METHOD FOR DETERMINING THE LAYER HEIGHT OF A PROCESS MATERIAL FEEDED TO A CRUSHING AND / OR SCREENING UNIT OF A MATERIAL PROCESSING EQUIPMENT

Description

[0001] The invention relates to a method for determining the layer height of a feed material that is conveyed to a crushing and / or screening plant of a material processing facility, wherein the feed material is conveyed in a conveying direction by means of a conveying device, wherein the layer height of the feed material on the conveying device is determined by means of a sensor array comprising a plurality of sensors, wherein the sensors each detect as a signal waves that are reflected at least partially along a detection volume of the respective sensor by the feed material, and wherein the detection volumes each have a longitudinal axis that extends in the direction of the longitudinal extent of the respective detection volume.

[0002] The invention also relates to a material processing device with a crushing and / or screening plant, wherein a feed material is conveyed to the crushing and / or screening plant in a conveying direction by means of a conveying device, wherein a sensor array comprising a plurality of sensors is provided, by means of which a layer height of the feed material on the conveying device can be determined, wherein the sensors are each configured to detect as a signal waves that are reflected at least partially along a detection volume of a respective sensor on the feed material, and wherein the detection volumes each have a longitudinal axis that extends in the direction of the longitudinal extent of the respective detection volume.

[0003] Material processing equipment of the type described above is used, for example, for crushing and / or sorting input material, particularly rock materials such as natural stone, concrete, bricks, or recycled materials. The material to be processed is fed into a feed unit of the material processing equipment, for example, in the form of a hopper, and conveyed via a conveying device, such as a vibratory feeder or a belt conveyor, to a crusher and / or a screen. A pre-screening stage may also be installed upstream of the crusher, for example, to remove fines or medium-sized particles that already have a suitable particle size.

[0004] The performance and efficiency of such material processing plants depend significantly on the demand-based feeding of the feed material. For example, an excessively high fill level in a crusher leads to high mechanical stress and excessive wear. If the fill level is too low, the desired quality of the end product is no longer achieved. In screening plants, on the other hand, the separation efficiency decreases noticeably with increasing layer thickness on the screen surface. Therefore, in order to operate material processing plants, and especially crushing and / or screening plants, within favorable operating ranges, feed control is essential.

[0005] For example, operating parameters such as crusher fill level, drive system utilization, or operating loads on the crusher or screen can be determined and used to control the feed rate. This allows for a response to overload or underload. It may also be desirable to determine the layer thickness of the conveyed feed material.

[0006] One way to determine the layer height is to use sensors that employ a measurement principle based on wave detection.

[0007] From DE 3411540 A1, a method for determining the material flow rate of belt conveyors is known. For this purpose, laser distance measuring devices are provided in a housing located above the surface of bulk material on a conveyor belt. The laser distance measuring devices each consist of a transmitter and a receiver. The transmitters send laser pulses to the surface of the bulk material, where they are reflected and thus reach the receivers. The distance to the surface is evaluated based on the pulse transit time. The laser distance measuring devices are arranged side by side, transverse to one direction of travel of the conveyor belt.

[0008] A method for the three-dimensional reconstruction of ore conveyed on a conveyor belt of a material crushing plant is known from US 2018 / 0369829 A1. An imaging system comprising a laser line light source is mounted above the conveyor belt. The laser line light source projects a line of light onto the conveyed ore. The light reflected from the surface of the ore is detected by two cameras positioned at an angle to the laser line light source. An algorithm is used to reconstruct the profile of the ore on the conveyor belt.

[0009] From DE 10 2012 016 332 B4, a method for controlling and / or regulating the volume flow of bulk material on a conveyor belt is known. In this method, a line laser and a camera are also arranged above the conveyed bulk material.

[0010] In material processing equipment, structures above the conveying system are often undesirable, as they can, for example, impair access to the conveying system or any existing feed units such as feed hoppers. Especially with mobile material processing equipment, additional requirements for a low overall height of the system must be considered.

[0011] The object of the invention is to provide a method by which the layer thickness of a feed material supplied to a material processing device can be reliably determined with minimal effort and without impairing the operation of the material processing device. A further object of the invention is to provide a material processing device configured to carry out such a method.

[0012] The layer height can be the extent of the conveyed material, for example, in the direction of gravity or in a direction perpendicular to a support surface of the conveying device on which the material rests. The conveying volume can be determined from the layer height, for example, in conjunction with the conveying speed.

[0013] The problem relating to the method is solved by a method according to claim 1.

[0014] According to the invention, the longitudinal axes of the detection volumes extend at least partially in and / or opposite to the conveying direction F. The direction of the longitudinal axes of the detection volumes thus has at least one component in the direction of and / or opposite to the conveying direction. The conveying direction can be understood as the mean direction of movement of the material conveyed by the conveying device. When using conveyor belts, the conveying direction can therefore largely correspond to the direction of movement of the conveyor belt.

[0015] Waves can include, for example, pressure waves such as sound or ultrasound waves, or electromagnetic waves such as light, radar, X-ray, radioactive or UV or infrared radiation.

[0016] The term "sensor" can refer to detectors designed to detect waves, such as cameras, camera chips, or microphones. It can also refer to devices that combine the functions of a transmitter and detector, thus enabling them to both emit and detect waves. In particular, distance measuring devices and / or speed measuring devices can also be considered sensors.

[0017] Waves reflected and / or scattered by the target material and directed towards the sensor can be detected. In particular, waves that travel along straight lines from the target material to the sensor can reach the sensor. The entirety of these straight lines is encompassed by the sensor's detection volume. The detection volume can be a small-diameter cylinder, or approximately a line leading from the target material to the sensor, for example, when using a laser. In this case, one longitudinal axis of the detection volume approximately coincides with the detection volume itself. However, the detection volume can also be shaped differently, particularly as a cone or a lobe, such as a radar beam. If the detection volume is conical, its longitudinal axis corresponds to the central longitudinal axis of the cone.

[0018] If the longitudinal axes of the detection volumes run at least partially in and / or opposite to the conveying direction F, the sensors do not need to be mounted above the conveying device. This generally allows for greater flexibility in sensor positioning. For example, they can be positioned at a greater distance in or against the conveying direction from the conveying device and / or the screening and / or crushing system. This allows the sensors to be located where they minimize disruption to the operation of the material processing equipment and where they are at least partially or largely protected from contamination, mechanical damage from the material being processed, or vibrations. Furthermore, the component is made accessible for measurements in the conveying direction. For example, this component can be used for velocity measurements.

[0019] The sensors of the sensor array can be controlled, for example, by a control unit of the material processing equipment or by a control unit of the sensor array itself. The evaluation of the signals can be performed, for example, by an evaluation unit. However, it is also conceivable that the evaluation of the signals can be carried out by the sensors themselves, especially if they are functioning as measuring devices such as speed or distance measuring devices.

[0020] Predictive process parameters, such as the layer height of the supplied material, can be used for control purposes to largely prevent overload and / or underload situations. This allows for improvements to the production process, thereby enhancing machine utilization, fuel efficiency, and the quality of intermediate and final products.

[0021] According to the invention, each sensor is assigned a layer height range, and the sensors determine whether feed material is present in the respective layer height ranges. For example, at least two, preferably at least three, particularly preferably at least four, more preferably five, and especially six layer height ranges can be provided. The layer height ranges can each comprise, for example, 100 mm, so that a first layer height range can, for example, comprise the range < 100 mm, a second layer height range 100-200 mm, etc. Preferably, each layer height range can be assigned a sensor. However, it can also be provided that some layer height ranges, e.g., < 100 mm, are not assigned a sensor. It is also conceivable to provide more than one sensor for one or more layer height ranges.The sensors therefore do not necessarily need to be able to measure distance, but only need to detect whether there is feed material in a given layer height range. If a sensor detects that there is material in a given layer height range, the layer height of the feed material can then be determined.

[0022] If the sensors and / or evaluation circuit are designed to only consider feed material located within a set measuring distance of the sensors, then the layer height of the feed material can be determined with exceptional reliability. This is particularly important if the longitudinal direction of the measured volumes is not parallel to the conveying direction; otherwise, material outside the set measuring distance could result in inaccurate layer height readings. The measuring distance can be a distance, for example, in the conveying direction and / or in the horizontal direction. For instance, only a signal can be evaluated that is assigned to a specific area within the measuring distance, perhaps based on a transit-time measurement.

[0023] According to an advantageous embodiment of the invention, it is proposed that the sensors are arranged transversely to the conveying direction, one above the other in the direction of gravity, preferably at least partially perpendicular to the conveying direction F, and in particular, are arranged in a row, either directly or indirectly, at least partially perpendicular to the conveying direction F. This results in a compact sensor array. The sensors can be aligned parallel to each other such that the longitudinal axes of the detection volumes of the sensors are parallel. Preferably, the sensors are aligned such that the longitudinal axes of the sensors diverge, and it is particularly advantageous for the sensors to be arranged in a convex, in particular circular arc-shaped, sensor arrangement.

[0024] According to the invention, it can be provided that the longitudinal axes of the detection volumes run at an angle α of less than 45°, preferably less than 30°, particularly preferably less than 15°, relative to the conveying direction F.

[0025] A variant of the invention can be characterized in that the sensors are radar sensors and / or ultrasonic sensors and / or laser distance sensors and / or laser Doppler vibrometers. Such sensors are readily available at low cost and sufficiently robust for use under potentially harsh operating conditions, such as those that can prevail in material processing equipment. Furthermore, such sensors can reliably detect the feed material. In particular, when using radar sensors and / or ultrasonic sensors and / or laser Doppler vibrometers, the velocities of the feed material can also be measured.

[0026] According to an advantageous embodiment of the invention, it is proposed that the measuring volumes do not overlap within the set measuring distance, and in particular that the detection volumes have vertical opening angles β that are less than 10°, preferably less than 7.5°, and most preferably less than 5°. This allows for a reliable assignment of detected feed material to the measuring volumes of the sensors. In particular, detected feed material can be reliably assigned to a respective layer height range. Alternatively, it can also be provided that the measuring volumes overlap only slightly within the set measuring distance. In particular, the angles γ between the measuring volumes can also be designed such that no or only a slight overlap occurs within the measuring distance.

[0027] One embodiment of the invention is such that the sensor array is formed from separate sensors. Alternatively, the sensor array can be designed as a single unit comprising several sensors. This simplifies the assembly of the sensor array. Furthermore, using a single unit allows for greater mechanical stability, resulting in a more robust construction and reduced measurement error. In particular, if the unit has a housing and the sensors are at least partially enclosed within it, the sensors are especially well protected from external influences.

[0028] Furthermore, it is conceivable that the speed of the feed material could be determined using a speed measuring device. Examples of suitable speed measuring devices include incremental sensors such as measuring wheels or non-contact speed measuring devices.

[0029] Preferably, the velocity measuring device is formed by at least one of the sensors, and in particular, the velocity measuring device is formed by several of the sensors, and preferably an average velocity of the feed material is determined using the several sensors. In this way, no additional sensors need to be used to determine the velocity of the feed material. Averaging the velocities determined by several sensors allows for a more accurate result, since, for example, outliers, which can be caused by rolling feed material, have less of an impact on the measurement result.

[0030] An advantageous embodiment of the invention can be characterized in that a volumetric flow rate of the feed material is determined from the velocity of the feed material, the layer height of the feed material, and the geometry of the conveyor. In particular, the volumetric flow rate of the feed material can be used as a predictive variable for controlling the material flow.

[0031] According to one embodiment of the invention, the sensors can be used to determine the properties of the feed material, in particular the type of rock and / or the feed size, preferably by determining the properties of the feed material based on its reflective properties. For example, the intensity of the signal echo, such as a radar echo, can provide information about the rock size and / or type. With this additional information, for example, the target conveying speed of the feed material can be adjusted, since the material properties significantly affect the processing time in the system.

[0032] It can also be advantageous to use the feed material's volume flow rate to control the conveyor, particularly to regulate the effective conveyor speed and / or the operation of a pre-screen. This allows for a more consistent processing process, as the conveyor speed can be reduced early if, for example, the crusher and / or screen is at risk of becoming too full. Conversely, the conveyor speed can be increased if the plant capacity and the predicted volume flow rate permit. In this way, overload and underload situations can be largely avoided. This can result in improved plant utilization and thus savings in time, costs, and / or energy.

[0033] Alternatively or additionally, it is conceivable that the volume flow rate is also used to adjust other parameters, such as the setting of a crushing gap, a rotor speed of an impact crusher, an excitation frequency and / or amplitude of a screening plant and / or a pre-screen.

[0034] According to an advantageous embodiment of the invention, it is proposed that the properties of the feed material are used to control the conveyor, in particular that an expected residence time of the feed material in the crushing and / or screening plant is determined from the properties and volume flow of the feed material, and that the expected residence time is used to control the effective conveying speed of the conveyor and / or to control a pre-screen.

[0035] The problem relating to the material processing equipment is solved by a material processing equipment according to claim 14.

[0036] According to the invention, the sensors are designed and / or aligned in such a way that the longitudinal axes of the detection volumes run at least partially in and / or opposite to the conveying direction F, that each sensor is assigned a layer height range, and that the sensors determine whether there is feed material in the respective layer height ranges.

[0037] A material processing device according to the invention can be characterized in that the sensors are arranged at a distance from the conveying device in and / or against the conveying direction.

[0038] The invention will be explained in more detail below with reference to an embodiment illustrated in the drawings. The drawings show: Figure 1 shows a side view, partially cut away, schematic representation of a material processing device, and Figure 2 shows a schematic representation of a sensor array consisting of several sensors with their respective detection volumes.

[0039] Figure 1 Figure 1 shows a side view, partially cut away, of a material processing unit 10. The material processing unit 10 can be designed as a mobile unit with a chassis 11 and, for example, a chain drive 13. The material processing unit 10 can include a crushing unit 50 and / or a screening unit 30.

[0040] The material processing unit 10, in particular a feed unit 20, may also be equipped with a hopper 21, which may have hopper walls 22. The hopper 21 may serve to receive feed material 70 from an upstream conveying system, for example an excavator, a wheel loader or a conveyor belt, and to direct it onto a conveying device 23.

[0041] The crushing plant 50 and / or the screening plant 30 can be fed feed material 70 in a conveying direction F for processing by means of the conveying device 23. In this case, the conveying device 23 is designed as a vibrating feed trough. However, other designs of a conveying device 23, in particular as a conveyor belt, are also conceivable.

[0042] The screening plant 30 can, for example, be installed upstream of the crushing plant 50 as a pre-screening unit. The pre-screening unit can have a double-deck heavy-duty screen 31, which can have an upper deck 32 designed as a coarser screen and a lower deck 34 designed as a finer screen. It can be set into circular vibration by a drive 33. The upper deck 32 can separate a fine fraction 71 and a medium fraction 72 from the material 73 to be crushed. The lower deck 34 can separate the fine fraction 71 from the medium fraction 72. The fine fraction 71 can optionally be discharged from the material shredding plant 10 or, for example, fed to the medium fraction 72 by appropriately positioning a bypass flap. The medium fraction 72 can be conveyed via a bypass past the crusher 50 to a crusher discharge conveyor 40. The material 73 to be crushed is fed to the crusher 50 via a crusher inlet at the end of the pre-screening.

[0043] The material processing unit 10 can include a crushing plant 50 designed as a jaw crusher. However, it is also conceivable to provide other types of crushing plant 50, for example, impact crushers, roller crushers, or cone crushers. The crushing plant 50 can have a fixed crushing jaw 51 and a moving crushing jaw 52, ​​which can be arranged at an angle towards each other, so that a conically tapered shaft is formed between them. The shaft can open into a crushing gap 56. The crushing plant 50 can, for example, be driven by a drive unit 12 via a drive shaft 55 connected to an eccentric 54.

[0044] The eccentric 54 moves the moving jaw 52 in an elliptical motion towards and away from the stationary jaw 51. During each stroke, the distance between the jaws 51 and 52 in the area of ​​the crushing gap 56 also changes. The movement of the jaw 52 continuously reduces the material 73 to be crushed along the conical shaft until it reaches a particle size that allows it to exit the shaft through the crushing gap 56. The crushed material 74 falls onto the crusher discharge conveyor 40 and is conveyed further. It may also be conveyed, for example, past a magnetic separator 41, which separates ferromagnetic components from the crushed material 74 and discharges them laterally.

[0045] As from the Figure 1As further shown, a level sensor 61 can be assigned to the crushing plant 50. This sensor can be an ultrasonic sensor. However, it is also conceivable to use other sensor types, such as optical sensors (e.g., a camera system) or mechanical sensors. The level sensor 61 can monitor the fill level of the crusher 50 with material 73 to be crushed. It can be part of a continuous feed control system for the material processing unit 10. For this purpose, the material-feeding components of the material processing unit 10, in particular the conveying unit 23, can be controlled according to the signals from the level sensor 61. This allows, for example, the volume flow rate of the material 73 to be crushed being fed into the crusher 50 to be regulated.

[0046] As in Figure 1As can be seen further, a sensor array 105 consisting of several sensors 101 can be provided on the material processing device 10. The layer height of the feed material 70 can be determined using the sensor array 105. In the illustrated embodiment, the sensor array 105 consists of three individual sensors 101 arranged one above the other in the direction of gravity. Of course, other arrangements and, in particular, different numbers of sensors 101 are also conceivable. Furthermore, the sensor array 105 need not consist of individual sensors 101, but can also be designed as a modular unit. In particular, the modular unit can have a housing that at least partially accommodates the unit.

[0047] The sensor array 105 can be held on the material processing device 10 by means of a sensor mounting device 110. The sensor mounting device 110 can be a mast to which the sensor array 105 is attached. The sensor array 105 can be attached to the material processing device 10 indirectly or directly by means of a sensor adjustment device 111. In this case, the sensor array 105 is attached to the material processing device 10 indirectly via the sensor mounting device 110 and a sensor adjustment device 111. The sensor adjustment device 111 can, for example, provide an articulated connection to the sensor mounting device 110, allowing the sensor array 105 to be pivoted, for example, to enable different orientations of the sensor array 105. It is also conceivable to attach the sensor array 105 to the material processing device 10 and / or the sensor holding device 110 in a height-adjustable manner.

[0048] In the illustrated embodiment, the sensors 101 are radar sensors. However, other sensors are also conceivable, in particular ultrasonic sensors, laser distance sensors, and / or laser Doppler sensors, especially laser Doppler vibrometers. The sensors 101 can emit waves, in this case radar waves, for example within a detection volume 103. If there is material, in particular feed material 70, within the detection volume 103 of a sensor 101, the waves can be reflected by this material. A portion of the reflected waves is bounced back along the detection volume 103 to the respective sensor 101 and can be detected by it.

[0049] As in the Figure 1 As can be seen, the conveying direction F can, for example, be horizontally oriented. However, inclined conveying directions F are also conceivable, for example, if the conveying device 23 has an incline. As the Figure 2 As shown, the detection volumes 103 can be lobe-shaped and / or conical. In this case, they are designed as radar lobes. However, other geometries for the detection volumes 103 are also conceivable. Each detection volume 103 can have a longitudinal axis 107. The longitudinal axis 107 can be the bisector of a vertical opening angle β of the detection volume 103.

[0050] The detection volumes 103 are aligned with their longitudinal axis 107 at least partially in the direction of the conveying direction F and / or opposite to it. As the Figure 2 As can be seen, the longitudinal axis 107 forms an angle α with the conveying direction F. The smaller this angle α is, the greater the absolute value of the component of the direction of the longitudinal axis 107 of a respective detection volume 103 in the direction and / or opposite to the conveying direction F.

[0051] The sensors 101 and / or their detection volumes 103 can be oriented such that the longitudinal axes 107 of adjacent detection volumes 103 form an angle γ with each other, as further described in the Figure 2 As can be seen. In the present case, diverging longitudinal axes 107 result from the angles γ. This can be achieved, for example, by arranging the sensors 101 in a convexly curved sensor arrangement 106.

[0052] Again Figure 2 As can be further seen, each sensor 101 can be assigned a layer height range 120. The layer height range 120 of a sensor 101 can, for example, be a range between a lower and an upper layer height to be detected, which is present within the detection volume 103 of the sensor 101 at a set measurement distance 108.

[0053] For this purpose, it can be provided that a sensor 101, for example, only evaluates a signal that is detected from an area within the set measurement distance 108. This can be determined, for example, using a pulse transit-time method. An evaluation device, not shown in the figures, can be provided for evaluating the pulse transit times.

[0054] A set measuring distance can, for example, be measured along the conveying direction F.

[0055] As in Figure 2 As can be further seen, the detection volumes 103 of the sensors 101 can be designed and / or aligned such that they do not overlap or only overlap slightly within the set measurement distance 108. In particular, the angles α, β, γ and the set measurement distance 108 can be adjusted accordingly for this purpose.

[0056] If, for example, the layer height of the feed material 70 is to be determined during the operation of the material processing unit 10, the sensors 101 can emit measuring waves, in particular radar waves, which are at least reflected by the feed material 70. The reflected measuring waves are then detected by the sensor 101 along whose detection volume 103 they are reflected. Of course, waves other than radar waves can also be used. Furthermore, preferably only the signal reflected by the feed material 70 that is located within the set measuring distance 108 is detected and / or evaluated.

[0057] For example, a sensor 101 can detect the presence of feed material 70 if any waves are reflected back to the sensor 101 as a signal. It is also conceivable to define a threshold value for the signal intensity above which the presence of feed material 70 is to be expected. The signal can be evaluated, for example, by means of an evaluation unit, which is not shown in the figures. However, the evaluation can also be performed by the sensors 101 themselves.

[0058] Each sensor 101 can thus detect whether there is feed material 70 within the set measuring distance 108 and within the layer height range 120 assigned to the sensor 101. From the information from several sensors 101, it is therefore possible to conclude whether several layer height ranges 120 are occupied by feed material 70 and thus to determine the layer height of the feed material 70.

[0059] Each sensor 101 can determine the velocity of the feed material 70, particularly when feed material 70 is located within its assigned layer height range 120. For this purpose, a Doppler velocity measurement can be used, for example. The evaluation of measurement signals for velocity determination can be performed by the sensors 101 or by an evaluation unit.

[0060] By means of the geometry of the conveying device 23, the layer height of the feed material 70, and the velocity of the feed material 70, a material flow, in particular a volumetric flow rate of the feed material 70, can be determined. It may be possible to use the volumetric flow rate of the feed material 70 when controlling the material processing device 10, especially when controlling a supplied material flow. For this purpose, a control device may be provided on the material processing device 10, which is not shown in the figures.

Claims

1. A method for determining the layer height of a feed material (70) supplied to a crushing (50) and / or screening plant (30) of a material processing device (10), wherein a conveyor device (23) is used to convey the feed material (70) in a conveying direction F, wherein a sensor array (105) comprising a plurality of sensors (101) is used to determine the layer height of the feed material (70) on the conveyor device (23), wherein the sensors (101) each detect as a signal waves, which are reflected at the feed material (70) at least partially along detection volumes (103) of respective sensors (101), and wherein the detection volumes (103) each have a longitudinal axis (107) extending in the direction of the extension of length of the respective detection volumes (103), wherein the longitudinal axes (107) of the detection volumes (103) extend at least partially in and / or counter to the conveying direction F, characterized in that a layer height range (120) is assigned to every sensor (101), and in that the sensors (101) are used to determine whether feed material (70) is located in the respective layer height ranges (120).

2. The method according to claim 1, characterized in that the sensors (101) and / or an evaluation circuit only take into account feed material (70) that is within a set gauge distance (108) from the sensors (101).

3. The method according to claim 1 or 2, characterized in that the sensors (101) are disposed transversely with respect to the conveying direction, one above the other in the direction of gravity, preferably at least partially perpendicular to the conveying direction (F), in particular are lined up indirectly or directly at least partially perpendicular to the conveying direction (F).

4. The method according to any of the claims 1 to 3, characterized in that the longitudinal axes (107) of the detection volumes (103) extend at an angle α of smaller than 45°, preferably smaller than 30°, particularly preferably smaller than 15°, with respect to the conveying direction F.

5. The method according to any of the claims 1 to 4, characterized that the sensors (101) are radar sensors and / or ultrasonic sensors and / or laser distance sensors and / or laser Doppler vibrometers.

6. The method according to any of the claims 2 to 5, characterized that the detection volumes (103) do not overlap within the set gauge distances (108), in particular that the detection volumes (103) have vertical opening angles β which are smaller than 10°, preferably smaller than 7.5°, particularly preferably smaller than 5°.

7. The method according to any of the claims 1 to 6, characterized in that the sensor array (105) is formed from separate sensors (101), or in that the sensor array (105) is designed as a structural unit consisting of several sensors (101), in particular in that the structural unit has a housing, and in that the sensors (101) are at least partially accommodated in the housing.

8. The method according to any of the claims 1 to 7, characterized in that speed measuring device is used to determine a speed of the feed material (70).

9. The method according to claim 8, characterized in that the speed measuring device is formed by at least one of the sensors (101), in particular in that the speed measuring device is formed by several of the sensors (101), and in that a speed, preferably the average speed, of the feed material (70) is determined by means of the several sensors (101).

10. The method according to claim 8 or 9, characterized in that a volumetric flow rate of the feed material (70) is determined from the speed of the feed material (70), the layer height of the feed material (70) and the geometry of the conveyor (23).

11. The method according to any of the claims 1 to 10, characterized in that a characteristic, in particular a rock type and / or a feed size, of the feed material (70) is determined by means of the sensors (101), preferably in that the characteristic of the feed material (70) is determined on the basis of the reflection properties of the feed material (70).

12. The method according to according to any of the preceding claims, characterized in that the volumetric flow of the feed material (70) is used to regulate the conveyor (23), in particular to regulate an effective conveying speed of the conveyor (23) and / or an actuation of a prescreen.

13. The method according to claim 11 or 12, characterized in that the characteristic of the feed material (70) is used to regulate the conveyor (23), in particular in that the characteristic and the volumetric flow of the feed material (70) are used to determine an anticipated dwell time of the feed material in the crushing (50) and / or screening plant (30), and in that the anticipated dwell time is used to regulate the effective conveying speed of the conveyor (23) and / or an actuation of a prescreen.

14. A material processing device (10) having a crushing (50) and / or screening plant (30), wherein a conveyor device (23) is used to convey a feed material (70) to the crushing (50) and / or screening plant (30) in a conveying direction F, wherein a sensor array (105) comprising a plurality of sensors (101) is provided, by means of which a layer height of the feed material (70) on the conveyor device (23) can be determined, wherein the sensors (101) are each designed to detect waves, which are reflected at the feed material (70) at least partially along detection volumes (103) of respective sensors (101) as signals, and wherein the detection volumes (103) each have a longitudinal axis (107), which extends in the direction of the longitudinal extension of the respective detection volumes (103), wherein the sensors (101) are designed and / or oriented such that the longitudinal axes (107) of the detection volumes (103) extend at least partially in and / or counter to the conveying direction F, characterized in that a layer height range (120) is assigned to every sensor (101), and in that the sensors (101) are used to determine whether feed material (70) is located in the respective layer height ranges (120).

15. The material processing device (10) according to claim 14, characterized in that the sensors (101) are disposed at a distance from the conveyor device (23) in and / or counter to the conveying direction F.

16. The material processing device (10) according to claim 14 or 15, characterized in that it is adapted to carry out the method according to any one of claims 1 to 13.