KR101846600B1 - Inflatable element for use inside a container - Google Patents

Abstract

The present invention relates to an inflatable element for use as a damper for fluid oscillation within a holder 2 having a holder bottom wall, a holder top wall 31, holder side walls 9 ', 9 ", 10', 10" And the holder is suitable for transporting a liquefied natural gas or a liquefied gas having a vapor such as LNG and the element wall 5 comprises the element lower wall 7, the element upper wall 8 and the element side wall 13, Wherein the element is in the use position the element lower wall 7 floats on the liquid load 3 and the inflatable element 4 has a thickness d smaller than the height between the liquid surface and the holder upper wall 31 of the holder And openings 11 extending from the element lower wall 7 to the element upper wall 8 are provided and constitute an open fluid connection.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an inflatable element used in a container,

The present invention relates to an inflatable element for use as a damper for fluid oscillation within a holder. The holder is an enclosed space suitable for storing liquid loads, and in particular, the holder is suitable for transporting liquefied natural gas or a liquefied gas such as LNG with the vapor. The closed holder is provided with a holder bottom wall, a holder top wall and holder side walls. The inflatable element includes an element wall defining a closed volume of a fixed volume for containing the inflation gas, and the element wall includes an element lower wall, an element upper wall and element sidewalls. In the use position, the inflatable element floats the element bottom wall above the free liquid surface of the liquid load.

The transport tank (tank lorry) and the cargo in the load truck may be driven by a high speed on a curved road, for example by accelerating or accelerating, braking or decelerating for various reasons It is known that by virtue of the redirection caused by the collision, it is possible to show undesired dynamic behavior which may even lead to vehicle overturning. This effect is mainly dependent on the type of cargo held in the storage tank, truck or tanker. For example, when there is a sudden movement of a tanker, a free (low viscosity) liquid will move easily. Movement back and forth, or liquid jolt, may be accompanied by an additional impact force to facilitate the overturning of the tanker or truck. In accordance with prestigious regulations, baffle plates are mounted within a holder having a volume that exceeds a certain limit, in order to prevent swelling or vibration of the liquid in the longitudinal or running direction of the tank. Such baffle plates have the disadvantage of buffering only liquid motion in the axial direction so that the movement of the liquid in a direction other than the axial direction, such as radial or tangential movement, is buffered only to a lesser extent or to a lesser extent. Furthermore, these plates have their own mass and volume, reducing the capacity of the holder. Moreover, these plates are usually fixedly mounted inside the holder, requiring labor intensive internal mounting, inspection, maintenance, and cleaning. Furthermore, the plates fixedly mounted in the holder will transmit some of the energy and impact force of the oscillating liquid to the holder and holder walls.

Even in a tanker ship for transporting / transporting over water or for storing liquids and gases in the sea, fluctuations of the liquid and ups and downs can occur due to the upward and downward movement of the boat and water. Gas tankers such as LNG (liquefied natural gas) tankers or carriers usually include two or more holders that are cooled to a temperature of about 162 ° C at atmospheric pressure to store / store or transport the gas as liquid. The holders are usually 'spherical' self-supporting, or they may be 'membrane-type' supported directly by the hull of the ship. Stand-alone holders form a lot of empty space between the balls, so that the capacity of such a ship will be smaller than the capacity of a 'membrane type' ship that better utilizes the available space in the holder. The stand-alone holders are preferred as a storage tank for the ocean because they have greater resistance to forces applied by the swirling liquid. In 'spherical' gas is stored under pressure, the wall thickness of the 'sphere' becomes thick, which involves high cost and high load.

In holders of the 'membrane type', the transported gas exists not only in a vapor state but also in a liquid state under atmospheric pressure. The fluid is boiled as a result of the energy supplied by the heat conduction and the energy absorbed by the liquid generated by the swirling or swirling liquids. Fluctuations and fluctuations of the liquid in the holders of the gas tanker depend not only on the swirling of the water but also on the degree of loading of the gas tanker. As the load increases, the ship will be placed deeper in the water, and the natural frequency, vibration and swing frequency of the cargo in the ship and the holder will change. Further, in the gas tanker, the swirling and swirling of the liquid causes energy absorption, thereby causing the liquid to evaporate, and it is required to remove excessive energy by additional cooling or other methods. Hereinafter, the term LNG (liquefied natural gas) tanker refers to a gas tanker for storage and / or transport of liquefied gas.

These effects make it impossible to fully utilize the capacity of the container and reduce the filling rate to a value between approximately 10% and 75%. This creates operational limitations, particularly for LNG shuttle tankers operating in the spot market, for example because of the inability to anchor in buoys due to dominant maritime conditions, reducing the amount of gas required commercially or operationally, This will result in failure of the transaction. It is also required to have the maximum capacity with the greatest possible safety for water swell and waves in the development of oilfields and gas fields using LNG tankers as a floating pool near the borehole. In addition, LNG tankers are used for so-called 'regasification', in which queues are used to evaporate liquid (natural) gas and transport gas to consumers.

The liquid gas forms liquid-vapor equilibrium in the holder with temperature and pressure. The pressure and temperature are selected so that the gas product in the holder is present as an essentially boiling liquid at atmospheric pressure. Thus, the free space above the liquid is completely filled with the vapor or gas of the liquid state product.

U.S. Pat. No. 3,120,902 discloses an expandable element used as a floating roof or cover in an open digester tank filled with water. The roof of the digester is provided with a metallic central tube which is opened to the inside of the digester from the bottom to collect the biogas produced in the digester and the collected digestion gas is then continuously fed to the gas- It is connected to the pressure relief valve and downstream channel on the top for treatment. Such a roof is not suitable for installation in a holder for (existing) liquefied gas to operate as a damper against vibrations of the liquefied gas during transport.

An inflatable bag, an air bag, a buffer cushion or a balloon is provided inside the holder of the transportation or storage device and is compressed by inflation gas such as nitrogen or air using, for example, inflation gas or a compressor from a high-pressure storage tank, It is well known that it fills most of the free space of this holder, thereby limiting the liquid gushing and vapor formation. Preferably, such an inflatable element forms a closed connection by shape and / or force on the holder inner wall, so that an excellent buffering effect against fluid movement or shaking is obtained. In a preferred embodiment, as inflatable gas is supplied to or discharged from the inflatable element, it constitutes an inflatable element with an accordion wall or other type of extensible wall or collapsible wall or walls, respectively folded and unfolded or stretched and shrunk. This type of inflatable element is not suitable for insertion into the holder of the LNG tanker because it must be in liquid and gas contact for cooling and discharging of the gas.

It is an object of the present invention to provide an inflatable element which cushions and greatly reduces the shaking or swelling of a fluid, such as liquefied gas, in a (transport) holder without the need to fill the entire free space with an inflatable element.

This object is achieved by the present invention by providing an inflatable element having a thickness less than the height between the free liquid surface and the holder top wall of the holder, wherein the inflatable element is provided with openings extending from the element bottom wall to the element top wall, Is achieved by constructing an open fluid connection between the liquefied gas and the vapor gas.

By means of the above-mentioned means, liquid wobble and swirling are buffered by the swellable element on the liquid surface, the liquid evaporated through the fluid connections formed by the openings of the swellable element can flow into the vapor space, You can go back to the gas.

In a preferred embodiment, the inflatable element is provided with a friction flap or stabilizing body near the holder side walls. Because of this configuration, the inflatable element obtains additional stability at that edge without creating additional resistance during displacement of the element due to changes in the liquid level.

Preferably the inflatable element is provided with a friction flap or stabilizing body in the vicinity of the four opposing holder side walls of the holder. In particular, the stabilizing body extends around the entire peripheral edge of the inflatable element and constitutes a single piece peripheral body. By attaching a friction flap to each of the four opposing holder sidewalls and providing a single stabilizing body, the inflatable element can not move easily upwards or downwards along the holder sidewalls, whereby the inflatable element has a stabilizing effect on vibration of the liquid and It provides a buffering effect.

Preferably, at the location of use, the element bottom wall is essentially flat and the element top wall is arcuate, curved, or multiple arcuate or curved. This will make deformation of the expandable element caused by the movement of the fluid in the holder more difficult and buffer the liquid vibration better.

In a preferred embodiment, the friction flap is an inflatable body or element comprising a closed interior space for containing inflation gas. By these means, the frictional flap is made wider or thicker in the horizontal direction and / or the friction flap is made longer in the vertical direction to form an enlarged friction surface between the friction flap and the inner wall of the holder, The amount of friction or resistance between the inner walls can be adjusted.

In particular, a connection channel is provided between the inner space of the frictional flap and the inner space of the expansive element. When the pressure in the interior space of the inflatable element is increased, such a connection channel will make the friction flap longer and thicker.

Embodiments in which the connection channel is a long slit and form an open fluid connection between the inflatable element and the friction flap is preferred. As a result, a good fluid connection between the inflatable element and the friction flap is formed, so that the stabilizing frictional force between the friction flap and the holder walls is maintained, and the clamping force applied to the upstanding walls of the holder by the inflatable element can be preserved.

In yet another embodiment, support elements extending from the element top wall of the inflatable element to the holder top wall of the holder are provided.

In particular, the support element is an inflatable element whose height can be adjusted by supplying or discharging the inflation gas.

These support elements will maintain the inflatable element in place over the liquid surface, thereby buffering the fluid vibration. The vertical position of the inflatable element can be adjusted according to the degree of loading of the holder, since the support elements can be expanded or broken by, for example, supplying or discharging the inflation gas.

In a first variant, the friction flap is characterized by being a substantially horizontal flexible flap which is connected to the element sidewall of the inflatable element by a turning point or a bending point.

In particular, the flexible flaps are made of a tough, resilient material such as rubber or plastic material. In this embodiment, providing a closure between the expandable element and the holder walls that can be easily moved along the protrusion of the holder wall, such as the wall bend / bend or wall tongue, within the 'membrane type' gas tanker It is possible.

A second variant of the friction flap is characterized in that the friction flap is a flexible roll rotatably mounted about the rotation axis at the element side wall of the inflatable element.

In particular, the flexible roll is made of a flexible and compressible material such as a spongy material and / or a fibrous material such as hair. The roller is rotated about its axis and the protrusions of the wall, such as the wall bend / flexure or tongue, are pressed together with the material of the roll, so that the inflatable element can be easily moved up and down and the wall and / or the inflatable element is not damaged .

The invention also relates to a transport or storage device comprising a container having an inflatable element.

The invention is further illustrated by the drawings of the inflatable element and some embodiments, and other advantages and configurations will be described.
Figure 1 is a perspective view of an LNG tanker having several holders for liquefied gas.
Figure 2 shows in greater detail the holder of Figure 1 with an inflatable element.
Figure 3 shows a top view of a holder with an inflatable element with openings.
Figure 4 shows the friction flap in the vicinity of the holder side wall in more detail.
Figure 5a shows a side view of an alternative embodiment of an inflatable element with support elements.
Figure 5b shows a perspective view of the support elements of Figure 5a.
Figure 5c shows a top view of the embodiment of Figure 5a.
Figs. 6A, 6B and 6C show a modification of the friction flap.
Figure 7 shows a roll flap which is another second variation of the friction flap.

Figure 1 shows a transport or storage device with several holders (2). The transport apparatus of the present example is a gas tanker 1 having eight holders 2 or tanks provided for transporting the liquid load 3 and in this example the liquid load is in particular LNG (Liquefied Natural Gas, Liquefied Natural Gas ). ≪ / RTI > Gas tankers suitable for liquefied gas transport are referred to below as LNG tankers. LNG tankers are provided with means and facilities for maintaining the correct temperature and pressure to keep the gas liquefied.

In Fig. 2 the holder 2 is shown in more detail. The holder 2 forms, for example, a sealed space for storing and optionally transporting a liquefied gas such as natural gas or LNG with its vapor. The closed holder has a holder bottom wall, a holder top wall 31, and a holder side wall 9 ', 9' ', 10', 10 ''. About three-quarters of the holder 2 is filled with the liquefied gas 3 so that the upper surface of the liquid is located approximately three-quarters of the height of the holder 2. An inflatable element or airbag 4 having an element wall 5 defining a closed internal space 6 floats on the top of the liquid 3 and the element wall 5 is floated with a flat element lower wall 7, A curved element upper wall 8, and element side walls 13. Friction flaps 20 ', 20 " are provided on the element side walls 13 to provide a hermetic connection to the holder side walls 9', 9 '', 10 ', 10' 'of the holder 2 do. The inflatable element 4 has a thickness d which is less than the height between the free liquid surface and the holder top wall 31 of the holder 2 so that the inflatable element 4 occupies only a small portion of the vapor space of the holder. The inflatable element 4 is connected to an inflating auxiliary means (not shown), such as an air compressor and a control unit, which supplies an inflation gas, such as air or other gas product, into and out of the inflatable element 4. Control means such as control lighting is also provided in the control room or control area of the gas tanker.

In the inflatable element 4 of Figure 2, openings 11 are provided extending from the element lower wall 7 to the element upper wall 8. Whereby the openings 11 constitute an open fluid connection between the liquefied gas and the vapor gas. Through these openings 11 the vapor state is openly connected to the liquid state so that the vaporized liquid exits through the expansive element 4 and the condensed vapor can return to the liquid. In such a holder 2 containing liquefied gas, energy is lost by the energy supplied by the heat conduction to the holder 2 and the energy absorption by the swinging or swirling of the liquid holder at a temperature much lower than the ambient temperature. The stabilization of the fluid and the buffering of the fluid vibration limits energy flow to the holder 2 and saves energy.

In the plan view of the holder 2 of Fig. 3, an inflatable element 4 with openings 11 is shown. The number of openings 11 can vary depending on the number and size thereof, and it can be said that it is generally advantageous that the openings 11 are regularly distributed in the element top wall 8.

4, which shows a cross-section taken along IV-IV of FIG. 3, the inflatable element 4 and the wall element 5 are shown in detail and in the present embodiment, the element upper wall 8 and the element lower wall 7). A portion of the element wall 5 may be provided with a reinforcing element such as a textile fiber network or a carrier. Preferably, the element lower wall 7 is provided with a reinforcing portion to prevent warping and maintain a flat surface, which is advantageous in buffering the vibration of the liquid 3. [ The inflatable element is provided with a connecting portion 12 between the element upper wall 8 and the element lower wall 7 in order to provide a curved surface that extends regularly longitudinally to the element upper wall 8 of the inflatable element 4. [ . The inflatable element 4 has a thickness d that is less than the distance between the liquid surface and the holder upper wall 31 of the holder 2. [

Further, FIG. 4 shows a friction valve 20 '' embodied in an inflatable body having an internal space 21. The friction flap 20 '' extends parallel to the holder side wall 10 '' together with the friction walls 23. The friction wall 23 is in contact with, preferably fixed to, the inner side 19 of the holder side wall 10 ". This creates a frictional force between the holder sidewall and the friction flap 20 " and the expandable element 4 attached thereto, so that it acts as a damper of the liquid vibration as the inflatable element 4 is positioned and stabilized on the surface of the liquid , Thereby preventing the occurrence of liquid vibration and buffering the liquid vibration. The friction flaps may be fixed to one, two, or all four of the element sidewalls of the inflatable element 4 or may be configured as a body extending around the entire peripheral edge of the inflatable element 4. The magnitude of the resistance between the holder side wall and the friction flap can be adjusted by adjusting the amount of air in the internal space 21 of the friction flap.

The friction flaps 20 ', 20 " may be provided with individual expansion means or control systems. Advantageously, the internal space 21 of the friction flap is in open communication with the internal space 6 of the inflatable element 4, thereby simultaneously changing the friction on the walls of the holder 2 by expanding or contracting the inflatable element . To this end, a connecting channel 22 may be provided between the internal space 6 of the inflatable element 4 and the internal space 21 of the friction flaps 20 ', 20' '. In a particular embodiment, the connecting channel 22 has the shape of a long slit, which extends horizontally long between the inflatable element 4 and the friction flaps 20 ', 20' '. The friction flaps 20 ', 20 " may sometimes be referred to as lids or wings.

Since the inflatable element 4 floats above the liquid surface of the liquid load 3 and does not fill the entire vapor space, the inflatable element 4 acts as a damper of the fluid vibration and has the effect of inhibiting or slowing the formation of the fluid vibration And also has the effect of buffering the movement of the liquid 3 in the holder 2 in the swinging or chattering. This buffering effect is further increased by further inflating the inflatable element 4 so that the friction flap 20 'can be deployed to such an extent that it contacts the inner side 19 of the holder side wall 10 " of the holder 2. In this inflated position, the inner space 21 of the friction flap 20 'is also completely filled with the expanded air so that friction occurs between the holder sidewall 10' 'and the friction flap 20' 2) will have a strong buffering effect on fluid vibration.

5A, 5B, 5C, the friction flaps 20 ', 20 "of the inflatable element 4' still having the thickness d and the through openings 11, Is replaced by support elements 30 extending from the element upper wall 8 of the holder 4 to the holder upper wall 31 of the holder 2. These support elements 30 also maintain the inflatable element 4 'in place on the surface of the liquid 3, creating a buffer action against fluid vibration. The support element 30 is preferably extendable and retractable so that the vertical position of the inflatable element 4 can be adjusted according to the degree of loading of the holder 2. [ Thus, preferably, a separate system for controlling, supplying, and discharging expanded air is provided to the support elements 30. To enable the support elements 30 to easily extend and retract, the support elements can include an accordion wall.

6A, 6B and 6C, there is shown a first variant of a friction flap adapted to be applied to a 'membrane-like' holder 2. In FIG. This holder (2) has a thin membrane wall (45). These membrane walls 45 are provided with bent portions 46 or accordion structures or sometimes protruding tongues of the overlying membrane to compensate for the expansion or contraction of the wall material by a large temperature difference. These raised bends or tongues 46 are disadvantageous for operation of the inflatable element according to the invention. Thus, the inflatable element 4 '' of the present embodiment is provided with a flexible flap 40 which is arranged with respect to the element side wall 13 of the inflatable element 4 by the pivot 41.

6A, the inflatable element 4 " and the flexible flap 40 move downwardly into the liquid surface of the holder 2. In Fig. 6B shows that the flexible flap 40 is tangent to the upper side of the wall bend 46 and slightly tilted about the pivot point 41 relative to the inflatable element 4 ".

6C shows that the flexible flap 40 of the upwardly-moving inflatable element 4 " is inclined downwardly about the pivot point 41 about the element side wall 13 of the inflatable element 4, The flap (40) moves over the wall bend (46). The flexible flap 40 provides an excellent seal against the membrane wall 45 of the holder while the inflatable element is moving up and down and also provides a clamping position for the inflatable element 4 to prevent entanglement, It provides buffering action.

In a second variant of the friction flap of figure 7, a flexible roll 50 applied to the element side wall 13 of the inflatable element 4 " 'is applied to rotate about the rotation axis 51. The axis of rotation is a known means such as braces or similar means connected to the inflatable element 4 " '. The flexible roll or roll flap 50 is made of a flexible compressible material, such as a spongy material or spongy fibers such as hair. This allows the roll flap 50 to easily pass through obstacles protruding from the membrane wall 45 because the material of the roll is pressed together at the location of the obstacle such as the wall bend or tongue 46. [ The flexibility of the material of the flexible roll 50 may be adjusted by mechanical strength of the membrane wall 45, or by a membrane mounted thereon, or by an expandable element, in order to prevent the liquid from slipping out, Can be easily adjusted as needed.

The inflatable elements 4, 4 ', 4' ', 4' '' may be one large inner space with a thickness d, or may be divided into compartments, such as element parts mounted longitudinally of the holder.

The inflatable element may be loosely inserted in the holder or fixedly attached to the holder, but preferably the element is arranged in the holder such that a small force is applied to the holder side walls of the holder.

The expandable element may be made of any suitable material, such as plastic or fabric.

Claims (15)

An expandable element for use as a damper for fluid oscillation within the holder (2)
The holder is an enclosed space suitable for storing the liquid load 3 and the holder is suitable for transporting liquefied natural gas or a liquefied gas such as LNG with the vapor,
The closed holder is provided with a holder lower wall, a holder upper wall 31 and holder side walls 9 ', 9'',10', 10 '',
The inflatable element 4 comprises an element wall 5 defining a fixed volume of enclosed interior space 6 for containing inflation gas and the element wall 5 comprises an element lower wall 7, Includes a wall (8) and an element side wall (13)
The inflatable element will float above the free liquid surface of the liquid load 3 in the use position and the element lower wall 7,
The inflatable element 4 has a thickness d which is less than the height between the free liquid surface and the holder upper wall 31 of the holder and the inflatable element 4 is provided with an element lower wall 7 to the element upper wall 8 Extending openings 11 are provided, the openings 11 constituting an open fluid connection between the liquefied gas and the vapor gas,
The inflatable element 4 is provided with friction flaps or stabilizing bodies 20 ', 20 " near the holder side walls 9', 10 '
The friction flaps 20 ', 20 " are an inflatable body or element comprising an enclosed inner space 21 for containing inflation gas,
Characterized in that a connecting channel (22) is provided between the internal space (21) of the friction flap (20 ', 20'') and the internal space (6) of the inflatable element (4).
delete The inflatable element according to claim 1, characterized in that the inflatable element (4) is provided with a friction flap or stabilizing body (20 ') in the vicinity of the four opposing holder side walls (9', 9 ", 10 ' , 20 "). ≪ / RTI > The inflatable element according to claim 3, characterized in that the stabilizing bodies (20 ', 20' ') extend around the entire peripheral edge of the inflatable element (4) and constitute a single peripheral body. The device according to any one of the preceding claims, wherein the element lower wall (7) is essentially flat in use position and the element upper wall (8) is arcuate, curved, Type. ≪ / RTI >
delete delete 2. A device according to claim 1, characterized in that the connecting channel (22) is a long slit and forms an open fluid connection between the inflatable element (4) and the friction flap (20 ' . The inflatable element according to claim 1, characterized in that support elements (30) extending from the element upper wall (8) of the inflatable element (4 ') to the holder upper wall (31) of the holder (2) are provided. 10. An inflatable element according to claim 9, characterized in that the support elements (30) are inflatable elements whose height can be adjusted by supplying or discharging inflation gas. A friction element according to claim 1, characterized in that the friction flap is a horizontal flexible flap (40) which is connected to the element side wall (13) of the inflatable element (4 ") by a turning point or bending point (41) , An inflatable element. 12. The inflatable element of claim 11, wherein the flexible flap (40) is made of a tough, resilient material such as rubber or plastic material. 2. The device according to claim 1, characterized in that the friction flap is a flexible roll (50) rotatably mounted about the rotation axis (51) at the element side wall (13) of the inflatable element (4 ' . 14. An inflatable element according to claim 13, characterized in that the flexible roll (50) is made of a flexible and compressible material, such as a spongy material or a fibrous material such as hair. A container (2) having an inflatable element (4, 4 ', 4'',4''') according to any one of claims 1, 3, 4 and 8 to 14 Container, transport or storage equipment (1).

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