Patent Grant
11953364
This patent application claims priority to German Patent Application 102019121378.9, filed on Aug. 7, 2019.
No federal government funds were used in researching or developing this invention.
Not applicable.
Not applicable.
The invention is a fill level measuring arrangement and method for operating a fill level measuring arrangement
From the prior art, various measuring arrangements are known for measuring fill levels or point levels in containers. For the sake of simplicity, only fill level measuring arrangements are discussed in the following, but all statements refer to fill level as well as point level measuring arrangements.
In order to be able to carry out maintenance work on fill level sensors during operation, isolating devices such as ball valves are used during the installation of the sensors in container connections. As a result, the sensor can be completely separated from the process without interrupting it. This leads to the sensor (fill level and point level) providing a presumably valid measurement value, although the isolating device is completely closed or only partially open. However, the measurement value can be negatively influenced by the (partially) closed isolating device.
In particular with foaming media, but also with measuring arrangements with strong movement of the medium, e.g. by stirring instruments or inflows, a fill level or point level measurement can be made significantly more difficult due to the foam or wave formation. In such cases, an arrangement of the measuring instrument in a bypass is often utilized, because it is best able to rectify the aforementioned problems. In addition, a fill level measuring instrument housed in the bypass can also be protected against mechanical effects.
A bypass is an additional vessel attached to the outside of the container, which is usually designed in the form of a tube. Generally, the tube is connected to the container at the lower end as well as at the upper end by means of a container connection, and the position of the upper and lower container connection also gives the maximum measuring range for the fill level. The connection to the upper end serves to equalize pressure. Container and bypass thus form a system of “communicating tubes,” for which reason the fill level in the tube is always equal to the container.
A measuring arrangement with a container 1 and a bypass 3 arranged on the container 1, as known from the prior art, is shown in
The measuring arrangement 100 according to the exemplary embodiment shown in
The bypass 3 is connected to the container 1 by means of two container connections 5. In order to not have to empty the complete container 1 but rather only the bypass 3 for work at the bypass 3, two valves 7, which are designed as isolating valves in the present case, are arranged between the container 1 and the bypass 3. If work must be carried out on the bypass 3, the valves 7 can be closed and thus the bypass 3 can be separated from the container 1.
Both in the case of measurements in bypass systems as well as for other measuring arrangements in which the sensor can be separated from the process by means of a container connection with an isolating device, the quality and reliability of the measurement depend upon the consistency of the container connections. If one of the container connections is closed, e.g. by an isolating valve or sedimentation, there is thus no longer a connection to the main process in the container, and the measured fill level in the bypass loses its validity. A fill level sensor that is arranged in the bypass, e.g. a continuously measuring fill level sensor, will continue to output a measurement value, because the process medium is still in the bypass; however, changes to the fill level in the container have only a delayed or reduced affect, or none at all, on the fill level in the bypass, such that the measurement results are no longer accurate.
In addition, there may be a safety risk if, for example, one of the container connection lines was not reopened after maintenance. Thus, the principle of the communicating tubes of a bypass system no longer functions. Previously, in the case of a closed isolating valve, the maintenance personnel have had to recognize that the measurement value of the fill level measuring instrument in the bypass no longer corresponds to the actual fill level in the container. However, because the fill level sensor outputs a valid measurement value that does not correspond to the actual fill level in the container, there can be significant problems with the monitored processes.
The same applies to other measuring arrangements in which the sensor can be separated from the process by means of a container connection with an isolating device if a container connection has been clogged by sedimentation in the process.
It is the objective of the present invention to provide a measuring arrangement that overcomes the disadvantages known from the prior art.
This objective is attained with a measuring arrangement having the features as described herein.
In a preferred embodiment, a measuring arrangement (100) for measuring a fill level in a container with a measuring instrument (9), in particular a fill level or point level measuring instrument, wherein the measuring instrument (9) is connected to the container by means of at least one container connection, characterized by a monitoring device (11) for monitoring a consistency of the at least one container connection (5) that is coupled with the measuring instrument (9).
In another preferred embodiment, the measuring arrangement (100) as described herein, characterized in that the monitoring device (11) has one measuring device (13) for each container connection (5).
In another preferred embodiment, the measuring arrangement (100) as described herein, characterized in that the measuring devices (13) have a radio module (15) for wireless communication with the measuring instrument (9).
In another preferred embodiment, the measuring arrangement (100) as described herein, characterized in that the measuring devices (13) have an integrated energy supply (19).
In another preferred embodiment, the measuring arrangement (100) as described herein, characterized in that the energy supply (19) has an energy harvesting module (21).
In another preferred embodiment, the measuring arrangement (100) as described herein, characterized in that a valve (7) is arranged between the container connections (5) and the bypass (3) and the energy harvesting module (21) is coupled with the valve (7) in such a way that it generates energy due to a movement of the valve (7).
In another preferred embodiment, the measuring arrangement (100) as described herein, characterized in that the measuring devices (13) transmit a valve position of the valve (7) to the measuring instrument (9).
In another preferred embodiment, the measuring arrangement (100) as described herein, characterized in that there is a communication between the monitoring device (11) and the measuring instrument (9) by means of a reliable transmission protocol.
In another preferred embodiment, the method for operating a measuring arrangement (100) for measuring a fill level or point level in a bypass (3) of a container (1) with a measuring instrument (9), in particular a fill level or point level measuring instrument, wherein the bypass (3) is connected to the container (1) by means of at least two container connections (5) and has a monitoring device (11) for monitoring a consistency of the container connections (5) that is coupled with the measuring instrument (9), having the following the steps:
In another preferred embodiment, the method as described herein, characterized in that the monitoring device (11) determines a status of the container connections (5) in an event-oriented manner and transmits a status message to the measuring instrument (9).
In another preferred embodiment, the method as described herein, characterized in that the monitoring device (11) cyclically determines a status of the container connections (5) and transmits a status message to the measuring instrument (9).
A measuring arrangement according to the invention, in particular a fill level or point level measuring arrangement for measuring a fill level or point level in a bypass of a container with a fill level or point level measuring instrument, wherein the bypass is connected to the container by means of at least two container connections, is characterized by a monitoring device for monitoring a consistency of the container connections that is coupled with the fill level measuring instrument.
Such a monitoring device allows a consistency of the container connection(s) to be monitored and a status of the container connections to a superordinate unit, e.g. a master display, a programmable control unit, or similar to be realized without additional cabling effort between the superordinate unit and the monitoring device. In this way, it can be ensured that the measurement values determined by the fill level or point level measuring instrument also reflect the situation in the container.
The term status should include status messages as well as fault messages, such as the signaling of a maintenance need or an error message.
“Coupled” in the sense of the present application does not mean that a permanent connection between the coupled devices must be present. In addition to a cabled connection, a radio connection is also meant here, in particular an asynchronous radio connection in which a transmission takes place as soon as data is available. In the present case, this means that a changed status of the consistency is transmitted as soon as it is detected. In a preferred embodiment, the monitoring device has one measuring device for each container connection. This means that each container connection can be monitored separately and a status can be determined, for example, for each container connection in the case of a design with two container connections. Such a measuring device can be implemented in a variety of ways, e.g. a rotation angle sensor, a position sensor, or a reed switch for determining a valve position can be used. Alternatively, an ultrasound sensor or a radiometric measuring method can be used to monitor a wall thickness of the container connections for sedimentation.
A particularly simple installation is possible when the measuring devices have a radio module for wireless communication with the measuring instrument. In this way, without additional transmission lines between the measuring devices and the measuring instrument, the status of the container connections can be transmitted. An additional cabling and installation effort is thus minimized. The radio module and a corresponding receiving device can communicate, for example, according to one of the standards Bluetooth, WLAN, LoRa, or Wireless HART. In order to enable an asynchronous radio connection, the receiving device on the measuring instrument should be supplied with electricity and should additionally be equipped with a battery or accumulator, so that a transmission can occur even in a power-free state.
If the measuring devices have an integrated power supply, supply lines for the measuring devices can also be omitted, and the cabling and installation effort can thus be reduced even further.
The smaller the additional cabling and installation effort is, the simpler the installation of monitoring devices with measuring devices can be for all container connections, for example of a bypass system, retrospectively.
A power supply of the measuring devices can occur, for example, in a battery-based manner and/or have an energy harvesting module. Battery-based measuring systems can now have operating times of up to ten years even with radio modules, so that the proposed monitoring arrangement can also be operated largely maintenance-free. An energy harvesting module can further support or completely replace a battery-based operation.
“Energy harvesting” refers to the obtaining of small quantities of electrical energy from the environment by means of energy converters. For example, these can be energy converters for obtaining electrical energy through energy conversion from kinetic, thermal, and electromagnetic energy existing the environment.
When, for example, an isolating valve is arranged between each of the container connections and the bypass and the energy harvesting module is arranged on the valve in such a way that it is possible to generate energy based upon the movement of the valve, then energy can also be generated for the determination and transmission of the status of the container connections, i.e. the status of the valves in the present case, whenever the valve is activated.
For example, the measuring devices can then transmit a valve position of the isolating valve to the measuring instrument. In this way, a valve position of the isolating valves is always known to the measuring instrument, and a corresponding status message can be transmitted along with the measurement values of the measuring instrument to the superordinate unit.
Preferably, communication between the monitoring device and the measuring instrument takes place by means of a reliable transmission protocol.
A “reliable transmission protocol” in the sense of the present application means that it is ensured that the state of the consistency of the container connections determined by the monitoring device or the measuring devices is safely received at the fill level measuring instrument. This can occur, for example, by means of a connection assembly with a handshake procedure and/or a confirmation of receipt and/or of the transmitted state by a so-called acknowledgement.
In this way, it is ensured that the information regarding the status of the container connections is reliably transmitted to the measuring instrument. This ensures that the measurement values determined by the measuring instrument are correctly evaluated by the measuring instrument and the superordinate unit.
A method according to the invention for the operation of a measuring arrangement for measuring a fill level or point level in a bypass of a container with a measuring instrument, in particular a fill level or point level measuring instrument, wherein the bypass is connected to the container by means of at least two container connections and which has a monitoring device for monitoring a consistency of the container connections that is coupled with the fill level measuring instrument, comprises the following steps:
First, a measurement, i.e. a fill level or point level measurement, is performed by means of the fill level or point level measuring instrument. In order to verify the validity of the determined measurement results, a status of the container connections is checked. Such an inspection can include both the requirement of a current status in the monitoring device as well as the retrieval of the last determined status from a memory. The second variant is particularly advantageous, because in this way the monitoring device must only transmit a message to the measuring instrument when a status change actually occurs, and thus energy can be saved. This is particularly advantageous in the case of battery operation of the monitoring device and/or the measuring devices.
A transmission of the status only when a status change occurs can also be called “event-oriented.” In particular, if an energy harvesting module is used for the energy supply, this is advantageous because, for example, energy for the energy harvesting module can be obtained through the change in the valve position.
In addition or alternatively, the monitoring device can cyclically determine a status of the container connections and transmit a status message to the measuring instrument. In particular, if a status change is not triggered by a movement as in the case of a valve, a cyclical transmission of the status of the container connections can be sensible. However, even in the case of an event-oriented transmission of the status, an additional cyclical transmission can be sensible in order to ensure that the status present in the measuring instrument is also current.
With the present invention, an increased level of security for the user and the monitored process is achieved. The measuring instrument detects independently whether, for example, isolating valves are open or closed or a tube diameter has changed. As a result, human errors in the previously manual process and errors caused by sedimentation in the process are avoided.
A simple retrofitting to existing containers is possible, because no time-consuming and costly conversion of the container or the bypass system is necessary. Further, no time-consuming calibration must be carried out on a superordinate unit, because only the measurement value of the sensor must be input, as is the case with any other measuring point. The plausibility check using the status of the container connections can be carried out completely in the measuring instrument.
All aforementioned embodiments apply equally for bypass systems and for measuring arrangements in which the sensor can be separated from the process by means of a container connection with an isolating device. For example, this can be a measuring arrangement with a radar fill level measuring instrument, in which the radar fill level measuring instrument can be separated from the process area by means of an isolating device, for example an isolating valve, an isolating slider, or a flap.
Detailed Description of the Figures
The assembly shown in
The measuring arrangement 100 shown in
In the exemplary embodiment shown in
In the exemplary embodiment shown in
The arrangement shown in
The measuring device 13 shown is supplied with energy by means of an internal energy supply 19, which in the present case is designed as a battery. Through a cyclical operation of the measuring device 13 at specified time intervals, it has only a very low energy consumption, such that a battery lifetime of up to ten years can be achieved for such a measuring device.
On the container 1 shown in
The slider 7 is equipped with a measuring device 13 with a radio module 15, so that a position of the slider 7 on the measuring instrument 9, which is similarly equipped with a radio module, can be further reported. From the measuring instrument 9, the determined measurement values and the status of the slider 7 are forwarded to the PLC used as the superordinate unit 99.
Unless indicated otherwise, identical reference numbers in the figures identify identical components with the same function. The terms drive unit and drive are used interchangeably herein.
The references recited herein are incorporated herein in their entirety, particularly as they relate to teaching the level of ordinary skill in this art and for any disclosure necessary for the commoner understanding of the subject matter of the claimed invention. It will be clear to a person of ordinary skill in the art that the above embodiments may be altered or that insubstantial changes may be made without departing from the scope of the invention. Accordingly, the scope of the invention is determined by the scope of the following claims and their equitable equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2019 121 378.9 | Aug 2019 | DE | national |
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| Entry |
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| GPTO office action for related German application 10 2019 121 378.9 dated May 25, 2020. |
| Number | Date | Country | |
|---|---|---|---|
| 20210041285 A1 | Feb 2021 | US |
