JP2010195331A - Liquid suction device, and ship - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid suction device capable of preventing occurrence of any liquid shortage even when a hull is rolled, and executing the continuous operation of a pump, and a ship. <P>SOLUTION: The liquid suction device 10 stores liquid as cargo, and is arranged inside a tank in which a flat part having the predetermined area is formed on a lowest part. The liquid suction device includes: a container 11 which is arranged in a vicinity of the lowest part of the tank, and has an opening on the upper side; a suction part 14 which constitutes a part of piping used for the cargo handling of the liquid, and is opened inside the container 11; and a flow-in unit 12 which is arranged on a lower part of the container 11 to permit the flow-in of the liquid inside the container 11 and to regulate any flow-out of the liquid outside. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid suction device and a ship suitable for use in a ship that transports a liquid such as liquefied natural gas (hereinafter referred to as “LNG”).

In general, a ship that transports a liquid includes a tank that stores a liquid that is a cargo, and is provided with a pump, a pipe, and the like that perform cargo handling.
In general, an open end disposed inside a tank in a pipe for handling a liquid is provided near the bottom of the tank in order to prevent air from being sucked in (see, for example, Patent Document 1). .

For example, even in an LNG ship that transports LNG as a load, pumps and pipes that handle LNG are arranged near the bottom of the tank.
And as for the LNG ship of recent years, what is equipped with the mixed-fuel engine (henceforth "DFE") which can use two types of different fuels as a main engine which is a propulsion engine is being put into practical use. Examples of the two kinds of different fuels include a combination of natural gas obtained by vaporizing LNG and diesel fuel.

  As natural gas supplied to DFE, what vaporized a part of LNG which is a cargo, for example can be used. In this case, the operation of the pump that handles LNG from the tank is indispensable.

JP 2006-123592 A

  However, in the case of an LNG ship equipped with a tank having a flat bottom surface (for example, a membrane tank or a square tank), there is a problem that the above-described pump may not be operated continuously. there were.

  In other words, when the hull of the LNG ship fluctuates when the amount of LNG loaded in the tank is low and the liquid level is low, the LNG in the tank flows in accordance with the fluctuation of the hull, and the pump suction port is on the liquid level of the LNG. May be exposed. When the suction port is exposed on the liquid level, the pump runs out of liquid and stops, so there is a problem that continuous operation cannot be performed.

  The present invention has been made in order to solve the above-described problems, and provides a liquid suction device and a ship that can prevent the occurrence of liquid breakage even when the hull is shaken, and that enables continuous operation of the pump. The purpose is to do.

In order to achieve the above object, the present invention provides the following means.
The liquid suction device of the present invention is a liquid suction device that is disposed inside a tank in which a liquid as a load is stored and a flat surface portion having a predetermined area is formed at the lowermost portion. A container disposed in the vicinity of the lower part and having an opening on the upper side; a part of a pipe used for cargo handling of the liquid; and a suction part that opens to the inside of the container; And an inflow portion that allows inflow into the container and restricts outflow to the outside.

  According to the present invention, since the liquid is accumulated in the container even when the hull provided with the tank is shaken at a low liquid level where the amount of liquid filled in the tank is small, the suction portion is liquid. There is no exposure on the liquid surface.

  In other words, even if the fluid inside the tank flows as the hull moves and the liquid disappears from the surroundings of the container, the outflow of liquid from the inside of the container to the outside is restricted. Yes. Therefore, the suction part is not exposed on the liquid surface.

Furthermore, even when the liquid level of the liquid inside the tank is lower than the upper surface of the container, since the liquid flows into the container from the inside of the tank through the inflow portion, the pump and the like are continuously operated, The liquid can be continuously sucked into the suction part.
On the other hand, when the liquid level of the liquid inside the tank is higher than the upper surface of the container, the liquid flows into the container from the opening formed on the upper surface of the container.

  For this reason, in the liquid suction device disposed in the tank provided in the hull that is periodically shaken, the liquid periodically flows into the container, so that the liquid in the container is not lost. In other words, the suction part is not exposed on the liquid surface.

  In the above invention, the inflow portion is provided with a check valve that opens and closes based on a hydraulic pressure difference between the water pressure of the liquid inside the container and the water pressure of the liquid outside the container. desirable.

  According to the present invention, when the hull provided with the tank is shaken and the liquid disappears from the periphery of the container, the check valve is closed due to the hydraulic pressure difference and the liquid is prevented from flowing out from the inside of the container. . In other words, when the liquid level inside the container becomes higher than the liquid level inside the tank, the check valve closes due to the hydraulic pressure difference.

  On the other hand, when the liquid inside the container is sucked out from the suction part and the liquid level inside the container is lowered, the check valve is opened due to the hydraulic pressure difference, and the liquid flows into the inside from the outside of the container. In other words, when the liquid level in the container is lower than the liquid level in the tank, the check valve is opened due to the hydraulic pressure difference.

  The ship according to the present invention is characterized in that a liquid that is a cargo handling is stored, a tank in which a flat portion having a predetermined area is formed at a lowermost part, and the liquid suction device according to the present invention are provided. .

  According to the present invention, since the liquid suction device of the present invention is provided, it is possible to prevent the occurrence of liquid shortage even when the hull is shaken and to enable continuous operation of the pump.

  According to the liquid suction device and the ship of the present invention, the container having the suction part disposed therein and the inflow part for allowing the liquid to flow into the container and restricting the flow to the outside are provided. Also, even when the hull is shaken, it is possible to prevent the occurrence of liquid breakage and to enable continuous operation of the pump.

It is a sectional view explaining composition of an LNG ship concerning one embodiment of the present invention. It is a schematic diagram explaining the structure of the LNG suction apparatus of FIG. It is a schematic diagram explaining the structure of the LNG suction apparatus of FIG. It is a schematic diagram explaining the structure of the inflow part of FIG. It is a schematic diagram explaining the structure of the inflow part of FIG.

An LNG ship according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a cross-sectional view illustrating the configuration of the LNG ship according to the present embodiment.
In the present embodiment, the present invention is described by applying it to an LNG ship (ship) 1 provided with a membrane tank 3.
The LNG ship 1 is a ship that transports LNG, and is a ship provided with a plurality of tanks 3 in which a hull 2 is filled with LNG.
In the present embodiment, description will be made by applying to a main engine of the LNG ship 1 using natural gas obtained by vaporizing LNG and DFE using other fuel (for example, diesel fuel) as fuel.

  The hull 2 constitutes the LNG ship 1 and has a plurality of tanks 3 inside. The plurality of tanks 3 are arranged side by side in the longitudinal direction of the hull 2 (perpendicular to the paper surface of FIG. 1).

The tank 3 is a low-temperature insulated container filled with cryogenic LNG inside, and is shaped to fit a square cargo space as shown in FIG. 1, with a bottom surface having a predetermined area at the bottom. This is a container provided with a (planar portion).
In addition, although the membrane-type tank can be mentioned as the tank 3 in this embodiment, It is not limited to this.

Inside the tank 3, as shown in FIG. 1, an LNG suction device (liquid suction device) 10 is provided.
The LNG suction device 10 sends out LNG from the inside of the tank 3 to the outside. Further, the LNG suction device 10 is disposed on the bottom surface of the tank 3 or in the vicinity of the bottom surface, and is disposed on the center line L of the hull 2.

2 and 3 are schematic views for explaining the configuration of the LNG suction device of FIG.
As shown in FIGS. 2 and 3, the LNG suction device 10 is provided with a container 11, an inflow portion 12, a pump 13, and a suction portion 14.

The container 11 prevents the suction part 14 from being exposed on the liquid level of LNG by storing LNG inside. The container 11 is arrange | positioned at the bottom face of the tank 3, or the bottom face vicinity, and is being fixed to the tank 3 via the fixing bracket 11B.
Further, an opening (opening) 21 is provided on the upper surface (upper side in FIG. 2) of the container 11, and a flange portion 22 to which the inflow portion 12 is attached is provided on the lower side of the side surface.

  The opening 21 is a part into which LNG flows into the container 11, and a part into which the pump 13 and the suction part 14 are inserted into the container 11. The opening 21 is provided with a mounting portion 23 to which the pump 13 and the suction portion 14 are attached.

As shown in FIGS. 2 and 3, the flange portion 22 is a portion to which the inflow portion 12 is attached. Further, the flange portion 22 is provided separately on the lower side of one side surface of the container 11 and on both end sides of the one side surface.
On the other hand, a through hole through which the LNG that has passed through the inflow portion 12 flows into the container 11 is provided in the flange portion 22.

4 and 5 are schematic diagrams illustrating the configuration of the inflow portion of FIG.
The inflow portion 12 allows the flow from the outside to the inside of the container 11 in the LNG and regulates the flow from the inside to the outside.
As shown in FIGS. 4 and 5, the inflow portion 12 is provided with a main body 31 and a check valve 32.

  The main body 31 is formed in a substantially disk shape or a columnar shape, and is provided with a through hole through which LNG flows. Furthermore, the main body 31 is a part attached to the flange part 22 and also a part provided with a check valve 32.

The check valve 32 is a difference between the liquid level of LNG inside the container 11 and the liquid level of LNG outside, that is, the difference between the liquid pressure of LNG inside the container 11 and the liquid pressure of LNG outside. It is a valve that opens and closes based on. Therefore, the check valve 32 allows the flow from the outside to the inside of the container 11 in the LNG and can regulate the flow from the inside to the outside.
As shown in FIGS. 4 and 5, the check valve 32 is provided with a valve body 41, a valve seat 42, and a shaft body 43.

  The valve body 41 is a part formed in a disk shape, and together with the valve seat 42, opens and closes a flow path through which the LNG formed in the main body 31 flows, and controls the flow of the LNG. The valve body 41 is rotatably attached to the main body 31 via the shaft body 43.

The shaft body 43 supports the valve body 41 and the valve seat 42 so as to be rotatable with respect to the main body 31.
When the inflow portion 12 is attached to the container 11, the valve body 41 is separated from the main body 31 when rotated toward the inside of the container 11, and the main body 31 when rotated toward the outside of the container 11. Is placed in contact with.

  The valve seat 42 is a portion protruding from the valve body 41 in a ring plate shape, and together with the valve body 41, opens and closes a flow path through which the LNG formed in the main body 31 flows, and controls the flow of LNG. The inside of the main body 31 formed in a cylindrical shape is a flow path through which LNG flows.

The pump 13 supplies natural gas (LNG) inside the tank 3 and the container 11 to the DFE. Further, the pump 13 is attached to the container 11 together with the suction part 14.
As the pump 13, a known pump used for LNG can be used and is not particularly limited.

  The suction part 14 is a part into which LNG inside the tank 3 and the container 11 flows. Furthermore, the suction part 14 is attached to the container 11 together with the pump 13 and is arranged inside the container 11.

Next, supply of natural gas (LNG) to DFE in the LNG suction apparatus 10 having the above-described configuration will be described.
When the tank 3 is filled with a sufficient amount of LNG, the LNG easily flows into the container 11 from the opening 21 as shown in FIGS. Therefore, by operating the pump 13, LNG is sucked from the suction portion 14 and supplied to the DFE as natural gas via the pump 13.

  On the other hand, when the amount of LNG filled in the tank 3 is small and the liquid level of LNG is below the opening 21 of the container 11, the LNG causes the check valve 32 of the inflow portion 12 to be turned off. Pass through and flow into the container 11.

  Specifically, when the LNG inside the container 11 is sucked into the pump 13 and the LNG liquid level inside the container 11 becomes lower than the outside LNG liquid level, the check valve 32 opens and the outside of the container 11 LNG flows inside. In other words, when the LNG hydraulic pressure inside the container 11 becomes lower than the outer LNG hydraulic pressure, the valve body 41 of the check valve 32 is pushed by the hydraulic pressure difference, and the valve body 41 and the valve seat 42 are separated from the main body 31. The check valve 32 opens away.

Further, when the LNG inside the tank 3 flows in accordance with the shaking of the hull 2, there are cases where the LNG exists around the container 11 and when it does not exist.
When LNG does not exist around the container 11, the check valve 32 is closed by the liquid pressure of LNG accumulated in the container 11. That is, the valve body 41 and the valve seat 42 of the check valve 32 are pressed against the main body 31 under the hydraulic pressure of LNG, and the check valve 32 is closed.

Then, the LNG is restricted from flowing out from the inside of the container 11, and the LNG is stored inside the container 11.
The LNG stored in the container 11 is sucked into the pump 13 and the suction part 14 until the LNG returns around the container 11 due to the shaking of the hull 2. Therefore, the suction part 14 is not exposed on the liquid level of LNG.

  Thereafter, when LNG returns to the periphery of the container 11, the check valve 32 of the inflow portion 12 is opened, and LNG flows into the container 11. As described above, since LNG flows into the container 11 in accordance with the fluctuation of the hull 2, the suction portion 14 is not exposed on the liquid level of the LNG.

  According to the above configuration, LNG is accumulated in the container 11 even when the hull 2 provided with the tank 3 is shaken at a low liquid level where the amount of LNG filled in the tank 3 is small. The suction part 14 is not exposed on the liquid level of LNG.

  That is, even if the LNG in the tank 3 flows due to the shaking of the hull 2 and the LNG disappears from the periphery of the container 11, the outflow of LNG from the inside of the container 11 to the outside is restricted. LNG is accumulated inside the. Therefore, the suction part 14 is not exposed on the liquid level of LNG.

Furthermore, even when the liquid level of LNG inside the tank 3 is lower than the upper surface of the container 11, LNG flows from the inside of the tank 3 into the inside of the container 11 through the inflow portion 12. Etc. can be continuously operated, and LNG can be continuously sucked into the suction portion 14.
On the other hand, when the liquid level of LNG inside the tank 3 is higher than the upper surface of the container 11, LNG flows into the container 11 from the opening 21 formed on the upper surface of the container 11.

  Therefore, in the LNG suction device 10 disposed in the tank 3 provided in the hull 2 that is periodically shaken, since LNG periodically flows into the container 11, the LNG inside the container 11 disappears. There is no. In other words, the LNG suction device 10 is not exposed on the liquid level of the LNG.

  When the hull 2 provided with the tank 3 is shaken and the LNG disappears from the periphery of the container 11, the check valve 32 is closed due to a hydraulic pressure difference and the LNG is prevented from flowing out of the container 11 to the outside. . In other words, when the liquid level of LNG inside the container 11 becomes higher than the liquid level of LNG inside the tank 3, the check valve 32 is closed due to the hydraulic pressure difference.

  On the other hand, when the LNG inside the container 11 is sucked out from the suction part 14 and the liquid level inside the container 11 is lowered, the check valve 32 is opened due to the hydraulic pressure difference, and the LNG is transferred from the outside to the inside of the container 11. Flows in. In other words, when the liquid level of LNG inside the container 11 becomes lower than the liquid level of LNG inside the tank 3, the check valve 32 opens due to a hydraulic pressure difference.

1 LNG ship (ship)
2 Hull 3 Tank 10 LNG suction device (liquid suction device)
11 Container 12 Inflow part 14 Suction part 21 Opening part (opening)

Claims (3)

A liquid suction device that is disposed inside a tank in which a liquid that is a cargo is stored and a flat surface portion having a predetermined area is formed at the bottom,
A container disposed near the bottom of the tank and having an opening on the upper side;
A part of a pipe used for the cargo handling of the liquid, and a suction part that opens into the container;
An inflow portion that is disposed at a lower portion of the container, allows the liquid to flow into the container, and restricts outflow to the outside;
A liquid suction device is provided. In the inflow part,
The liquid suction device according to claim 1, further comprising a check valve that opens and closes based on a hydraulic pressure difference between a water pressure of the liquid inside the container and a water pressure of the liquid outside the container. . A tank in which a liquid that is a cargo handling is stored, and a flat part having a predetermined area is formed at the bottom,
A liquid suction device according to claim 1 or 2,
A ship characterized by that.

Images