JP2008248193A - Dehydrator for gas hydrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dehydrator for a gas hydrate slurry which has a simple structure and a small size. <P>SOLUTION: This dehydrator is equipped with an outer cylinder that has a closed lower end, a filtration part at an intermediate part and an open upper end, and a double tubular inner cylinder, in the outer cylinder, that has an open lower end, a filtration part at an intermediate part and a closed upper end. While the gas hydrate slurry is introduced from a lower part of the outer cylinder, unreacted water is discharged from the slurry at a drainage part set in a nearly intermediate part between the inner cylinder and the outer cylinder, and a dehydrated gas hydrate is discharged from the open part of the upper end. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention introduces a dehydration apparatus, more specifically, a gas hydrate (slurry gas hydrate) produced by reacting gas and water into a cylindrical dehydration tower provided with a filtration part in the middle part. Thus, the present invention relates to a so-called gravitational dehydration type dehydrator that is raised from the bottom to the top of the dehydration tower, and that unreacted water is allowed to flow out of the tower from the filtration section during the rise.

  Recently, the use of natural gas has become popular as clean energy. In order to efficiently transport and store the natural gas, attention has been paid to the production of gas hydrate by reacting the natural gas with water. This gas hydrate generates a gas hydrate by contacting and reacting natural gas such as methane with water at a predetermined pressure (for example, 5.4 MPa) and temperature (for example, 4 ° C.). Gas hydrate is a so-called slurry contained in unreacted water, and it becomes necessary to separate (dehydrate) unreacted water from this slurry.

For this reason, various dehydration apparatuses for dehydrating unreacted water from gas hydrate have been proposed. As one of them, the applicant of the present invention firstly aims to increase the dewatering efficiency as a double-pipe structure dewatering tower by using an outer tube and an inner tube having a filtering part, and to reduce the size of the dewatering device. Proposed as 257359.
JP 2006-257359 A

  However, in the above-described dewatering tower having a double-pipe structure, the gas hydrate dehydrated in the filtration portions of the outer cylinder and the inner cylinder reaches the upper part of the outer cylinder and the inner cylinder, and the inside of the inner cylinder is crushed from here. Since it is crushed by the device and dropped and taken out from its lower part, it cannot be downsized in a structurally satisfactory manner, and a gas hydrate take-out device or slurry introduction pipe or There is a problem that the structure becomes complicated because the discharge pipes of reaction water are concentrated.

The present invention was made to solve the conventional problems as described above, and the dehydration tower is
1) Double an outer cylinder whose lower end is closed and has a filtering part in the middle part and whose upper end is opened, and an inner cylinder whose lower end is opened in this outer cylinder and whose filtering part is in the middle part and whose upper end is closed It is arranged in a tubular shape, and gas hydrate slurry is introduced from below the outer cylinder, and unreacted water is discharged from the slurry at a drainage portion provided at a substantially intermediate portion between the outer cylinder and the inner cylinder, and the upper end is opened. The gas hydrate dehydrated from the part is discharged.

2) Water is allowed to flow down to the outer surface side of the outer cylinder and / or the inner surface side of the inner cylinder.

And the dehydrating apparatus according to the present invention comprises:
3) The dehydration tower is arranged inside a high-pressure vessel.

  According to the invention of claim 1, since the unreacted water contained in the gas hydrate is drained from the outside and inside of the outer cylinder, the moisture content of the gas hydrate located on the outer cylinder center side is reduced. As a result, a gas hydrate with a high dehydration rate is obtained.

  In addition, since unreacted water is drained from the outside and inside of the outer cylinder, the dewatering tower can be made smaller than the conventional dewatering tower that has been dewatered only outside. And the driving | operation power of the slurry pump which pumps gas hydrate slurry to a dehydration tower is also reduced.

  According to the invention of claim 2, since the gas hydrate is washed away before clogging in the filtration part of the dehydration tower, the reduction of the dehydration efficiency due to clogging of the filtration part is prevented, and clogging is prevented. The number of times of maintenance is drastically reduced, and the stoppage of the apparatus due to maintenance is prevented. Therefore, a decrease in dehydration efficiency and a decrease in productivity can be prevented, and a constant amount of gas hydrate having a constant quality can be continuously produced.

  According to the invention of claim 3, the gas hydrate slurry generated by reacting the raw material gas and raw material water in a high pressure atmosphere is introduced into the dehydration tower through a slurry pump or the like in the high pressure state. Since the dehydration tower itself is disposed in the high-pressure vessel maintained in the high pressure state, the dehydration tower itself does not need to have a pressure-resistant structure, so that it can be produced with a capacity for producing a conventional dehydration tower, and the production cost is reduced. There is no increase. Further, since the dehydration tower itself does not need to have pressure resistance, it can be easily improved in accordance with operating conditions.

  Hereinafter, an embodiment of the dehydrating apparatus according to the present invention will be described with reference to FIGS.

  In FIG. 1, the dehydrating apparatus A is configured by arranging a dehydrating tower 2 in a high-pressure vessel 1. More specifically, the dehydration tower 2 is configured such that the outer cylinder 4 having the filtration unit 3 and the inner cylinder 6 having the filtration unit 5 in the middle part are arranged so as to have the interval L1 to form the section 7. It looks like a double tube.

  The upper portion of the compartment 7 is opened and a bottom plate 8 is provided at the lower portion and closed. A slurry supply pipe 9 is connected to the lower part of the compartment 7 as shown in FIG. 1, and the gas hydrate slurry S is supplied into the compartment 7 from the slurry supply pipe 9. This section 7 is a flow path for the gas hydrate slurry S.

  The filtration part 3 formed in the outer cylinder 4 is provided with a large number of small holes of such a size that the gas hydrate crystals contained in the gas hydrate slurry do not flow out, and unreacted water in the slurry is drained. It has become so.

  A first spray header 10 is attached to the outer upper portion of the filtration unit 3, and water or a part of water w of unreacted water is supplied to the spray header 10 from the first water supply pipe 11. The gas hydrate h to be deposited on the filtration unit 3 is peeled off when flowing down the filtration unit 3 to prevent clogging.

  The upper end of the inner cylinder 6 is closed by a closing member 12, and the lower end thereof is opened so that the outside of the outer cylinder 4 communicates with the inside of the inner cylinder 6 to form a water tank 15. Then, a second spray header 13 is attached to the inside of the inner cylinder 6 and at the top of the filtration unit 5 as shown in FIG. 3, and the second spray header 13 is not connected to the second water supply pipe 14. A part of the water w of the reaction water is supplied, and this water w peels off the gas hydrate h to be deposited on the filtration unit 5 when flowing down the filtration unit 5 to prevent clogging. Yes.

  The dehydration tower 2 configured as described above is attached by a support member (not shown) so as to form a section 16 having a predetermined interval L2 in the high-pressure vessel 1, and at the upper part thereof by an annular closing plate 17 A section 16 is partitioned. In this way, a part of the water tank 15 is formed in the lower part of the section 16 and the section 18 above the closing plate 17 of the section 16 is formed.

  A scraping / dispensing device 19 is provided in the upper part (section 18) of the dehydrating tower 2 disposed in the high-pressure vessel 1, and the scraping / dispensing device 19 includes a driving device 20 such as an electric motor, a scraper 21, and a screw conveyor. The gas hydrate h rising to the upper part of the dewatering tower 2 is scraped out by the scraper 21 and supplied to the screw conveyor 22, and the screw conveyor 22 is driven by a driving device (not shown) and arranged on the downstream side. For example, it is supplied to a molding apparatus.

  Unreacted water w flowing into the water tank 15 is absorbed by the drain pump 23 and supplied to the first generator (not shown) through the drain pipe 24. Of course, the drain pump 23 is controlled by a signal from the liquid level detector 25 so that the liquid level of the water tank 15 is always maintained within a predetermined range.

1 is a schematic side sectional view showing an embodiment of a dehydrator according to the present invention. 1 is a schematic cross-sectional view of a dehydrator according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High pressure vessel 2 Dehydration tower 3, 5 Filtration part 4 Outer cylinder 6 Inner cylinder 7,16 Section 8 Bottom plate 9 Slurry supply pipe 10 First spray header 11 First water supply pipe 12 Closing member 13 Second spray header 14 First Water supply pipe 15 Water tank 17 Closing plate 19 Scraping device 20 Drive device 21 Scraper 22 Screw conveyor 23 Drain pump 24 Drain pipe 25 Liquid level detector

Claims (3)

A dehydration tower for gas hydrate produced by reacting raw material gas and raw material water,
The dehydration tower has an outer cylinder whose lower end is closed and has a filtration part in the middle part and whose upper end is opened, and an inner cylinder whose lower end is opened in the outer cylinder and has a filtration part in the middle part and whose upper end is closed. Arranged in a double tubular,
Gas hydrate slurry was introduced from below the outer cylinder, and unreacted water was discharged from the slurry at a drainage portion provided at a substantially intermediate portion between the outer cylinder and the inner cylinder, and dehydrated from the open portion at the upper end. A gas hydrate dehydration tower which discharges gas hydrate.   The dehydration tower for gas hydrate according to claim 1, wherein water is allowed to flow down to the outer surface side of the outer cylinder and / or the inner surface side of the inner cylinder.   3. A gas hydrate dehydration apparatus, wherein the dehydration tower according to claim 1 is disposed inside a high-pressure vessel.

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