JP2011145142A - Bubble type liquid level gauge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bubble type liquid level gauge which is simply constructed by using a sounding pipe and general service air, and allows easy portability and efficient cargo handling. <P>SOLUTION: The liquid level gauge has: an air supply pipe 5 into which compressed air is supplied; a pressure sensor for measuring a pressure in the air supply pipe 5; and a display part 20 displaying a liquid level in a tank, based on a detection signal of the pressure sensor. The air supply pipe 5 is portable and windable, inserted into a sounding pipe 6 hanging within a tank from upside of the tank; a general service air pipe 3 installed in a ship is used as a compressed air supply source; the general service air pipe 3 and the air supply pipe 5 are connected by having an attachable part 21 with the general service air pipe 3 and an attachable part 22 with the air supply pipe 5; and a portable detector body 1 equipped with the pressure sensor and the display part 20 displaying a liquid level in the tank based on a detection output of the pressure sensor is provided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention particularly relates to a portable bubble level gauge that is suitable as a level gauge for a ballast tank of a ship and can realize an efficient ballast operation.

  Ships, especially container ships, tankers, and cargo ships such as bulk carriers, are equipped with ballast tanks for maintaining balance by ensuring the draft in light load for safe voyage and adjusting the weight balance with the load. The ballast water is supplied to and discharged from the ballast tank according to the status of cargo handling at the port. In order to efficiently carry out cargo handling, it is desirable that the amount of ballast water in each ballast tank is accurately grasped in real time. In a ship equipped with a liquid level gauge in the ballast tank, the ballast amount can be measured quickly and accurately by the liquid level gauge to support efficient cargo handling.

  However, relatively small ships, such as bulk carriers (commonly called “bulk carriers”), usually do not have a level gauge in their ballast tanks to reduce costs, making efficient cargo handling difficult. Is in the situation. In particular, when loading cargo, the ballast water is drained as the loading progresses. It is necessary to finely adjust the drainage pump while measuring.

  Therefore, manual ship sounding tapes (commonly called “sounding tapes”) are used on ships that are not equipped with a level gauge. The sounding tape is a tape that hangs down from the top of the tank, and measures the liquid level by measuring the wet position after reaching the liquid level. A sounding pipe (also referred to as “sounding pipe”) for hanging the sounding tape is installed from the ceiling of the tank toward the bottom of the tank, and the sounding tape is inserted into the sounding pipe. When the sounding tape reaches the bottom of the ballast tank, the color of the portion submerged in the ballast water changes. Therefore, the level of the ballast water surface can be measured by measuring the tape length to the position where the color has changed.

  However, the measurement of the liquid level with the sounding tape is inefficient. This inefficient liquid level measurement must be frequently performed in the above-mentioned preparation stage, and the liquid level measurement is increasingly made inefficient. In addition, when measuring the liquid level with a sounding tape in the rain, it is difficult to distinguish whether the sounding tape is wet by rain or wet by rain, so accurate measurement is possible. There is a difficulty that can not be done.

  On the other hand, as a part of improving the berth utilization rate, some ports set a minimum loading rate standard based on the size of cargo to be loaded. If this rate is not met, a warning is issued by the terminal operator, and unless the improvement plan submitted by the shipowner or operator is approved in response to the warning, strict measures are taken not to allow further port entry. The handling time is restricted by the loading rate standard, and the ballast discharge time is limited accordingly, and if the ballast cannot be discharged within the handling time, the handling will be interrupted. As a result, it has been pointed out that many operating ships are below the loading rate and lack performance. Many of the performance deficiencies are caused by the skill of the crew, including the level of skill in measuring the liquid level using the sounding tape. However, it is also necessary to consider the lack of hardware that is not equipped with a ballast console or ballast level gauge (ballast level gauge) that can observe the liquid level of each ballast tank sequentially.

  By the way, the ballast tank of ships of a certain size or more is equipped with a level gauge that can grasp the level of ballast one by one. There are various methods for measuring the liquid level meter. For example, a bubble-type liquid level as described in Patent Document 1 is one measurement method. The bubble-type liquid level gauge has an air supply pipe in which at least the lower end is immersed in the liquid in the tank, a compressed air supply source that supplies compressed air into the air supply pipe, a pressure sensor that measures the atmospheric pressure in the air supply pipe, And a display unit for displaying the liquid level in the tank based on the detection signal of the pressure sensor. When compressed air is supplied from the compressed air supply source until compressed air leaks from the lower end portion of the supply pipe, the pressure in the supply pipe changes based on the liquid level in the tank. The compressed air supply source is a dedicated compressed air supply source provided for use in the bubble-type liquid level gauge, and is a relatively clear air supply source.

Japanese Patent No. 3992153

  A ship not equipped with a liquid level gauge for measuring the liquid level of the ballast tank includes a sounding tube for hanging the sounding tape toward the bottom of the ship or the tank. Moreover, not only a comparatively small ship but the ship generally has a miscellaneous air pipe for supplying compressed air called “chore air” being routed around the deck.

  Therefore, the present invention can easily configure a bubble-type liquid level gauge using the above-described depth measuring tube and chores air, and can be easily carried, for example, equipped with a liquid level gauge for a ballast tank. An object of the present invention is to provide a bubble-type liquid level gauge that can easily measure the liquid level even on a ship that has not been operated, and can thus contribute to the efficiency of cargo handling at a port.

The present invention
An air supply pipe to which compressed air is supplied from a compressed air supply source, a pressure sensor for measuring the air pressure in the air supply pipe, and a display unit for displaying a liquid level in the tank based on a detection signal of the pressure sensor. It is a bubble type liquid level gauge constituted by having,
The air supply pipe is a portable air supply pipe that can be inserted into and taken up from a depth measuring pipe hanging from the upper part of the tank into the tank,
As the compressed air supply source, a miscellaneous air pipe piped to a ship is used,
By having the attachment / detachment portion with the air supply pipe and the attachment / detachment portion with the air supply pipe, the air supply pipe and the air supply pipe can be relayed, and the pressure sensor and the detection output of the pressure sensor The main feature is that it includes a portable detector body having a display unit for displaying the liquid level.

  The detector main body is portable, and the air supply pipe can also be wound and portable, so that it can be carried anywhere. Carry the detector body and the air supply pipe over the tank where the liquid level needs to be measured, insert the air supply pipe into the depth measuring pipe and let the lower end dip into the liquid and hang down until it reaches the bottom of the tank, the other end is Attach to the air supply tube attachment / detachment part of the detector body. The detector main body can supply compressed air from the chore air pipe to the air supply pipe by connecting the choke air pipe to the attachment / detachment portion with the choke air pipe. In a state where compressed air leaks from the lower end of the air supply pipe, the air pressure in the air supply pipe changes corresponding to the liquid level in the tank, so this change is detected by the pressure sensor, and the liquid level is displayed on the display unit based on this detection output. The level can be displayed.

  As described above, according to the bubble type liquid level gauge according to the present invention, the miscellaneous air in the miscellaneous air pipe generally routed in the ship, the windable and portable supply pipe, and the portable detector Because the liquid level in the tank can be measured using the main body, for example, even a ship that is not equipped with a ballast tank liquid level gauge can easily measure the liquid level in the ballast tank. This can contribute to efficient cargo handling at the port.

It is a perspective view which shows notionally the Example of the bubble type liquid level gauge which concerns on this invention. It is a systematic diagram which shows piping of the said Example.

  Embodiments of a bubble-type liquid level gauge according to the present invention will be described below with reference to the drawings.

  The embodiment of the bubble-type liquid level gauge shown in FIG. The detector main body 1 includes an attachment / detachment unit 22 with the air supply pipe 5, an attachment / detachment unit 21 with a general air pipe, and a display unit 20 that displays the liquid level in the tank to be measured. The detector body 1 is portable so that it can be carried to any place, and a battery is built in as a power source necessary for the operation of each part. The air supply pipe 5 connected to the detachable portion 22 has flexibility, can be wound around the reel 52, and can be carried together with the reel 52 to an arbitrary place. As the air supply pipe 5, for example, a urethane tube having an outer diameter of 8 mm can be used. One end of the air supply pipe 5 can be connected to the attachment / detachment part 22 of the detector main body 1, and the other end of the air supply pipe 5 is an air discharge part (bubble mouse) 51 that also serves as a weight.

  The air supply pipe 5 is inserted into the depth measuring pipe 6 from the air discharge part 51 side. As described above, the depth measuring tube 6 is provided so as to hang down from the top of the tank to the bottom of the tank in order to suspend the sounding tape, and the depth measuring tube 6 reaches the same level as the liquid in the tank. Holes are arranged in the peripheral wall so that the liquid enters the inside of the peripheral wall. The bottom 7 of the tank has a receiving plate directly below the depth measuring tube 6 so that the sounding tape inserted into the depth measuring tube 6 or the tip of the air supply tube 5 reaches the bottom of the tank so that the bottom of the tank is not damaged. 8 is fixed. The inner diameter of the depth measuring pipe 6 is determined by a classification rule so as to be 32 to 65 mm, and is large enough to insert the air supply pipe 5 having an outer diameter of 8 mm.

  The other end of the hose 9, one end of which is connected to the miscellaneous air pipe 3, is connected to the attachment / detachment portion 21 of the detector body 1 with the miscellaneous air pipe. The miscellaneous air pipe 3 is generally provided in ships, and compressed air for various uses is distributed to various parts of the ship including the deck. The miscellaneous air pipe 3 is provided with an air supply valve 4 at an appropriate position. By connecting a hose 9 to the air supply valve 4, the miscellaneous air can be introduced into the detector body 1. Yes.

Next, a specific configuration inside the detector body 1 will be described with reference to FIG. In FIG. 2, the detector main body 1 is provided with an air supply unit 11 for supplying to the air supply pipe 5 the miscellaneous air received through the attachment / detachment portion 21 with the miscellaneous air pipe 3. Since the miscellaneous air supplied from the miscellaneous air pipe 3 contains dust, moisture, and the like, the air supply unit 11 includes a filter and a drain plug 12 for removing dust in the miscellaneous air and removing moisture. . Since the air for the above-mentioned chores is unstable in air pressure, the air supply unit 11 is also provided with a pressure regulating valve 13 behind the filter and drain plug 12, and a pressure gauge 14 for measuring and displaying the adjusted pressure. Yes. The chore air is depressurized to about 0.4 MP (about 4.08 kgf / cm ² ) by the pressure regulating valve 13 of the air supply unit 11.

  In the detector main body 1, the miscellaneous air having passed through the air supply unit 11 is supplied to the air supply pipe 5 connected to the detachable portion 22 through the first valve 15 and the flow rate adjusting valve 16 in parallel. It is piped. The first valve 15 is composed of an electromagnetic valve controlled by a control unit 19 which will be described later, and opens and closes the passage of the chore air. In the operation mode in which the first valve 15 is “open”, the miscellaneous air is directly supplied from the miscellaneous air pipe 3 through the air supply unit 11 to the air supply pipe 5 so as to blow the air supply pipe 5 at the full speed of the miscellaneous air. It is piped in. In the operation mode in which the first valve 15 is “closed”, the above-described miscellaneous air having passed through the air supply unit 11 is piped so as to be supplied to the air supply pipe 5 via the flow rate adjusting valve 16.

  A pipe in the detector main body 1 leading to the air supply pipe 5 is connected to the second valve 17. The second valve 17 is an electromagnetic valve, and is controlled by the control unit 19 so that the air pressure in the air supply pipe 5 can be applied to the pressure sensor 18, and the pressure sensor 18 is released to the atmospheric pressure and the pressure sensor 18 is operated. It is piped so that the operation mode in which the zero point adjustment is performed can be taken. When the air decelerated by the flow rate adjusting valve 16 is supplied to the supply pipe 5, the control unit 19 releases the pressure sensor 18 to the atmospheric pressure at regular time intervals so as to adjust the zero point of the pressure sensor 18. In addition, a control program for the first valve 15 and the second valve 17 is configured. The control unit 19 is also configured to calculate the liquid level in the tank from the atmospheric pressure in the supply pipe 5 detected by the pressure sensor 18 and display the result on the display unit 20 as the liquid level or water depth. Yes.

  Next, the operation procedure and operation of the embodiment described above will be described. Since the detector main body 1 and the air supply pipe 5 are portable, the liquid level is taken over the tank to be measured, and the air supply pipe 5 is drawn out from the reel 52 and inserted into the depth measuring pipe 6 provided in the tank. To do. The air supply pipe 5 is inserted until the air discharge part 51 at the lower end reaches the bottom of the tank. It suffices that the air discharge part 51 reaches the bottom of the tank, and the air supply pipe 5 may be loosened. The other end of the air supply pipe 5 is connected to the attaching / detaching portion 22 of the detector main body 1. Further, one end of the hose 9 is connected to the air supply valve 4, and the other end of the hose 9 is connected to the attaching / detaching portion 21 of the detector main body 1. Thus, by connecting the choke air pipe 3 and the detector main body 1 via the air supply valve 4 and the hose 9, the detector main body 1 relays the chores air pipe 3 and the air supply pipe 5. The air supply pipe 5 is provisionally installed in advance for each tank, and the detector main body 1 is carried on a tank whose liquid level needs to be measured, and the air supply pipe 5 is connected to the detector main body 1. May be connected.

  The above is the preparation for the liquid level measurement, and the liquid level measurement is performed as follows. The detector main body has a power switch (not shown), and the operation of each unit starts when the power switch is turned on. At the beginning of the operation, the control unit 19 “opens” the first valve 15 for a few seconds to introduce the chore air directly from the choke air pipe 3 through the air supply unit 11 to the air supply pipe 5. Blow to fill the air supply tube with air. After that, the control unit 19 closes the first valve 15 and supplies the air for air that has passed through the air supply unit 11 to the air supply pipe 5 via the flow rate adjustment valve 16. The air in the air supply pipe 5 leaks from the air discharge part 51 at the lower end and rises in the liquid as bubbles, and the air pressure in the air supply pipe 5 becomes an air pressure corresponding to the level of the liquid level. By blowing the air supply pipe 5 when starting the measurement as described above, the time until the liquid level measurement can be shortened. Moreover, the clogging by the dust or sludge of the air discharge part 51 etc. can be eliminated.

  In the supply mode of miscellaneous air that has passed through the flow rate adjustment valve 16, the control unit 19 sets the second valve 17 to a pressure detection mode by the pressure sensor 18. That is, the second valve 17 is switched so that the air pressure in the supply pipe 5 is applied to the pressure sensor 18. The pressure sensor 18 detects the atmospheric pressure in the supply pipe 5 and outputs a detection signal corresponding to the atmospheric pressure. The control unit 19 performs a predetermined calculation from this detection signal, calculates the liquid level in the tank or the depth of the liquid in the tank, and displays the result on the display unit 20. As described above, by supplying the miscellaneous air whose flow rate is adjusted by passing through the flow rate adjusting valve 16 at the time of pressure detection, bubbles are leaked little by little from the air discharge unit 51, and the bubbles in the air supply pipe 5 due to the leaking of the bubbles It is possible to perform accurate measurement by suppressing atmospheric pressure change or atmospheric pressure pulsation to a small range.

  The atmospheric pressure changes with time, and even if the liquid level in the tank is constant, the detection value of the pressure sensor 18 and thus the display value of the display unit 20 fluctuate due to the change in atmospheric pressure. The operation of the valve 17 is switched to adjust the zero point of the pressure sensor. That is, when the second valve 17 is switched, the pressure-sensitive side of the pressure sensor 18 is disconnected from the air supply pipe 5 and opened to the atmospheric pressure. Adjustment is made so that the display on the display unit 20 at this time becomes zero. After the zero point adjustment, the second valve 17 is switched to the pressure measurement side. A control program by the control unit 19 may be configured so that the zero point adjustment is performed at intervals of several seconds. The liquid level detection operation after the power source of the detector main body 1 is turned on is continuously performed, for example, for 5 minutes, and then the power source is automatically turned off, so that waste of the power source can be avoided.

According to the embodiment of the bubble type liquid level gauge described above, the following effects can be obtained in addition to the effects described so far.
1. Since compressed air can be obtained from the general air pipe 3 arranged on the deck of a general ship, the liquid level can be measured in almost all existing ships.
2. The air supply pipe 5 can be carried with the detector main body 1 while being connected to the detector main body 1 and drawn to another tank. When trying to measure the liquid level of a plurality of tanks, the air supply pipe 5 is connected each time. There is no need to redo.
3. It can be handled regardless of the shape of the hull, tank, or depth tube.
4). By automatically performing valve control for adjusting the zero point of the pressure sensor 18, it is possible to perform accurate measurement that is not affected by temperature changes or atmospheric pressure fluctuations.
5. Since the power is automatically turned off after a certain time has passed in the measurement mode in which the power is turned on, the consumption of the power battery can be reduced.
6). Measurement accuracy is ± 1.0% F. S. Thus, the liquid level can be measured with sufficiently high accuracy as a liquid level gauge for a ship's cargo handling tank or ballast tank.
7). The air supply pipe 5 is convenient to carry with the detector main body 1 by winding it around a reel 52.
8). Compared to liquid level measurement with sounding tape, it is quicker and more accurate, and can handle cargo efficiently.

Next, the modification of each component part is given.
1. The hoses and tubes, that is, the air supply pipe 5 and the hose 9 in the illustrated embodiment may be attached to and detached from the attaching / detaching portions 22 and 21 of the detector main body 1 with one touch. As a result, the work time required for measurement can be shortened.
2. The display unit 20 may be an analog display by an indicating instrument, or may be a digital display, that is, a numerical display.

  Since the bubble type liquid level gauge according to the present invention can be used if there is a miscellaneous air pipe, it is not necessary to have a dedicated compressed air pipe for the bubble type liquid level gauge, and the equipment is fully equipped. It is possible to measure the liquid level in the tank even in a small ship with no. In addition, since the liquid level can be accurately measured even at the so-called stage of preparation, it is possible to perform efficient cargo handling work and to use it on ships that do not have a liquid level gauge. Demand is expected.

DESCRIPTION OF SYMBOLS 1 Detector main body 3 Miscellaneous air pipe 5 Air supply pipe 6 Sounding pipe 11 Air supply unit 12 Filter and drain plug 13 Pressure control valve 15 1st valve 16 Flow control valve 17 2nd valve 18 Pressure sensor 19 Control part 20 Display part 21 Detachable part with air pipe for general purpose 22 Detachable part with air supply pipe

Claims (8)

An air supply pipe to which compressed air is supplied from a compressed air supply source, a pressure sensor for measuring the air pressure in the air supply pipe, and a display unit for displaying a liquid level in the tank based on a detection signal of the pressure sensor. It is a bubble type liquid level gauge constituted by having,
The air supply pipe is a portable air supply pipe that can be inserted into and taken up from a depth measuring pipe hanging from the upper part of the tank into the tank,
As the compressed air supply source, a miscellaneous air pipe piped to a ship is used,
By having the attachment / detachment portion with the air supply pipe and the attachment / detachment portion with the air supply pipe, the air supply pipe and the air supply pipe can be relayed, and the pressure sensor and the detection output of the pressure sensor A bubble type liquid level gauge provided with a portable detector main body provided with a display unit for displaying a liquid level.   The bubble type liquid level gauge according to claim 1, wherein the detector body includes a filter for removing dust in the air for miscellaneous supply supplied from the miscellaneous air pipe.   The bubble type liquid level gauge according to claim 1 or 2, wherein the detector body includes a pressure adjusting valve that adjusts the pressure of the miscellaneous air supplied from the miscellaneous air pipe to an appropriate pressure.   The detector main body includes a first valve that switches between a mode in which miscellaneous air is directly supplied from the chore air pipe to the air supply pipe and a mode in which the miscellaneous air is guided to the air supply pipe via a flow rate adjusting valve. The bubble type liquid level gauge according to 2 or 3.   The detector main body includes an aspect for guiding the air pressure of the supply air to the pressure sensor, and a second valve for adjusting the zero point of the pressure sensor by opening the pressure receiving surface of the pressure sensor to the atmospheric pressure. Bubble type liquid level gauge.   The detector main body includes a control unit that controls the first valve, the second valve, and the flow rate adjusting valve. The control unit directly introduces the miscellaneous air into the supply pipe at the beginning of the operation and blows the supply pipe. 6. The bubble type liquid level gauge according to claim 5, wherein the first valve is controlled so that the air supply pipe is filled with air and then the air adjusted by the flow rate adjusting valve is supplied to the air supply pipe.   The control unit controls the first valve and the second valve so that the air pressure in the supply pipe is guided to the pressure sensor when the air adjusted by the flow rate adjustment valve is supplied to the supply pipe. The bubble type liquid level gauge as described.   When the air adjusted by the flow rate adjusting valve is supplied to the supply pipe, the control unit releases the pressure sensor to the atmospheric pressure at regular time intervals so that the zero point adjustment of the pressure sensor is performed. The bubble type liquid level gauge according to claim 7, which controls the two valves.

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