Spiral chute capable of reducing sintering return ore rate

Abstract

The invention discloses a spiral chute capable of reducing the sintering return ore rate, and belongs to the technical field of sintered ore, the spiral chute comprises a spiral chute body, and a baffle is arranged on a chute bottom plate of the spiral chute body; the total mileage of the spiral chute is L, the radius of the spiral chute is R, and the spiral angle is theta; the three meet the following relation: L = 2piR * [1 + sin (theta-15)]; the height of the baffle is h, and the width of the chute bottom plate is l; the relationship between the two is # imgabs0 #, a is a constant, and the value range of a is 2-10. According to the method, the constraint relation among the total mileage of the spiral chute, the radius of the spiral chute and the spiral angle is constructed; the height of the baffle and the width of the chute bottom plate are restrained; according to the spiral chute designed based on the two constraint relations, the purpose of better reducing the sintering return ore rate can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of sintered ore, and in particular relates to a spiral chute for reducing the sintering return rate. Background Art

[0002] From the sintering plant, sintered ore needs to go through multiple storage, loading and transportation links before finally arriving at the blast furnace as the main raw material for ironmaking. During belt or chute transportation, height difference is a key factor that causes sintered ore to fall and hit. Due to differences in sintered ore quality, some sintered ore has low crushing strength, which can easily lead to sintered ore breakage during transportation or relocation, thereby increasing the return rate. This problem has not been effectively solved for a long time.

[0003] According to the application of Chinese patent application No. 2020105931132, a chute for reducing the crushing rate of sintered ore in a steel plant is disclosed. This chute adopts a spiral structure, which can reduce the impact force of the sintered ore during the falling process to a certain extent, thereby effectively reducing the crushing rate. However, in the actual application process, it is found that the size parameters and structural parameters of the spiral chute have a decisive influence on the crushing rate. For example, if the total mileage of the spiral chute is increased alone or the spiral angle is increased alone, the crushing rate will increase; on the contrary, if the radius of the spiral chute is increased alone or the number or height of the baffles is increased alone, the crushing rate will decrease. However, in the specific actual operation process, the size parameters and structural parameters of the spiral chute are often limited by the on-site environment, and it is not possible to simply and arbitrarily revise a certain parameter to meet the needs of the site. Therefore, how to reasonably adjust the size parameters and structural parameters of the spiral chute to achieve the purpose of reducing the crushing rate under the premise of meeting the restrictions of the on-site environment has become an important problem that we need to solve. Summary of the invention

[0004] In order to solve the technical problems existing in the known technology, the present invention provides a spiral chute for reducing the sintering return rate, and achieves the purpose of better reducing the sintering return rate by constructing a reasonable matching relationship between different parameters of the spiral chute.

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

[0006] The total mileage of the spiral chute is L, the radius of the spiral chute is R, and the spiral angle is θ; the following relationship is satisfied between the three:

[0007] L = 2πr × [1 + sin (θ-15)];

[0008] The height of the baffle is h, and the width of the chute bottom plate is l; the following relationship is satisfied between the two: Wherein, a is a constant, and the value range of a is 2 to 10.

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

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

[0011] The value range of θ is 45°<θ<60°;

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

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

[0014] Preferably, the value range of a is 4-8.

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

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

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

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

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

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

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

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

[0023] In the research process, the present invention makes full use of a large amount of real test data and cleverly combines computer simulation technology. First, a constraint relationship model between the total mileage of the spiral chute, the radius of the spiral chute and the spiral angle is constructed. Through in-depth analysis and repeated verification, the intrinsic relationship between the three parameters is successfully revealed, and the law of mutual influence between them is established. Then, the constraint relationship between the baffle height and the width of the chute bottom plate is further studied, and the optimal matching relationship between the two parameters is found through careful experiments and data analysis. Based on the above two constraint relationship models, the present invention designs a spiral chute that reduces the sintering return rate. This spiral chute fully considers the mutual constraint relationship between various parameters in structure, thereby ensuring its high efficiency and reliability in practical applications. Finally, a drainage test of sintered ore is carried out using a spiral chute that satisfies the above two constraint relationships. The test results show that this spiral chute can more effectively reduce the sintering return rate, thereby improving production efficiency and economic benefits. Through this series of studies and experiments, not only the accuracy of the theoretical model is verified, but also a practical technical solution is provided for actual production. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0026] Figure 3 It is a structural diagram of the second viewing angle of the interior of the spiral chute in the preferred embodiment of the present invention;

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

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

[0029] Figure 6 is the simulation result of the original chute;

[0030] Figure 7 The simulation results of different helical angles;

[0031] Figure 8 The simulation results of different baffle heights when the spiral angle of the spiral chute is 45°;

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

[0033] Fig.10 The simulation results for different numbers of baffles.

[0034] Among them: 1. chute feed port; 2. chute cover; 3. chute side plate; 4. chute bottom plate; 5. chute discharge port; 6. baffle; 7. chute discharge end. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned purpose, control system and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

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

[0037] A spiral chute for reducing the sintering return rate includes a spiral chute body, and a baffle 6 is arranged on the chute bottom plate of the spiral chute body; the number of baffles 6 is related to the total mileage of the spiral chute, and the number of baffles increases accordingly as the total mileage of the spiral chute increases; by evenly arranging multiple baffles on the chute bottom plate, the material can fill the space formed by the baffle and the chute; the design can transform the static friction between the sintered ore and the chute into rolling friction between the sintered ore, thereby effectively reducing the return rate of the sintered ore and increasing the average particle size of the sintered ore. In addition, the sintered ore accumulated between the baffle and the chute bottom plate forms a wear-resistant layer, avoiding direct contact between the sintered ore and the chute bottom plate, thereby reducing the wear caused by the sintered ore to the chute bottom plate. Similarly, the sintered ore accumulates between the side baffle and the chute bottom plate, and also forms a protective layer, avoiding direct contact between the sintered ore and the chute side plate, reducing the wear of the chute side plate, thereby extending the service life of the spiral chute.

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

[0039] 1. 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 the spiral chute refers to the total length of the spiral section of the spiral chute.

[0041] The spiral chute radius refers to the radius of the spiral chute in the top view ( Figure 4 ) is the radius of the circle enclosed by the midlines of the spiral sections of the spiral chute.

[0042] The spiral angle refers to the angle between the tangent line of the spiral section of the spiral chute and the horizontal direction.

[0043] Among them: the total mileage of the spiral chute is L, the radius of the spiral chute is R, and the spiral angle is θ; the following relationship is satisfied between the three:

[0044] L=2πR×[1+sin(θ-15)]; (1)

[0045] 2. The constraint relationship between the baffle height and the chute bottom plate width;

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

[0047]

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

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

[0050] In order to more deeply understand the technical solution of the present invention, the following non-limiting examples are given:

[0051] The main structure of the spiral chute is mainly composed of a chute cover 2, a chute side plate 3 and a chute bottom plate 4. Specifically, the chute cover and the chute bottom plate are arranged in parallel, and the chute side plate is composed of two pieces to connect the chute cover and the chute bottom plate. These parts together constitute a spiral sealed logistics channel, which can effectively prevent the sintered ore from escaping from the chute during transportation and causing splashing. At the chute discharge port 5, the chute discharge end 7 is designed to be arc-shaped and tangent to the chute bottom plate 4 to reduce the impact force on the sintered ore. In addition, at the end of the chute discharge port 5, a grid-shaped pit is provided, the width of which matches the conveyor belt for storing sintered ore.

[0052] The size of the chute feed port 1 is limited by the size of the feeding machine, and the cross-section of the spiral chute body, that is, 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 the 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, wherein the range of α is set to be 60° to 90°. It should be noted that Figure 2 and Figure 3 In order to explain more clearly, Figure 3 for Figure 2 As for the terminal width of the chute discharge port 5, it ranges from 1000 mm to 1400 mm, which is basically consistent with the width of the conveyor belt.

[0053] A plurality of baffles 6 having the same width as the chute bottom plate 4 are arranged on the chute bottom plate 4 , and the baffles 6 are respectively fixedly connected to the chute bottom plate 4 and the chute side plates 3 , for example, by welding, bolt connection, etc.

[0054] The value range of spiral chute radius R is 2m <R<2.8m。

[0055] The value range of the helix angle θ is 45°<θ<60°.

[0056] The value range of baffle height h is 100mm <h<200mm。

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

[0058] The further value range of the constant a is 4 to 8.

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

[0060] Contrast ratio setting

[0061] Simulate the original inclined chute in Example 1:

[0062] Table 1 Equipment parameters of inclined ore chute

[0063]

[0064] The simulation and subsequent processing revealed the velocity profile of the sinter particles as they were transported in the original chute. Figure 6 The two main collision areas are clearly revealed (a is the first collision point between the sintered ore and the chute, b represents the flow of the sintered ore down the chute, and c is the second collision point between the sintered ore and the chute): First, when the sintered ore enters the chute, it will collide with the chute for the first time, causing its movement direction to change; second, when the sintered ore is transported to the end point, it will collide with the baffle of the chute to slow down and change its movement direction to ensure that it can accurately fall on the conveyor belt. Since the sintered ore accelerates in the chute and reaches the second collision point at a speed of 7 to 8 meters per second, the impact force at this point is extremely significant, and the crushing effect on the sintered ore is also very strong, resulting in a large amount of return ore in this area, thereby increasing the return ore rate.

[0065] In summary, there are two collision points in the comparative inclined chute when transporting sintered ore, which reduces the particle size of the sintered ore and increases the return rate of the sintered ore.

[0066] Example Setup

[0067] Embodiment 1:

[0068] Table 2 Parameter settings for comparative example 2

[0069]

[0070] Embodiment 2:

[0071] Table 3 Parameter settings for comparative example 3

[0072]

[0073] Embodiment 3:

[0074] Table 4 Parameter settings for comparative example 4

[0075]

[0076] Comprehensive analysis of Example 1, Example 2 and Example 3, the following conclusions can be drawn: According to the actual situation of Tiantie sintered ore transportation, the spiral angles of the spiral chute are determined to be 50°, 45° and 40° respectively. In order to ensure that the transportation volume and transportation speed of the sintered ore remain at an appropriate level, it is decided to use a spiral chute with a single spiral design, and its pitch is uniformly set to 14 meters.

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

[0078] Simulation 1 (helix angle 50°) Simulation 2 (helix angle 45°) Simulation 3 (helix angle 40°) Maximum material flow speed (m / s) 7.67 6.80 5.62 Minimum flow rate (m / s) <![CDATA[6.26×10 -6 ]]> <![CDATA[2.17×10 -5 ]]> <![CDATA[7.17×10 -6 ]]>

[0079] Simulation by EDEM Figure 7 As shown in Table 5, the maximum speed of the sintered ore flow is: simulation 1 (spiral angle 50°) > simulation 2 (spiral angle 45°) > simulation 3 (spiral angle 40°). The minimum speed 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 shows that as the spiral angle of the spiral chute decreases, the maximum sliding speed of the sintered ore also shows a downward trend. At the same time, the minimum sliding speed of the sintered ore shows a trend of first rising and then falling, reaching a peak value of 2.17×10^-5m / s when the spiral angle of the spiral chute is 45°. This result shows that when the spiral angle of the spiral chute is set to 45°, it can not only ensure the feeding efficiency of the sintered ore, but also avoid the blockage of the sintered ore in the spiral chute, thereby ensuring the smooth transportation speed of the sintered ore.

[0080] The Grid Bin Group grid grouping function was introduced into the model, and a single grid was set in the three dimensions of X, Y, and Z. By adjusting the size and position of the grid, the precise detection of the sintered ore velocity at the outlet of the spiral chute was achieved. From the simulation results, it can be seen that simulation 1 (the spiral angle is 50 degrees) shows that the stable outlet velocity of the sintered ore is 3.02 m / s, simulation 2 (the spiral angle is 45 degrees) The stable outlet velocity is 3.14 m / s, and simulation 3 (the spiral angle is 40 degrees) is 3.48 m / s. In addition, when the spiral angle of the spiral chute is set to 40 degrees, the sintered ore velocity at the outlet shows instability, and the velocity fluctuation range is between 2.84 and 3.06 m / s. When the spiral angle is 45 and 50 degrees, the sintered ore velocity at the outlet tends to be stable.

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

[0082] Embodiment 4:

[0083] Table 6 Parameter settings for comparative example 5

[0084]

[0085] Embodiment 5:

[0086] Table 7 Parameter settings for comparative example 6

[0087]

[0088] By comprehensively analyzing Example 4 and Example 5, the following conclusions can be drawn: Figure 8 The simulation results of changing the height of the baffles in the spiral chute show that the storage capacity of the baffles is as follows: simulation 2 (50 baffles, baffle height 100mm) < simulation 7 (50 baffles, baffle height 150mm) < simulation 8 (50 baffles, baffle height 200mm). Further observation Fig. 9 The influence of changing the height of the baffles on the feed port of the spiral chute shows that although the storage capacity of simulation 8 (50 baffles, baffle height 200mm) is the strongest, its feed port is prone to blockage. The sintered ore stored in the chute occupies about 50% of the entire chute volume, which leads to a decrease in the actual sintered ore transportation capacity of the chute, which in turn causes the problem of insufficient sintered ore supply. Fig. 9 In the figure, f means that when the baffle height is 200 mm, the feed port is at risk of being blocked.

[0089] from Figure 8From the simulation results of the paving situation on the surface of the middle chute, the paving effect of simulation 2 (50 baffles, baffle height 100mm) is 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 is 100mm, there is a large empty area on the inner surface of the spiral of the chute between the baffles, and the sintered ore fails to completely cover the bottom of the chute; when the baffle height is 150mm, the empty area on the inner surface of the spiral of the chute between the baffles disappears, and the sintered ore is evenly spread on the entire chute surface; when the baffle height is 200mm, the empty area on the inner surface of the spiral of the chute between the baffles also disappears, which is similar to the situation when the baffle height is 150mm.

[0090] Figure 8 In the figure, d indicates that when the height of the spiral chute baffle is 100mm, the sintered ore does not cover the entire surface of the chute, leaving an empty area. E indicates that when the height of the spiral chute baffle is 150mm and 200mm, the material has basically filled the gap between the two baffles.

[0091] Based on the above analysis, the simulation results of EDEM software show that the optimal working conditions of the spiral chute are: cross-sectional size 800mm*800mm, pitch 14m, spiral radius 2.37m, spiral angle 45°, number of baffles 50, and baffle height 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 sintered ore can be stored between the baffles, which reduces the wear between the sintered ore and the chute to varying degrees and reduces the sintering return rate.

[0093] Embodiment 6:

[0094] Table 8 Parameter settings for comparative example 7

[0095]

[0096] Embodiment 7:

[0097] Table 9 Parameter settings for comparative example 8

[0098]

[0099] Embodiment 8:

[0100] Table 10 Parameter settings for comparative example 9

[0101]

[0102] Comprehensive analysis of Example 6, Example 7 and Example 8 can draw the following conclusions: Through simulation experiments, the number of spiral chute baffles is changed, and the results are as follows: Fig.10As shown in the figure, the degree of baffle stock is 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 sintered ore fails to completely cover the bottom of the chute; when the number of baffles increases to 40, the gaps are reduced but still not completely filled; and when the number of baffles reaches 50, the stock between the baffles has basically covered the bottom and side wall surface of the chute, effectively reducing the wear of the sintered ore on the chute, while reducing the contact area between the sintered ore and the surface of the spiral chute, thereby extending the service life of the spiral chute.

[0103] Fig.10 In the figure, h means that when the number of baffles of the spiral chute is 30, the material does not fill the chute, leaving an empty area; i means that when the number of baffles of the spiral chute is 40, the material does not fill the chute, leaving an empty area, but the empty area has been significantly reduced; j means that when the number of baffles of the spiral chute is 50, the material has basically filled the distance between the two baffles;

[0104] As the number of baffles increases, the surface of the chute is gradually filled with sintered ore, and the wear mode of the sintered ore sliding down changes from the wear between the sintered ore and the chute to the wear between the sintered ore. Over time, a sintered ore channel is gradually formed inside the spiral chute, which enhances the protection ability of the chute. However, this also leads to a slight increase in the maximum sliding speed of the sintered ore. The maximum sliding speed of the sintered ore in simulation 4 (30 baffles, 600mm*600mm) is 2.9m / s, the maximum sliding speed of the sintered ore in simulation 5 (40 baffles, 800mm*800mm) is 4.7m / s, and the maximum sliding speed of the sintered ore in simulation 6 (50 baffles, 800mm*800mm) is 6.8m / s. This relatively increases the transportation speed of the sintered ore, which becomes a favorable factor for increasing iron production.

[0105] In summary, when the number of baffles in the spiral chute is in the range of 30 to 50, a certain amount of sintered ore can be stored between the baffles, thereby reducing the wear between the sintered ore and the chute to varying degrees and reducing the sintering return rate.

[0106] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A spiral chute for reducing the sintering return rate, comprising a spiral chute body, wherein a baffle (6) is arranged on the chute bottom plate of the spiral chute body; characterized in that: The total mileage of the spiral chute is L, the radius of the spiral chute is R, and the spiral angle is θ; the following relationship is satisfied between the three: L = 2πR × [1 + sin (θ-15)]; The height of the baffle is h, and the width of the chute bottom plate is l; the following relationship is satisfied between the two: Wherein, a is a constant, and the value range of a is 2 to 10.

2. The spiral chute for reducing sintering return rate according to claim 1, characterized in that: The pitch of the spiral chute is S, and the height of the spiral chute is H. When S=H, 3. The spiral chute for reducing the sintering return rate according to claim 1, characterized in that: The value range of R is 2m <R<2.8m; The value range of θ is 45°<θ<60°; The value range of h is 100mm <h<200mm; The value range of l is 800mm <l<1600mm。 4. The spiral chute for reducing sintering return rate according to claim 1, characterized in that: The value range of a is 4 to 8.

5. The spiral chute for reducing sintering return rate according to claim 1, characterized in that: The baffle height is 100 mm to 200 mm.

6. The spiral chute for reducing sintering return rate according to claim 1, characterized in that: The baffles are evenly distributed in the channel of the spiral chute body, and the number of the baffles is 50.

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

8. The spiral chute for reducing sintering return rate according to claim 1, characterized in that: The spiral chute body comprises a chute cover (2) and a chute bottom plate (4) which are parallel to each other; the chute cover (2) and the chute bottom plate (4) are connected via two chute side plates (3) which are parallel to each other.

9. The spiral chute for reducing sintering return rate according to claim 8, characterized in that: The angle between the chute bottom plate (4) and the chute cover (2) and the horizontal plane is in the range of 30° to 50°, and the angle between the baffle plate (6) and the chute bottom plate (4) is in the range of 60° to 90°.

10. The spiral chute for reducing sintering return rate according to claim 8, characterized in that: The bottom plate at the chute discharge port (5) is an arc-shaped bottom plate, which is tangent to the chute bottom plate (4), and a grid-shaped concave pit (7) is arranged at the end of the chute discharge port (5).

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