JP6741312B1 - Bubble type liquid level gauge and water immersion detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a bubble type liquid level gauge and a water immersion detection device capable of solving problems caused by wasteful discharge of compressed air and wasteful operation of a compressor. SOLUTION: An air supply pipe 110 at least a lower end of which is immersed in a liquid contained in a storage chamber, a compressed air supply source for supplying compressed air into the air supply pipe, and a pressure sensor for measuring an atmospheric pressure in the air supply pipe. , And measures the liquid level in the storage chamber based on the detection signal of the pressure sensor when compressed air leaks from the lower end of the air supply pipe. The opening/closing unit 1 opens and closes the lower end of the air supply pipe. The opening/closing unit 1 closes the lower end of the air supply pipe until the liquid is detected, and opens the lower end of the air supply pipe when the liquid is detected. [Selection diagram] Figure 2

Description

TECHNICAL FIELD The present invention relates to a bubble type liquid level gauge and a water immersion detection device capable of eliminating wasteful discharge of compressed air.

Mainly in ships such as tankers, a liquid level gauge is installed in each of the storage chambers in order to detect the liquid level of the crude oil or LNG in the cargo or the ballast. There is a bubble type or air purge type liquid level meter as one of the liquid level level detection methods of the liquid level meter. Hereinafter, in the present application, the air purge type liquid level gauge is also referred to as “bubble type liquid level gauge”.

The bubble type liquid level gauge measures an air supply pipe in which at least a lower end portion is immersed in a liquid contained in a storage chamber, a compressed air supply source for supplying compressed air into the air supply pipe, and an air pressure in the air supply pipe. And a pressure sensor that operates. The liquid level in the storage chamber can be measured based on the detection signal of the pressure sensor when compressed air leaks from the lower end of the air supply pipe.

Prior art documents describing the bubble type liquid level gauge include the inventions described in Patent Document 1 and Patent Document 2.

In the bubble type liquid level meter, an air supply pipe hangs down toward the bottom of the space in which it is installed, and the lower end of the air supply pipe is located, for example, about 20 cm above the bottom of the space. Therefore, when the liquid surface is within 20 cm from the bottom surface, the compressed air continues to leak from the lower end of the air supply pipe, and a release sound is generated. If the compressed air continues to leak, the compressed air stored in the compressor tank will be unnecessarily discharged, increasing the consumption of compressed air, increasing the power consumption of the compressor, and shortening the life of the compressor. Occurs.

Japanese Patent No. 3983240 Japanese Patent No. 3992153

According to the present invention, compressed air is not supplied until the lower end of the air supply pipe is submerged below the liquid level, and it is possible to eliminate problems caused by wasteful discharge of compressed air and wasteful operation of the compressor. Another object of the present invention is to provide a water immersion detection device.

The bubble type liquid level gauge according to the present invention,
An air supply pipe at least a lower end of which is immersed in the liquid contained in the storage chamber, a compressed air supply source for supplying compressed air into the air supply pipe, and a pressure sensor for measuring the air pressure in the air supply pipe are provided. A bubble type liquid level gauge for measuring the liquid level in the storage chamber based on the detection signal of the pressure sensor when compressed air leaks from the lower end of the air supply pipe,
An opening and closing unit for opening and closing the lower end of the air supply pipe,
The opening and closing unit is characterized by closing the lower end of the air supply pipe until detecting the liquid, and opening the lower end of the air supply pipe when detecting the liquid.

The water immersion detection device according to the present invention,
A frame body, a float mounted in the frame body, and an open/close valve that opens and closes a lower end portion of the air supply pipe by vertical movement of the float,
The frame has a structure that allows a liquid to flow thereinto,
In the natural state, the opening/closing valve closes the air inlet/outlet by gravity of the float, opens the lower end portion of the air supply pipe by allowing the liquid to flow into the frame body, and the float floats up. It is characterized in that the inundation is detected by the pressure change of the trachea.

According to the bubble type liquid level gauge of the present invention, since the lower end of the air supply pipe is closed until the opening/closing unit detects the liquid, wasteful discharge of compressed air and Useless operation of the compressor can be eliminated.

According to the inundation detection device of the present invention, when the air inlet/outlet is released due to the rise of the float, the air pressure of the compressed air supply path connected to the opening/closing valve of the air inlet/outlet changes, and the inundation is detected by the change in the air pressure. You can The compressed air is not discharged unnecessarily until the inundation is detected, and the compressor does not operate unnecessarily.

It is a top view showing an example of an opening-and-closing unit used for a bubble type level gauge and a water immersion detection device concerning the present invention. It is sectional drawing of the said opening/closing unit which follows the AA line in FIG. It is a front view of the said opening/closing unit. It is a perspective view which shows the main components of the said opening/closing unit. It is a top view of the said main component part. It is a conceptual diagram which shows the Example of the bubble type liquid level gauge which concerns on this invention.

Hereinafter, embodiments of a bubble type liquid level gauge and a water immersion detection device according to the present invention will be described with reference to the drawings.

[Outline of bubble type liquid level gauge]
In FIG. 6, reference numeral 150 indicates a hull, and the hull 150 is provided with a cargo accommodating chamber 160. In the illustrated example, the hull 150 is a tanker, and the storage chamber 160 is a space for storing a liquid, such as crude oil. A stand piece 115 for installing a bubble type liquid level gauge is fixed to a ceiling portion of the accommodation chamber 160, and an air supply pipe 110 hangs down from the stand piece 115 toward a bottom surface of the accommodation chamber 160. The lower end of the air supply pipe 110 extends to near the bottom surface of the accommodation chamber 160, and the opening/closing unit 1 is attached to the lower end of the air supply pipe 110.

The opening/closing unit 1 opens and closes the lower end of the air supply pipe 110, closes the lower end of the air supply pipe 110 until the liquid is detected, and opens the lower end of the air supply pipe 110 when the liquid is detected. That is, the lower end of the air supply pipe 110 is closed by the opening/closing unit 1 until the lower end of the air supply pipe 110 is submerged in the liquid. When the liquid level rises above the lower end of the air supply pipe 110 and the lower end of the air supply pipe 110 is submerged in the liquid, the opening/closing unit 1 opens the lower end of the air supply pipe 110 to start the operation as a bubble type liquid level gauge.

[Specific configuration of opening/closing unit]
As shown in FIGS. 1 to 3, the opening/closing unit 1 has a rectangular parallelepiped frame body 10 serving as a base body thereof. The frame 10 includes a front plate 11, a bottom plate 12, a top plate 13, a back plate 14, and both side plates 15. The opening/closing mechanism 100 shown in FIGS. 4 and 5 is assembled to the frame body 10 to form the opening/closing unit 1. The opening/closing unit 1 is installed by fixing the frame body 10 near the bottom surface of the accommodation chamber 160. A hole or a gap is formed in at least one of the plates constituting the frame body 10 so that the liquid such as the crude oil can flow into the inside.

The opening/closing mechanism 100 is attached to the inner surface side of the front plate 11 of the frame body 10. 2, 4, and 5, the opening/closing mechanism 100 includes a pedestal 31, an opening/closing valve 45, a joint 50, L around a support member 70 that is closely attached and fixed to the inner surface side of the front plate 11 of the frame body 10. It has a character-shaped lever 60 and the like.

As shown in FIG. 2, the pedestal 31 penetrates through a hole formed in the support member 70 from the inner surface (the surface on the left side in FIG. 2) of the support member 70 toward the outside. A nut 35 is fastened to a male screw formed on the pedestal 31. The pedestal 31 is fixed to the front plate 11 of the frame body 10 together with the support member 70 by sandwiching the support member 70 and the front plate 11 of the frame body 10 by the flange portion of the pedestal 31 and the nut 35.

As shown in FIG. 2, the pedestal 31 has an air inlet/outlet port 30 formed along the central axis thereof. The surface of the pedestal 31 on the left side in FIG. 2 is a contact surface with an opening/closing valve 45, which will be described later, and the contact surface of the pedestal 31 with the opening/closing valve 45 makes surface contact with the air inlet/outlet port 30 of the pedestal 31. To close.

A female screw 32 is formed on the inner circumference of the outer end portion (right end portion in FIG. 2) of the pedestal 31, and a male screw at one end of the joint 50 is screwed into the female screw 32 to connect the joint 50 to the pedestal 31. ing. The joint 50 is bent in an L shape, one end thereof projects horizontally from the pedestal 31, and the other end thereof rises vertically to form a connecting portion 52 with the air supply pipe 110 described with reference to FIG. 6. An air passage 51 is formed inside the joint 50 along the central axis, and the air passage 51 communicates with the air inlet/outlet port 30.

As shown in FIGS. 4 and 5, a float support plate 75 is fixed to the inner surface side of the support member 70. Both side portions of the float support plate 75 are bent at right angles, and the float support plate 75 has a "U" shape in plan view. The bent portions on both sides of the float support plate 75 are parallel to each other and form a pair of bearing portions 76.

The shaft 65 is horizontally supported by the pair of bearings 76. A tube shaft 66 is rotatably inserted around the shaft 65 around the shaft 65. An L-shaped lever 60 is fixed to the tube shaft 66 at the center in the length direction. One arm portion 61 of the L-shaped lever 60 is long and the other arm portion 62 is short, and the boundary portion between these arm portions 61, 62 is fixed to the tube shaft 66.

The float 20 is attached to one arm 61 of the L-shaped lever 60. The outer circumference of the float 20 is a gentle conical surface whose diameter decreases toward the tip of the arm 61. The float 20 is penetrated by one arm portion 61 of the L-shaped lever 60 along the central axis thereof, and is sealed to the internal space to be coupled to the arm portion 61.

The other arm portion 62 of the L-shaped lever 60 extends downward from the tube shaft 66 to the side of the pedestal 31, and the opening/closing valve 45 is fixed to the surface of the arm portion 62 facing the pedestal 31. The on-off valve 45 takes a surface contact state with the contact surface of the pedestal 31 or a mode separated from the contact surface of the pedestal 31, as described above, depending on the rotational position of the L-shaped lever 60.

The rotational position of the L-shaped lever 60 is determined by the position of the float 20, and the position of the float 20 differs depending on whether the liquid is flowing into the frame 10 or not. The mode shown in FIG. 2 is a case where the liquid does not flow into the frame body 10, the float 20 is in a natural state and descends due to its gravity, and the L-shaped lever 60 rotates counterclockwise in FIG. The on-off valve 45 is in surface contact with the contact surface of the pedestal 31 by rotating. In this mode, the air inlet/outlet port 30 is closed by the opening/closing valve 45.

When the liquid flows into the frame body 10, the float 20 is lifted by its buoyancy, and the L-shaped lever 60 rotates clockwise around the shaft 65 in FIG. 2 so that the on-off valve 4 separates from the contact surface of the pedestal 31. Then, the air inlet/outlet port 30 is opened.

In the opening/closing mechanism 100 shown in FIGS. 4 and 5, the support member 70 is fixed to the inner surface side of the front plate 11 of the frame body 10 as shown in FIG. 2, and the joint 50, the pedestal 31 and the like are provided outside the front plate 11. It is attached in a protruding manner.

In FIG. 6, a pipe 117 communicating with the air supply pipe 110 is drawn out from the stand piece 115, and the pipe 117 is drawn into the chamber 170 and connected to the control unit 120. The control unit 120 is connected to an air tank of a compressor that generates compressed air.

The compressor has a pressure pump and the air tank for storing the compressed air generated by the pressure pump. The control unit 120 controls the supply and stop of the compressed air stored in the air tank to the air supply pipe 110. The control of the compressor is autonomously performed so that the compressed air in the air tank is maintained at a predetermined air pressure.

The control unit 120 has a pressure sensor that detects the air pressure in the air supply pipe 110, and calculates the level of the liquid level housed in the housing chamber 160 from the output signal of the pressure sensor. Further, the output signal of the pressure sensor is output from the control unit 120, the output signal is input to the indicator 125, and the liquid level corresponding to the output signal is displayed. The output signal is also input to the two comparators 130 and 140.

In the example shown in FIG. 6, the lower end of the air supply pipe 110 is closed by the open/close valve 45 of the open/close unit 1 until the liquid level reaches 20 cm from the bottom of the storage chamber 160. When the liquid level reaches 20 cm from the bottom of the storage chamber 160, the opening/closing unit 1 operates to open the lower end of the air supply pipe 110. When the lower end of the air supply pipe 110 is opened, the air pressure inside the air supply pipe 110 suddenly drops, and this decrease in air pressure is detected by a sensor in the control unit 120. Based on this detection signal, the lower end of the air supply pipe 110 is detected. Display or alarm that the liquid has submerged below the liquid surface. Further, from the time when the above detection signal is output, it operates as a bubble type liquid level gauge as described below.

[Operation as a bubble level gauge]
After the lower end of the air supply pipe 110 is submerged below the liquid level, it can be measured by detecting the air pressure in the air supply pipe 110 with a pressure sensor, as in a general bubble type liquid level gauge. The air pressure in the air supply pipe 110 increases according to the depth at which the lower end of the air supply pipe 110 is submerged from the liquid surface, and the detection output of the pressure sensor changes in accordance with this change in pressure. The control unit 120 converts the detection output of the pressure sensor into an electric signal corresponding to the depth at which the lower end of the air supply pipe 110 is submerged from the liquid surface, and the value corresponding to the electric signal is displayed on the instruction unit 125. , The liquid level can be displayed.

However, as described in FIG. 6, the lower end portion of the air supply pipe 110 is installed above the bottom surface of the cargo accommodating chamber 160. In the example shown in FIG. 6, it is installed 20 cm above the bottom surface of the accommodation chamber 160. Therefore, the control unit 120 adds 20 cm to the depth signal from the liquid surface based on the output signal of the pressure sensor, and displays this on the instruction unit 125 as the liquid surface level from the bottom surface of the storage chamber 160. Since the air pressure of the air supply pipe 110 changes according to the liquid level that changes moment by moment, it is possible to display the liquid level corresponding to this change in atmospheric pressure.

[Operation as a flood detection device]
By using the opening/closing unit 1, this can be made to function as a water infiltration detection device. It is assumed that the cargo storage chamber 160 shown in FIG. 6 is a chamber in which no liquid is stored or a storage chamber other than liquid, such as coal or powder. An external compressed air supply path is connected to the opening/closing unit 1 via a joint 50 shown in FIGS. A pressure sensor is arranged in the compressed air supply path, and the pressure sensor is connected to the detection circuit. The pressure sensor may be composed of a semiconductor element, or may be a traditional meter called a barometer, or the like.

In the case of detecting water immersion in a storage chamber that stores ore such as coal, powder, food, etc., it is necessary to have a structure that allows water to enter the frame body 10 that constitutes the opening/closing unit 1. On the other hand, it is necessary to have a structure in which a cargo such as coal or powder cannot enter the frame 10. Further, it is necessary to have a sturdy structure so that the frame body 10 is not deformed by the heavy pressure of the load such as coal or powder. Therefore, for example, most of the frame body 10 is made of a sturdy metal, a window hole is formed in a part thereof, and the window hole is covered with a mesh made of fine metal.

The basic structure and operation of the water immersion detection device are not so different from the liquid level gauge shown in FIG. The compressed air supply path corresponds to the air supply pipe 110, and the detection circuit may be arranged in the control unit 120. When water does not flow into the frame body 10, the opening/closing valve 45 closes the air inlet/outlet port 30 as described above, and the compressed air supply path communicating with the air inlet/outlet port 30 is maintained at a high air pressure. The pressure sensor outputs a detection signal corresponding to a high air pressure, and a detection circuit that processes this output signal does not output a signal indicating that water is inundated.

When water flows into the frame body 10, the float floats on the water and rises as described above, and the L-shaped lever 60 rotates clockwise in FIG. 2, whereby the opening/closing valve 45 opens the air inlet/outlet port 30. Due to the opening of the air inlet/outlet 30, the compressed air in the compressed air supply passage communicating with the air inlet/outlet 30 leaks from the air inlet/outlet 30, and the air pressure in the compressed air supply passage decreases. The pressure sensor detects the decrease in the air pressure, outputs a detection signal corresponding to the decrease, and a detection circuit that processes the output signal issues a flood alarm.

[Operation as a level detector]
The opening/closing unit 1 can be used to function as a level detector. The level detector detects when the liquid level reaches a certain level and issues a signal or alarm. FIG. 6 shows an embodiment that operates as a level gauge as described above and also as a level detector. In the example shown in FIG. 6, when operating as a level detector, a signal or alarm is issued when the liquid level reaches 50 cm or 2.0 m.

In FIG. 6, the opening/closing unit 1 is configured so that the opening/closing unit 1 is actuated and the lower end portion of the air supply pipe 110 is opened when the liquid level reaches 20 cm from the bottom surface of the storage chamber 160, as described above. There is. The reference input terminal of one of the comparators 130 and 140 is set to the detection signal level output from the control unit 120 when the liquid level is 30 cm. The reference input terminal of the other comparator 140 is set to the detection signal level output from the control unit 120 when the liquid level is 1.8 m.

As described above, the air pressure inside the air supply pipe 110 increases according to the depth at which the lower end of the air supply pipe 110 is submerged from the liquid surface. When the liquid level reaches 50 cm from the bottom surface of the storage chamber 160, and thus reaches 30 cm from the lower end of the air supply pipe 110, the signal level input from the control unit 120 to the comparator 130 reaches the signal level of the reference input terminal. As a result, the output signal of the comparator 130 is inverted, and a signal or alarm indicating that the liquid level has reached 50 cm is issued.

When the liquid level reaches 2.0 m from the bottom of the storage chamber 160, and thus reaches 1.8 m from the lower end of the air supply pipe 110, the signal level input from the control unit 120 to the comparator 140 reaches the signal level of the reference input terminal. .. As a result, the output signal of the comparator 140 is inverted, and a signal or alarm indicating that the liquid surface has reached 2.0 m is issued.

[Effects of Examples of Bubble Type Liquid Level Gauge and Water Immersion Detector]
According to the embodiment of the bubble type liquid level gauge according to the present invention, the lower end of the air supply pipe 110 is closed by the opening/closing valve 45 of the opening/closing unit 1 until the lower end of the air supply pipe 110 is submerged below the liquid surface. Therefore, various problems found in conventional bubble level gauges such as increased consumption of compressed air, generation of compressed air emission noise, waste of power due to wasteful operation of the compressor, and shortened life of the compressor are eliminated. can do.

The embodiment of the bubble type liquid level gauge according to the present invention has the opening/closing unit 1 that closes the lower end of the air supply pipe 110 until the liquid is detected. When the opening/closing unit 1 detects the liquid, it opens the lower end of the air supply pipe 110 and lowers the air pressure inside the air supply pipe 110. Therefore, a water infiltration detection device can be configured by detecting this decrease in air pressure.

As can be seen from FIGS. 1 to 3, the opening/closing unit 1 has a relatively simple structure including the float 20, the opening/closing valve 45, and the joint 50 as main components, and requires installation of a liquid level gauge and a water immersion detection device. It can be installed in a space without being bulky.

As shown in FIG. 2, the frame 10 of the opening/closing unit 1 may be provided with an operation confirmation window 18 of the opening/closing unit 1 including a float 20 and the like. When the opening/closing unit 1 operates normally and the opening/closing valve 45 closes the air inlet/outlet 30, when the operation confirmation window 18 is opened and the float 20 is lifted with a fingertip, the opening/closing valve 45 opens the air inlet/outlet 30 to open the air inlet/outlet. Compressed air leaks from 30. The sound generated at this time can confirm that the opening/closing unit 1 is operating normally.

The operation of the opening/closing unit 1 is abnormal if the float 20 is still floating even though there is no liquid, or if there is a sound of compressed air leaking even when the float 20 is in a position where it does not float. Can be determined.

[Modification]
In the illustrated embodiment, the float 20 has a hollow structure, but the float 20 is not limited to a hollow structure as long as it has a buoyancy with respect to a liquid such as water. For example, the float may be made of Styrofoam. Further, the float may have any shape, for example, a spherical shape.

In the illustrated embodiment, the float 20 is attached to one arm of the L-shaped lever 60, and the air inlet/outlet 30 is opened/closed by the rotation of the L-shaped lever 60. However, the structure is not limited to this. Absent. For example, the float may be configured to move linearly up and down, the air inlet/outlet may be directly closed by descending the float, and the air inlet/outlet may be opened by ascending due to buoyancy of the float.

The inundation detection unit and the inundation detection device according to the present invention are not limited to those for ships, and may be used on land as long as they are places or facilities where detection of inundation is required.

1 Opening/closing unit 10 Frame 20 Float 30 Air inlet/outlet 31 Pedestal 45 Open/close valve 50 Joint 51 Air flow path 60 Lever 70 Support member 75 Float support plate 100 Open/close mechanism 110 Air supply pipe 120 Control part

Claims (10)

An air supply pipe at least a lower end of which is immersed in the liquid contained in the storage chamber, a compressed air supply source for supplying compressed air into the air supply pipe, and a pressure sensor for measuring the air pressure in the air supply pipe are provided. A bubble type liquid level gauge for measuring the liquid level in the storage chamber based on the detection signal of the pressure sensor when compressed air leaks from the lower end of the air supply pipe,
An opening and closing unit for opening and closing the lower end of the air supply pipe,
The opening and closing unit, the supply to the lower end of the trachea is death in the liquid closes the lower end of the supply pipe, the lower end portion of the supply pipe opens the lower end portion of deaths Then the air charge to the liquid bubble formula A bubble type liquid level gauge that starts operating as a liquid level gauge. The bubble level gauge according to claim 1, wherein the opening/closing unit is disposed in a lower portion of the accommodation space and opens a lower end portion of the air supply pipe when a liquid level of the accommodation space is equal to or higher than a predetermined level. The opening/closing unit includes a frame body, a float mounted in the frame body, and an opening/closing valve that opens/closes a lower end portion of the air supply pipe by vertical movement of the float, and the opening/closing valve is provided in the accommodation space. The bubble type liquid level gauge according to claim 1 or 2, wherein the lower end portion of the air supply pipe is opened when liquid enters and the float floats. The frame is a structure that allows liquid to flow inside,
The opening/closing unit closes a lower end portion of the air supply pipe by gravity of the float in a natural state, and opens a lower end portion of the air supply pipe when liquid flows into the frame body and the float rises. Bubble type liquid level gauge. The bubble type liquid level gauge according to claim 3 or 4, wherein a joint for communicating with the lower end portion of the air supply pipe is attached to the frame body. The bubble according to claim 3 or 4, wherein the float is attached to one arm of an L-shaped lever rotatably supported by the frame, and the other arm of the L-shaped lever constitutes the on-off valve. Liquid level gauge. 7. The bubble type liquid level gauge according to claim 3, wherein a window for checking the operation of the float is formed in the frame body. Having a plurality of bubble type liquid level gauges, the compressed air supply path connected to each air supply pipe of each bubble type liquid level gauge gathers in a centralized control room, and centrally manages inundation detection by each of the bubble type liquid level gauges. The bubble type liquid level gauge according to any one of claims 1 to 7, which can be used. A frame body, a float mounted in the frame body, and an opening/closing valve that opens and closes a lower end portion of the air supply pipe by vertical movement of the float,
The frame has a structure that allows a liquid to flow thereinto,
In the natural state, the opening/closing valve closes the air inlet/outlet by gravity of the float, opens the lower end portion of the air supply pipe by allowing the liquid to flow into the frame body, and the float floats up. An infiltration detection device that detects infiltration by fluctuations in air pressure in the trachea. The infiltration detection device according to claim 8, wherein the air supply pipe is an air supply pipe of a bubble type liquid level gauge and is connected to a compressed air supply source.

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