A method of stockpiling for a blending stockpile reclaimer

Abstract

The application discloses a method for mixing and stacking of a stacker, and relates to the technical field of material conveying, and comprises the following steps: S1, obtaining a stacking running speed V according to a target function one; S2, segmenting a top of the stack according to a length L of each segment to obtain an actual target stacking height h L , obtaining a delta h according to a target function two, and substituting the delta h into the target function one in the step S1 to achieve the purpose of adjusting the stacking running speed V.

Description

Technical Field

[0001] This invention relates to the field of material conveying technology, and in particular, to a stacking method for a mixing stacker. Background Technology

[0002] A raw material yard is a site for receiving, storing, processing, and blending raw materials and fuels for iron and steel metallurgy. Modern large-scale raw material yards include ore yards, coal yards, auxiliary raw material yards, and blending yards. They not only store incoming iron ore, iron concentrate, pellets, manganese ore, limestone, dolomite, serpentine, silica, coking coal, and thermal coal, but also store some sintered ore, pellets, and recycled materials from the steel plant, such as iron oxide scale, blast furnace ash, coke crushing, sinter powder, and end-of-life materials for blending. Stacker cranes are commonly used for stockpiling materials in the yard, especially in blending yards, where they move while simultaneously and evenly stacking materials to achieve a proportional distribution scheme.

[0003] The existing method of stacking mixed materials mainly adopts a herringbone pattern. In this method, the stacking point is on the longitudinal centerline of the material pile. The mixing stacker moves from one end to the other along the length of the material pile at a certain speed, and in this process, one layer of material is completed. The first layer of mixed material is a small strip of material with an isosceles triangle cross-section. The second layer is a layer of mixed material covering this small triangle. In this way, the material is stacked layer by layer. Except for the first layer, each layer of material forms a "V" shape when viewed from the cross-section, hence the name herringbone stacking.

[0004] However, during the material stacking process, the feed flow rate may change, resulting in an uneven top of the material pile. This can lead to the reclaimer experiencing empty digging or blockage. Furthermore, it can cause instability in the feed flow of the mixed material conveyor belt leaving the material yard, thus affecting subsequent production.

[0005] Therefore, it is necessary to propose a material stacking method for a mixing stacker to solve or at least alleviate the above-mentioned defects. Summary of the Invention

[0006] The main objective of this invention is to provide a material stacking method for a mixing stacker, which aims to solve existing technical problems.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A stacking method for a mixing stacker includes the following steps:

[0009] S1. Calculate the stockpile travel speed V according to objective function one;

[0010] Objective function 1:

[0011] Where Δh is the difference between the target pile height and the current pile height h, h is the current pile height, θ is the angle of repose preset based on the target pile height, and W t It is the current flow rate of the material conveying equipment;

[0012] S2. Divide the top of the stockpile into segments of length L to obtain the actual target stockpile height h. L Δh is obtained from objective function two, and then substituted into objective function one in step S1 to achieve the purpose of adjusting the stockpile travel speed V.

[0013] Objective function two:

[0014] As a preferred option, the following steps are also included:

[0015] S100, Stockpile Modeling:

[0016] (1) When there is no material, the first material stacking area is manually divided. The material drop point is obtained by the pitch angle of the stacker boom and the speed of the boom belt. Then, the angle of repose θ is obtained according to the material characteristics.

[0017] The volume of the material is obtained based on the material characteristics and the weight of the unloaded material weighed by the cantilever belt scale; and a material pile model is established based on the drop point, the angle of repose θ, and the volume.

[0018] (2) Then, based on the stockpile model, obtain the ridgeline of the stockpile, and select a line segment on the ridgeline that matches the height of the stockpile as the second stockpile area.

[0019] Preferably, step S1 includes the following:

[0020] Step 1000: Obtain the current height h of the stockpile, and calculate the current cross-sectional area S1 of the stockpile according to the objective function.

[0021]

[0022] Step 1001: Calculate the cross-sectional area S2 of the target stockpile and obtain the area difference ΔS;

[0023]

[0024] ΔS = S2 - S1;

[0025] Step 1002: Calculate the material volume ΔV required for the target stockpile;

[0026] ΔV = ΔS × V × t;

[0027] Step 1003: Based on the conveying equipment used and the functions in the above steps, obtain the objective function of the traveling speed V;

[0028] ΔV=W t ×t.

[0029] Preferably, the current height h of the material pile in step S1 is obtained by measuring the layer thickness at the discharge port of the mixing and stacking machine boom.

[0030] Preferably, the W t The calculations were performed after modeling the material conveying equipment using lidar.

[0031] Preferably, the W t The specific calculation steps are as follows:

[0032] 1) Weigh the average weight of the material being transported and stacked over a certain period of time, and record it as M;

[0033] 2) Based on the density ρ of the mixed material, W is obtained according to the following function. t ;

[0034]

[0035] The present invention has the following beneficial effects:

[0036] The stacking device moves back and forth within a designated stacking area to unload materials, employing a mode of simultaneous movement and uniform stacking to achieve proportional mixing of materials. As the material pile continuously accumulates and grows taller during the stacking process, to avoid collisions due to the unloading port being too close to the pile, and to prevent dust and material scattering outside the designated stacking area due to excessive distance between the unloading port and the pile, the distance between the pile and the unloading port needs to be dynamically and adaptively adjusted during the stacking process. This distance adjustment is achieved by adjusting the pitch angle of the boom. This application adds a threshold range constraint to the distance adjustment. When the distance is within the threshold range, no adjustment is needed. If the distance exceeds the threshold range, the boom is controlled according to the target pitch angle, rotating to the position corresponding to the target pitch angle, thus maintaining a suitable distance between the material pile surface and the unloading port. When the current pile height reaches the preset pile height, i.e., the stacking area is full, stacking can be stopped. This application can adaptively adjust the distance between the stockpile and the unloading port during the stockpiling process, ensuring the reliability of the stockpiling, eliminating the need for manual operation, improving the efficiency and accuracy of stockpiling, ensuring the safe and stable operation of the on-site stockpiling device, and realizing unmanned and automated stockpiling of the stockpiling device.

[0037] 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

[0038] 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:

[0039] Figure 1 This is a schematic diagram of the overall process architecture in this invention;

[0040] Figure 2 This is a schematic diagram of the specific process architecture of step S1 in this invention;

[0041] Figure 3 This is a schematic diagram of the material pile area in this invention;

[0042] Figure 4 This is a flowchart illustrating the specific operation steps of the present invention. Detailed Implementation

[0043] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0045] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0046] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0047] Before understanding the proposed solution, we need to know that currently, the operation of stockpiling materials in the mixing yard is all done manually. This is labor-intensive, involves long working hours, and the dust pollution from the bulk materials can have a significant impact on the physical and mental health of the operators.

[0048] During operation, the operator manually controls the movement of the large machine in the cab to stack materials. This requires the operator to concentrate for a long time, resulting in high labor intensity. There are also many interfering factors on site, such as water mist, dust, and obstructed visibility at night, which can easily cause collisions and threaten the safe operation of the equipment. The material stacking process of the mixing stacker is mainly divided into two parts: one is the initial general stacking, and the other is the leveling of the top of the stack after the general stack is formed. The leveling of the top of the stack is also achieved by the repeated movement of the large machine. This invention adjusts the traveling speed of the large machine by calculating the height of the top of the stack and combining it with the material flow of the conveyor belt during the leveling process.

[0049] like Figure 1 The stacking method of the mixing stacker shown includes the following steps:

[0050] S1. Calculate the stockpile travel speed V according to objective function one;

[0051] Objective function 1:

[0052] Where Δh is the difference between the target pile height and the current pile height h, h is the current pile height, θ is the angle of repose preset based on the target pile height, and W t It is the current flow rate of the material conveying equipment;

[0053] Specifically, step S1 includes the following: the specific derivation process of the objective function is shown below.

[0054] Step 1000: Obtain the current height h of the stockpile, and calculate the current cross-sectional area S1 of the stockpile according to the objective function.

[0055]

[0056] In this embodiment, the current height h of the material pile is obtained by a layer thickness gauge installed at the discharge port of the boom of the mixing stacker. It should be noted that this mixing stacker is the mainstream equipment currently used in the market, and its structure has not been optimized. Therefore, the specific structure of the mixing stacker will not be described here.

[0057] Step 1001: Calculate the cross-sectional area S2 of the target stockpile and obtain the area difference ΔS;

[0058]

[0059] ΔS = S2 - S1;

[0060] Step 1002: Calculate the material volume ΔV required for the target stockpile;

[0061] ΔV = ΔS × V × t;

[0062] Step 1003: Based on the conveying equipment used and the functions in the above steps, obtain the objective function of the traveling speed V;

[0063] ΔV=W t ×t;

[0064] In this embodiment, the conveying device is a belt scale, W t In this application, the belt conveyor material is modeled and calculated using LiDAR. However, due to the inherent instability of the belt scale during the feeding process, errors exist. Therefore, to improve the accuracy of this material stacking method, the average weight M of the material fed onto the belt over a certain period is measured, and combined with the density ρ of the mixed material, W is calculated according to the following function. t ;

[0065]

[0066] It should be noted that in the above content, "a certain time" refers to any time interval, which can be adjusted and selected by those skilled in the art according to actual needs. Furthermore, this "certain time" and "t" in steps 1002 and 1003 are the same time interval. The material stacking speed V is a uniform motion. Specifically, during the stacking process, combined with the attached... Figure 3 Generally speaking, the speed of the stacker's discharge port remains constant from point A to point B. However, the material flow of the belt conveyor fluctuates in actual production, but not significantly. Therefore, an average or integral is needed to determine the material flow rate over a certain period of time. This period of time varies depending on the scale and production conditions of different owners' secondary or tertiary mixing equipment, so only a general explanation is given, and the specific circumstances will determine the appropriate measure.

[0067] However, since the discharge flow rate is not constant, different areas at the top of the stockpile have varying heights. This problem is addressed through the following step S2.

[0068] S2. Divide the top of the stockpile into segments of length L to obtain the actual target stockpile height h. L Δh is obtained from objective function two, and then substituted into objective function one in step S1 to achieve the purpose of adjusting the stockpile travel speed.

[0069] Objective function two:

[0070] Step S2 is used to adjust the moving speed of the stacker boom in real time, i.e. the walking speed V of the stack, so as to make the two reference points A and B of the ridge line of the material pile on the same horizontal plane, ensuring that all areas of the top of the material pile are aligned.

[0071] Furthermore, to ensure that the stockpile is a standard herringbone shape when it is completed, the following steps are also included:

[0072] S100, Stockpile Modeling:

[0073] (1) When there is no material, manually divide the material stacking area, obtain the material drop point by the pitch angle of the stacker boom and the speed of the boom belt, and then obtain the angle of repose θ according to the material characteristics;

[0074] The volume of the material is obtained based on the material characteristics and the weight of the unloaded material weighed by the cantilever belt scale; and a material pile model is established based on the drop point, the angle of repose θ, and the volume.

[0075] (2) Then, based on the material pile model, obtain the ridge line of the material pile, and select a line segment on the ridge line that matches the height of the material pile as the material pile area; it should be noted that the second material pile area mentioned in (2) and the first material pile area mentioned in (1) are different to some extent. First, the first material pile area in (1) is a space that is convenient for placing materials, while the second material pile area in (2) is a material pile space that is not flat enough to reach a certain height.

[0076] In practical terms, when the stacker has piled the material into a preliminary shape, the lidar installed on the boom of the mixing stacker begins to scan the distance from the boom to the top of the material pile, thereby modeling the height of the pile top. Subsequently, with each movement of the stacker, the height of the material pile will change, and the model of the pile top will be updated in real time. It should be noted that in this invention, it is not necessarily necessary to suggest a three-dimensional model of the material pile; what is mainly needed is the height data of the material pile and the flatness of the top of the material pile.

[0077] Furthermore, to facilitate understanding of the specific working principle of this method, in conjunction with the appendix... Figure 4 To illustrate, the specific steps of this method are as follows:

[0078] Step SS0, Start;

[0079] Step SS1: Initialize the stacker system and set the key parameters required for the target stockpile. The key parameters include the travel area, the stockpile angle of repose θ, and the segment length L.

[0080] Step SS2: The stacker performs its first travel to obtain the top model of the current stockpile;

[0081] Step SS3: Based on the top model obtained in step SS2, and combined with the key parameters in step SS1, calculate the target stack height difference Δh for each walking section.

[0082] Step SS4: Calculate the travel speed V in different sections during the next travel based on the target material height difference Δh and key parameters;

[0083] Step SS5: Perform the "next travel" to stack the material, and measure the height of the top of the material pile after the travel while stacking the material. It should be understood that the "next travel" here actually means stacking the material based on the travel speed obtained in step SS4.

[0084] Step SS6: Compare whether the material pile after travel has reached the preset pile height and flatness;

[0085] Step SS7, End.

[0086] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0087] The above are merely preferred embodiments of the present invention and are not intended to limit the present 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 stacking method for a mixing stacker, characterized in that, Includes the following steps: S1. Calculate the stockpile travel speed according to objective function one. ; Objective function 1: ; in, The target stockpile height and the current stockpile height The difference, This is the current height of the stockpile. The angle of repose is preset based on the target stockpile height. It is the current flow rate of the material conveying equipment; S2. For the top of the stockpile, according to the length of each section... Divide the material into segments to obtain the actual target stacking height. According to objective function two, the following is obtained: Substituting this into the objective function in step S1 achieves the goal of adjusting the stockpile travel speed. Purpose; Objective function two: ; It also includes the following steps: S100, Stockpile Modeling: (1) When there is no material, the first material stacking area is manually divided. The material drop point is obtained by the pitch angle of the stacker boom and the speed of the boom belt. Then, the angle of repose is obtained according to the material characteristics. ; The volume of the material is obtained based on the material characteristics and the weight of the unloaded material weighed by the cantilever belt scale; and the volume is obtained based on the drop point and the angle of repose. The aforementioned volume is used to establish a stockpile model; (2) Then, based on the material pile model, obtain the ridge line of the material pile, and select a line segment on the ridge line that matches the height of the material pile as the second material pile area; The steps also include the following: SS1, Stacker system initialization, i.e., setting the key parameters required for the target stockpile; SS2, the stacker makes its first pass and obtains the top model of the current stockpile; SS3. Based on the top model obtained in step SS2, and combined with the key parameters in step SS1, calculate the target stack height difference for each walking section. ; SS4. Based on the target stockpile height difference And key parameters are used to calculate the travel speed in different sections during the next travel. ; SS5. Proceed to the "next travel" to stockpile materials, and measure the top height of the stockpile after the travel while stockpiling materials; SS6. Compare whether the material pile after travel has reached the preset pile height and flatness; if yes, proceed to step SS7; if no, return to step SS3. SS7, End.

2. The stacking method of a mixing stacker according to claim 1, characterized in that, The specific content of step S1 includes: Step (1000): Obtain the current height of the stockpile. The cross-sectional area of ​​the current stockpile is obtained based on the objective function. : ； Step (1001): Calculate the cross-sectional area of ​​the target stockpile. Calculate the area difference ; ； ； Step (1002): Calculate the volume of material required for the target stockpile. ; ； Step (1003): Calculate the traveling speed based on the conveying equipment used and the function from the above steps. Objective function one; 。 3. The stacking method of a mixing stacker according to claim 1, characterized in that, The current height of the material pile in step S1 The thickness was measured by a layer thickness gauge at the discharge port of the mixing and stacking machine boom.

4. A stacking method for a mixing stacker according to any one of claims 1-3, characterized in that, The The calculations were performed after modeling the material conveying equipment using lidar.

5. The stacking method of a mixing stacker according to claim 4, characterized in that, The The specific calculation steps are as follows: 1) Weigh the average weight of the material transported and piled over a certain period of time, and record it as . ; 2) Combining the density of the mixed material The following function is used to obtain the result. ; 。 6. The stacking method of a mixing stacker according to claim 5, characterized in that, The key parameters include the travel area and the angle of repose of the stockpile. and segment length .

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