KR20190130475A - Level indicators, and high-level alarm apparatus - Google Patents

Abstract

The present invention provides a level indicator (1) having multiple transmitting and receiving modules with simple composition, to monitor a liquid surface of a tank storing a liquid. The level indicator (1) includes: the multiple transmitting and receiving modules (11, 12) independent from each other and transmitting and receiving a radar signal; a transducer (20) connected to the multiple transmitting and receiving modules and converting a transmitted radar signal transmitted from the multiple transmitting and receiving module into a radar wave; and a wave guide (30) propagating the radar waves toward the liquid surface and propagating the radar waves reflected from the liquid surface to the transducer. The transducer converts the radar waves transmitted by the wave guide into a reflected radar signal and inputs the reflected radar signal in the multiple transmitting and receiving modules. At least one among the transmitting and receiving modules measures the height of the liquid surface based on the transmitted radar signal and the reflected radar signal.

Description

Level indicators, and high-level alarm apparatus

The present invention relates to a liquid level meter and a high level liquid level alarm device.

Background Art A liquid level meter for measuring the height of a liquid level of a tank storing liquid or the like is known. Moreover, a high level liquid level alarm apparatus which detects that the liquid level has reached a predetermined height and issues an alarm is known.

In a full wave type liquid level meter and a high level liquid level alarm device, that is, a radar signal transmitted from a transmission / reception module is converted into an electromagnetic wave, that is, a radar wave by a transducer. This radar wave is propagated toward the liquid level, reflected from the liquid level, and inversely converted into a radar signal by the transducer. The transmission / reception module estimates the height of the liquid level based on the inversely converted radar signal. Conventionally, in preparation for the failure of the liquid level gauge and the high level liquid level alarm device, a plurality of liquid level meters and the high level liquid level alarm device have been mounted in one housing to monitor one liquid level. However, it was necessary to set it as the structure provided with all the components other than the housing which accommodates each apparatus.

Therefore, a liquid level meter having a plurality of transmission and reception modules and a high level liquid level alarm device have been required with a simple configuration.

Patent Literature 1 discloses a liquid level height of a liquid including a radar antenna, a plurality of radar measurement channels that are functionally independent, and a feeder that is connected to the plurality of channels and transmits an electromagnetic wave signal from the plurality of channels to the antenna. A system for measuring is disclosed. However, since electromagnetic signals are transmitted from a plurality of channels, it is obvious that this system includes a transducer for each channel.

Patent Literature 2 discloses a configuration in which waves that can be distinguished from each other according to characteristics of each channel are transmitted through the same antenna by different radar measurement channels. However, there is no disclosure as to how waves from multiple radar measurement channels are transmitted and received from one antenna.

Patent Literature 3 discloses a high level liquid level alarm device in which a first liquid level alarm unit and a second liquid level alarm unit are connected to a common waveguide 30. However, it is described that radio waves are transmitted from the first liquid level alarm unit and the second liquid level alarm unit, and there is no disclosure about the configuration in which a plurality of liquid level alarm units are connected to one transducer.

Patent Document 1: US Patent No. 6765524 Patent Document 2: Japanese Patent Publication No. 2003-503724 Patent Document 3: Japanese Patent No. 6211725

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid level gauge having a plurality of transmission and reception modules with a simple configuration in liquid level monitoring of a tank storing liquid or the like.

The liquid level meter according to the present invention includes a plurality of transceiving modules which transmit and receive radar signals and a plurality of transceiving modules connected to the plurality of transceiving modules, and converting the transmission radar signals transmitted from the plurality of transceiving modules into radar waves. And a waveguide that propagates the radar wave toward the liquid surface and propagates the radar wave reflected on the liquid surface to the transducer, wherein the transducer is the radar wave transmitted by the waveguide. Is converted into a reflection radar signal and input to the plurality of transmission / reception modules, and at least one of the transmission / reception modules measures the height of the liquid level based on the transmission radar signal and the reflection radar signal.

According to the present invention, it is possible to provide a liquid level meter having a plurality of transmission and reception modules with a simple configuration.

1 is a longitudinal sectional view showing an embodiment of a liquid level meter according to the present invention.
2 is a functional block diagram of the liquid level gauge.
3 is a functional block diagram showing a second embodiment of a liquid level meter according to the present invention.
4 is a functional block diagram showing a third embodiment of the liquid level meter according to the present invention.
5 is a functional block diagram showing a fourth embodiment of the liquid level meter according to the present invention.
6 is a functional block diagram showing a fifth embodiment of the liquid level meter according to the present invention.

Liquid level meter (1)

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of the liquid level meter which concerns on this invention is described, referring drawings.

In FIG. 1, the liquid level meter 1 is an apparatus which measures the height of the liquid etc. as a to-be-measured object stored in the tank, or determines whether a liquid level exists in a predetermined height.

As shown in FIG. 1, the liquid level meter 1 includes a housing 10, a liquid level measurement module 11, a liquid level alarm module 12, a transducer 20, and a waveguide 30. The liquid level measurement module 11 and the liquid level alarm module 12 are examples of transmission and reception modules.

The housing 10 is a substantially cylindrical member which holds the liquid level measurement module 11 and the liquid level alarm module 12, each operation circuit, etc. The housing 10 is fixed to the upper surface of the tank which is not shown in figure. The housing 10 and the inside of the housing 10 are shielded from the liquid in the tank except for the waveguide 30. The upper part of the housing 10 is sealed by the lid 40.

On the lower end of the housing 10, a substantially circular mounting flange 41 is fixed by means of welding or the like in plan view, and the mounting flange 41 is a bottom plate of the housing 10. A hole is drilled in the mounting flange 41, and a waveguide 30, which will be described later, penetrates the hole and protrudes out of the housing 10.

In addition, the mounting flange 41 may be molded integrally with the housing 10.

The liquid level measurement module 11 is a module for measuring the height of the liquid level by a radio wave method. As shown in FIG. 2, the liquid level measuring module 11 includes a transmitting unit 111, a receiving unit 112, and a measuring unit 113 of high frequency energy, that is, a radar signal. The transmitter 111 and the receiver 112 are connected to the transducer 20. The transmitter 111 transmits a radar signal toward the transducer 20. The receiver 112 receives the radar signal from the transducer 20. The measurement unit 113 includes a radar signal (hereinafter referred to as a "transmission radar signal") transmitted from the transmitter 111 and a radar signal (hereinafter referred to as a "reflection radar signal") received by the receiver 112. Based on this, the height of the liquid level is calculated.

The liquid level warning module 12 is a module that determines whether or not the liquid level has reached a predetermined height by a radio wave system. The liquid level alarm module 12 includes a radar signal transmitter 121, a receiver 122, and a determiner 123. The transmitter 111 and the receiver 112 are connected to the transducer 20. The transmitter 121 transmits a transmission radar signal toward the transducer 20. The receiver 122 receives the reflected radar signal from the transducer 20. The determination unit 123 determines whether the liquid level has reached a predetermined height based on the transmission radar signal and the reflection radar signal.

The liquid level measurement module 11 and the liquid level alarm module 12 are modules independent from each other, and are directly connected to a plurality of ports of the transducer 20 by separate cables, respectively.

The transducer 20 is a structure which converts the transmission radar signal transmitted from the liquid level measurement module 11 and the liquid level alarm module 12 into a radar wave. The transducer 20 includes a plurality of input / output ports 21 and 22 corresponding to the number of the liquid level measurement module 11 and the liquid level alarm module 12, and a radar wave generated by converting an input transmission radar signal. It has a radar wave transceiver 23 for transmitting toward the inside of the tube of the waveguide 30 and receiving the radar wave reflected by the liquid surface and transmitted inside the tube. In the present embodiment, since the total number of the transmission / reception modules is two, the input / output ports of the transducer 20 are two, but the transducer having three or more input / output ports may be used.

As shown in FIG. 1, the waveguide 30 is a hollow cylinder extending downward from the bottom surface by a predetermined length perpendicular to the mounting flange 41 constituting the bottom surface of the housing 10, In this embodiment, it is a cylinder. The waveguide 30 extends in the liquid surface direction at the time of installation. The lower end of the waveguide 30 is open, the lower end is immersed in the liquid in the tank, and the liquid can penetrate inside the tube. The liquid level of the liquid penetrating into the inside of the pipe is the same as that of the liquid in the tank. The waveguide 30 propagates the radar wave transmitted from the transducer 20 toward the liquid level, and propagates the radar wave reflected by the liquid that has entered the waveguide 30 toward the transducer 20. The material of the waveguide 30 is metal, for example, and is stainless steel in this embodiment.

The waveguide 30 can be measured when the lower end is immersed in the liquid. The length of the waveguide 30 is arbitrary.

The liquid level measurement module 11 transmits the radar wave toward the liquid level inside the waveguide 30 through the transducer 20 and the waveguide 30, and based on the reflected radar wave reflected from the liquid level, the liquid level in the tank. Calculate the height of. Similarly, the liquid level alarm module 12 determines whether or not the liquid level in the tank has reached a predetermined height, that is, an alarm point. Information on the liquid level and whether or not the liquid level has reached the alarm point is appropriately displayed on the user interface. The user can grasp the height of the liquid level in the tank through the user interface.

The waveguide 30 does not transmit radar waves. Therefore, by propagating the radar wave inside the waveguide 30, the radar wave is not enlarged, and the radar wave can be propagated to the liquid level with little attenuation. Since the radar wave propagates only inside the waveguide 30, the radar wave does not reach and reflect the ladder, pump, etc. provided in the tank. That is, according to the liquid level meter and the liquid level warning device using a waveguide, the possibility of the false measurement by unintentional reflection is alleviated.

Since the waveguide 30 has a shape which does not diffuse in the horizontal direction compared with the horn antenna, it can be disposed in a narrow space.

According to the configuration in which the radar signals from the plurality of transmission / reception modules are converted into radar waves by one transducer, it is not necessary to include a plurality of transducers, thereby saving space, and the plurality of transmission / reception modules are simpler and inexpensive. Can be monitored.

In addition, the two transmission / reception modules may both be liquid level measurement modules, and both may be liquid level alarm modules. Two liquid level alarm modules, a transducer and a waveguide constitute a liquid level alarm device. According to the configuration in which the two transmitting / receiving modules measure the same liquid level or monitor the height of the liquid level, it can be determined that an abnormality has occurred when any one module produces different calculation results.

When both the transmitting and receiving modules are liquid level alarm modules, each of the transmitting and receiving modules 11 and 12 can monitor different liquid levels as alarm points. For example, the transmission / reception module 11 may be an overflow liquid level alarm module, and the transmission / reception module 12 may be set as a high level liquid level alarm module. The high liquid level alarm module is a unit for preliminarily warning that the liquid in the tank has exceeded a predetermined amount. The overflow liquid level alarm module is a module that alerts that the liquid level of the liquid in the tank has reached the limit exceeding the alarm point of the high liquid level alarm module.

The transmission / reception module 12 is a spare unit for the failure of the transmission / reception module 11 and may be non-energized in normal use. In this case, the transmission / reception module 12 detects a failure of the transmission / reception module 11 and starts operation. At that time, the transmission / reception module 12 can monitor the alarm point by sharing the information of the alarm point monitored by the transmission / reception module 11.

The transmission / reception module can distinguish whether the received reflection radar signal is a radar signal generated based on a transmission radar signal from the transmission / reception module or a radar signal generated based on a transmission radar signal from another transmission / reception module. For example, two transmission / reception modules may be configured to transmit and receive radar waves of different frequencies. In addition, two transmitting / receiving modules may predetermine timings of transmitting and receiving radar waves and transmit and receive alternately. In addition, the two transmitting / receiving modules respectively determine whether or not the radar wave is transmitted based on the radar signal from the other, and the own radar when the radar wave is not transmitted based on the radar signal from the other unit. You may comprise so that a radar wave based on a signal may be transmitted.

By the above-described configuration, it is possible to prevent the radar wave of one transceiver module from interfering with the other transceiver module.

The alarm points of the transmission / reception module 11 and the transmission / reception module 12 can be updated in software. The transmission / reception module 11 and the transmission / reception module 12 are connected to an upper control device (not shown) which stores respective alarm points. By updating the alarm points stored in the host controller, the alarm points of the transmission and reception modules 11 and 12 can be changed without performing a physical design change. With this configuration, it is not necessary to determine the size of the product in correspondence with the distance to alert. That is, the mass productivity of the apparatus is greatly improved.

The alarm points of the transmission and reception modules 11 and 12 may be stored in the host controller or may be stored in the transmission and reception modules 11 and 12.

The alarm point change of each transmission / reception module 11 and 12 may be updated manually, or may be comprised so that it may be changed automatically by the host controller. In addition, you may change the alarm point to monitor periodically. Specifically, liquid level A is performed in the first determination, liquid level B different from the liquid level A in the second determination, liquid level C different from the liquid level A and the liquid level B in the third determination, and the liquid level is determined. Repeat. In this case, it is possible to monitor the liquid level A, B and C with one transmission module. In this case, the periodic change of the alarm point can be easily realized by automatic change by the host controller.

In this way, the alarm point is automatically changed, so that a plurality of alarm points can be monitored by one transmission / reception module. In addition to the high liquid level alarm and the overflow alarm, the type of alarm may be a notice alarm having a lower liquid level than the alarm point of the high liquid level alarm. By enabling a warning alarm, the liquid level can be monitored more reliably.

In addition, with the configuration in which the alarm point is automatically changed, even if one transmission / reception module fails, the other transmission / reception module can monitor the alarm point to be monitored by the failed transmission / reception module. For example, upon detecting that the transmission / reception module 11 has failed, the transmission / reception module 12 alternately determines an alarm point of the transmission / reception module 11 and an alarm point of the transmission / reception module 12. The transmission / reception module 12 may operate as a preliminary device of the transmission / reception module 11. In contrast, the transmission / reception module 11 may operate as a preliminary device of the transmission / reception module 12.

Operation of each transceiver module

The transmission and reception modules 11 and 12 alternately transmit radar signals to the transducers at regular time intervals. Each transmitting / receiving module detects whether another transmitting / receiving module has transmitted a radar signal by a detector (not shown), and does not transmit a radar signal when another transmitting / receiving module is transmitting a radar signal. Accordingly, the transducer 20 alternately converts radar signals transmitted from the transmission and reception modules 11 and 12 into radar waves and transmits the radar waves toward the liquid level. In other words, the transmission / reception modules 11 and 12 monitor two alarm points with one waveguide by time division control.

Each transmitting / receiving module 11, 12 may have a predetermined timing for transmitting the radar signal so as to transmit the radar signal when the other transmitting / receiving module does not transmit the radar signal. At this time, each transmission / reception module has a status sharing function for sharing the status of whether the other transmission / reception module has transmitted the radar signal. This status sharing function is realized by communication means between a plurality of transceiver modules mounted. Specifically, the optical coupling method using a photocoupler or the like, or the electronic coupling method using an insulation transformer determines whether other transmission / reception modules are transmitting a radar signal.

The transmission and reception modules 11 and 12 may monitor two alarm points with one waveguide 30 by frequency division control. That is, the frequency of the radar wave generated by converting the radar signal transmitted by the transmission / reception module 11 and the frequency of the radar wave generated by converting the radar signal transmitted by the transmission / reception module 12 may be different. . In this case, since the radar waves transmitted by the transmission / reception modules 11 and 12 do not interfere with each other, the two transmission / reception modules can monitor different alarm points at the same time.

● Calibration function of liquid level gauge (1)

The liquid level meter 1 can be comprised so that the reference object which can determine a reference position by an electromagnetic wave is provided, and has a function which always compares and corrects a reference position and a measurement position in operation. To realize this function, for example, a reference object, which is pre-positioned relative to the transmission / reception modules 11 and 12, is installed in the space in the tank. As the reference object, for example, a flat object having a reflective surface orthogonal to the measurement direction of the liquid level meter 1 can be used. The shape of the flat object can be appropriately set.

The position of the reference object, that is, the reference position, with respect to the transmission and reception modules 11 and 12 is stored in the host controller or the like.

The reference object is disposed within the detection range of the transmission / reception modules 11 and 12 in the tank. As a form of arrangement | positioning, a reference object is installed in the waveguide 30, for example. Since the reference material is provided in the waveguide 30, the reference material can be disposed in the tank only by providing the liquid level gauge 1. That is, compared with the case where the reference material is installed independently of the liquid level gauge 1, the work of installing the reference material in the tank becomes unnecessary.

The waveguide 30 itself may be a reference object. That is, the transmission / reception modules 11 and 12 may measure the electromagnetic wave reflected from the lower end of the waveguide 30 with the lower end of the waveguide 30 as a reference position.

The transmission and reception modules 11 and 12 periodically measure the actual position with the reference object and compare it with the reference position. When the measurement position and the reference position are different, the liquid level meter 1 corrects the measurement result based on the measurement position and the reference position. When the measurement position differs greatly from the reference position, the liquid level meter 1 issues an alarm through the user interface to notify the user that the transmission / reception modules 11 and 12 may not operate correctly.

Liquid level meter (2)

2nd Embodiment of the liquid level meter which concerns on this invention is demonstrated centering on a different part from 1st Embodiment. The liquid level meter of the second embodiment differs from the first embodiment in that a plurality of transmission and reception modules are connected to the transducer via a distribution synthesizer.

As shown in FIG. 3, the transmission / reception module 11 and the transmission / reception module 12 of the liquid level meter 101 are connected to a distribution synthesizer 24.

The distributing synthesizer 24 is a member having a plurality of first ports 241 and 242 on one side and one second port 243 on the other side. The distribution synthesizer 24 synthesizes the energy input to the first ports 241 and 242 and outputs the energy to the second port 243. In addition, the distribution synthesizer 24 distributes the energy input to the second port 243 to the first ports 241 and 242 and outputs it.

The first ports 241 and 242 are connected to the transmission and reception modules 11 and 12, respectively. The second port 243 is connected to the transducer 20. The transmission radar signals output from the transmission units 111 and 121 of the transmission and reception modules 11 and 12 are input to the distribution synthesizer 24 from the first ports 241 and 242 and output from the second port 243. The radar signal of the reflected wave, which is converted and generated by the transducer 20, is input to the distribution synthesizer 24 from the second port 243, and receives the reception units 112 and 122 of the transmission and reception modules 11 and 12. Is entered.

The transmission / reception modules 11 and 12 are concepts including a liquid level alarm module and a liquid level measurement module, one of which may be a liquid level measurement module, the other of which may be a liquid level alarm module, or both may be a liquid level measurement module or a liquid level alarm module. .

According to this configuration, even if the input / output port is one transducer 20, it is possible to transmit and receive radar signals with a plurality of transmission / reception modules.

Liquid level meter (3)

3rd embodiment of the liquid level meter which concerns on this invention is demonstrated centering on a different part from 1st embodiment. The liquid level meter of the third embodiment differs from the first embodiment in that three or more transmission / reception modules are provided. The transceiving module in the following description may be any of a liquid level measurement module and a liquid level alarm module.

As shown in FIG. 4, the liquid level meter 102 includes a transducer 20 having two input / output ports 21, 22. The input / output port 21 is connected to the transmission / reception module 11. The input / output port 22 is connected to the second port 243 of the distributing synthesizer 24. The first ports 241 and 242 of the distribution synthesizer 24 are connected to the transmission and reception modules 12 and 13, respectively.

In addition, as a fourth embodiment, as shown in FIG. 5, the liquid level meter 103 includes a second port 243, 253 of the distributing synthesizer 24, 25 at each of the two input / output ports 21, 22. Connected. Transmitting and receiving modules 11, 12, 13, and 14 are connected to the first ports 241, 242 of the distributed synthesizer 24 and the first ports 251, 252 of the distributed synthesizer 25, respectively.

In addition, as a fifth embodiment, as shown in FIG. 6, the dispensing synthesizer 24 is connected to the input / output port 21 of the transducer 20, and the liquid level meter 104 is formed of the dispensing synthesizer 24. One port 241, 242 is connected to the second ports 253, 263 of the different distributing synthesizers 25, 26, respectively.

According to this structure, by combining the transducer 20 which has two input / output ports, and the distribution synthesizer which has two 1st ports, the radar signal from three or more transmission / reception modules is converted into a radar wave by one transducer. Thus, it is possible to propagate from one waveguide toward the liquid level.

1 level gauge
11 Liquid Level Measurement Module (Transmission / Reception Module)
12 Liquid level alarm module (transmit and receive module)
20 transducer
30 waveguide

Claims (6)

A plurality of transmission and reception modules independent of each other, for transmitting and receiving radar signals,
A transducer connected to the plurality of transmission / reception modules and converting a transmission radar signal transmitted from the plurality of transmission / reception modules into a radar wave;
A waveguide for propagating the radar wave toward the liquid surface, and propagating the radar wave reflected on the liquid surface to the transducer,
The transducer converts the radar wave transmitted by the waveguide into a reflected radar signal and inputs the radar wave to the plurality of transmission / reception modules,
At least one of the transmission / reception module measures a height of the liquid level based on the transmission radar signal and the reflection radar signal. The method according to claim 1,
And a distribution synthesizer for distributing and synthesizing radar signals, wherein the plurality of transmission / reception modules are connected to the distribution synthesizer, and the radar signals transmitted from the plurality of transmission / reception modules are input to the transducer through the distribution synthesizer. , Level gauge. The method according to claim 1,
The transducer has a plurality of ports, and the plurality of ports are connected to each of the plurality of transmit / receive modules, and radar waves generated by the transducer are input to each of the plurality of transmit / receive modules through the plurality of ports. Level meter. The method according to claim 1,
The transceiving module is capable of distinguishing whether a received reflection radar signal is a radar signal generated based on a transmission radar signal from the transmission / reception module or a radar signal generated based on a transmission radar signal from another transmission / reception module. . The method according to claim 1,
At least one of the plurality of transmission and reception modules is a liquid level measurement module for measuring the height of the liquid level, and the other at least one is a liquid level alarm module that detects that the liquid level has reached a predetermined height and issues an alarm. A plurality of transmission and reception modules independent of each other, for transmitting and receiving radar signals,
A transducer connected to the plurality of transmission / reception modules and converting a transmission radar signal transmitted from the plurality of transmission / reception modules into a radar wave;
A waveguide for propagating the radar wave toward the liquid level and propagating the radar wave reflected to the liquid level to the transducer,
The transducer converts the radar wave transmitted by the waveguide into a reflected radar signal and inputs the radar wave to the plurality of transmission / reception modules,
At least one of the transmitting and receiving modules, the high level liquid level alarm device for detecting that the liquid level has reached a predetermined height.

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