DE102020130132A1 - Belt conveyor system and method for determining a section-related running friction resistance of the belt conveyor system - Google Patents

Abstract

The present invention relates to a belt conveyor system and a method for determining a section-related running friction resistance of the belt conveyor system that is in operation. The method includes at least the following steps: A) dividing the conveyor section of the belt conveyor system into "m" system-specific sections, B) entering constant data at least with regard to the transport length of the belt conveyor system, the length of the sections and the incline or decline per section the evaluation device, C) continuous acquisition of varying data at least with regard to the current conveyor belt speed and the drive power or drive torque, D) determination of determination data comprising at least a current material section mass and a section-specific belt loading qm the entire belt conveyor system based on the measured material mass flow at the measuring point, E) storage the completely recorded varying data and the determination data in the evaluation device after each passage through a defined conveyor belt section of the conveyor belt, each passage with a consecutive index "j" is numbered, andF) calculating the load-dependent running friction resistance for each section and the idle power of the belt conveyor system by the evaluation device using an equation system using the constant data, the varying data and the determination data.

Description

The present invention relates to a belt conveyor system, in particular for bulk goods, having a conveyor belt and at least one drive for driving the conveyor belt and at least one idler station comprising at least one idler roller and a measuring system arranged at the measuring point, having at least one speed sensor for determining the conveyor belt speed, one drive sensor for determining the drive power or the drive torque and a material flow sensor for determining the material mass flow. The invention also relates to a method for determining a section-related running friction resistance of the belt conveyor system that is in operation.

STATE OF THE ART

Belt conveyor systems that are used above or below ground have been known for decades, particularly in mining and in industry. They are primarily used to transport bulk goods such as overburden, ores, fuel and building materials, even over longer distances. Belt conveyor systems can therefore be several kilometers long and transport several thousand tons of bulk material per hour. Well-known belt conveyor systems consist of a conveyor belt that is threaded as an endless loop in the belt structure with a large number of support roller stations and one or more drive and deflection drums. This conveyor belt is set in motion by one or more drive drums with one or more conveyor belt drives at a defined conveyed material speed and is advantageously continuously operated at this conveyor belt speed.

Basically, belt conveyor systems are known which have frequency-related drives. Such frequency-related drives facilitate the starting and stopping processes considerably. Nevertheless, these belt conveyor systems are operated with a defined, constant conveyor belt speed in order to ensure the necessary throughput capacity, even in phases with a reduced conveying quantity or a variable conveying capacity.

It is also fundamentally known that the belt conveyor system consists of a large number of sections, such as trough areas, trough areas, vertical curves, horizontal curves, straight sections, inclines, inclines, etc. In addition, these sections often have different carrier roller distances and, accordingly, different rolling resistances for the conveyor belt. The rolling resistances are also dependent, in a known manner, on the loading condition and the conveyor belt speed, which in turn is also dependent on the belt conveyor system specification and the outside temperature.

A relative distance-related evaluation of the rolling resistance is particularly desirable from a service point of view and also from a design point of view, but can only be implemented at great expense, for example by installing a large number of force sensors in the conveyor belt. For example, describes the DE10 2015 212 267 A1 a method and a device for determining a section-specific energy consumption of belt conveyors. In addition to the known sensors for determining a drive line and the loading of the belt conveyor system, the belt conveyor described here also has an additional, third sensor system. This third sensor system is used to detect the tensile forces in the connecting sections between conveyor belt sections. The conveyor belt is also designed as a steel cable conveyor belt, so that the third sensor system includes a coil or at least one magnetic field sensor for detecting an accumulation of steel in the connecting sections. Consequently, the device described and the method described require not only an additional sensor system, but also a specific design of the conveyor belt and is consequently more expensive to manufacture and to operate the belt conveyor system. Without additional sensors for the belt tension is in the DE10 2007 002 015 A1 a method for determining the specific power requirement of an operating belt conveyor system for bulk goods with non-constant loading is described. For this purpose, a load-dependent movement resistance for each of the n-sections of the same length of the belt conveyor is determined with the help of an estimated specific movement resistance and a current section load, as well as a lifting capacity (gradient resistance) required for each section. The ancillary, special and acceleration services are estimated and thus a total power requirement of the belt conveyor system is calculated. By comparing the calculated total power requirement with a measured electrical power requirement, a specific resistance to movement for the entire conveyor system is determined. The theoretical power requirement for each individual section of the belt conveyor system is therefore determined with the help of estimated values for section-specific movement, shunt and special resistances, with the subsequent comparison of the theoretical values with the measured values of the total drive power not separately evaluating the actual local running friction resistance coefficients via the different Sections of the belt conveyor system is carried out.

DISCLOSURE OF THE INVENTION

It is therefore the object of the present invention to at least partially eliminate the disadvantages described above in a belt conveyor system and a method for determining a distance-related running friction resistance of the belt conveyor system in operation. In particular, the object of the present invention is to create a belt conveyor system and a method that enables a route-related running friction resistance of the belt conveyor system in operation to be determined in a simple and cost-effective manner, i.e. without the use of additional measuring equipment, sensors, etc.

The above object is achieved by a belt conveyor system with the features of claim 1 and by a method for determining a distance-related running friction resistance of an operating belt conveyor system with the features according to claim 2. Further features and details of the invention result from the subclaims, the description and the drawings. Features and details that are described in connection with the belt conveyor system according to the invention naturally also apply in connection with the method according to the invention and vice versa, so that the disclosure of the individual aspects of the invention is or can always be referred to mutually. In addition, the method according to the invention can be carried out with the belt conveyor system according to the invention.

According to a first aspect of the invention, the belt conveyor system, which is used in particular for transporting bulk goods, has a conveyor belt and at least one drive for driving the conveyor belt and at least one idler roller station comprising at least one idler roller, advantageously three idlers, and a measuring system arranged at a measuring point. According to the invention, the measuring system has at least one speed sensor for determining the conveyor belt speed, a drive sensor for determining the drive power or the drive torque and a material flow sensor for determining the material mass flow. The belt conveyor system according to the invention is characterized in that it has at least one evaluation device for determining a distance-related running friction resistance, in particular during operation of the belt conveyor system. The speed sensor, the drive sensor and the material flow sensor are connected to the evaluation device for data transmission. The evaluation device advantageously has an input unit for the manual input of data by an operator, for example. Data can be entered using a keyboard, a touch panel, voice input, and so on. It is also conceivable that the evaluation device has an output unit, such as a screen for the visual output of data, diagrams, etc. The evaluation device advantageously also has a memory unit, for example a memory unit designed as a ring memory, at least for the temporary storage of data, in particular constant and variable data and values and results etc. The evaluation device also advantageously includes a computing unit for determining at least the values of the distance-related running friction resistance, in particular the distance-related running friction resistance values. In order to receive data, values, etc. outside of the input unit, the evaluation device advantageously has a receiving and transmitting unit. Additional data can be transmitted to the evaluation device via this receiving and transmitting unit, also wirelessly via Bluetooth, WLAN, etc. The receiving and transmitting unit advantageously also has interfaces for connecting data cables, such as AUX cables, HDMI cables, etc., so that other end devices or USB data sticks can also be connected to the evaluation device. It is also conceivable to send data, values, diagrams, etc. to other end devices (wired or wireless) via the receiving and transmitting unit of the evaluation device. The speed sensor, the drive sensor and the material flow sensor also send their determined data and values advantageously via a wireless connection to the evaluation device and in particular to the receiving and transmitting unit of the evaluation device. The transmitted data are then advantageously stored in the storage unit and transmitted to the processing unit. It is also conceivable that the evaluation device has a comparison unit for comparing determined ACTUAL data/values with stored TARGET data/values.

Advantageously, with the belt conveyor system according to the invention, without additional sensors, in particular without force sensors in the conveyor belt, a section-related evaluation of the rolling resistance or the running friction resistances along the conveyor section can be carried out during normal operation of the belt conveyor system in order to determine local deviations in the running friction resistance from normal or permissible values. Without additional sensors means in the context of the invention that only the basic sensors used in belt conveyor systems, such as the speed sensor for determining the conveyor belt speed or the engine speed, the drive sensor for determining the drive line or the drive torque and the Material flow sensor for determining the material flow. The distance-related running frictional resistance is determined purely mathematically using a linear system of equations, as explained in more detail below. The result of the route-related running friction resistance is then advantageously used, for example, by a service team of the belt conveyor system to prepare appropriate repair measures/maintenance measures in order to quickly and easily determine the faulty route section that requires maintenance. It is also conceivable that the results of the determination of the distance-related running friction resistance offer a relevant basis for the modification of the belt conveyor system, especially with regard to increasing competitiveness.

1. A) Aufteilen der Förderstrecke der Gurtförderanlage in „m“ anlagenspezifischen Teilstrecken, insbesondere mit unterschiedlicher oder auch gleicher Teilstreckenlänge,
2. B) Eingabe von konstanten Daten zumindest hinsichtlich der Transportlänge der Gurtförderanlage, der Länge der Teilstrecken, insbesondere auch der Anzahl der Teilstrecken, und der Steigung oder dem Gefälle pro Teilstrecke in die Auswerteeinrichtung,
3. C) kontinuierliche Erfassung variierender Daten zumindest hinsichtlich der momentanen Fördergurtgeschwindigkeit, des Materialmassenstroms und der Antriebsleistung bzw. des Antriebsdrehmomentes,
4. D) Bestimmung von Ermittlungsdaten umfassend eine momentane Materialstreckenmasse und eine teilstreckenspezifische Gurtbeladung der gesamten Gurtförderanlage basierend auf dem gemessenen Materialmassenstrom am Messpunkt,
5. E) Speicherung der vollständig erfassten variierenden Daten sowie der Ermittlungsdaten in der Auswerteeinrichtung nach jedem Durchlaufen eines definierten Fördergurtabschnittes des Fördergurtes, wobei vorteilhaft jedes Durchlaufen mit fortlaufendem Index „j“ nummeriert ist, und
6. F) Berechnen des beladungsabhängigen Laufreibungswiderstandes für jede Teilstrecke und der Leerlaufleistung der Gurtförderanlage durch die Auswerteeinrichtung mittels eines Gleichungssystems unter Verwendung der konstanten Daten, der variierenden Daten und der Ermittlungsdaten.

According to a further aspect of the invention, the method for determining a section-related running friction resistance of a belt conveyor system in operation, as described above, has at least the following steps:

1. A) Dividing the conveyor section of the belt conveyor system into "m" system-specific sections, in particular with different or the same section lengths,
2. B) Input of constant data at least with regard to the transport length of the belt conveyor system, the length of the sections, in particular the number of sections, and the incline or decline per section into the evaluation device,
3. C) continuous acquisition of varying data at least with regard to the current conveyor belt speed, the material mass flow and the drive power or drive torque,
4. D) Determination of determination data comprising a current material line mass and a section-specific belt loading of the entire belt conveyor system based on the measured material mass flow at the measuring point,
5. E) storage of the completely recorded varying data and the determination data in the evaluation device after each passage of a defined conveyor belt section of the conveyor belt, each passage being advantageously numbered with a consecutive index “j”, and
6. F) Calculation of the load-dependent running friction resistance for each section and the idling power of the belt conveyor system by the evaluation device using an equation system using the constant data, the varying data and the determination data.

According to step A), the conveyor section is divided at least into m>=2 sections. The conveyor section is understood to mean that section of the belt conveyor system which is used to transport the goods, in particular bulk goods, and runs from a receiving area for receiving the bulk goods to a discharge area for dropping the bulk goods (e.g. onto another belt conveyor system). The sections are determined depending on the belt conveyor system. More precisely, depending on the structure and course of the belt conveyor system, taking into account the straight sections, curved sections, etc., at least the number of sections is defined. Advantageously, the route length/partial route length is also specified for each defined route section. Accordingly, it is conceivable that the sections can each have a different length from one another. It is also possible for sections to have the same section lengths as one another, in particular if the sections are essentially the same, such as straight sections, etc.

According to step B), constant and known data are entered into the evaluation unit, in particular manually. Constant data is understood to mean data that does not change during the operation of the belt conveyor system or has unchanged/unchangeable values over a defined period of time/period of time and can be assigned specifically to the belt conveyor system in question. This is, for example, data regarding the length of the conveyor belt or the transport length of the belt conveyor system, the number of sections, as divided up in step A), and/or the length of the individual sections, as well as the indication of gradients and/or gradients per leg.

According to step C), during the operation of the belt conveyor system, data, in particular varying data, is continuously determined or recorded via the existing sensors, such as the speed sensor for determining the conveyor belt speed, the drive sensor for determining the drive power or the drive torque and the material flow sensor for determining the material mass flow and advantageously transmitted to the evaluation device. These varying data primarily affect the entire belt conveyor system. In order to determine or determine, in particular to calculate, a section-specific belt loading q _m or a section-specific mass flow, in step D) a calculation of so-called determination data takes place. This is data resulting from calculations between constant data and varying ones data are generated. These determination data are, for example, an instantaneous material section mass (M ₁ , . . . , M _m ) and a section-specific belt loading, which is advantageously determined using a belt loading matrix q. The determination data primarily relate to the entire belt conveyor system and are therefore based at least on the material mass flow measured at the measuring point, the conveyor belt speed and the section layout. The belt loading matrix q is advantageously stored as a calculation model in the evaluation device. This belt loading matrix is explained in more detail below. The determined or calculated values with regard to the section-specific belt loading q _m are now also stored as varying values/data, in particular as determination data, as well as all other varying data, in the evaluation device, in particular in its memory unit, according to step E). The values of the material gravity distribution (q ₁ , q ₂ , . . . , q _m ) per conveying section can be determined as the product of the material line masses ( _{M 1} , .

According to step F), the load-dependent running friction resistances f _i for each defined section i=1, ..., m as well as the no-load power of the entire belt conveyor system P ₀ are then finally calculated using an equation system stored in the evaluation device, in particular in the memory unit , in particular a linear system of equations. The computing power for this is advantageously taken over by the computing unit of the evaluation device.

Consequently, with the described method according to the invention, a complete course of the conveyor belt loading along the conveyor section of the belt conveyor belt is advantageously determined for a current or later point in time with a previously defined division of the conveyor section into sections based on the mass flow and conveyor belt speed and as a data set together with the time-associated data Drive line or drive torque or driving force detected. By collecting at least m+1 data sets with conveyor belt loads that differ from one another and then resolving the collected data using the linear system of equations, both the local route-specific running friction resistance f _i related to the transport mass and a load-independent no-load power P ₀ of the belt conveyor system can be determined. The friction losses in the overall drive of the belt conveyor system are also advantageously taken into account. It should also be noted that when using the linear system of equations, a linear dependency of the running frictional resistance on the transport mass or the mass flow is assumed.

It is advantageously conceivable that the system of equations for determining the load-dependent running friction resistance vector f is generated for each complete revolution of the belt, with the system of equations including the corresponding data with regard to a belt loading matrix q and a total movement resistance force vector ΔR as follows: $$\text{q}\times \text{f=}\Delta \text{R}$$

A multiple overdetermination of the linear system of equations, in particular with an even distribution of the determined data sets over at least one complete loop revolution of the entire conveyor belt of the belt conveyor system, results in a significant increase in the determination/calculation accuracy both for the section-related running friction resistances "f _i " and for the load-independent no-load power “ _P0 ” reached.

According to a further embodiment, an instantaneous lifting capacity "P _H , _j " of the total transported mass of material flow of the belt conveyor system as the sum of the instantaneous lifting capacities (P _H,i,j ) of all sections (i=1, ..., m) determined and stored in the evaluation device. If the lifting power specific to the conveyor belt loading is subtracted from the currently conveyed mass of material when recording the drive power, or if the local incline of the conveyor section is subtracted after determining the running resistance related to the transport mass, the result is the running friction resistance "adjusted" from the lifting work. These "adjusted" running friction resistances serve as an indication of the functional condition of the idlers in the respective track area with a comparable idler support (idler distances and diameters, curves) and a comparable belt tension.

Within the scope of the invention, “P _H,i,j ” is used to indicate the lifting capacity of the material to be conveyed on section no. “i” at time “t _j ”. Furthermore, within the scope of the invention, “t _j ” indicates the point in time when the conveyor belt passes through a new conveyor belt section ΔL with the consecutive number “j”. In particular, within the scope of the invention, “ΔL” indicates the conveyor belt section length when the conveyor belt runs through, in order to generate a new recording of the measurement data for the equation system.

It is also possible that as constant data, in particular as constantly acceptable data, the section-specific belt and idler gravity (q _0,i ) per section Back length (L ₁ , ..., L _m ) are entered into the evaluation device (20). In particular, they are entered manually by an operator. However, it is also conceivable that constant data is recorded on an external storage medium, such as a data stick for each belt conveyor system, and this external storage medium is then connected to the evaluation unit (LAN or WLAN), so that this data is then automatically or semi-automatically (plug and play) transferred or copied to the evaluation unit.

According to a further embodiment, the belt loading matrix q is calculated as the respective section-specific gravity distribution of the material mass flow q _i,j , in particular the belt loading, for each section i=1,..,m and for each measurement j=1,..,nk, and as a quotient of the drive efficiency η and the conveyor belt speed V _B,j is determined as follows: $$q=\left|\begin{array}{cccccc}{q}_{1.1}& q_{2.1}& q_{3.1}& & q_{m\mathrm{,1}}& n\text{/}{V}_{B\mathrm{,1}}\\ q_{1.2}& q_{2.2}& q_{3.2}& ...& q_{m\mathrm{,2}}& n\text{/}{V}_{B\mathrm{,2}}\\ q_{1.3}& q_{2.3}& q_{3.3}& & q_{m\mathrm{,3}}& n\text{/}{V}_{B\mathrm{,3}}\\ ...& ...& ...& ...& ...& ...\\ {\mathrm{<figure-callout\; id="1"\; label="q"\; filenames="DE102020130132A1\_0010.png,DE102020130132A1\_0011.png"\; state="\{\{state\}\}">q</figure-callout>}}_{\mathrm{1,}\mathrm{<figure-callout\; id="2"\; label="n\; k\; q"\; filenames="DE102020130132A1\_0010.png,DE102020130132A1\_0011.png"\; state="\{\{state\}\}">n</figure-callout>}k}& q_{}{}_{\mathrm{2,}\mathrm{<figure-callout\; id="3"\; label="n\; k\; q"\; filenames="DE102020130132A1\_0010.png,DE102020130132A1\_0011.png"\; state="\{\{state\}\}">n</figure-callout>}k}& q_{}{}_{\mathrm{3,}nk}& ...& q_{m,nk}& n\text{/}{V}_{B,nk}\end{array}\right|$$

The sequential number of the sections is denoted by "i = 1, ..., m". The sum of the sections "i" results in the conveying distance of the belt conveyor system. Furthermore, within the scope of the invention, “q _i,j ” denotes the gravitational force of the material mass flow for distance “i” in data record “j”.

It is conceivable that the respective gravitational force of the material mass flow q _i,j is the product of the respective section-specific mass (M _1,j , M _2,j ,...M _m , _j ) of conveyed material (material mass) and the gravitational acceleration g per measurement j=1, 2, ..., nk during the last "n" full revolutions of the conveyor belt.

Within the scope of the invention, “n′” is advantageously used to indicate the number of the last complete belt rotations that are to be used to evaluate the distance-related running resistances in the system of equations.

According to a further embodiment, the total motion resistance force vector ΔR is determined as the quotient of the difference between the instantaneous drive power P _j - multiplied by the drive efficiency η - and the instantaneous lifting power P _H,j , and the conveyor belt speed V _B,j as follows: $$\Delta R=\left|\begin{array}{c}\left(P_{1}n-P_{H\mathrm{,1}}\right)\text{/}{V}_{B\mathrm{,1}}\\ \left(P_{2}n-P_{H\mathrm{,2}}\right)\text{/}{V}_{B\mathrm{,2}}\\ ...\\ ...\\ \left(P_{nk}n-P_{H,nk}\right)\text{/}{V}_{B,nk}\end{array}\right|$$

Furthermore, the distance-related running friction resistance vector f to be determined consists of load-independent factors f ₁ ,...,f _m for each section L ₁ ,..., L _m and the average no-load power P ₀ of the entire belt conveyor system, especially within the last n full conveyor belt revolutions : $$ƒ=\left[\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="ƒ"\; filenames="DE102020130132A1\_0010.png,DE102020130132A1\_0011.png"\; state="\{\{state\}\}">ƒ</figure-callout>}}_1\\ {\mathrm{<figure-callout\; id="2"\; label="ƒ"\; filenames="DE102020130132A1\_0010.png,DE102020130132A1\_0011.png"\; state="\{\{state\}\}">ƒ</figure-callout>}}_2\\ ...\\ {ƒ}_m\\ P_0\end{array}\right]$$

For the specific acquisition of the varying data, in particular measurement data such as the mass flow, the conveyor belt speed and/or the drive power or the drive torque, a time correction of the signals and a correct derivation of the conveyor belt loading along the conveyor line based on this is required. This detection, correction and derivation are advantageously possible by the evaluation device, in particular the receiving and transmitting unit, the computing unit and/or the comparison unit of the evaluation device. By means of the evaluation device, a chronological sequence of the data sets is advantageously completed and a length-specific distribution of the total load on the conveyor section is determined. In order to record the large number of data sets and to determine the route-related (route-specific, transport mass-related) running friction resistances, the complete data records are advantageously temporarily stored in the evaluation device, in particular the evaluation device's memory unit. This memory unit is advantageously designed as a ring memory. With this ring memory, the oldest data record is continuously overwritten with the youngest (newest) data record. As a result, the ring memory is always only filled with the current information (data/data sets) about at least one last complete revolution of the conveyor belt (loop). The distance-related running friction resistances f _i and the load-independent idling power P ₀ are determined by regularly querying the storage unit, in particular the ring memory, with subsequent formation of the belt loading matrix q and the resolution of the linear system of equations. These determined or Calculated data are then in turn stored in the evaluation device, in particular in the storage unit of the evaluation device or in a separate long-term storage unit of the evaluation device, advantageously together with the associated operating parameters of the belt conveyor system. This data can then be displayed in tabular or graphic form, as required, via the output unit of the evaluation device.

It is conceivable that with regard to an optimized evaluation of the current condition of the rollers, all recorded and/or determined data (constant data and/or varying data) can be limited according to date, throughput, conveyor belt speed and temperature ranges and can be displayed overlaid with a regression curve.

According to a further embodiment, the number of complete data sets "k" for the solution of the linear system of equations has at least twice the value of "m" and is consequently stored in the evaluation device in accordance with an integer number n of the complete revolution of the conveyor belt, in particular of the complete revolution of the conveyor belt.

It is therefore advantageously conceivable that the number of data sets of varying data stored in the evaluation device corresponds to at least twice the number of sections of the conveyor route for each revolution of the conveyor belt to be stored, with the oldest data set of varying data stored in the evaluation device continuously increasing from the most recent Record of varying dates is overwritten. This multiple evaluation by solving a multiply overdetermined linear equation system, based on the measurements over the last complete revolution of the conveyor belt of the belt conveyor system (loop), evenly distributed over time, leads to an advantageous increase in the determination accuracy of the section-related running friction resistances. The last measurements are advantageously superimposed in such a way that outliers, such as local increases in the running friction resistances due to damage to the supporting rollers, can be reliably identified.

This means that, in order to duplicate or multiply the number of equations in the system of equations compared to the number of unknown data in the system of equations, the currently determined varying data per complete revolution of the conveyor belt is overlaid with the varying data of one or more previous complete revolutions of the conveyor belt.

It should also be noted that ΔL is the length of the conveyor belt per measurement. ΔL advantageously has a large number of sections L ₁ , . . . , L _m and can also be referred to as a conveyor belt measurement section. In the context of the invention, a large number is to be understood as meaning at least one partial route, advantageously two or more partial routes. L _B indicates the total length of the conveyor belt. "k" is an integer number of conveyor belt measurement sections per complete conveyor belt length L _B or a number of data sets generated for a complete conveyor belt circulation or a complete conveyor belt rotation. $$L_B=k\ast \Delta L$$

More precisely, each measurement advantageously takes place per conveyor belt measurement section, with the conveyor belt having a number “k” of conveyor belt measurement sections.

It is conceivable that route-related running friction resistance values based on variable data are determined at least until each of the defined sections during the last complete revolution of the conveyor belt, in particular during the last complete revolution of the conveyor belt, there is a minimal change in the material mass flow (load change) from one calculated for this section Mean value, especially in the range above 5% of the nominal load, is assigned. This means that a minimal change in the conveyor belt loading of the material mass flow Δq _i,min in each section "i" (corresponds to the column number in the belt loading matrix q) between the different data sets "j" (corresponds to the columns in the belt loading matrix q) is required. If the material mass flow does not change for one or more sections "i", for example due to idling, full loading or an unfavorable loading section, the measurement or data acquisition is extended or postponed so that each section "i" shows a minimal load change (Δq _i = q _i,max - q _i,min ) of, for example, 5% of the nominal load.

Advantageously, within the scope of the invention, the consecutive number of the data record recording, which takes place after a new conveyor belt section has been passed through, is identified with “j”. Furthermore, within the scope of the invention, “q _i,max ” indicates the maximum and “q _i,min ” indicates the minimum gravity of the material mass flow occupancy for distance “i” in the belt loading matrix “q”.

According to a further embodiment, the transported mass quantities of a defined number of adjacent sections are added and the measured values with regard to the instantaneous drive power P _j and the instantaneous conveyor belt speed V _B are averaged in order to create a reduced system of equations. When adding the transported mass of material to the defined number of sections, it is conceivable to add at least two sections that are adjacent to one another, in particular to add the sections in pairs, for example L ₁ +L ₂ , . . . , L _m−1 +L _m .

All the advantages that have already been described for the belt conveyor system according to the first aspect of the invention result from the method described.

According to a further alternative method, it is possible to change the conveyor belt speed of the belt conveyor system at least temporarily with a defined periodicity in a sinusoidal or zigzag manner or in the form of a ramp. The resulting changes in the conveyor belt occupancy (material mass flow) result in increased determination accuracy for determining the section-related running friction resistances with the desired number and distribution of sections.

It goes without saying that the features mentioned above and those still to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

• 1 eine Ausführungsform einer Aufteilung einer Förderstrecke einer erfindungsgemäßen Gurtförderanlage,
• 2 einen Ausführungsform einer grafischen Darstellung erfasster variabler Daten, und
• 3 einen Ausführungsform einer grafischen Darstellung ermittelter/berechneter Daten pro Teilstrecke.

Graphic representations of the method according to the invention of a belt conveyor system according to the invention that is in operation are explained in more detail below with reference to drawings. They each show schematically:

• 1 an embodiment of a division of a conveyor section of a belt conveyor system according to the invention,
• 2 an embodiment of a graphical representation of captured variable data, and
• 3 an embodiment of a graphical representation of determined/calculated data per leg.

Elements with the same function and mode of action are in the 1 until 3 each provided with the same reference numerals.

In the 1 is an embodiment of a belt conveyor system 1 according to the invention having a conveyor belt 10, at least one drive 11 for driving the conveyor belt 10 and at least one idler station 12, advantageously two or more idler stations 12, each comprising at least one idler roller 13, and a measuring system S arranged at a measuring point 3 The measuring system S advantageously comprises a speed sensor, not shown here, for determining the conveyor belt speed, a drive sensor, not shown here, for determining the drive power or drive torque, and a material flow sensor, not shown here, for determining the material mass flow. Furthermore, the belt conveyor system 1 has at least one evaluation device 20 for determining a distance-related running friction resistance, the speed sensor, the drive sensor and the material flow sensor being connected to the evaluation device 20 for data transmission (shown with a dashed line). in the in 1 The illustrated embodiment of the belt conveyor system 1 according to the invention also shows an exemplary division of a conveyor section 2 of the embodiment of the belt conveyor system 1 according to the invention. The conveyor section 2 is divided into m=18 sections L ₁ - L ₁₈ (L1, L2, ..., L _i , ..., Lm). Q _E shows the instantaneous (current) conveyed quantity of bulk material at the input point 4, ie the quantity of bulk material that is currently being introduced/applied to the belt conveyor system 1. Q _A shows the instantaneous (current) delivery quantity of bulk material at the discharge transfer point 5, ie the quantity of bulk material which is currently being released from the belt conveyor system to, for example, another belt conveyor system not shown here. The sensors S, in particular the speed sensor for determining the conveyor belt speed V _B , the drive sensor for determining the drive power P or the drive torque or the drive speed n _A and the material flow sensor for determining the material mass flow Q _S are arranged at measuring point 3 . The measurement point 3 is formed at a defined distance X _s from the input point 4 . The determined material mass flow Qs, taking into account the conveyor belt speed V _B and the distance x _S , is converted into a material mass flow allocation q _x or into the material section masses M _i (material mass per section - M ₁ , M ₂ , ..., M _i ..., M _m )) converted. With "x" is according to the 1 to understand the longitudinal coordinates along the belt conveyor system 1 starting from the input point 4 and with “x _S ” the distance of the mass flow sensor along the belt conveyor system 1. As a basis for the formation of the linear system of equations, the entire conveyor section 2 is divided into clearly defined sections L ₁ -L _m with known section lengths, gradients, gradients, curves and support rollers. The material mass flow occupancies M ₁ -M _m corresponding to the measurement time and the corresponding conveyor belt speed V _B are then recorded for these specified sections L ₁ -L _m or determined. For at least "m+1" complete data sets, the measurement data (varying data on material mass flow occupancy q _x along the entire conveyor section 2, drive power P and conveyor belt speed V _B ) are recorded and a belt loading matrix q of the linear system of equations is formed. The running friction resistance coefficients of the individual sections (f ₁ , f ₂ , ...fi, ..., f _m ) are calculated together with the load-independent idling power P ₀ from at least "m+1" linear equations with different loads M ₁ , M ₂ , . .., Mi..., Mm of the corresponding sections L1 - Lm determined. The one in the 1 The exemplary division of the conveying path into m=18 sections L ₁ -L ₁₈ shown shows, for example, in section L ₁₂ a significantly higher value than in the vicinity of this section L ₁₂ , as can be seen from the bar chart. A bar chart can, for example, be an embodiment of a graphical representation of the calculated/determined results with regard to the distance-related running friction resistances. However, other representations are also possible, such as in particular in 2 and 3 demonstrated, conceivable. This illustrated deviation can be understood by the service team of the belt conveyor system 1 as an indication that an inspection of the support rollers is necessary, particularly in this area of section L ₁₂₂ .

In the 2 shows the measured drive power P (in kW) of the entire belt conveyor system in relation to the determined total running friction resistance TRR (in %) over time (in h) by means of a line diagram. The relative total (total) running friction resistance TRR of the entire belt conveyor system, determined as the ratio of the increase in running resistance force to the gravity of the mass of material currently being transported, is shown with a dotted line. The idle power of the belt conveyor system is shown as a dashed line with P ₀ . With P _H the lifting capacity of the entire belt conveyor system is shown with a long dashed line. All powers determined are plotted over time t. The performance was determined within one hour (60 minutes) and recurring rashes associated with cyclical load changes with a period of approx. 12 minutes were shown. The belt rotation time is 7 minutes. Thanks to the evaluation of the data over a full revolution of the conveyor belt, no conveyor-belt-related periodicity can be identified in the recording or in the determination data. The idle mileage and total running frictional resistance remain essentially stable over the entire acquisition time and can be used for further route-specific resolution.

3 shows a visualization of determined section-related running friction resistance values f _i over a conveyor section 2 of a belt conveyor system 1 divided into m=16 sections L ₁ - L ₁₆ (as in Fig 1 shown). The solid line graphically depicts a total of 16 results of the distance-related running friction resistance values f _i determined, in particular one result per section L ₁ - L ₁₆ (LRR, 16). If a complete resolution of the linear system of equations becomes impossible, the number of or the division of sections L ₁ -L _m is reduced in such a way that an occupancy of two, three, four or more adjacent sections L ₁ -L _m is added to one another or divided will. The averaged values/data regarding the conveyor belt speed V _B and the drive power P are then used for these sections. This is reflected in the dashed lines LRR,8 and LRR,4. Here, the original 16 sections L ₁ - L ₁₆ were either reduced to a total of eight sections (L ₁ - L ₈ , LRR, 8) in such a way that two sections that were adjacent to one another were combined. Or the originally 16 sections L ₁ - L ₁₆ were reduced to a total of four sections (LRR, 4) in such a way that four sections that were adjacent to one another were now combined into just four sections L ₁ - L ₄ . In this way, a coarser resolution of the course of the running frictional resistance is obtained, which can subsequently be made more precise by superimposing further (new) data from subsequent or previous measurements. The value averaged over all sections L ₁ - L ₁₆ is given as TRR (dash-dot line).

To perform a simplified conversion of the initial system of linear equations with “m” sections (in the 3 with 16 sections) in a two-, three-, four- or six-fold reduced linear equation system, the number "m" of the sections is set as a minimum or multiple divisible number for the desired reduced number, such as m = 12, 24, 36, 48, 60, etc. It should be noted that the length per section when using a maximum resolution of "m" sections is not significantly less than the distance between the idlers in the belt conveyor system. This means that a method for determining section-related running friction resistances, in particular key figures of section-related running friction resistances, begins with a determination of the conveyor belt occupancy with the highest resolution on “m” sections and after each passage of the conveyor belt a new data set with a current occupancy on “m” Sections, the current drive power P and the conveyor belt speed VB is stored in the cache. The last "k" data records of the last complete conveyor belt revolution (loop) of the belt conveyor system are first used to form the linear equation system with "m+1" unknowns used. Since there are k>m+1, i.e. more data sets than unknowns in the system of equations, the overdetermined system of equations is solved with an approximation, so that all "m" unknown distance-related running friction resistance parameters (f ₁ , f ₂ , ..., f _i , . .., f _m ) and the unknown load-independent no-load power of the entire conveyor belt system P ₀ can be determined. In order to increase the meaningfulness of the running friction resistance indices (f ₁ , f ₂ , ..., f _i , ..., f _m ), it is conceivable to redetermine the respective route-related running friction resistances after receiving a new data set and to use the last saved "nk" datasets to form an average value for each distance-related running friction resistance. In particular, “m” indicates the total integer number of sections on the conveyor section of the belt conveyor system.

Even if the accuracy determined for determining the section-related running friction resistances is not sufficient, for example because the scatter of the determined values/data over several conveyor belt revolutions is too high, it is advantageous to carry out the reduced resolution of the sections already described above. As previously mentioned, two or more adjacent sections are combined, which advantageously reduces the number of unknown variables to m/2+1, m/3+1, etc., as well as the corresponding number of data sets to k/2, k/3 , etc. reduced. Advantageously, solving a correspondingly reduced system of linear equations leads to a more precise determination of the characteristics of the section-related running friction resistances of the “enlarged” (summarized) sections described. This can also be used to advantage for the precise evaluation of the changes in the section-related running friction resistances over time, the temperature and/or the conveyor belt loading (material mass flow) or also for evaluating the condition of the idlers.

Reference List

1

belt conveyor system

2

conveyor line

3

measuring point

4

entry point

5

drop transfer point

10

conveyor belt

11

drive

12

idler station

13

support roller

14

measuring point

20

evaluation device

fi

track-specific running friction resistance/track-related running friction resistance index

L1, ..., Lm

Length of the individual sections along the belt conveyor system

LRR

distance-related running friction resistance

LRR,4

Distance-related running friction resistance for four sections

LRR,8

Distance-related running friction resistance for eight sections

LRR, 16

distance-related running friction resistance at sixteen partial distances

m

Number of sections on the belt conveyor system

Wed, Wed - Wed

Material masses per section

n / A

input speed

P

drive power

PH

lifting capacity

P0

No-load power of the entire belt conveyor system, which includes all drive power losses and the product of all load-independent running resistances with the conveyor belt speed

QA

Material mass flow on the conveyor belt in the measuring range of the mass flow sensor

qx

Material mass flow occupancy at the longitudinal coordinate x

S

sensors/measuring system

TRR

Relative total running friction resistance TRR of the entire belt conveyor system, determined as the ratio of the increase in running resistance force to the gravity of the material mass currently being transported

vb

conveyor belt speed

x

Longitudinal coordinate along the conveyor from the input point

xS

Distance of the mass flow sensor along the belt conveyor

ΔR

total motion drag force vector

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102015212267 A1 [0005]
• DE 102007002015 A1 [0005]

Claims (13)

Belt conveyor system (1) having a conveyor belt (10), at least one drive (11) for driving the conveyor belt (10) and at least one idler roller station (12) comprising at least one idler roller (13), and a measuring system (S) arranged at a measuring point at least having a speed sensor for determining the conveyor belt speed (V _B ), a drive sensor for determining the drive power (P) or the drive torque and a material flow sensor for determining the material mass flow (Qs), characterized in that the belt conveyor system (1) has at least one evaluation device (20 ) for determining a section-related running friction resistance (fi), the speed sensor, the drive sensor and the material flow sensor being connected to the evaluation device (20) in terms of data transmission. Method for determining a distance-related running friction resistance (f _i ) of an operating belt conveyor system (1) according to claim 1 , with at least the following steps: A) dividing the conveyor section (2) of the belt conveyor system (1) into "m" system-specific sections (L ₁ , ..., L _m ), B) entering constant data at least with regard to the transport length of the belt conveyor system (1), the length of the sections (L ₁ , ..., L _m ) and the incline or descent per section (L ₁ , ..., L _m ) into the evaluation device (20), C) continuous detection of varying Data at least with regard to the current conveyor belt speed (V _B ), the material mass flow (Qs) and the drive power (P) or the drive torque, D) Determination of determination data comprising at least one current material line mass (M ₁ , ..., M _m ) and a Section-specific belt loading (q ₁ , ..., q _m ) of the entire belt conveyor system (1) based on the measured material mass flow (Qs) at the measuring point (3), E) storage of the completely recorded varying data and the determination data in the evaluation unit direction (20) after each passage through a defined conveyor belt section (ΔL) of the conveyor belt (10), each passage being numbered with a consecutive index "j", and F) calculating the load-dependent running friction resistance (f _1,j ,..., f _{m , j} ) for each section (L ₁ , ..., L _m ) and the no-load power (P ₀ ) of the belt conveyor system (1) by the evaluation device (20) by means of an equation system using the constant data, the varying data and the determination data . procedure according to claim 2 , characterized in that the system of equations for determining the load-dependent distance-related running friction resistance vector (f) for the last "n" complete belt rotations is generated, the system of equations comprising the corresponding data with regard to a belt loading matrix (q) and a total movement resistance force vector (ΔR) as follows: $$q\times f=\Delta R$$

Method according to any of the foregoing claims 2 or 3 , characterized in that a current lifting capacity (P _H,j ) of the total transported material flow mass of the belt conveyor system (1) as the sum of current lifting capacity (P _H,i,j ) of all sections (i=1,..., m) is determined and stored in the evaluation device (20). Method according to any of the foregoing claims 2 until 4 , characterized in that the section-specific belt and idler gravity (q _0,i ) per section length (L ₁ , ..., L _m ) are also input into the evaluation device (20) as constant data. Method according to any of the foregoing claims 3 until 5 characterized in that the belt loading matrix (q) as the respective section-specific gravity distribution of the material mass flow q _i,j , in particular the belt loading (q ₁ , ..., q _m ), for each section (i = 1, .., m) and for each measurement (j=1,..,nk) and as a quotient of the drive efficiency η and the conveyor belt speed V _B,j is determined as follows: $$\text{q}=\left|\begin{array}{cccccc}{\text{q}}_{\text{1}\text{,1}}& {\text{q}}_{\text{2}\text{,1}}& {\text{q}}_{\text{3}\text{,1}}& & {\text{q}}_{\text{m}\text{,1}}& {\text{h/v}}_{\text{B}\text{,1}}\\ {\text{q}}_{\text{1}\text{,2}}& {\text{q}}_{\text{2}\text{,2}}& {\text{q}}_{\text{3}\text{,2}}& ...& {\text{q}}_{\text{m}\text{,2}}& {\text{h/v}}_{\text{B}\text{,2}}\\ {\text{q}}_{\text{1}\text{,3}}& {\text{q}}_{\text{2}\text{,3}}& {\text{q}}_{\text{3}\text{,3}}& & {\text{q}}_{\text{m}\text{,3}}& {\text{h/v}}_{\text{B}\text{,3}}\\ ...& ...& ...& ...& ...& ...\\ {\text{q}}_{\text{1}\text{,nk}}& {\text{q}}_{\text{2}\text{,nk}}& {\text{q}}_{\text{3}\text{,nk}}& ...& {\text{q}}_{\text{m}\text{,nk}}& {\text{h/v}}_{\text{B}\text{,nk}}\end{array}\right|$$

Method according to any of the foregoing claims 3 until 6 , characterized in that the total motion resistance force vector (ΔR) as the quotient of the difference between the instantaneous drive power (P _j ) multiplied by the drive efficiency (η η)), and the instantaneous lifting power (P _H,j ), and the conveyor belt speed (V _{B, j} ) is determined as follows: $$\Delta \text{R}=\left|\begin{array}{c}\left({\text{P}}_1\mathrm{n}-{\text{P}}_{\text{H}\text{,1}}\right){\text{/v}}_{\text{B}\text{,1}}\\ \left({\text{P}}_2\mathrm{n}-{\text{P}}_{\text{H}\text{,2}}\right){\text{/v}}_{\text{B}\text{,2}}\\ ...\\ ...\\ \left({\text{P}}_{\text{nk}}\mathrm{n}-{\text{P}}_{\text{H}\text{,nk}}\right){\text{/v}}_{\text{B}\text{,nk}}\end{array}\right|$$

Method according to any of the foregoing claims 2 until 7 , characterized in that the distance-related running friction resistance vector (f) to be determined consists of factors (f ₁ , ..., f _m ) that are independent of the load for each section (L ₁ , ..., L _m ) and the mean no-load power (P ₀ ) of the entire belt conveyor system (1) consists of: $$ƒ=\left[\begin{array}{c}{ƒ}_1\\ {ƒ}_2\\ ...\\ {ƒ}_m\\ P_0\end{array}\right]$$

Method according to any of the foregoing claims 3 until 8th , characterized in that the number of complete data sets “k” for the solution of the linear system of equations have at least twice the value of “m” and are consequently stored in the evaluation device (20) corresponding to an integer number “n” of complete conveyor belt revolutions. Method according to any of the foregoing claims 2 until 9 , characterized in that the number of data sets of varying data stored in the evaluation device (20) is at least twice the number (>2m) of sections (L ₁ ,..., L _m ) of the conveyor section (2) for each conveyor belt revolution to be stored corresponds, wherein the temporally oldest data set of varying data stored in the evaluation device (20) is continuously overwritten by the temporally most recent data set of varying data. Method according to any of the foregoing claims 2 until 10 , characterized in that for doubling or multiplying the number of equations in the equation system in comparison to the number of unknown data present in the equation system, the currently determined varying data per complete conveyor belt revolution are superimposed with the varying data of one or more previous complete conveyor belt revolutions. Method according to any of the foregoing claims 2 until 11 , characterized in that the section-related running friction resistances (f _i ) based on variable data are determined at least until each of the defined sections (L ₁ ,..., L _m ) during the last complete revolution of the conveyor belt shows a minimal change in the material mass flow (Qs ) is assigned by a mean value calculated for this section (L ₁ ,..., L _m ), particularly in the range above 5% of the nominal load. Method according to any of the foregoing claims 2 until 12 , characterized in that the transported mass quantities of the defined number of adjacent sections are added and the measured values with regard to the instantaneous drive power (P _j ) and the instantaneous conveyor belt speed (V _j ) are averaged in order to create a reduced system of equations.

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