A spiral chute for reducing sinter return rate

Abstract

This invention discloses a spiral chute for reducing sinter return rate, belonging to the field of sintering technology. It includes a spiral chute body with a baffle plate installed on the bottom plate. The total mileage of the spiral chute is L, the radius is R, and the spiral angle is θ. These three satisfy the following relationship: L = 2πR × [1 + sin(θ - 15)]. The baffle height is h, and the bottom plate width is l. These two satisfy the following relationship: where a is a constant, and the value of a ranges from 2 to 10. This invention establishes the constraint relationship between the total mileage, radius, and spiral angle of the spiral chute; and the constraint relationship between the baffle height and the bottom plate width. The spiral chute designed based on these two constraint relationships can achieve a better reduction in sinter return rate.

Description

Technical Field

[0001] This invention belongs to the field of sintered ore technology, specifically relating to a spiral chute for reducing the sintering return rate. Background Technology

[0002] Starting from the sintering plant, sintered ore undergoes multiple storage, loading, and transportation stages before finally arriving at the blast furnace as a primary raw material for ironmaking. During belt conveyor or chute transport, the height difference is a key factor causing sintered ore to fall and impact. Due to variations in sintered ore quality, some sintered ore has low fracture resistance, which easily leads to breakage during transportation or transshipment, thus increasing the return rate. This problem has long remained unresolved.

[0003] According to Chinese Patent Application No. 2020105931132, a chute for reducing the breakage rate of sintered ore in steel plants is disclosed. This chute adopts a spiral structure, which can reduce the impact force on the sintered ore during its descent to a certain extent, thereby effectively reducing the breakage rate. However, in practical applications, it has been found that the dimensional and structural parameters of the spiral chute have a decisive influence on the breakage rate. For example, if the total length of the spiral chute or the spiral angle is increased alone while other parameters remain unchanged, the breakage rate will increase; conversely, if the radius of the spiral chute or the number or height of the baffles is increased alone, the breakage rate will decrease. However, in specific operations, the dimensional and structural parameters of the spiral chute are often limited by the site environment, and a single parameter cannot be simply modified arbitrarily to meet the site requirements. Therefore, how to reasonably adjust and combine the dimensional and structural parameters of the spiral chute while meeting the site environment constraints to achieve the goal of reducing the breakage rate has become an important problem that needs to be solved. Summary of the Invention

[0004] To address the technical problems existing in the prior art, this invention provides a spiral chute for reducing the sintering return rate. By constructing a reasonable combination of different parameters of the spiral chute, the invention achieves a better reduction in the sintering return rate.

[0005] The purpose of this invention is to provide a spiral chute for reducing sintering return rate, comprising a spiral chute body, wherein a baffle is provided on the bottom plate of the spiral chute body;

[0006] The total length of the spiral chute is L, the radius of the spiral chute is R, and the spiral angle is . The three satisfy the following relationship:

[0007] ;

[0008] The baffle height is h, and the chute bottom plate width is l; the following relationship exists between them: Where a is a constant, and the value of a ranges from 2 to 10.

[0009] Preferably, the pitch of the spiral chute is S, and the drop of the spiral chute is H. When S=H, .

[0010] Preferably, the value range of R is 2m. <R<2.8m;

[0011] The value range is 45°< <60°;

[0012] The value of h is in the range of 100mm. <h<200mm;

[0013] The value of l is in the range of 800mm. <l<1600mm。

[0014] Preferably, the value of a ranges from 4 to 8.

[0015] Preferably, the height of the baffle is 100mm~200mm.

[0016] Preferably, the width of the chute bottom plate is 4 to 8 times the height of the baffle.

[0017] Preferably, the baffles are evenly distributed in the channel of the spiral chute body, and the number of baffles is 50.

[0018] Preferably, the channel cross-section of the spiral chute body is square, and the side length of the square is 800mm~1000mm.

[0019] Preferably, the spiral chute body includes a chute cover and a chute bottom plate that are parallel to each other; the chute cover and the chute bottom plate are connected by two parallel chute side plates.

[0020] Preferably, the angle between the chute bottom plate and the chute cover and the horizontal plane is 30° to 50°, and the angle between the baffle and the chute bottom plate is 60° to 90°.

[0021] Preferably, the bottom plate at the discharge port of the chute is an arc-shaped bottom plate, which is tangent to the bottom plate of the chute, and a grid-like recess is provided at the end of the discharge port of the chute.

[0022] The advantages and positive effects of this invention are:

[0023] This invention fully utilizes a large amount of real experimental data and cleverly combines computer simulation technology during the research process. First, a constraint relationship model was constructed between the total mileage of the spiral chute, the spiral chute radius, and the spiral angle. Through in-depth analysis and repeated verification, the intrinsic relationship between these three parameters was successfully revealed, and their mutual influence law was established. Next, the constraint relationship between the baffle height and the width of the chute bottom plate was further studied. Through meticulous experiments and data analysis, the optimal matching relationship between these two parameters was discovered. Based on the above two constraint relationship models, this invention designs a spiral chute to reduce the sinter return rate. This spiral chute fully considers the mutual constraint relationships between various parameters in its structure, thereby ensuring its high efficiency and reliability in practical applications. Finally, a sinter diversion test was conducted using a spiral chute that satisfies the above two constraint relationships. The test results show that this spiral chute can more effectively reduce the sinter return rate, thereby improving production efficiency and economic benefits. Through this series of studies and experiments, not only was the accuracy of the theoretical model verified, but a practical and feasible technical solution was also provided for actual production. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a preferred embodiment of the present invention;

[0025] Figure 2 This is a structural diagram of the interior of the spiral chute from a first-view perspective in a preferred embodiment of the present invention;

[0026] Figure 3 This is a structural diagram of the spiral chute from a second perspective in a preferred embodiment of the present invention;

[0027] Figure 4 This is a top view of a preferred embodiment of the present invention;

[0028] Figure 5 This is a side view of a preferred embodiment of the present invention;

[0029] Figure 6 The simulation results are for the original chute;

[0030] Figure 7 Simulation results for different helix angles;

[0031] Figure 8 The simulation results show the height of different baffles when the spiral angle of the spiral chute is 45°.

[0032] Figure 9 The simulation results of the feed inlet at different baffle heights when the spiral angle of the spiral chute is 45°.

[0033] Figure 10 The simulation results show the results for different numbers of baffles.

[0034] The components are: 1. Sluice inlet; 2. Sluice cover; 3. Sluice side plate; 4. Sluice bottom plate; 5. Sluice outlet; 6. Baffle; 7. Sluice outlet. Detailed Implementation

[0035] To make the above-mentioned objectives, control system design, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0036] like Figures 1 to 10 As shown, the technical solution of the present invention is as follows:

[0037] A spiral chute for reducing sinter return rate includes a spiral chute body with baffles 6 installed on the bottom plate of the spiral chute body. The number of baffles 6 is related to the total mileage of the spiral chute; as the total mileage of the spiral chute increases, the number of baffles increases accordingly. By uniformly arranging multiple baffles on the bottom plate of the chute, the material can fill the space formed by the baffles and the chute. This design can transform the static friction between the sinter and the chute into rolling friction between the sinter, thereby effectively reducing the sinter return rate and increasing the average particle size of the sinter. Furthermore, the sinter accumulated between the baffles and the bottom plate of the chute forms a wear-resistant layer, preventing direct contact between the sinter and the bottom plate, thus reducing wear on the bottom plate. Similarly, the accumulation of sinter between the side baffles and the bottom plate of the chute also forms a protective layer, preventing direct contact between the sinter and the side plates, reducing wear on the side plates, and thus extending the service life of the spiral chute.

[0038] This application utilizes a large amount of real experimental data and combines it with computer simulation technology to first construct the following two constraint relationships:

[0039] I. The constraint relationship between the total mileage of the spiral chute, the radius of the spiral chute, and the spiral angle;

[0040] The total mileage of a spiral chute refers to the total length of the spiral section of the spiral chute.

[0041] The radius of the spiral chute refers to the radius in the top view ( Figure 4 The radius of the circle enclosed by the centerline of the spiral section of the spiral chute.

[0042] The helix angle refers to the angle between the tangent of the helical segment of the helical chute and the horizontal direction.

[0043] Wherein: the total length of the spiral chute is L, the radius of the spiral chute is R, and the spiral angle is... The three satisfy the following relationship:

[0044] (1)

[0045] II. Constraint relationship between baffle height and chute bottom plate width;

[0046] The baffle height is h, and the chute bottom plate width is l; the following relationship exists between them:

[0047] (2)

[0048] Where a is a constant, and the value of a ranges from 2 to 10;

[0049] Then, based on the above two constraints, a spiral chute is designed.

[0050] To gain a deeper understanding of the technical solution of this invention, non-limiting examples are given below:

[0051] The main structure of the spiral chute consists of a chute cover 2, chute side plates 3, and a chute bottom plate 4. Specifically, the chute cover and the chute bottom plate are arranged parallel to each other, while the chute side plates consist of two pieces connecting the chute cover and the chute bottom plate. These parts together form a spiral-shaped sealed material flow channel, which effectively prevents sinter from detaching from the chute and splashing during transportation. At the chute outlet 5, the chute outlet end 7 is designed to be arc-shaped and tangent to the chute bottom plate 4 to reduce the impact force on the sinter. In addition, at the end of the chute outlet 5, there is a grid-like recess with a width matching the conveyor belt for storing sinter.

[0052] The size of the chute inlet 1 is limited by the size of the feeding machinery, while the cross-section of the spiral chute body, i.e., the material channel, is a square structure with a side length between 800 mm and 1000 mm. The inclination angle of the chute bottom plate and chute cover relative to the horizontal plane is set within the range of 30 degrees to 50 degrees. Figure 2 and Figure 3 As shown, the angle between the upper surface of the baffle 6 and the bottom plate 4 of the chute is α, where α is set to a range of 60° to 90°. It should be noted that... Figure 2 and Figure 3 To make the explanation clearer, Figure 3 for Figure 2 The expression is horizontal. As for the width of the end of the chute outlet 5, it ranges from 1000 mm to 1400 mm, which is basically consistent with the width of the conveyor belt.

[0053] The bottom plate 4 of the chute is provided with several baffles 6 of the same width as the bottom plate 4 of the chute. The baffles 6 are fixedly connected to the bottom plate 4 of the chute and the side plate 3 of the chute, for example by welding or bolt connection.

[0054] The radius R of the spiral chute ranges from 2m. <R<2.8m。

[0055] Helix angle The value range is 45°< <60°.

[0056] The value of the baffle height h is within 100mm. <h<200mm。

[0057] The width l of the chute bottom plate is within the range of 800mm. <l<1600mm。

[0058] The constant a can take values ​​from 4 to 8.

[0059] For example, the height of the baffle 6 inside the chute can be 100mm to 200mm, the width of the chute bottom plate is 4 to 8 times the height of the baffle, the baffles are evenly distributed inside the chute, and there are 50 of them. The baffle 6 is horizontally arranged on the upper part of the chute bottom plate 4.

[0060] Scale settings

[0061] Simulation of the original inclined chute in Scale 1:

[0062] Table 1. Parameters of Inclined Mine Pit Equipment

[0063]

[0064] Through simulation and subsequent processing, the velocity distribution of sintered ore particles during transport in the original chute can be displayed. Figure 6 The study clearly reveals two main collision zones (a) the first collision point between the sinter and the inclined chute, b) the sinter flowing down the chute, and c) the second collision point between the sinter and the inclined chute: First, upon entering the chute, the sinter undergoes an initial collision with the inclined chute, causing a change in its direction of movement. Second, as the sinter reaches its destination, it collides with the baffle of the inclined chute to decelerate and change its direction of movement, ensuring it lands accurately on the conveyor belt. Because the sinter accelerates as it slides down the inclined chute, its speed at the second collision point can reach 7 to 8 meters per second. Therefore, the impact force at this point is extremely significant, resulting in a strong crushing effect on the sinter and causing a large amount of return ore to be generated in this area, thus increasing the return ore rate.

[0065] In summary, the comparative inclined ore trough has two collision points during the transfer of sinter, which reduces the particle size of the sinter and increases the sinter return rate.

[0066] Example Setup

[0067] Example 1:

[0068] Table 2 Parameter Settings for Comparative Example 2

[0069]

[0070] Example 2:

[0071] Table 3 Parameter Settings for Comparative Example 3

[0072]

[0073] Example 3:

[0074] Table 4 Parameter Settings for Comparative Example 4

[0075]

[0076] Based on a comprehensive analysis of Examples 1, 2, and 3, the following conclusions can be drawn: Considering the actual situation of sinter transfer at the TianTie mine, the spiral angles of the spiral chute were determined to be 50°, 45°, and 40°, respectively. To ensure that the transport volume and speed of the sinter remain at an appropriate level, a single-spiral spiral chute design was adopted, with a uniform pitch of 14 meters.

[0077] Table 5 Simulation of changing the spiral angle of the spiral chute

[0078]

[0079] Based on EDEM simulation Figure 7 As shown, the maximum velocity of the sintered ore flow is: Simulation 1 (spiral angle 50°) > Simulation 2 (spiral angle 45°) > Simulation 3 (spiral angle 40°). The minimum velocity of the sintered ore flow is: Simulation 2 (spiral angle 45°) > Simulation 3 (spiral angle 40°) > Simulation 1 (spiral angle 50°). Further analysis of the data in Table 5 leads to the conclusion that as the spiral angle of the spiral chute decreases, the maximum downward velocity of the sintered ore also shows a decreasing trend. Simultaneously, the minimum downward velocity of the sintered ore exhibits a trend of first increasing and then decreasing, reaching a peak of 2.17 × 10⁻⁵ m / s when the spiral angle of the spiral chute is 45°. This result indicates that when the spiral angle of the spiral chute is set to 45°, it can both ensure the feeding efficiency of the sintered ore and prevent blockage within the spiral chute, thus ensuring a smooth transfer speed of the sintered ore.

[0080] A Grid Bin Group function was introduced into the model, with individual grids set in the X, Y, and Z dimensions. By adjusting the size and position of the grids, the velocity of the sinter at the outlet of the spiral chute was accurately detected. Simulation results show that Simulation 1 (spiral angle 50 degrees) exhibits a stable outlet velocity of 3.02 m / s, Simulation 2 (spiral angle 45 degrees) shows a stable outlet velocity of 3.14 m / s, and Simulation 3 (spiral angle 40 degrees) shows a stable outlet velocity of 3.48 m / s. Furthermore, when the spiral angle of the spiral chute is set to 40 degrees, the outlet sinter velocity exhibits instability, fluctuating between 2.84 and 3.06 m / s. However, when the spiral angle is 45 and 50 degrees, the outlet sinter velocity tends to stabilize.

[0081] Comprehensive analysis shows that when the spiral angle of the spiral chute is set between 40 and 50 degrees, the situation is similar, both of which can effectively reduce the return rate of sinter, reduce the wear between sinter and the chute, and thus extend the service life of the chute.

[0082] Example 4:

[0083] Table 6 Parameter settings for Comparative Example 5

[0084]

[0085] Example 5:

[0086] Table 7 Parameter settings for Comparative Example 6

[0087]

[0088] By comprehensively analyzing Examples 4 and 5, the following conclusions can be drawn: According to Figure 8 Simulation results of varying baffle heights in the spiral chute show the following material storage capacity: Simulation 2 (50 baffles, baffle height 100mm) < Simulation 7 (50 baffles, baffle height 150mm) < Simulation 8 (50 baffles, baffle height 200mm). Further observation is needed. Figure 9 The effect of changing the baffle height on the feed inlet of the spiral chute is investigated. Although Simulation 8 (50 baffles, baffle height 200mm) has the strongest material storage capacity, blockage is prone to occur at its feed inlet. The sinter stored in the chute occupies approximately 50% of the total chute volume, which reduces the actual sinter transport capacity of the chute and leads to a shortage of sinter supply. Figure 9 In the diagram, 'f' indicates that when the baffle height is 200mm, there is a risk of the feed inlet becoming blocked.

[0089] from Figure 8Based on the simulation results of the material spreading on the surface of the chute, the spreading effect of Simulation 2 (50 baffles, baffle height 100mm) was not as good as that of Simulation 7 (50 baffles, baffle height 150mm) and Simulation 8 (50 baffles, baffle height 200mm). When the baffle height was 100mm, there was a large void on the inner surface of the chute spiral between the baffles, and the sintered ore could not completely cover the bottom of the chute. However, when the baffle height was 150mm, the void on the inner surface of the chute spiral between the baffles disappeared, and the sintered ore was evenly spread across the entire chute surface. When the baffle height was 200mm, the void on the inner surface of the chute spiral between the baffles also disappeared, similar to the situation when the baffle height was 150mm.

[0090] Figure 8 In the diagram, d represents the empty area left when the height of the spiral chute baffle is 100mm and the sinter does not cover the entire surface of the chute; e represents the area where the material basically fills the gap between the two baffles when the height of the spiral chute baffle is 150mm and 200mm.

[0091] Based on the above analysis, the simulation results using EDEM software indicate that the optimal working conditions for the spiral chute are: cross-sectional dimensions of 800mm*800mm, pitch of 14m, spiral radius of 2.37m, spiral angle of 45°, number of baffles of 50, and baffle height of 150mm.

[0092] Therefore, it can be concluded that when the height of the spiral chute baffle is between 100mm and 200mm, a certain amount of sinter can be stored between the baffles, which reduces the wear between the sinter and the chute to varying degrees and lowers the sinter return rate.

[0093] Example 6:

[0094] Table 8 Parameter Settings for Comparative Example 7

[0095]

[0096] Example 7:

[0097] Table 9 Parameter Settings for Comparative Example 8

[0098]

[0099] Example 8:

[0100] Table 10 Parameter Settings for Comparative Example 9

[0101]

[0102] Based on a comprehensive analysis of Examples 6, 7, and 8, the following conclusions can be drawn: Through simulation experiments, changing the number of baffles in the spiral chute yields the following results: Figure 10As shown, the material retention levels of the baffles are in the following order: Simulation 4 (30 baffles, 600mm*600mm) < Simulation 5 (40 baffles, 600mm*600mm) < Simulation 6 (50 baffles, 600mm*600mm). When the number of baffles is 30, there are large gaps between the baffles, and the sinter cannot completely cover the bottom of the chute. When the number of baffles increases to 40, the gaps are reduced, but it is still not completely filled. When the number of baffles reaches 50, the material retention between the baffles basically covers the bottom and sidewall surfaces of the chute, effectively reducing the wear of the sinter on the chute and reducing the contact area between the sinter and the surface of the spiral chute, thereby extending the service life of the spiral chute.

[0103] Figure 10 In the diagram, h represents the empty area left when the number of spiral chute baffles is 30, i represents the empty area left when the number of spiral chute baffles is 40, but the empty area has been significantly reduced, and j represents the material that has basically filled the gap between the two baffles when the number of spiral chute baffles is 50.

[0104] As the number of baffles increases, the surface of the chute gradually fills with sinter, and the wear pattern of the sinter changing from wear between the sinter and the chute to wear between the sinter particles. Over time, sinter channels gradually form inside the spiral chute, enhancing its protective capabilities. However, this also leads to a slight increase in the maximum sinter velocity: 2.9 m / s in Simulation 4 (30 baffles, 600mm*600mm), 4.7 m / s in Simulation 5 (40 baffles, 800mm*800mm), and 6.8 m / s in Simulation 6 (50 baffles, 800mm*800mm). This relatively increases the sinter transfer speed, becoming a favorable factor for increasing iron production.

[0105] In summary, a spiral chute with 30 to 50 baffles can store a certain amount of sinter between the baffles, reducing wear between the sinter and the chute to varying degrees and lowering the sinter return rate.

[0106] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. A spiral chute for reducing sinter return rate, comprising a spiral chute body, wherein a baffle (6) is provided on the bottom plate of the spiral chute body; characterized in that: The spiral chute body includes a chute cover (2) and a chute bottom plate (4) that are parallel to each other; the chute cover (2) and the chute bottom plate (4) are connected by two parallel chute side plates (3); the included angle between the baffle (6) and the chute bottom plate (4) is 60°~90°; the baffle (6) is fixedly connected to the chute bottom plate (4) and the chute side plate (3) respectively; The total length of the spiral chute is L, the radius of the spiral chute is R, and the spiral angle is . The three satisfy the following relationship: ； The baffle height is h, and the chute bottom plate width is l; the following relationship exists between them: Where a is a constant, and the value of a ranges from 2 to 10.

2. The spiral chute for reducing sinter return rate according to claim 1, characterized in that, The pitch of the spiral chute is S, and the drop of the spiral chute is H. When S=H, .

3. The spiral chute for reducing sinter return rate according to claim 1, characterized in that: The range of R is 2m <R<2.8m; The value range is 45°< <60°; The value of h is in the range of 100mm. <h<200mm; The value of l is in the range of 800mm. <l<1600mm。 4. The spiral chute for reducing sinter return rate according to claim 1, characterized in that, The value of a ranges from 4 to 8.

5. The spiral chute for reducing sinter return rate according to claim 1, characterized in that, The height of the baffle is 100mm~200mm.

6. The spiral chute for reducing sinter return rate according to claim 1, characterized in that, The baffles are evenly distributed in the channel of the spiral chute body, and there are 50 baffles in total.

7. The spiral chute for reducing sinter return rate according to any one of claims 1-6, characterized in that, The channel cross-section of the spiral chute body is square, with a side length of 800mm to 1000mm.

8. The spiral chute for reducing sinter return rate according to claim 1, characterized in that, The angle between the bottom plate (4) and the chute cover (2) and the horizontal plane is 30°~50°.

9. The spiral chute for reducing sinter return rate according to claim 1, characterized in that, The bottom plate at the discharge port (5) of the chute is an arc-shaped bottom plate, which is tangent to the bottom plate (4) of the chute. A grid-shaped pit (7) is provided at the end of the discharge port (5) of the chute.

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