JP4054592B2 - Gas hydrate pellet carrier - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas hydrate pellet transport ship for pelletizing and transporting a so-called gas hydrate composed of a gas mainly composed of methane such as natural gas and water.
[0002]
[Prior art]
Conventionally, natural gas is transported in the form of liquefied natural gas (hereinafter referred to as LNG) or compressed natural gas.
[0003]
However, LNG needs to be transported with the cargo temperature kept at minus 162 ° C., and a special ship (LNG ship) equipped with an expensive tank specially manufactured for transport is required. In addition, LNG needs to invest a lot of energy in its production in order to make natural gas a liquid of minus 162 ° C. In addition, LNG is very dangerous because it rapidly vaporizes when temperature control is poor. Furthermore, as described above, LNG has an extremely low temperature and thus has a high vaporization rate and is not suitable for long-term storage.
[0004]
On the other hand, as a clean energy source and a raw material of various structures, researches have been conducted to artificially or industrially make gas hydrate (hereinafter referred to as NGH), which is mainly composed of methane such as natural gas.
[0005]
In brief, NGH has a crystal structure in which gas molecules are contained one by one in a cage made of water molecules. For example, methane hydrate has a methane hydrate of 1 m ³ at normal pressure. It is said that 164m ³ of methane can be stored inside. Of these, water is 0.8 m ³ .
[0006]
Thus, since methane hydrate has a high gas storage property, it attracts attention as a new transport and storage body of natural gas to replace LNG. The density of methane gas in methane hydrate is about 3.5 times lower than that of LNG. However, when it is manufactured artificially or industrially, examples up to the liquefaction temperature (less than minus 162 ° C) like LNG Since there is no need to cool, there is an advantage that energy efficiency is greatly improved.
[0007]
In the case of artificially producing methane hydrate, for example, water or antifreeze is distributed from a distribution means in a pressure vessel maintained at a temperature of 1 to 10 ° C. and a pressure of 30 to 100 atm. Supply gas (methane). Then, the water or antifreeze liquid distributed from the distributing means and natural gas (methane) are synthesized to generate powdered methane hydrate.
[0008]
Since powder methane hydrate has a small filling rate (volume of methane hydrate / volume of storage container), it is pelletized (eg, small spherical) by a granulator such as a pelletizer in order to increase the efficiency of transportation and storage. It is considered to form a solid.
[0009]
[Problems to be solved by the invention]
In order to increase the transport efficiency of such methane hydrate, development of a transport ship of gas hydrate pellets (hereinafter referred to as NGP) manufactured by solidifying powder is desired.
[0010]
[Means for Solving the Problems]
As described in claim 1, the gas hydrate pellet transport ship according to the present invention has a double shell structure on the side wall and bottom wall of the hull, and partitions the hull with bulkheads to form a plurality of holds in the ship length direction. Forming and arranging independent tanks covered with a heat insulating material in the plurality of holds, the independent tanks being arranged on the tank side walls formed along the hold, and on the tank side walls, The upper part of the hold is divided into four planes, each section is shaped like a reverse funnel, and the upper part of the unit upper wall with the inlet at the center is connected to one wall, and placed on the lower part of the tank side wall A bottom wall formed by combining a plurality of unit bottom walls configured in a funnel shape, a screw conveyor having a suction port at a lower end in the independent tank, and the suction port serving as the bottom wall. At the tip of the funnel-shaped part of the unit bottom wall The gas hydrate pellets are loaded and unloaded while being positioned and inclined so as to straddle the compartments partitioned into the independent tanks with the upper part protruding from the upper wall of the independent tank. Yes.
[0011]
According to the gas hydrate pellet transport ship having such a structure, the NGP loaded in the independent tank is unloaded directly from the independent tank by the screw conveyor, so that the inside of the hold can be effectively used. The hull structure can be simplified.
[0013]
Moreover, the lifting efficiency by the screw conveyor is improved, and as a result, the cargo handling time can be shortened.
[0014]
As described in claim 2, the gas hydrate transport ship of the present invention has a double-shell structure on the side wall and bottom wall of the hull, and partitions the hull with bulkheads to form a plurality of holds in the ship length direction. And an independent tank covered with a heat insulating material is disposed in each of the plurality of holds,
The independent tank includes a tank side wall formed along a hold, an upper wall connecting a plurality of unit upper walls each having a reverse funnel-like shape and disposed at an upper portion of the tank side wall and having an input port on the upper side, A screw conveyor having a suction port at the lower end is provided in the independent tank, and is formed of a bottom wall formed by combining a plurality of unit bottom walls configured in a funnel shape and disposed at a lower portion of the tank side wall. Is positioned at the lower end of the unit bottom wall constituting the bottom wall, and the upper part is erected so as to protrude from the upper part of the independent tank, and is wound around the outer periphery of the screw conveyor in a spiral shape. A spiral chute is provided, and gas hydrate pellets are slid down along the spiral chute and loaded.
[0015]
According to the gas hydrate pellet transport ship having such a configuration, when NGP is loaded into the independent tank, NGP falls while sliding on the slide chute, so that the speed is adjusted moderately and impact is applied. The slide chute is integrally mounted on the outer periphery of the screw conveyor, so that the structure is simple and the installation place can be reduced.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a gas hydrate pellet transport ship according to the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of a gas hydrate pellet transport ship, and FIG. 2 is a plan view thereof.
[0017]
In these drawings, reference numeral 1 denotes a hull, and a side wall 2, a partition wall 3, and a ship bottom 4 form a plurality of (5 in the figure) compartments 5 in the front-rear direction of the hull 1. An independent tank 6 is arranged.
[0018]
More specifically, as shown in the cross-sectional view of FIG. 3, the side wall 2 constituting the hull 1 is arranged by a side tank 7, and the bottom tank 8 and the bottom side tank 9 are arranged on the ship bottom 4. By maintaining the strength of the hull 1 with a double shell structure, seawater is prevented from flowing into the hold 5 even if the outer plate 1a is damaged.
[0019]
The independent tank 6 disposed in the hold 5 is composed of a tank side wall 10, an upper wall 11, and a bottom wall 12. The inside can be filled with an inert gas and the outer surface is covered with a heat insulating material 13. The internal temperature is cooled at about minus 10 ° C. to minus 25 ° C.
[0020]
The upper wall 11 has a reverse funnel shape formed with an inclination angle α substantially the same as the repose angle of NGP, and a plurality of unit upper walls 15a to 15d provided with inlets 14 for loading NGP at the top. As shown in FIG. 2, the bottom wall 12 has a plurality of funnel-shaped unit bottom walls 16a and 16b each having an inclination angle β that is easy to discharge NGP. It is composed by combining.
[0021]
Inclined screw conveyors 17a and 17b are arranged in the independent tank 6 thus configured. At the lower ends of the inclined screw conveyors 17a and 17b, suction ports 18a and 18b are opened, respectively. The suction port 18a of the inclined screw conveyor 17a is formed at the bottom of the unit bottom wall 16a constituting the bottom wall 12 and inclined screws. The suction port 18b of the conveyor 17b is provided so as to contact the bottom of the unit bottom wall 16b.
[0022]
Further, the upper parts of the inclined screw conveyors 17 a and 17 b are arranged obliquely so as to penetrate the unit upper walls 15 a and 15 b constituting the upper wall 11 and protrude above the independent tank 6.
[0023]
Of course, the inclined screw conveyors 17a and 17b may be arranged in the vertical direction. Preferably, as shown in the figure, the inclined screw conveyors 17a and 17b are arranged so as to have an inclination angle θ of, for example, about 45 degrees. The sliding phenomenon can be reduced, and therefore the lifting efficiency can be improved.
[0024]
19 is a first conveyor for loading NGP into the independent tank 6, 20 is a second conveyor for loading NGP extending in the front-rear direction of the hull 1, and 21 is a conveyor for unloading.
[0025]
FIG. 4 shows a second embodiment, in which slide chutes 23a and 23b are respectively arranged on the outer periphery of vertical screw conveyors 22a and 22b arranged vertically.
[0026]
Since these slide chutes 23a and 23b have the same structure, one slide shot 23a will be described. As shown in part of FIG. 5, the slide chutes 23a and 23b are attached so as to be wound around the outer periphery of the casing 24 of the vertical screw conveyor 22a. The slide plate 25 and a side plate 26 attached to the slide plate 25 are configured.
[0027]
The NGP transported by the first conveyor 27 and the second conveyor 28 for loading NGP is supplied onto the slide plate 25 from the insertion port 14.
[0028]
Then, this NGP (preferably a ping-pong-shaped spherical body and a mixture of different diameters) slides on the slide plate 25 by its own weight and falls. In this way, the NGP is loaded into the independent tank 6. At this time, the impact generated in the NGP is alleviated, so that the breakage is prevented.
[0029]
The NGP loaded in this way is transported to a predetermined consumption place, sucked from the lower suction ports 29a, 29b by the screw conveyors 22a, 22b, and extends in the front-rear direction of the first unloading conveyor 30 and the hull 1. It is loaded / unloaded to the consumption area via the second unloading conveyor 31 arranged to do so.
[0030]
【The invention's effect】
As is clear from the above description, according to the gas hydrate pellet transport ship of the present invention, the NGP loaded in the independent tank 6 is configured to be loaded and unloaded by the screw conveyors 17a and 17b, and the independent tank 6 The upper wall 11 is formed by connecting a side wall 10 and a plurality of reverse funnel-shaped unit upper walls disposed on the upper side of the side wall 10, and a plurality of funnel-shaped unit bottom walls are connected to the lower portion of the side wall 10. The volume of the independent tank 6 disposed in the hold 5 can be increased, and the amount of NGP filled in the independent tank 6 can be increased. .
[0031]
Moreover, the effect can be further improved by combining a screw conveyor and a slide chute.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a gas hydrate pellet transport ship according to the present invention.
2 is a plan view of FIG. 1. FIG.
FIG. 3 is a cross-sectional view of the gas hydrate pellet transport ship of the present invention.
FIG. 4 is a cross-sectional view of another embodiment of a transport ship.
FIG. 5 is an enlarged perspective view of the vertical conveyor of FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Hull 2 ... Side wall 3 ... Bulkhead 4 ... Ship bottom 5 ... Ship hold 6 ... Independent tank 7 ... Side tank 8 ... Bottom tank 9 ... Bottom side Part tank 10 ... tank side wall 11 ... upper wall 12 ... bottom wall 13 ... heat insulating material 14 ... inlet 15a-15d ... unit upper walls 16a, 16b ... unit bottom wall 17a, ······························································································································································ Unload conveyor 22b ··· Vertical conveyor 23 ··· Slide chute 24 ··· Casing 25 ··· Slide plate 26 ··· Side plate 24 · · · Screw conveyor 26, 27 ··· Conveyor

Claims (2)

The side wall and bottom wall of the hull are constructed in a double shell structure, and the hull is partitioned by bulkheads to form a plurality of holds in the direction of the ship, and independent tanks covered with heat insulating materials are arranged in the plurality of holds, respectively. The independent tank is disposed on a tank side wall formed along a hold and an upper part of the tank side wall, and the upper part of the hold is divided into four pieces in a plane, and each section has a reverse funnel shape. A bottom wall formed by joining a plurality of unit bottom walls arranged at the lower part of the tank side wall and configured in a funnel shape to a unit wall having a unit top wall having a charging port at the center thereof. A screw conveyor having a suction port at the lower end in the independent tank, the suction port is located at the tip of the funnel-shaped portion of the unit bottom wall constituting the bottom wall, and the upper part is the independent tank Projects from the upper wall of the tank and Is inclined so as to straddle the partitioning the compartment into the click arranged, the gas hydrate pellets transport ship, characterized by being configured so as to unload the gas hydrate pellets. The side wall and bottom wall of the hull are constructed in a double shell structure, and the hull is partitioned by bulkheads to form a plurality of holds in the direction of the ship, and independent tanks covered with heat insulating materials are arranged in the plurality of holds, respectively. The independent tank includes a tank side wall formed along the hold and a plurality of unit upper walls each having a reverse funnel shape disposed on the upper side of the tank side wall and having an inlet in the upper part. A screw conveyor having a wall and a bottom wall formed by combining a plurality of unit bottom walls configured in a funnel shape and disposed at a lower portion of the tank side wall, and having a suction port at a lower end in the independent tank The suction port is located upright at the lower end of the unit bottom wall that constitutes the bottom wall, and the upper part protrudes from the upper part of the independent tank, and the outer periphery of the screw conveyor is spiral. Winding Attached as provided spiral chute, gas hydrate pellets transport ship, characterized in that loading is slid drop along the gas hydrate pellets in the spiral chute.

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