Level gauge for monitoring the surface topology of bulk material

Description

Field of the invention

[0001] The invention relates to a level measuring device for monitoring the surface topology of a bulk material, an external control and evaluation unit for such a level measuring device, a method for monitoring the surface topology of a bulk material, a program element and a computer-readable medium. Technical background

[0002] Bulk materials are stored in silos or on dumps. The silos have one or more inlets for filling and one or more outlets for emptying. Both filling and emptying processes typically result in irregularities in the surface of the bulk material, typically in the form of cones or slumps.

[0003] If you want to determine the volume of the bulk material stored in the silo, it is recommended to scan the bulk material surface to determine the surface topology and thus determine the volume with sufficient accuracy. The topology measurement data can be transmitted to an external control and evaluation unit, which performs the volume calculation and controls the silo's filling and emptying processes.

[0004] EP 2 803 952 A1 describes a measuring device control system for determining the topology of a bulk material surface. The control system acquires a series of echo curves from different antenna directions. The antenna directions are modified in such a way that all generated echo curves in the series can be used to determine the topology of the bulk material surface.

[0005] It is an object of the present invention to provide an alternative level measuring device which is designed to efficiently monitor the surface topology of a bulk material.

[0006] This object is achieved by the subject matter of the independent patent claims. Further developments of the invention emerge from the subclaims and the following description of embodiments.

[0007] A first aspect of the present disclosure relates to a level measuring device configured to monitor the surface topology of a bulk material or a liquid. It comprises a sensor unit configured to scan a first region of the surface of the bulk material and a second region of the surface of the bulk material.

[0008] Furthermore, an evaluation unit is provided which is configured to calculate a first volume and / or a first mass and / or a first average filling height of that part of the bulk material which is located below the first region of the surface of the bulk material, and a second volume and / or a first mass and / or a second average filling height of another part of the bulk material which is located below the second region of the surface of the bulk material.

[0009] The terms "sensor unit" and "evaluation unit" are to be interpreted broadly.

[0010] The level measuring device can, for example, be a radar level measuring device, and in particular a radar level measuring device that can scan the entire surface of the bulk material. In principle, it can also be a measuring device based on a different technology, such as an optical measuring device or an ultrasonic measuring device. The key feature is the device's ability to scan individual, predefined areas of the bulk material's surface one after the other.

[0011] The level gauge thus enables profile detection, for example, using radar technology, as a replacement for single-point measurements. This prevents uneven surface formation of the bulk material, which can occur during filling or emptying, from distorting the measurement result.

[0012] In particular, the level transmitter can be equipped with two-wire technology, i.e., configured for connection to a 4 to 20 mA HART interface. In this case, the amount of data that can be transmitted from the level transmitter is severely limited. By dividing the surface of the bulk material into areas or segments and calculating the underlying volume and / or average fill level for each area of ​​the surface, the amount of data that needs to be transmitted to an external control and evaluation unit can be effectively reduced.

[0013] According to a further embodiment, the sensor unit is configured to scan the first area with a first resolution and to scan the second area with a second resolution that is lower than the first resolution.

[0014] This allows energy and computing power to be saved during the measurement and subsequent data evaluation, since certain areas of the bulk material surface that have not changed or have hardly changed compared to the previous measurement, for example, can be scanned with lower resolution than areas in which a major change has occurred or is expected.

[0015] According to a further embodiment, the first region has a different size than the second region. For example, it is larger.

[0016] According to a further embodiment, the first region has a different shape than the second region.

[0017] The level measuring device can be designed to be self-learning and observe under which circumstances which areas of the bulk material surface change significantly and which areas change less or not at all. An example of this is the formation of a discharge funnel, where the annular area around the funnel does not change. If a discharge funnel forms, the first area can be selected to be circular and the second area to be annular around the first area. The scanning resolution in the second area can be lower than that in the first area. In particular, the level measuring device can be set up to regularly change the size and shape of the different areas.

[0018] Further examples where size and shape can be adjusted: In a silo such as Fig. 3AAs shown, a process can be connected to 1-3 outlets. Another process is connected to the remaining outlet. This results in different areas being used in the silo. Depending on which outlets are currently in use, the measurement is only carried out in the area with high dynamic range and high sampling. Conversely, for example, for removal, the supply can also take place via multiple filling lines. The area being monitored is adjusted depending on which line is used for filling.

[0019] A silo can also be mobile, for example, for supplying building materials to construction sites. During transport, the silo is horizontal. After installation, the contents form an inclined plane. The sensor must monitor the entire area. When the silo is refilled at the construction site, a classic cone of material forms. The area monitoring adapts to the new topology and records the dynamics of the cone of material.

[0020] According to the invention, the level measuring device has a communication unit which is configured to transmit the calculated volumes or the calculated filling levels to an external control and evaluation unit.

[0021] According to a further embodiment, the communication unit is configured to transmit only a subset of the calculated volumes or fill levels during data transmission to the external control and evaluation unit.

[0022] For example, the communication unit is configured to transmit a calculated volume or a calculated fill level to the external control and evaluation unit only if it has changed compared to the previous calculation or has changed more than a predetermined threshold value.

[0023] According to a further embodiment, the level measuring device is designed for connection to a 4 to 20 mA two-wire interface and / or for radio transmission of the calculated volumes or filling levels.

[0024] According to a further embodiment, the position of the first region is above an outlet or below an inlet of the container containing the bulk material. Likewise, the position of the second region can also be above an outlet or below an inlet.

[0025] A further aspect of the present disclosure relates to the use of an external control and evaluation unit with a level measuring device, which is configured to visualize the volumes or fill levels transmitted by the level measuring device.

[0026] A further aspect of the present disclosure relates to the use of an external control and evaluation unit for a level measuring device described above and below, for visualizing the volumes or fill levels transmitted by the level measuring device.

[0027] Another aspect of the present disclosure relates to a method for monitoring the surface topology of a bulk material, in which a first area of ​​the surface of the bulk material and a second area of ​​the surface of the bulk material are scanned, whereupon a first volume and / or a first average fill height of the bulk material located below the first area of ​​the surface of the bulk material is calculated. Likewise, a second volume and / or a second average fill height of the bulk material located below the second area of ​​the surface of the bulk material is calculated.

[0028] According to the invention, the calculated volumes and / or fill levels are then transmitted to an external control and evaluation unit.

[0029] According to a further embodiment, the volumes and / or fill levels transmitted by the level measuring device are then visualized on the external control and evaluation unit.

[0030] Another aspect of the present disclosure relates to a program element which, when executed on a system for monitoring the surface topology of a bulk material, instructs the system (which comprises the level measuring device described above and below and the control and evaluation unit described above and below) to perform the steps described above.

[0031] Another aspect of the present disclosure relates to a computer-readable medium on which the program element described above is stored.

[0032] Further embodiments of the invention are described below with reference to the figures. The representations in the figures are schematic and not to scale. Where the same reference numerals are used in the description of the figures, they denote identical or similar elements. Short description of the characters

[0033] Fig. 1 shows a silo with a level measuring device according to one embodiment. Fig. 2 shows a system for monitoring the surface topology of a bulk material according to one embodiment. Fig. 3A shows a schematic view of a silo from above. Fig. 3B shows a bulk material surface divided into nine areas. Fig. 3C shows a round bulk material surface divided into three circular segments. Fig. 4A shows nine areas to be scanned in a silo. Fig. 4B shows two areas to be scanned in a silo. Fig. 4C shows four areas to be scanned in a silo. Fig. 5shows the visualization of the measured volumes or average fill levels according to one embodiment. Fig. 6 shows a flowchart of a method according to an embodiment. Detailed description of embodiments

[0034] Fig. 1 shows a container 110 in the form of a silo containing a bulk material 111. The bulk material 111 has a surface 112, which will usually be irregular.

[0035] In the upper area of ​​the silo 110, a level measuring device 100 is arranged, for example a level radar device, which can scan the surface 112 of the bulk material 111.

[0036] The level gauge 100 is designed for targeted profile monitoring of the bulk material 111 and for reduced data transmission. The low data volume can be achieved by not recording the entire surface profile in the silo with high resolution (similar to an image), but by dividing the silo into sections and using only these sections for evaluation and visualization. The level gauge uses its internal raw data to determine the actual load of the segment for each section, not the profile. This significantly reduces the amount of data to be transmitted. The sum of all sections then yields the total volume.

[0037] The division of the silo into the different zones depends on the silo itself and the customer's requirements for accuracy. Depending on the size of the silo and the existing inlets and outlets, the division of the zones can have different characteristics. Examples of this are shown in the Fig. 3A to 3C shown.

[0038] Fig. 3A shows a schematic view of a silo from above, which has four outlets 107 and one inlet 108. Typical dimensions for such a silo are 6 m x 6 m.

[0039] The customer now has the option of freely choosing the division of the areas to be scanned.

[0040] In the example of Fig. 3BThe silo is divided into nine sections. The first section 103 is located in a corner of the silo, and the second section 104 is located next to it. For example, all nine sections have the same floor plan and size, for example, a square shape with an edge length of 2 m.

[0041] Fig. 3C shows another example of the division of the areas to be scanned, using a round silo as an example. Here, the areas are formed in the form of circular sections or segments.

[0042] The areas in the silo can be connected or have different geometries, as shown in the Fig. 4A to 4C can be seen. The areas can be square or rectangular and all have the same size (see Fig. 4A ). However, they can also have very different sizes, as shown in the Fig. 4B and 4C can be seen. They can also have different shapes.

[0043] In the example of Fig. 4B The customer can see whether area 103 has already been emptied and whether there is still material in area 104. This allows filling to be started when only area 103 is empty. A single-point measurement that only monitors area 104 would result in a downtime in area 103 because the silo area is empty.

[0044] Conversely, the single-point measurement in area 103 may report an empty silo even though there is still material in segment 104. This can lead to overfilling of the silo or to batch mixing in sensitive media such as food.

[0045] The visualization of the calculated volumes or filling levels of the bulk material in the operating tool of the external control and evaluation unit can be done as in Fig. 5This is shown as an example for rectangular segments. However, the visualization can also be done using circular segments or other shapes.

[0046] To implement the visualization, the calculated data can be transmitted to the external control and evaluation unit via the HART protocol. The analog value and four additional variables are available for this purpose. This allows the total volume, along with the calculated volume data or average fill levels from four areas, to be transmitted cyclically. The calculated data from the other areas can be transmitted via acyclic communication using the HART protocol.

[0047] Data compression is particularly useful for acyclic communication. This way, a new measured value is only transmitted for a segment when the previous measured value has changed.

[0048] This process has two main benefits for the customer. Firstly, it provides information about the volume of the silo and the distribution of the bulk material within it. Secondly, the historical data on the movement of the bulk material in the various areas (caused by filling and emptying) can be evaluated individually and in relation to each other. Artificial intelligence can be used for this purpose. This ensures the efficient use of the silo and also the detection of certain conditions within the silo. In particular, effects such as "bridging," "arching," "funneling," or "rat holing" can be detected and / or predicted.

[0049] Fig. 2shows a measuring system for monitoring the surface topology of a bulk material according to one embodiment. The measuring system comprises a level measuring device 100 and an external control and evaluation unit 106. Both can be configured for communication via a wired interface (e.g., a two-wire interface) and / or wireless communication, for example, via Bluetooth or APL.

[0050] The level measuring device 100 has in particular a sensor unit 101 and an evaluation unit 102 as well as a communication unit 105.

[0051] The level gauge can also be designed as a standalone device powered by a battery. In this case, the data can be transmitted via a mobile communication channel, such as LoRa, where the reduced data volume is also helpful.

[0052] Fig. 6shows a flowchart of a method according to one embodiment. In step 601, a first area of ​​the surface of the bulk material is scanned. In step 602, a second area of ​​the surface of the bulk material is scanned. In step 603, the volume and / or the average fill level of the bulk material below the first area is calculated, and in step 604, the volume or the average fill level of the bulk material below the second area is calculated. In step 605, the calculated variables (volumes / fill levels) are transmitted to an external control and evaluation unit, which can then visualize the transmitted data.

[0053] In particular, the information to be transmitted can be reduced to the essential silo areas. These are, for example, areas where a change has occurred. The division of the areas can depend on the geometry of the silo and customer requirements, such as size, shape, inlets, and outlets.

[0054] The geometry of the segments is generally selectable. Communication can take place via a simple data channel, such as HART, or, alternatively, via a wireless interface. Silo utilization can be monitored and optimized using historical data. This makes it possible to determine whether a particularly large amount of bulk material is being removed through a silo outlet. It can also be determined whether an outlet is blocked, for example, because the level measuring device detects that the volume in the area assigned to the outlet never falls below a certain amount.

[0055] By evaluating the historical data of the areas individually and in combination with other areas, adhesions can be detected, tunneling can be detected, one-sided charging can be detected and dead zones can be detected.

[0056] Additionally, it should be noted that "comprising" and "having" do not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. Furthermore, it should be noted that features or steps described with reference to one of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference signs in the claims are not to be considered limitations.

Claims

1. A level measuring device (100), configured to monitor the surface topology of a bulk material (111) or liquid, comprising: a sensor unit (101) configured to scan a first area (103) of the surface of the bulk material and a second area (104) of the surface of the bulk material; and characterized in that it comprises the following: an evaluation unit (102) configured to calculate a first volume and / or a first mass and / or a first average filling height of the bulk material located below the first area of the surface of the bulk material, and a second volume and / or a second mass and / or a second average filling height of the bulk material located below the second area of the surface of the bulk material; a communication unit (105), configured to transmit the calculated volumes or fill levels to an external control and evaluation unit (106).

2. The level measuring device (100) according to claim 1, wherein the sensor unit (101) is configured to scan the first area with a first resolution and to scan the second area with a second resolution that is lower than the first resolution.

3. The level measuring device (100) according to one of the preceding claims, wherein the first area (103) has a different size than the second area (104).

4. The level measuring device (100) according to one of the preceding claims, wherein the first region (103) has a different shape than the second region (104).

5. The level measuring device (100) according to one of the preceding claims, wherein the communication unit (105) is configured to transmit only a subset of the calculated volumes or fill levels during a data transmission to the external control and evaluation unit (106).

6. The level measuring device (100) according to one of the preceding claims, wherein the communication unit (105) is configured to transmit a calculated volume or a calculated filling level to the external control and evaluation unit (106) only if it has changed compared to the previous calculation.

7. The level measuring device (100) according to any one of the preceding claims, configured to connect to a 4-20 mA two-wire interface or for radio transmission of the calculated volumes or fill levels.

8. The level measuring device (100) according to any one of the preceding claims, wherein the position of the first region (103) is above an outlet (107) or below an inlet (108) of a container in which the bulk material is stored.

9. Use of an external control and evaluation unit (106) with a level measuring device (100) according to one of the preceding claims, configured to visualize the volumes or levels transmitted by the level meter.

10. Method for monitoring the surface topology of a bulk material, comprising the following steps: scanning a first region (103) of the surface of the bulk material and a second region (104) of the surface of the bulk material; calculating a first volume and / or a first mass and / or a first average fill height of the bulk material located below the first area of the surface of the bulk material, and a second volume and / or a second mass and / or a second average fill height of the bulk material located below the second area of the surface of the bulk material; transferring the calculated volumes or fill levels to an external control and evaluation unit (106).

11. Method according to claim 10, further comprising the step: visualizing the volumes or levels transmitted by the level meter.

12. Program element that, when executed on a system for monitoring the surface topology of a bulk material, directs the system to perform the steps of one or more of claims 10 to 11.

13. A computer-readable medium on which is stored a program element according to claim 12.