LEVEL MEASURING DEVICE FOR MONITORING THE SURFACE TOPOLOGY OF A BULK MATERIAL

Abstract

A level measuring device is provided. The level measuring device can be configured to monitor the surface topology of a bulk material, and can include a sensor unit for scanning several areas of the bulk material surface and an evaluation unit for calculating the volumes under these areas.

Claims

1. A level measuring device configured to monitor the surface topology of a bulk material or liquid, comprising: a sensor unit configured to scan a first area of the surface of the bulk material and a second area of the surface of the bulk material; and an evaluation unit 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.

2. The level measuring device according to claim 1, wherein 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.

3. The level measuring device according to claim 1, wherein the first area has a different size than the second area.

4. The level measuring device according to claim 1, wherein the first area has a different shape than the second area.

5. The level measuring device according to claim 1, further comprising: a communication unit configured to transmit the calculated volumes or fill levels to an external control and evaluation unit.

6. The level measuring device according to claim 5, wherein the communication unit 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.

7. The level measuring device according to claim 5, wherein the communication unit is configured to transmit a calculated volume or a calculated filling level to the external control and evaluation unit only if it has changed compared to the previous calculation.

8. The level measuring device according to claim 1, wherein the level measuring device is configured to connect to a 4-20 mA two-wire interface or for radio transmission of the calculated volumes or fill levels.

9. The level measuring device according to claim 1, wherein the position of the first area is above an outlet or below an inlet of a container in which the bulk material is stored.

10. An external control and evaluation unit for the level measuring device according to claim 1, wherein the external control and evaluation unit is configured to visualize the volumes or levels transmitted by the level meter.

11. A method for monitoring the surface topology of a bulk material, the method comprising: scanning a first region of the surface of the bulk material and a second region of the surface of the bulk material; and 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.

12. The method according to claim 11, further comprising: transferring the calculated volumes or fill levels to an external control and evaluation unit.

13. The method according to claim 11, further comprising: visualizing the volumes or levels transmitted by the level meter.

14. A program element that, when executed on a system for monitoring the surface topology of a bulk material, directs the system to perform the method of claim 11.

15. A computer-readable medium on which is stored the program element according to claim 14.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0036] FIG. 1 shows a silo with a level measuring device according to one embodiment.

[0037] FIG. 2 shows a system for monitoring the surface topology of a bulk material according to one embodiment.

[0038] FIG. 3A shows a schematic view of a silo from above.

[0039] FIG. 3B shows a bulk material surface divided into nine areas.

[0040] FIG. 3C shows a round bulk material surface divided into three circular segments.

[0041] FIG. 4A shows nine areas to be scanned in a silo.

[0042] FIG. 4B shows two areas to be scanned in a silo.

[0043] FIG. 4C shows four areas to be scanned in a silo.

[0044] FIG. 5 shows the visualization of the measured volumes or average fill heights according to one embodiment.

[0045] FIG. 6 shows a flow diagram of a process according to one embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

[0046] FIG. 1 shows a container 110 in the form of a silo in which a bulk material 111 is located. The bulk material 111 has a surface 112, which will normally be irregular.

[0047] A level measuring device 100, such as a level radar device, is disposed in the upper portion of the silo 110 and is capable of scanning the surface 112 of the bulk material 111.

[0048] The level measuring device 100 is set up for targeted profile monitoring of the bulk material 111 as well as for reduced data transmission. The small amount of data can be achieved by not recording the entire surface profile in the silo with a high resolution (similar to an image), but by dividing the silo into areas and using only these areas for evaluation and visualization. The level measuring device uses its internal raw data to determine the actual loading of the segment for each area, rather than the profile. This greatly reduces the amount of data to be transmitted. The sum of all areas then gives the total volume.

[0049] The division of the silo into the different areas depends on the silo itself and the customer's requirements for accuracy. Depending on the size of the silo and the available inlets and outlets, the division of the areas can have different characteristics. Examples of this are shown in FIGS. 3A to 3C.

[0050] FIG. 3A schematically shows a silo viewed from above, which has four outlets 107 and one inlet 108. Typical dimensions for such a silo are 6 m×6 m.

[0051] The customer now has the option of freely selecting the division of the areas to be scanned.

[0052] In the example of FIG. 3B, the silo is divided into nine areas. The first area 103 is located in one corner of the silo and the second area 104 is located next to it. For example, all nine areas have the same floor plan and size, such as a square shape with an edge length of 2 meters.

[0053] FIG. 3C shows another example of the division of the areas to be scanned using the example of a round silo. Here, the areas are in the form of circle sections or circle segments.

[0054] The areas in the silo can be contiguous or also assume different geometries, as can be seen in FIGS. 4A to 4C. For example, 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 can be seen in FIGS. 4B and 4C. They can also have different shapes.

[0055] In the example of FIG. 4B, the customer can see whether first area 103 has already been emptied and whether material is still present in second area 104. Thus, filling can be started if only first area 103 is empty. A single-point measurement that only monitors second area 104 would result in an operational failure in first area 103 because the area of the silo is empty.

[0056] In the opposite case, the single-point measurement in first area 103 can report an empty silo, although material is still present in second area 104. This can lead to overfilling of the silo or to batch mixing in the case of sensitive media such as foodstuffs.

[0057] The visualization of the calculated volumes or filling heights of the bulk material in the operating tool of the external control and evaluation unit can be realized as shown in FIG. 5. This is exemplary for rectangular segments. However, the visualization can also be done by circular segments or other shapes.

[0058] To realize the visualization, the calculated data can be transmitted to the external control and evaluation unit via the HART protocol. For this purpose, the analog value is available on the one hand and four other variables on the other. Thus, the total volume can be transmitted cyclically together with the calculated volume data or average fill levels of four areas. The calculated data of the other areas can be transmitted via acyclic communication using the HART protocol.

[0059] Data compression is particularly useful for acyclic communication. Thus, a new measured value is only transmitted for a segment if the measured value has undergone a change.

[0060] For the customer, this process has two main benefits. On the one hand, he receives the information how much volume is in the silo and how the distribution of the bulk material in the silo looks like. Secondly, the history data of the movement of the bulk material in the different 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 in the silo. In particular, effects such as bridging, arching, funneling or rat holing can be detected and/or predicted.

[0061] FIG. 2 shows 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 of which may be designed for communication by means of a wired interface (for example, two-wire interface) and/or wireless communication, for example, by means of Bluetooth or APL.

[0062] In particular, the level measuring device 100 has a sensor unit 101 and an evaluation unit 102, as well as a communication unit 105.

[0063] The level measuring device can also be self-sufficient and powered by a battery. In this case, the data can be transmitted via a mobile communication channel, such as LoRa, for example, where the reduced amount of data is also helpful.

[0064] FIG. 6 shows a flow diagram 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 average fill height of the bulk material below the first region is calculated, and in step 604, the volume and/or average fill height of the bulk material below the second region is calculated. In step 605, the calculation variables (volumes/fill heights) are transmitted to an external control and evaluation unit, which can then visualize the transmitted data.

[0065] In particular, the information to be transmitted can be reduced to the essential silo areas. These are, for example, areas in which a change has taken place. The division of the areas can depend on the geometry of the silo and on the customer requirements, such as size, shape, inlets, and outlets.

[0066] The geometry of the segments is basically selectable. Communication can take place via a simple data channel, such as HART, or, alternatively, via a wireless interface. From the history data, the silo utilization can be monitored and optimized. For example, it can be determined whether a particularly large amount of bulk material is being removed via an outlet of the silo. It can also be determined if an outlet is clogged, for example, because the level measuring device determines that the volume in the area associated with the outlet never goes below a certain amount.

[0067] By evaluating the history data of the areas individually and in combination with other areas, buildup can be detected, tunneling can be detected, one-sided loading can be detected, and dead zones can be detected.

[0068] 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. It should further be noted that features or steps that have been described with reference to any 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 regarded as limitations.