JP7228909B2 - Bubble type liquid level gauge and immersion detection device - Google Patents

Description

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

2. Description of the Related Art Mainly in ships such as tankers, a liquid level gauge is installed in each storage chamber in order to detect the liquid level of crude oil, LNG, or ballast. One of the liquid level detection methods of the liquid level gauge is the bubble type or air purge type liquid level gauge. Hereinafter, in the present application, the term "bubble type level gauge" including the air purge type level gauge will be used.

The bubble-type liquid level gauge measures an air supply pipe whose lower end is submerged in a liquid contained in a storage chamber, a compressed air supply source that supplies compressed air into the air supply pipe, and the air pressure in the air supply pipe. and a pressure sensor. 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.

Inventions described in Patent Document 1 and Patent Document 2 are prior art documents describing the bubble type liquid level gauge.

The air supply pipe hangs down toward the bottom of the space in which the bubble type liquid level gauge is installed, and the lower end of the air supply pipe is positioned, for example, about 20 cm above the bottom of the space. Therefore, when the liquid level is within 20 cm from the bottom surface, the compressed air continues to leak from the lower end of the air supply pipe and emits noise. In addition, if the compressed air continues to leak, the compressed air stored in the compressor tank will be wasted and the compressed air consumption will increase, causing problems such as an increase in the power consumption of the compressor and a shortened compressor life. occurs.

Japanese Patent No. 3983240 Japanese Patent No. 3992153

The present invention prevents the supply of compressed air until the lower end of the air supply pipe is submerged under the liquid level, thereby eliminating problems caused by wasteful discharge of compressed air and wasteful operation of the compressor. and to provide a water immersion detection device.

The bubble type liquid level gauge according to the present invention is
An air supply pipe having at least a lower end immersed in a liquid contained in a storage chamber, a compressed air supply source for supplying compressed air to the air supply pipe, and a pressure sensor for measuring the air pressure in the air supply pipe. and a bubble type liquid level gauge that 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,
Having an opening and closing unit that opens and closes the lower end of the air supply pipe,
The opening/closing unit has a frame, a float mounted in the frame, and an opening/closing valve that opens and closes the lower end of the air supply pipe by vertical movement of the float,
The frame body has a structure in which liquid can flow into the interior and objects other than liquid such as ores, powders, and foods cannot enter,
The on-off valve closes the lower end of the air supply pipe until the lower end of the air supply pipe is submerged in liquid, and when the liquid enters the accommodation space and the float floats, the lower end of the air supply pipe is closed. The most important feature is that it opens and starts to operate as a bubble level gauge.

The inundation detection device according to the present invention includes:
a frame, a float mounted in the frame, and an on-off valve that opens and closes a lower end of an air supply pipe by vertical movement of the float,
The frame body is made of metal and partially has window holes, and the window holes are covered with a metal mesh so that liquid can flow into the inside, and ores other than liquid, powder, Objects such as food are structures that cannot enter,
In a natural state, the on-off valve closes the air inlet/outlet by the gravity of the float, and when liquid flows into the frame and the float rises, the lower end of the air supply pipe is opened. It is characterized by detecting inundation based on air pressure fluctuations in the trachea.

According to the bubble level gauge of the present invention, the lower end of the air supply pipe is closed until the opening/closing unit detects the liquid. Wasteful operation of the compressor can be eliminated.

According to the water ingress detection device of the present invention, when the air inlet/outlet is opened due to the rise of the float, the air pressure in the compressed air supply path leading to the open/close valve of the air inlet/outlet fluctuates, and water ingress is detected from this air pressure fluctuation. can be done. Compressed air will not be wasted and the compressor will not operate until water immersion is detected.

FIG. 4 is a plan view showing an example of an opening/closing unit used in the bubble type liquid level gauge and the water intrusion detection device according to the present invention; 2 is a cross-sectional view of the opening/closing unit taken along line AA in FIG. 1; FIG. It is a front view of the said opening-and-closing unit. FIG. 3 is a perspective view showing main components of the opening/closing unit; It is a top view of the said main components. 1 is a conceptual diagram showing an embodiment of a bubble type liquid level gauge according to the present invention; FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a bubble type liquid level gauge and a water intrusion detection device according to the present invention will be described with reference to the drawings.

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

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 liquid is detected, and opens the lower end of the air supply pipe 110 when liquid is detected. That is, the opening/closing unit 1 closes the lower end of the air supply pipe 110 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 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 10 serving as its base. The frame 10 is composed of a front plate 11 , a bottom plate 12 , a top plate 13 , a back plate 14 and side plates 15 . An opening/closing mechanism 100 shown in FIGS. 4 and 5 is assembled to the frame 10 to constitute the opening/closing unit 1 . The opening/closing unit 1 is installed by fixing the frame 10 near the bottom surface of the storage chamber 160 . A hole or gap is formed in at least one of the plates constituting the frame 10 so that the liquid such as crude oil can flow into the inside.

The opening/closing mechanism 100 is attached to the inner surface of the front plate 11 of the frame 10 . 2, 4, and 5, the opening/closing mechanism 100 includes a base 31, an opening/closing valve 45, a joint 50, an L arm around a supporting member 70 fixed in close contact with the inner surface of the front plate 11 of the frame 10. It has a glyph lever 60 and the like.

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

As shown in FIG. 2, the base 31 is formed with an air inlet/outlet 30 along its central axis. The left side surface of the base 31 in FIG. 2 is a contact surface with an on-off valve 45 which will be described later. to close.

A female thread 32 is formed on the inner periphery of the outer end (the right end in FIG. 2) of the base 31 , and the male thread of one end of the joint 50 is screwed into the female thread 32 to connect the joint 50 to the base 31 . ing. The joint 50 is bent in an L shape, one end projecting horizontally from the pedestal 31 and the other end rising vertically to form a connecting portion 52 with the air supply pipe 110 described in FIG. An air flow path 51 is formed inside the joint 50 along the central axis, and the air flow path 51 communicates with the air inlet/outlet 30 .

As shown in FIGS. 4 and 5, a float support plate 75 is fixed to the inner surface of the support member 70 . Both sides of the float support plate 75 are bent at right angles, and the float support plate 75 has a U-shaped planar shape. 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 pipe shaft 66 is inserted on the outer periphery of the shaft 65 so as to be rotatable around the shaft 65 . An L-shaped lever 60 is secured to the tube shaft 66 at its longitudinal center. One arm 61 of the L-shaped lever 60 is long and the other arm 62 is short.

A float 20 is attached to one arm 61 of an L-shaped lever 60 . The outer circumference of the float 20 is a gently conical surface whose diameter decreases toward the tip of the arm portion 61 . The float 20 is penetrated by one arm 61 of an L-shaped lever 60 along its central axis, and is connected to the arm 61 with its internal space sealed.

The other arm portion 62 of the L-shaped lever 60 extends downward from the tube shaft 66 to the side of the base 31 , and the on-off valve 45 is fixed to the surface of the arm portion 62 facing the base 31 . Depending on the rotational position of the L-shaped lever 60, the on-off valve 45 is in surface contact with the contact surface of the pedestal 31 as described above, or separated from the contact surface of the pedestal 31 as described above.

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 the case where no liquid has flowed into the frame 10, the float 20 is in a natural state and is lowered by its gravity, and the L-shaped lever 60 is rotated counterclockwise in FIG. , and the on-off valve 45 is in surface contact with the contact surface of the base 31 . In this embodiment, the air inlet/outlet 30 is closed by the open/close valve 45 .

When the liquid flows into the frame 10, the float 20 rises due to its buoyancy, and the L-shaped lever 60 rotates clockwise in FIG. and the air inlet/outlet 30 is opened.

The opening/closing mechanism 100 shown in FIGS. 4 and 5 has a support member 70 fixed to the inner surface of the front plate 11 of the frame 10 as shown in FIG. Mounted in a protruding manner.

6, a pipe 117 communicating with the air supply pipe 110 is pulled out from the stand piece 115, and the pipe 117 is pulled into the chamber 170 and connected to the control section 120. As shown in FIG. The controller 120 is in communication with the air tank of the compressor that produces compressed air.

The compressor has a pressurizing pump and the air tank for storing compressed air generated by the pressurizing pump. The control unit 120 controls supply and stop of the compressed air stored in the air tank to the air supply pipe 110 . The compressor is controlled autonomously 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 contained in the housing chamber 160 from the output signal of the pressure sensor. Further, the control unit 120 outputs the output signal of the pressure sensor, the output signal is input to the indicator 125, and the liquid level corresponding to this output signal is displayed. The output signal is also input to two comparators 130,140.

In the example shown in FIG. 6 , 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 liquid level reaches 20 cm from the bottom surface of the storage chamber 160 . When the liquid level reaches 20 cm from the bottom surface of the storage chamber 160, the opening/closing unit 1 operates to open the lower end of the air supply pipe 110. As shown in FIG. When the lower end of the air supply pipe 110 is opened, the air pressure inside the air supply pipe 110 drops rapidly. is submerged below the surface of the liquid. Further, from the time when the 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 under the liquid level, the air pressure in the air supply pipe 110 can be measured by detecting it with a pressure sensor in the same manner as a general bubble level gauge. The air pressure in the air supply pipe 110 increases according to the depth to 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 pressure change. 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 indicator unit 125 displays the value corresponding to this electric signal. , can display the liquid level.

However, as explained in FIG. 6, the lower end of the air supply pipe 110 is installed above the bottom of the cargo storage chamber 160 . In the example shown in FIG. 6, it is installed 20 cm above the bottom surface of the storage chamber 160 . Therefore, the controller 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 indicator 125 as the liquid level from the bottom surface of the storage chamber 160 . Since the air pressure in the air supply pipe 110 changes according to the liquid level that changes from moment to moment, the liquid level can be displayed according to the change in the air pressure.

[Operation as a water ingress detection device]
The opening/closing unit 1 can be used to function as a water intrusion detection device. It is assumed that the cargo storage chamber 160 shown in FIG. 6 is a chamber that does not contain liquid or a chamber that contains 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 consist of a semiconductor device, a traditional instrument called a barometer, or the like.

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

The basic configuration and operation of the water intrusion detection device are not much different from those of the liquid level gauge shown in FIG. The compressed air supply path corresponds to the air supply pipe 110 and the detection circuit can be arranged in the control section 120 . When water does not flow into the frame 10, the on-off valve 45 closes the air inlet/outlet 30 as described above, and the compressed air supply path communicating with the air inlet/outlet 30 is maintained at high air pressure. The pressure sensor outputs a detection signal corresponding to high air pressure, and the detection circuit that processes this output signal does not output a signal indicating that the vehicle is flooded.

When water flows into the frame 10, the float rises on the water as described above, and the L-shaped lever 60 rotates clockwise in FIG. By opening the air inlet/outlet 30, the compressed air in the compressed air supply path communicating with the air inlet/outlet 30 leaks from the air inlet/outlet 30, and the air pressure in the compressed air supply path decreases. The pressure sensor detects this decrease in air pressure and outputs a corresponding detection signal, and a detection circuit that processes this output signal issues a water ingress alarm.

[Operation as a level detector]
The opening/closing unit 1 can be used to function as a level detector. A level detector detects when the liquid level reaches a certain level and issues a signal or alarm. FIG. 6 shows an embodiment that operates both as a liquid level gauge and as a level detector as described above. 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 and 2.0 m.

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

As described above, 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 below the liquid surface. When the liquid level reaches 50 cm from the bottom surface of the storage chamber 160, ie, 30 cm from the lower end of the air supply pipe 110, the signal level input from the controller 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 therefore reaches 1.8 m from the lower end of the air supply pipe 110, the signal level input from the control section 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 level has reached 2.0 m is issued.

[Effects of Examples of Bubble Level Gauge and Water Ingress Detection Device]
According to the embodiment of the bubble type liquid level gauge of the present invention, the lower end of the air supply pipe 110 is closed by the open/close valve 45 of the opening/closing unit 1 until the lower end of the air supply pipe 110 is submerged under the liquid surface. Therefore, it eliminates various problems seen in conventional bubble level gauges, such as increased compressed air consumption, generation of compressed air discharge noise, waste of power due to unnecessary operation of the compressor, and shortened compressor life. can do.

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

As can be seen from FIGS. 1 to 3, the opening/closing unit 1 has a relatively simple structure with the float 20, the opening/closing valve 45, and the joint 50 as main parts, and requires installation of a liquid level gauge and a water intrusion detection device. It can be installed without taking up too much space.

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 and the air inlet/outlet is closed. Compressed air leaks from 30. By the sound generated at this time, it can be confirmed that the opening/closing unit 1 is operating normally.

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

[Modification]
In the illustrated embodiment, the configuration of the float 20 has been described as having a hollow structure. For example, the float may be made of expanded polystyrene. Also, the shape of the float is arbitrary, and may be, for example, spherical.

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 and closed by the rotation of the L-shaped lever 60, but the structure is not limited to this. do not have. For example, the float may move up and down linearly so that the float directly closes the air inlet/outlet when the float descends and the air inlet/outlet is opened when the float rises due to its buoyant force.

The inundation detection unit and the inundation detection device according to the present invention are not limited to use on ships, and can 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 opening/closing valve 50 joint 51 air flow path 60 lever 70 support member 75 float support plate 100 opening/closing mechanism 110 air supply pipe 120 control unit

Claims (2)

An air supply pipe having at least a lower end immersed in a liquid contained in a storage chamber, a compressed air supply source for supplying compressed air to the air supply pipe, and a pressure sensor for measuring the air pressure in the air supply pipe. and a bubble type liquid level gauge that 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,
Having an opening and closing unit that opens and closes the lower end of the air supply pipe,
The opening/closing unit has a frame, a float mounted in the frame, and an opening/closing valve that opens and closes the lower end of the air supply pipe by vertical movement of the float,
The frame body has a structure in which liquid can flow into the interior and objects other than liquid such as ores, powders, and foods cannot enter,
The on-off valve closes the lower end of the air supply pipe until the lower end of the air supply pipe is submerged in liquid, and when the liquid enters the accommodation space and the float floats, the lower end of the air supply pipe is closed. A bubble level gauge that opens to start operating as a bubble level gauge. a frame, a float mounted in the frame, and an on-off valve that opens and closes a lower end of an air supply pipe by vertical movement of the float,
The frame body is made of metal and partially has window holes, and the window holes are covered with a metal mesh so that liquid can flow into the inside, and ores other than liquid, powder, Objects such as food are structures that cannot enter,
In a natural state, the on-off valve closes the air inlet/outlet by the gravity of the float, and when liquid flows into the frame and the float rises, the lower end of the air supply pipe is opened. An inundation detection device that detects inundation based on air pressure fluctuations in the trachea.

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