the edge effect;

[0035] When distributing the material, the bedding material is distributed in a way that is thick in the middle and thin at both sides, and the mixed material is distributed above the bedding material in a way with multiple openings. In this embodiment, the bedding material is distributed into a material layer that is thick in the middle and thin at both sides along the width direction of the sintering trolley, and then the mixed material is evenly distributed above the bedding material in the width direction, and the total material layer thickness after distribution meets the first thickness. From the cross-section of the material layer, as Figure 7As shown, the lower material layer (i.e., the bed material) is thick in the middle and thin at both sides, and the upper material layer (i.e., the mixed material) is thin in the middle and thick at both sides. The air permeability in the middle and at the edges of the total material layer after being arranged together can be taken into account, effectively reducing the edge effect and being beneficial to improving the quality of sinter. In addition, by adjusting the thickness ratio of the bed material and the mixed material, where the thickness includes the middle thickness and the edge thickness, the content of small particle sizes (particle size less than 10 mm) in the sinter can be reduced, and the strength and yield rate of the sinter are improved. Moreover, the relatively large amount of mixed material is arranged above the bed material in a manner of being arranged through multiple openings, realizing the reasonable segregation of the mixed material along the height of the material layer, solving the problem of uneven longitudinal air permeability of the material layer on the sintering trolley, stabilizing the sintering process, and making the thickness of the red ore layer at the tail of the sintering machine uniform, which plays a certain role in improving the quality of sinter and increasing the ore-forming rate.

[0036] Preferably, the first thickness is 950 - 1050 mm. The increase in the total material layer thickness makes the high-temperature retention time in the sintering zone longer, which is beneficial to the formation of the liquid phase of calcium ferrite with good strength, improving the strength of sinter. With a long high-temperature retention time in the material layer, the minerals in the sinter crystallize sufficiently, which is beneficial to the improvement of the internal structure of sinter. In addition, the increase in the total material layer thickness results in an enhanced self-heating capacity of sintering, which is beneficial to reducing the consumption of solid fuel, relatively reducing the vitreous matter on the surface layer of sinter, and having sufficient heat supply in the upper part, which is beneficial to reducing the proportion of sinter with poor surface strength.

[0037] Preferably, the middle thickness of the bed material is 40 - 50 mm, and the edge thickness at both sides is 20 - 30 mm. In this embodiment, the lower bed material is thick in the middle and thin at both sides, with a convex cross-section, while the upper mixed material is thin in the middle and thick at both sides, with a concave cross-section, which can not only ensure that the thickness of the total material layer meets the requirements but also take into account the air permeability of the middle and edge material layers.

[0038] Preferably, the mixed material is arranged through the second distributor 22, and the bottom of the second distributor 22 is configured to form a plurality of discharge ports when the openings are opened.

[0039] Preferably, the discharge ports include two groups, one group facing the middle position of the bed material, and the other group facing the edge position of the bed material. It should be noted that the large-particle-size materials inside and outside the distributor can be led to the middle position of the sintering trolley through an arc-shaped pipe 7 as shown, or an angled baffle can be provided at the discharge port to push the materials to the middle position of the sintering trolley. No specific limitation is made here as long as the same function can be achieved. Figure 6 As shown, the large-particle-size materials inside and outside the distributor can be led to the middle position of the sintering trolley through an arc-shaped pipe 7, or an angled baffle can be provided at the discharge port to push the materials to the middle position of the sintering trolley. No specific limitation is made here as long as the same function can be achieved.

[0040] Preferably, there are at least two discharge ports facing the edge of the bed material. It should be noted that the number of the two groups of discharge ports is not specifically limited and can be one, two, three, or even more.

[0041] Preferably, the discharge ports are evenly distributed circumferentially along the second distributor.

[0042] Preferably, a discharge gate is movably provided at the discharge port to open or close the discharge port.

[0043] In the actual production process, during the process of the material entering the bunker, a particle size segregation phenomenon will occur, that is, the large-particle material rolls to the outside due to fast flow, while the small-particle material accumulates in the middle, resulting in uneven mixing of the material. If only one opening is provided at the bottom of the distributor, then when the material is distributed on the sintering trolley, the large-particle material will still be on the outside and the small-particle material will be in the middle, resulting in uneven mixing of the distributed material layer, affecting the air permeability of the material layer, and further affecting the quality of the sintered ore. Therefore, in the technical solution of this application, a multi-opening distribution method is adopted, that is, two groups of discharge ports are provided at the bottom of the second distributor 22, one group of openings faces the middle position of the bedding material, so that the large-particle material in the second bunker and the second distributor 22 slides to the middle position of the sintering trolley, while the small-particle material slides to the edge position of the sintering trolley, to ensure reasonable air permeability in the longitudinal height of the material layer and effectively avoid the particle size segregation phenomenon.

[0044] Preferably, the particle size of the bedding material is 10 - 20 mm.

[0045] Preferably, during feeding, the bedding material is distributed by the first distributor 21, and a reflector 23 is added along the lower edge of the first distributor 21. The cross-section of the reflector 23 is concave, so that the cross-section of the distributed bedding material is convex. As Figure 2 shown, the reflector in this embodiment is provided at the bottom of the first distributor 21, and it has a structure with a groove in the middle. Its cross-section is the concave part as shown in Figure 3 shown. The width of the bottom of its groove can be flexibly selected according to the actual width of the material layer. The bedding material is distributed along the reflector 23 after passing through the first distributor 21, so that the distributed bedding material is convex with a thick middle and thin sides.

[0046] Preferably, a movable pressure roller 4 is provided between the second distributor 22 and the ignition chamber 3 to flatten the surface layer of the mixed material and control its compaction thickness.

[0047] Preferably, the movable pressure roller 4 is arranged above the mixed material, and its length covers the transverse width of the mixed material.

[0048] Preferably, the movable pressure roller 4 is arranged on the ignition chamber 3, and it includes two groups. One group is close to the second distributor 22 and is used to compact the middle material layer; the other group is close to the baffle of the sintering trolley 1 and is used to compact the two side edge material layers. It should be noted that the first distributor 21 and the second distributor 22 are common structures in the art, and can be multi-roller distributors, or shuttle distributors, or other structures. Specific limitations are not made here as long as the same functions can be achieved.

[0049] Example 1:

[0050] Taking a sintering trolley with a cross-sectional area of 230 square meters as an example, the thickness of the sintering material layer (i.e., the first thickness) is 1000 mm, and the width of the total material layer is 3.5 meters. As Figure 1 shown, multiple sintering trolleys 1 are connected together to form a rolling annular structure. As the wheels rotate, the sintering trolley 1 moves counterclockwise. The distributor is connected to the bunker, and the bedding material and the mixed material are successively laid on the sintering trolley 1.

[0051] Above the sintering trolley 1, a first distributor 21, a second distributor 22, and an ignition chamber 3 are respectively provided from right to left. The three are respectively fixed on other buildings, and their working positions are aligned with the sintering trolley 1. The first distributor 21 is used to lay the bedding material, and the second distributor 22 is used to lay the mixed material so that the sum of their thicknesses meets the first thickness of 1000 m.

[0052] The first distributor 21 is a multi-roll distributor, which is connected to the first bunker, and a reflecting plate 23 as shown in Figure 3 is provided along the lower edge. The bedding material in the first bunker enters the sintering trolley 1 along the reflecting plate after passing through the first distributor for bedding. The reflecting plate 23 is a concave structure so that the cross-section of the bedding material laid on the sintering trolley 1 is convex.

[0053] The second distributor 22 is a gate distributor, which is connected to the second bunker. A plurality of gates are movably arranged at the bottom of the second distributor 22. The gates are movably arranged at the openings to open and close the discharge ports. The gates are connected to the hydraulic cylinder through the telescopic rod, and the hydraulic cylinder is driven to adjust the opening size of the discharge port by the telescopic rod to realize the adjustable discharge amount. As Figure 5 shown, the second group of openings facing the edge position of the bedding material are arranged at the bottom of the second distributor 22 through the transition pipe 6. Two openings are provided at the bottom of the transition pipe 6, and both can discharge materials, leading the small-particle-size materials in the middle position to the edge position of the sintering trolley 1. Figure 6 shown, an arc-shaped pipe 7 communicating with the inside of the second distributor 22 is provided at the first group of openings facing the middle position of the bedding material. The radian of the arc-shaped pipe 7 can be flexibly adjusted according to the actual length to direct the large-particle-size mixed material to the middle position of the sintering trolley 1, thereby making the material layer distribution uniform, solving the problem of uneven longitudinal air permeability of the trolley material layer, and playing a certain role in improving the quality of sintered ore and increasing the ore-forming rate. It should be noted that from the longitudinal plane perpendicular to the ground, the first group of openings and the second group of openings are respectively in two longitudinal planes so that the discharging does not interfere with each other, that is, the orientations of the two groups of openings are along different orientations and will not affect the normal bedding work. In this embodiment, as Figure 5 shown, the two second group of openings are respectively facing the left and right sides, and as Figure 6 shown, the two first group of openings are respectively facing the front and back sides.

[0054] On the left side of the second distributor 22, there is an ignition chamber 3. On the right side of the ignition chamber 3, a movable pressure roller 4 along the width direction of the sintering trolley 1 is fixed. As Figure 4 shown, the movable pressure roller 4 includes two groups. An oval roller is arranged in the middle with a length of 3 meters for compacting the middle part of the material layer. On both sides, there is a short roller near the baffle of the sintering trolley 1 for compacting the edge material layers on both sides and the intermediate transition material layer. The three rollers are arranged in a three-section superposition layout of one long and two short, and are connected to the ignition chamber 3 through an adjusting bracket 5 so that the contact between the movable pressure roller 4 and the material layer can be adjusted, facilitating the control of the compaction thickness. The movable pressure roller 4 rotates flexibly and is not prone to jamming, which is beneficial to promoting the flatness of the material surface and reasonable segregation, and effectively suppressing the "edge effect" of the trolley.

[0055] The advantages and positive effects of the present invention are as follows: Different feeding methods are adopted for the bedding material and the mixed material respectively to simultaneously consider the air permeability of the middle and the edges of the material layer, effectively reducing the edge effect and being beneficial to improving the quality of the sintered ore; The cross-section of the bottom bedding material is convex, and the cross-section of the top mixed material is concave. By adjusting the thickness ratio between the two, not only can the overall thickness of the material layer be ensured, but also the content of small particle sizes in the sintered ore can be reduced, contributing to improving the strength and yield of the sintered ore; A movable pressure roller is provided to ensure the compaction degree of the material layer, reducing the gap between the mixed material particles, facilitating the liquid phase generated during sintering to tightly bond the ore powder particles, improving the bonding force, and at the same time enhancing the consolidation effect between the ore powders, thereby achieving the purpose of pressing the material.

[0056] The above has described the embodiments of the present invention in detail, but the content described is only the preferred embodiments of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention shall still fall within the scope covered by the patent of the present invention.

Claims

1. A production method for reducing the edge effect of a sintering trolley, characterized in that: It includes the following steps: Successively lay the bed material and the mixed material through a placer so that the total thickness of the material layer on the sintering trolley is the first thickness; On the premise that the first thickness remains unchanged, adjust the thickness ratio of the bed material and the mixed material to reduce the edge effect; During feeding, the bed material is laid in a way that it is thick in the middle and thin on both sides, and the mixed material is laid above the bed material by means of simultaneous feeding through multiple openings.

2. The production method for reducing the edge effect of a sintering trolley according to claim 1, wherein: The first thickness is 950 - 1050 mm.

3. The production method for reducing the edge effect of a sintering trolley according to claim 1 or 2, characterized in that: The middle thickness of the bed material is 40 - 50 mm, and the thickness of both side edges is 20 - 30 mm.

4. The production method for reducing the edge effect of a sintering trolley according to claim 3, characterized in that: During feeding, the bed material is laid by a first placer, and a reflector is added along the lower edge of the first placer. The cross-section of the reflector is concave so that the cross-section of the laid bed material is convex.

5. The production method for reducing the edge effect of a sintering trolley according to claim 1, characterized in that: The mixed material is laid by a second placer, and the bottom of the second placer is configured to form multiple discharge ports when the openings are opened.

6. The production method for reducing the edge effect of a sintering trolley according to claim 5, characterized in that: The discharge ports include two groups. One group faces the middle position of the bed material, and the other group faces the edge position of the bed material.

7. The production method for reducing the edge effect of a sintering trolley according to claim 5 or 6, characterized in that: A discharge gate is movably provided at the discharge port to open or close the discharge port.

8. The production method for reducing the edge effect of a sintering trolley according to claim 5 or 6, characterized in that: A movable pressure roller is arranged between the second placer and the ignition chamber to flatten the surface layer of the mixed material and control its compaction thickness.

9. The production method for reducing the edge effect of a sintering trolley according to claim 8, characterized in that: The movable pressure roller is arranged above the mixed material, and its length covers the transverse width of the mixed material.

10. The production method for reducing the edge effect of a sintering trolley according to claim 9, characterized in that: The movable pressure roller is arranged on the ignition chamber and includes two groups. One group is close to the second placer and is used to compact the middle material layer; the other group is close to the baffle of the sintering trolley and is used to compact the side edge material layers.

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