Method for positioning material distribution in a belt conveyor process

Abstract

The present application relates to the technical field of belt conveyor material positioning, in particular to a belt conveyor process material distribution positioning method, which performs grid processing on the material conveyed by the belt conveyor; performs grid processing on the transfer hopper between the upstream and downstream belts in the belt conveyor process; sets a pulse distance measurement mode; establishes data modules of each belt conveyor and hopper in the PLC, and forms a data chain according to the process path; drives the data flow of the belt conveyor and hopper modules in the PLC; when the belt conveyor process is restarted under heavy load, the data flow of the belt conveyor module is driven in the pulse distance measurement mode; real-time tracking of the belt conveyor material carrying capacity; determination of the belt conveyor empty material time; prediction of the material head generated when the belt conveyor process is restarted under heavy load. The present application can real-time track the material carrying capacity of each belt conveyor, determine the belt conveyor empty material time and the material position, control the distribution of the material load, and improve the operation stability of the belt conveyor process.

Description

Technical Field

[0001] This invention relates to the field of belt conveyor material positioning technology, and in particular to a method for distributing and positioning materials in a belt conveyor process. Background Technology

[0002] In industries such as manufacturing, transportation, and metallurgy, belt conveyors are commonly used to transport bulk raw materials. Belt scales are also installed to dynamically weigh the materials. When transporting materials to different locations or over long distances, multiple belts are usually required to work together to form a belt conveyor process.

[0003] In belt conveyor processes, materials flow rapidly over long distances, involving numerous transfer points, yet the continuity between belt conveyors is critical and difficult to manage. The impact of material load on belt conveyor processes mainly includes three aspects: First, material flow exceeding load capacity at certain points on the belt conveyor, commonly known as "material head," impacts the entire process, leading to overload shutdowns and spillage. Second, due to the dynamic nature of belt conveyor processes, materials can only be transported step-by-step. During start-up and shutdown phases, prolonged periods of idling can occur, resulting in energy waste and material accumulation, creating material head. Third, changes in material load can cause belt misalignment, tearing, and other malfunctions. Therefore, a method for material distribution and positioning in belt conveyor processes has been developed. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for locating and distributing materials in a belt conveyor process. This method can track the material load of each belt conveyor in real time, determine the empty time of the belt conveyor, and analyze the linkage relationship between the material position and related equipment of the belt conveyor. By monitoring and controlling the distribution of material load, the stability of the belt conveyor process operation is improved.

[0005] The present invention adopts the following technical solution:

[0006] A method for material distribution and positioning in a belt conveyor system includes the following steps:

[0007] 1) The material conveyed by the belt conveyor is processed into a grid:

[0008] In a process consisting of multiple belt conveyors, the speed of the belt conveyor during stable operation is V, and the distance traveled within a fixed time T is S. Therefore, each belt in the belt conveyor process is divided into a continuous grid of length S, and the length of the last grid that is less than S is rounded to the nearest integer.

[0009] A belt scale is installed on the belt conveyor where the material source is located. The weight of the material in a single square is M, that is, the time for the belt conveyor to operate stably in a single square is T, the corresponding belt square length is S, and the weight of the material in the square is M.

[0010] When the belt conveyor is running stably, the material flows at a uniform speed through all the downstream squares until the end of the belt conveyor process; the weight of the material in each square of the belt extends from M0 at the initial drop position of the belt to Mn at the end of the belt conveyor.

[0011] 2) In the belt conveyor process, the transfer hoppers between the upstream and downstream belts are gridded:

[0012] The material falls into each hopper for a time td, and the drop in the hopper is h. When the belt conveyor is running stably, the material in the hopper is divided into td / T squares with a duration of T. The number of squares is rounded to the nearest integer. Therefore, the weight of the material in the hopper extends from Md0 at the end of the upstream belt to Mdn at the drop point of the downstream belt conveyor.

[0013] 3) When the pulse ranging mode is set, the conveying distance is as follows during heavy-load start-up and shutdown of the belt conveyor:

[0014] An induction plate is installed on the central shaft of the driven roller of each belt conveyor. A proximity switch is installed on the outside of the driven roller. The proximity switch is connected to the PLC. When the driven roller rotates, when the induction plate passes the proximity switch, the proximity switch generates a pulse signal to the PLC. The induction time is Ta and the non-induction time is Tb. When the PLC receives two consecutive pulse signals, the driven roller with radius Rc runs one revolution, and the corresponding distance traveled by the belt conveyor is C=2πRc. When the belt conveyor starts and stops under heavy load, the cumulative length C of the belt travel distance is added every two consecutive pulse signals received by the PLC. Each travel distance S is divided into one square.

[0015] 4) Establish data modules for each conveyor belt and hopper in the PLC, and form a data chain according to the process path:

[0016] The number of formatted squares is calculated based on the structural drawings of the belt conveyor and the hopper. Data blocks with the corresponding number of squares are created in the PLC according to the material flow direction. When the belt conveyor process is started, the PLC automatically loads and unloads data for each belt conveyor and hopper module according to the start process number.

[0017] 5) Driving data flow in the belt conveyor and funnel module via PLC:

[0018] When the belt conveyor is running stably, the PLC drives the data flow at a fixed time T. Every time T, the data of all belt conveyors and funnel modules in the process advances one grid. The data flow of the funnel module is continuously driven by time T, and the data in the internal squares flows from the first grid of the funnel to the last grid.

[0019] 6) During heavy-load start-up and shutdown of the belt conveyor, the flow of data in the belt conveyor module is driven by pulse ranging mode:

[0020] The belt running distance is calculated based on the pulse count of the proximity switch on the belt conveyor. Every time the length S of 1 grid is reached, the data moves forward 1 grid, and the remaining length under the current pulse count is accumulated into the distance corresponding to the next consecutive pulse. In this way, the belt conveyor data flows in the form of integer squares.

[0021] 7) When the data flow of the belt conveyor module switches between heavy load start / stop and stable operation, when the PLC receives 6 consecutive pulse signals from the proximity switch, the driven roller with radius Rc runs for 5 cycles, and the time taken is Tc. At this time, the average speed of the belt is Vp=10πRc / Tc. If Vp reaches 95% of the normal stable operating speed V of the belt conveyor, it is considered that the belt conveyor has been running stably, and the data flow is driven by a fixed time T. If the belt conveyor is tripped or Vp is lower than 90% of the normal speed V, it is considered that the belt conveyor is in heavy load start / stop state, and the pulse ranging mode is switched to drive the data flow. If Vp is between 90% and 95%, the original state is maintained and no switching is performed.

[0022] 8) Real-time tracking of material load on the belt conveyor to determine the belt conveyor's idle time:

[0023] In the PLC, the total weight of materials in each cell of each data module is calculated in real time, Mz=M0+M1+…+Mn, Mdz=Md0+Md1+…+Mdn, where Mz and Mdz are the current material load of the corresponding belt conveyor or hopper. The overload or no-load time is calculated based on the upper and lower thresholds set according to the rated load capacity of the belt conveyor.

[0024] 9) Anticipate the material head generated during the heavy load restart of the belt conveyor:

[0025] After a heavy-load shutdown, the weight of the material in the last cell of each funnel module in the PLC is calculated. If it exceeds the weight of the material in a single cell of the belt conveyor when it is fully loaded, it will result in a certain length of material head when the downstream belt conveyor restarts.

[0026] Once a material head appears at the source of the conveyor belt process or at the end of each hopper, the total number of squares N between the material head and the downstream equipment in the conveyor belt and hopper modules can be calculated. This allows for the estimation of the time it takes for the material head to reach a specific device as Tn=N*T during stable operation of the conveyor belt, thus enabling the collection of countermeasures in advance.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] This invention divides the belt and hopper into individual squares to track the material load on each belt conveyor in real time. By using the PLC to switch different modes to drive data flow based on the belt conveyor operation status, it can accurately determine the empty time of the belt conveyor, analyze the relationship between the material position and related equipment of the belt conveyor, effectively monitor and control the material load, and improve the stability of the belt conveyor process.

[0029] Furthermore, the preferred embodiment adopted in this invention is:

[0030] The arc length of the sensing element is L, the radius of the sensing element is R, the hardware delay time of the proximity switch digital input is Ty, the PLC software delay time is Tr, and the PLC scan cycle is Ts. To ensure that each sensing pulse can be recognized by the PLC, the following must be met:

[0031] Ta≥2*(Ts+Ty+Tr),Tb>(Ts+Ty+Tr)

[0032] The relationship between the arc length L and radius R of the sensing element and the driven radius roller Rc should satisfy:

[0033] L=Ta*V*R / Rc. Attached Figure Description

[0034] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, are not intended to limit the scope of the invention. In the drawings:

[0035] Figure 1 This is a schematic diagram of the material flow direction on the belt conveyor.

[0036] Figure 2 This is a schematic diagram showing the direction of material flow in the funnel.

[0037] Figure 3 This is a schematic diagram of the pulse signal generated by the proximity switch to the PLC.

[0038] Figure 4 Here is a flowchart of the pulse ranging mode switching process;

[0039] Figure 5 This is a schematic diagram of the duration of two consecutive pulses;

[0040] In the diagram: Driven roller 1; Induction plate 2; Proximity switch 3. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. Here, the illustrative embodiments and descriptions of this invention are used to explain the invention, but are not intended to limit the invention.

[0042] A method for material distribution and positioning in a belt conveyor system includes the following steps:

[0043] 1) The material conveyed by the belt conveyor is processed into a grid:

[0044] In a process consisting of multiple belt conveyors, the speed of the belt conveyor during stable operation is V, and the distance traveled within a fixed time T is S. Therefore, each belt in the belt conveyor process is divided into a continuous grid of length S, and the length of the last grid that is less than S is rounded to the nearest integer.

[0045] A belt scale is installed on the belt conveyor where the material source is located. The weight of the material in a single square is M, that is, the time for the belt conveyor to operate stably in a single square is T, the corresponding belt square length is S, and the weight of the material in the square is M.

[0046] When the belt conveyor is running stably, the material flows at a uniform speed through all the downstream squares until the end of the belt conveyor process; the weight of the material in each square of the belt extends from M0 at the initial drop position to Mn at the end of the belt conveyor (e.g., ...). Figure 1 (As shown).

[0047] T and S determine the resolution of the material formatting of the belt conveyor and the number of data corresponding to a single belt conveyor, which depends on the distance of the longest belt conveyor in the belt conveyor process.

[0048] In this embodiment, the belt speed of the belt conveyor is 3.8 m / s, the rated conveying capacity is 7200 tons / hour, the longest belt conveyor in the belt process is 1500 m, and T is set to 0.5 s and S to 1.9 m.

[0049] 2) In the belt conveyor process, the transfer hoppers between the upstream and downstream belts are gridded:

[0050] The material falls into each hopper for a time td, and the drop height within the hopper is h. When the belt conveyor is running stably, the material in the hopper is still divided into td / T squares based on the time T, and the number of squares is rounded to an integer. Therefore, the weight of the material in the hopper extends from Md0 at the upstream end of the belt conveyor to Mdn at the downstream drop point (e.g., ...). Figure 2 (As shown).

[0051] 3) When the pulse ranging mode is set, the conveying distance is as follows during heavy-load start-up and shutdown of the belt conveyor:

[0052] A sensing element 2 is installed on the central shaft of the driven roller 1 of each belt conveyor. A proximity switch 3 is installed on the outside of the driven roller 1. All proximity switches 3 are connected to the PLC. When the driven roller 1 rotates, when the sensing element passes the proximity switch 3, the proximity switch 3 generates a pulse signal to the PLC. The sensing time is Ta, and the non-sensing time is Tb. When the PLC receives two consecutive pulse signals (such as...), the signal is transmitted to the PLC. Figure 5 As shown), the driven roller 1 with radius Rc runs one revolution, and the corresponding distance traveled by the belt conveyor is C=2πRc. When the belt conveyor starts and stops under heavy load, the PLC accumulates the belt travel distance C for every two consecutive pulse signals received. Each travel distance S is divided into one square.

[0053] The arc length of sensor 2 is L, the radius of sensor 2 is R, the hardware delay time of the digital input of proximity switch 3 is Ty, the PLC software delay time is Tr, and the PLC scan cycle is Ts. To ensure that each sensing pulse can be recognized by the PLC, the following must be met:

[0054] Ta≥2*(Ts+Ty+Tr), Tb>(Ts+Ty+Tr).

[0055] The relationship between the arc length L and radius R of the sensing element 2 and the driven radius roller Rc should satisfy:

[0056] L=Ta*V*R / Rc.

[0057] In this embodiment, Ts+Ty+Tr=12ms, and all belt conveyors uniformly use sensing plates with L=100mm and R=Rc=300mm.

[0058] 4) Establish data modules for each conveyor belt and hopper in the PLC, and form a data chain according to the process path:

[0059] In the PLC, a data flow path is set for each belt conveyor, and the data flow of each belt conveyor module and hopper module is connected to form a data chain. The number of formatted squares is calculated based on the structural drawings of the belt conveyor and hopper, and data blocks with the corresponding number of squares are created in the PLC according to the material flow direction. When the belt conveyor process is started, the PLC automatically loads and unloads data for each belt conveyor and hopper module according to the start process number.

[0060] 5) Driving data flow in the belt conveyor and funnel module via PLC:

[0061] When the belt conveyor is running stably, the PLC drives the data flow at a fixed time T. Every time T, the data of all belt conveyors and hopper modules in the process advances one grid. Taking T=0.5s as an example, the increase in the cumulative amount of the belt scale is calculated every 0.5 seconds and used as the weight value M of the material in the current grid. This value is then stored in the grid of the belt conveyor process data chain and the entire data chain is pushed forward grid by grid.

[0062] The data flow of the funnel module is continuously driven by time T. Data in the internal cells flows from the first cell to the last. When the conveyor belt process starts or stops under heavy load, if the downstream belt data flow speed is lower than the upstream belt, the data will be accumulated in the last cell of the funnel. When downstream belt data flows, the last cell of the funnel can only output the maximum material weight of a single fully loaded cell of the conveyor belt at a time, until the material weight in the last cell is less than the full load value. For example, if a single fully loaded cell of the conveyor belt corresponds to a material weight of 2 tons, after the material data from the upstream conveyor belt accumulates in the last cell of the funnel, each time the downstream belt data flows in one cell, the weight decreases by 2 tons, until it is less than 2 tons.

[0063] 6) During heavy-load start-up and shutdown of the belt conveyor, the flow of data in the belt conveyor module is driven by pulse ranging mode:

[0064] The belt running distance is calculated based on the pulse count of the proximity switch on the belt conveyor. Every time the length S of 1 grid is reached, the data moves forward 1 grid, and the remaining length under the current pulse count is accumulated into the distance corresponding to the next consecutive pulse. In this way, the belt conveyor data flows in the form of integer squares.

[0065] For example, if the belt speed of the conveyor is 3.8 m / s and T = 0.5 s, then S = 1.9 m. Each time the sensor and proximity switch generate a rising pulse signal, the measured belt running distance is 1.885 m. After the PLC receives two pulse signals, the conveyor data moves forward one division, corresponding to a belt running distance of 1.9 m. The remaining amount of 1.87 m will be combined with the distance corresponding to the next pulse to form one division. The remaining amount of 1.855 m generated by the next pulse will be combined with the distance corresponding to the next pulse, and so on.

[0066] 7) When the data flow of the belt conveyor module switches between heavy load start / stop and stable operation, when the PLC receives 6 consecutive pulse signals from the proximity switch, the driven roller with radius Rc runs for 5 cycles, and the time taken is Tc. At this time, the average speed of the belt is Vp=10πRc / Tc. If Vp reaches 95% of the normal stable operating speed V of the belt conveyor, it is considered that the belt conveyor has been running stably, and the data flow is driven by a fixed time T. If the belt conveyor is tripped or Vp is lower than 90% of the normal speed V, it is considered that the belt conveyor is in heavy load start / stop state, and the pulse ranging mode is switched to drive the data flow. If Vp is between 90% and 95%, the original state is maintained and no switching is performed.

[0067] 8) Real-time tracking of material load on the belt conveyor to determine the belt conveyor's idle time:

[0068] In the PLC, the total weight of materials in each cell of each data module is calculated in real time, Mz=M0+M1+…+Mn, Mdz=Md0+Md1+…+Mdn, where Mz and Mdz are the current material load of the corresponding belt conveyor or hopper. The overload or no-load time is calculated based on the upper and lower thresholds set according to the rated load capacity of the belt conveyor.

[0069] 9) Anticipate the material head generated during the heavy load restart of the belt conveyor:

[0070] After a heavy-load shutdown, the weight of the material in the last cell of each funnel module in the PLC is calculated. If it exceeds the weight of the material in a single cell of the belt conveyor when it is fully loaded, it will result in a certain length of material head when the downstream belt conveyor restarts.

[0071] After the material head appears at the source of the belt conveyor process or at the end of each hopper, the time it takes for the material head to reach a specific device can be estimated as Tn=N*T by calculating the total number of squares N between the material head and the downstream equipment of the belt conveyor and hopper modules during stable operation of the belt conveyor.

[0072] For belt conveyors that stop without faults in the process, the downstream belt conveyor is delayed in stopping based on pulse ranging and material distribution. This allows some of the upstream material to be transferred to the downstream belt conveyor with higher load capacity, thus preventing overloading of low-power belt conveyors such as trolleys and material overflow from related small-capacity hoppers.

[0073] In the above embodiments, after calculating the theoretical length of each belt conveyor by pulse counting, the data is compared with the length calculated by timing under stable operation to verify and correct the belt conveyor distance corresponding to a single pulse; when the belt conveyor process is under heavy load, a marker is thrown from the installation position of the belt scale, and the time node of the marker arriving at each belt conveyor and hopper is recorded. This time is compared with the theoretical time of the established PLC process data chain to verify and correct the speed value of PLC driven data flow.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for distributing and positioning materials in a belt conveyor process, characterized in that, Includes the following steps: 1) The material conveyed by the belt conveyor is processed into a grid: In a process consisting of multiple belt conveyors, the speed of the belt conveyor during stable operation is V, and the distance traveled within a fixed time T is S. Therefore, each belt in the belt conveyor process is divided into a continuous grid of length S, and the length of the last grid that is less than S is rounded to the nearest integer. A belt scale is installed on the belt conveyor where the material source is located. The weight of the material in a single square is M, that is, the time for the belt conveyor to operate stably in a single square is T, the corresponding belt square length is S, and the weight of the material in the square is M. When the belt conveyor is running stably, the material flows at a uniform speed through all the downstream squares until the end of the belt conveyor process; the weight of the material in each square of the belt extends from M0 at the initial drop position of the belt to Mn at the end of the belt conveyor. 2) In the belt conveyor process, the transfer hoppers between the upstream and downstream belts are gridded: The material falls into each hopper for a time td, and the drop in the hopper is h. When the belt conveyor is running stably, the material in the hopper is divided into td / T squares with a duration of T. The number of squares is rounded to the nearest integer. Therefore, the weight of the material in the hopper extends from Md0 at the end of the upstream belt to Mdn at the drop point of the downstream belt conveyor. 3) When the pulse ranging mode is set, the conveying distance is as follows during heavy-load start-up and shutdown of the belt conveyor: An induction plate is installed on the central shaft of the driven roller of each belt conveyor. A proximity switch is installed on the outside of the driven roller. The proximity switch is connected to the PLC. When the driven roller rotates, when the induction plate passes the proximity switch, the proximity switch generates a pulse signal to the PLC. The induction time is Ta and the non-induction time is Tb. When the PLC receives two consecutive pulse signals, the driven roller with radius Rc runs one revolution, and the corresponding distance traveled by the belt conveyor is C=2πRc. When the belt conveyor starts and stops under heavy load, the cumulative length C of the belt travel distance is added every two consecutive pulse signals received by the PLC. Each travel distance S is divided into one square. 4) Establish data modules for each conveyor belt and hopper in the PLC, and form a data chain according to the process path: The number of formatted squares is calculated based on the structural drawings of the belt conveyor and the hopper. Data blocks with the corresponding number of squares are created in the PLC according to the material flow direction. When the belt conveyor process is started, the PLC automatically loads and unloads data for each belt conveyor and hopper module according to the start process number. 5) Driving data flow in the belt conveyor and funnel module via PLC: When the belt conveyor is running stably, the PLC drives the data flow at a fixed time T. Every time T, the data of all belt conveyors and funnel modules in the process advances one grid. The data flow of the funnel module is continuously driven by time T, and the data in the internal squares flows from the first grid of the funnel to the last grid. 6) During heavy-load start-up and shutdown of the belt conveyor, the flow of data in the belt conveyor module is driven by pulse ranging mode: The belt running distance is calculated based on the pulse count of the proximity switch on the belt conveyor. Every time the length S of 1 grid is reached, the data moves forward 1 grid, and the remaining length under the current pulse count is accumulated into the distance corresponding to the next consecutive pulse. In this way, the belt conveyor data flows in the form of integer squares. 7) When the data flow of the belt conveyor module switches between heavy load start / stop and stable operation, when the PLC receives 6 consecutive pulse signals from the proximity switch, the driven roller with radius Rc runs for 5 cycles, and the time taken is Tc. At this time, the average speed of the belt is Vp=10πRc / Tc. If Vp reaches 95% of the normal stable operating speed V of the belt conveyor, it is considered that the belt conveyor has been running stably, and the data flow is driven by a fixed time T. If the belt conveyor is tripped or Vp is lower than 90% of the normal speed V, it is considered that the belt conveyor is in heavy load start / stop state, and the pulse ranging mode is switched to drive the data flow. If Vp is between 90% and 95%, the original state is maintained and no switching is performed. 8) Real-time tracking of material load on the belt conveyor to determine the belt conveyor's idle time: In the PLC, the total weight of materials in each cell of each data module is calculated in real time, Mz=M0+M1+…+Mn, Mdz=Md0+Md1+…+Mdn, where Mz and Mdz are the current material load of the corresponding belt conveyor or hopper. The overload or no-load time is calculated based on the upper and lower thresholds set according to the rated load capacity of the belt conveyor. 9) Anticipate the material head generated during the heavy load restart of the belt conveyor: After a heavy-load shutdown, the weight of the material in the last cell of each funnel module in the PLC is calculated. If it exceeds the weight of the material in a single cell of the belt conveyor when it is fully loaded, it will result in a certain length of material head when the downstream belt conveyor restarts. Once a material head appears at the source of the conveyor belt process or at the end of each hopper, the total number of squares N between the material head and the downstream equipment in the conveyor belt and hopper modules can be calculated. This allows for the estimation of the time it takes for the material head to reach a specific device as Tn=N*T during stable operation of the conveyor belt, thus enabling the collection of countermeasures in advance.

2. The method for material distribution and positioning in a belt conveyor system according to claim 1, characterized in that: The arc length of the sensing element is L, the radius of the sensing element is R, the hardware delay time of the proximity switch digital input is Ty, the PLC software delay time is Tr, and the PLC scan cycle is Ts. To ensure that each sensing pulse can be recognized by the PLC, the following must be met: Ta≥2*(Ts+Ty+Tr),Tb>(Ts+Ty+Tr) The relationship between the arc length L and radius R of the sensing element and the driven radius roller Rc should satisfy: L=Ta*V*R / Rc.

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