JP4219282B2 - Stirring blade structure of gas hydrate dehydrator - Google Patents

Description

  The present invention relates to a stirring blade structure of a gas hydrate dehydrator that removes water adhering to a gas hydrate.

  Conventionally, as a method for industrially generating gas hydrate, a water spray method in which water is sprayed in a reaction tower filled with a reaction gas such as methane gas or natural gas, and the above reaction gas is bubbled into water. There are known two methods of blowing a reaction gas and stirring the reaction gas with a stirring device.

  However, in any of these methods, the generated gas hydrate has a high moisture content of 30 to 90%. Therefore, when storing and transporting the gas hydrate, a large amount of cost is required. Become.

Accordingly, a dehydrator for reducing the moisture content of the produced gas hydrate is required. As such a dehydrator, a mechanical dehydrator such as a screw press type dehydrator has been conventionally known (for example, , See Patent Document 1).
JP 2003-73678 A (pages 4-8, FIG. 3)

  However, even if the gas hydrate is dehydrated with a screw press type dehydrator, it is difficult to completely dehydrate. In addition, gas hydrate is introduced into the tank and stirred with a stirring blade, and a reaction gas such as methane or natural gas is introduced into the tank to react with the adhering water adhering to the gas hydrate. There are some that remove water adhering to the gas hydrate, but the stirring blades used in this dehydrator are equipped with blades such as turbine blades attached to the rotating shaft, so sufficient stirring effect Is unlikely to be obtained.

  That is, the gas hydrate changes from a sherbet shape to a powder shape (powder snow shape) in a dehydration process with stirring, so that the gas hydrate adheres to a blade such as a blade of a turbine and a sufficient stirring effect is obtained. Because there is no.

  The present invention has been made to solve such problems, and is configured as follows.

  According to the first aspect of the present invention, gas hydrate is introduced into the tank and stirred by the low power consolidation prevention blade, and a reaction gas such as methane or natural gas is introduced into the tank to adhere to the gas hydrate. In the gas hydrate dehydrator in which the water adhering to the gas hydrate is removed by re-reacting with the water being generated and generating new gas hydrate by this reaction, the low power consolidation prevention blade A gas hydrate dehydrator agitator comprising: a wing body extending along the inner wall surface of the tank and extending in the direction of the rotating shaft; and a leg body for attaching the wing body to the rotating shaft. It is a wing structure.

  The invention according to claim 2 is the gas hydrate dewatering according to claim 1, wherein a plurality of low power consolidation prevention blades constituted by the legs and the blades are arranged in the rotation direction and the axial direction of the rotation shaft. This is a stirring blade structure of the machine.

  According to a third aspect of the present invention, a plurality of low power consolidation prevention blades configured by the legs and wings are arranged on a boss that can be fixed to a rotating shaft to form a stirring unit, and the stirring unit is a shaft of the rotating shaft. The stirring blade structure of the gas hydrate dehydrator according to claim 1 or 2, wherein a plurality of the hydrate dehydrators are arranged in a central direction.

  The invention according to claim 4 is the stirring blade structure of the gas hydrate dehydrator according to any one of claims 1 to 3, wherein the cross-sectional shape of the leg is configured to project in the rotational direction. is there.

  The invention according to claim 5 is the stirring blade structure of the gas hydrate dehydrator according to any one of claims 1 to 3, wherein a rake face is provided on the blade body.

  The invention according to claim 6 is the stirring blade structure of the gas hydrate dehydrator according to claim 1, 2, 3 or 5, wherein the blade body is provided with a scraper.

  The invention according to claim 7 is the stirring blade structure of the guy hydrate dehydrator according to claim 6, wherein a blade portion is formed on the outer edge of the scraper.

  The invention described in claim 8 is the stirring blade structure of the gas hydrate dehydrator according to claim 6 or 7, wherein a plurality of notches are provided in the outer edge of the scraper.

  According to a ninth aspect of the present invention, a plurality of scrapers are provided, and the positions of the cutout portions are shifted in the axial direction of the rotation shaft so that the cutout portions provided on the outer edge portions of the respective scrapers do not overlap. The stirring blade structure of the gas hydrate dehydrator according to any one of the above.

  According to the first aspect of the present invention, gas hydrate is introduced into the tank and stirred by the low power consolidation prevention blade, and a reaction gas such as methane or natural gas is introduced into the tank to adhere to the gas hydrate. In the gas hydrate dehydrator in which the water adhering to the gas hydrate is removed by re-reacting with the water being generated and generating new gas hydrate by this reaction, the low power consolidation prevention blade Is formed of a wing body that extends along the inner wall surface of the tank and extends in the direction of the rotation shaft, and a leg body for attaching the wing body to the rotation shaft. It becomes possible to suppress adhesion. As a result, the gas hydrate is not consolidated and does not adhere to the low power consolidation seal blade. Further, the power consumption can be reduced and the stirring effect of the gas hydrate can be improved.

  In the invention according to claim 2, since a plurality of the low power consolidation prevention blades configured by the legs and the blades are arranged in the rotation direction and the axial direction of the rotation shaft, the stirring effect is improved and the stability of the stirring is improved. To increase the reaction efficiency.

  According to a third aspect of the present invention, a plurality of low power consolidation prevention blades configured by the legs and wings are arranged on a boss that can be fixed to a rotating shaft to form a stirring unit, and the stirring unit is a shaft of the rotating shaft. Since multiple units are arranged in the direction of the heart, not only can the legs and wings be assembled as an agitation unit, but they can be removed in units of the agitation unit when they are not needed. It becomes easy.

  In the invention according to claim 4, since the cross-sectional shape of the leg is configured to protrude in the rotation direction, not only the gas hydrate is difficult to adhere to the leg, but also the gas hydrate is cut and rotated. Therefore, the rotational force can be reduced. That is, power consumption is reduced.

  In the invention according to claim 5, since the rake face is provided on the wing body, the gas hydrate attached to the inner surface of the tank by centrifugal force can be easily removed. Moreover, the rotational force for rotating can also be made small. That is, power consumption is reduced.

  In the invention described in claim 6, since the scraper is provided on the wing body, not only the gas hydrate adhered to the inner surface of the tank can be removed very easily by the scraper, but also the scraper is held by the reinforcing member. Therefore, the scraper can have a relatively light structure. Since the hydrate adhering to the inner surface of the tank is removed, the heat transfer effect on the jacket surface is improved.

  According to the seventh aspect of the present invention, since the blade portion is formed on the outer edge of the scraper, the gas hydrate adhered to the inner surface of the tank can be more effectively removed. For this reason, unnecessary power is not required and power consumption is reduced.

  In the invention according to claim 8, since the plurality of notches are provided at the outer edge of the scraper, the gas hydrate attached to the inner surface of the tank by the action of the notches can be more effectively removed. For this reason, unnecessary power is not required and power consumption is reduced.

  The invention according to claim 9 is provided with a plurality of scrapers, and the positions of the notches are shifted in the axial direction of the rotary shaft so that the notches provided on the outer edge of each scraper do not overlap. Gas hydrate adhering to the inner surface can be removed. For this reason, unnecessary power is not required and power consumption is reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In FIG. 1, reference numeral 1 denotes a gas hydrate dehydrator, which includes a gas hydrate dehydrator (hereinafter referred to as a dehydrator) 2, a blower 3, a cooler 4, a brine unit 5, and a drive device 6. ing.

  The dehydrator 2 includes a jacket 7, an introduction port 8 for introducing a gas hydrate a generated by a gas hydrate production apparatus (not shown), and an exhaust port 9 for discharging the dehydrated gas hydrate a ′. A rotating shaft 11 is provided in the horizontal tank 10. The rotating shaft 11 is provided with a transfer screw 12, a hammer blade 13, a stirring blade 14 as a low power consolidation prevention blade, and a dispensing blade 15. Further, an inclined plate 16 is provided below the payout blade 15 and a movable weir 17 is provided on the discharge side thereof. In some cases, the hammer blade 13 is not provided.

  The low power consolidation prevention blade has a function of scraping off gas hydrate adhering to the inner wall of the tank and a function of scraping gas hydrate accumulated in the lower part of the tank. The low power consolidation prevention blade stirs the hydrate powder and does not send the reaction gas introduced into the tank.

  The movable weir 17 includes a fixed portion 18 and a movable portion 19, and the height of the movable portion 19 can be arbitrarily adjusted by rotating a screw shaft 20 that is rotatably attached to the movable portion 19. ing. The screw shaft 20 is screwed into a female screw portion 21 attached to the horizontal tank 10.

  The stirring blade 14 is formed in a portal shape, and, for example, the most upstream stirring blade 14 is mounted symmetrically with respect to the rotating shaft 11. These stirring blades 14 are attached with a phase shifted with respect to the rotation direction of the rotary shaft 11 as going downstream. In addition, the stirring blade 14 is not only vertically symmetrical with respect to the rotating shaft 11 but may have three or more blades.

  The stirring blade 14 is formed in a gate shape as described above. Specifically, as shown in FIGS. 2 and 3, the stirring blade 14 has two legs 22 each having one end attached to the rotary shaft 11. The wing body (stirring portion) 23 is attached to the other ends of the two leg bodies 22 and extends along the inner wall surface 10a of the layer body 10 and extends in the axial direction X of the rotary shaft 11. .

  More specifically, as shown in FIG. 4, the leg body 22 is formed of a hollow triangular prism, and one point s <b> 1 is directed in the rotation direction d of the leg body 22. Therefore, since the leg 22 rotates by cutting the gas hydrate by the tip s1, not only can the power load of the drive device be reduced, but also the adhesion of the gas hydrate can be prevented. The angle θ1 of the tip of the leg 22 is preferably 45 to 120 °.

  On the other hand, as shown in FIG. 5, the wing body 23 attached to the other end (free end) of the leg body 22 is formed by a triangular member when viewed from the side, and the tip s <b> 2 is directed toward the rotation direction d of the leg body 22. It has been. The wing body 23 has a rake face 23a inclined in front of the rotation direction, and the rake angle θ2 is 30 to 60 ° with respect to the vertical plane Y.

Further, the angle θ ₃ between the wing body 23 and the vertical plane Y is 90 ° or more, that is, 90 to 130 °. Moreover, although the clarification of the tip s2 of the wing | blade body 23 and the inner surface 10a of the horizontal tank 10 is based on the scale of the dehydrator 2, 2-20 mm is preferable. Furthermore, it is preferable that the back plate 23b of the wing body (stirring portion) 23 is inclined backward. In this case, it is possible to prevent the gas hydrate entrained by the negative pressure generated on the rear side (back side) of the blade body (stirring unit) 23 from being pressed against the tank inner surface 10a.

  In such a gas hydrate dehydrator, after the movable portion 19 of the movable weir 17 is adjusted to a predetermined height, the rotating shaft 11 is rotated by the driving device 6, and further, a predetermined temperature (for example, 5 ° C. to 5 ° C. The brine c cooled to −20 ° C. is supplied to the jacket 7 through the pipe 24 and when the blower 3 and the cooler 4 are driven, the reaction gas b such as methane and natural gas circulates through the pipes 25 and 26. Then, the inside of the horizontal tank 10 is cooled to a predetermined temperature. At this time, the reaction gas b is counterflowed with the gas hydrate a.

  After that, when the gas hydrate a having a water content of about 10 to 60% is introduced into the horizontal tank 10 from the introduction port 8, it is transferred to the crushing part by the transfer screw 12, and the lump is crushed by the hammer blade 13. The refined gas hydrate a is introduced into the mixing portion (mixing zone) 27 and stirred at this portion by the stirring blade 14 to promote the reaction with the reaction gas b.

  That is, the water adhering to the gas hydrate a reacts with the reaction gas b to generate new gas hydrate, whereby the gas hydrate a is dehydrated. The heat of hydration reaction at this time is removed through the jacket heat transfer surface (sometimes provided on the stirring blade).

  In order to sufficiently react the gas hydrate a in the mixing unit 27, the residence time of the gas hydrate a is adjusted by the movable weir 17 and dehydrated so that the water content becomes about 5 to 30%. The dehydrated gas hydrate a 'is discharged from the discharge port 9 by the discharge blade 15 and transferred to a storage tank (not shown). An inclined plate 16 is provided to facilitate the discharge of the gas hydrate a ′ generated by the mixing unit 27.

  The stirring of the gas hydrate a in the reaction step is performed by the gas hydrate scraping action by the blade body 23 of the stirring blade 14, and the two legs 22 mainly function as a holding material for the blade body 23. Yes.

  By the way, in the above reaction step, a part of the gas hydrate a adheres to the inner surface 10a of the horizontal tank 10 by centrifugal force. The attached gas hydrate a is a blade of the stirring blade 14 that rotates along the inner surface 10a. It is scraped off by the body 23. The stirring of the gas hydrate in such a reaction process is mainly performed by the lifting action of the blade body 23 of the stirring blade 14, and the two legs 22 function as a holding material, so that they adhere to the stirring blade 14. The amount of deposited gas hydrate can be greatly reduced.

  Therefore, the reaction efficiency of the gas hydrate a can be improved. In addition, adhesion of gas hydrate can be further prevented by applying the polytetrafluoroethylene coating to the blade body 23 of the stirring blade 14.

  In the above example, the stirring blade 14 is configured to have a so-called portal shape (front view) in which both ends of the blade body 23 are supported by the two leg bodies 22, but the stirring blade 14 is limited to this. Instead, for example, it may be configured to be a torii shape (see FIG. 6) or a T shape (see FIG. 7).

  8 and 9 show the agitation blade 14 as a unit. The stirring unit 28 is provided with a plurality of notches 30 at one end of a tube 29 having a predetermined length that can penetrate the rotating shaft 11, and a protrusion 31 at the other end, and two stirring blades 14 are provided on the outer surface of the tube 31. It is attached symmetrically with respect to 29. The stirring unit 28 may be fixed to the shaft with a key (not shown) without providing a notch.

  When the stirring unit 28 is used, the plurality of stirring units 28 are inserted and fixed so that the protrusions 31 are fitted in the notches 30 of the other adjacent stirring units 28. In this way, not only can the stirring unit 28 be easily manufactured at the factory, but also assembly and disassembly are facilitated, and manufacturing, maintenance, and inspection work are facilitated.

  FIG. 10 shows a case where the scraper 35 is attached to the blade body 23 of the stirring blade 14, and the scraper 35 is attached to the lower rake face 23 a of the blade body 23 by a press plate 33 and a bolt 34. Bolt holes (not shown) provided in the scraper 35 are elongated holes, and the distance h between the outer edge 35a of the scraper 35 and the tank inner surface 10a can be adjusted as necessary.

  When the scraper 35 is attached to the wing body 23 as described above, the gas hydrate a can be easily scraped off by the scraper 35 even if the gas hydrate a is firmly attached to the tank inner surface 10a.

  The scraper 35 in FIG. 11 is provided with an inclined surface 37 having an inclination angle α on the back side of the outer edge portion (blade edge portion) of the scraper 35 so as to prevent the adhesion of gas hydrate.

  The scraper 35 of FIG. 12 is provided with a plurality of V-shaped notches 38 at the outer edge (blade edge). In this case, since the outer edge portion (blade edge portion) is divided into a plurality of blocks, the scraper 35 can scrape off the gas hydrate a adhering to the tank inner surface 10a of the horizontal tank 10 more easily. If desired, the outer edge of the scraper 35 may have a sawtooth shape.

  FIG. 13 shows that a pair of upper and lower scrapers 35 provided symmetrically with the rotary shaft 11 are provided with V-shaped notches 38 and their phases are shifted by a predetermined length L in the axial direction of the rotary shaft 11 and overlap each other. This is what I did not. In this case, the gas hydrate a of the tank inner surface 10 a remaining without being removed by one of the crepers 35 can be removed by the other one of the crepers 35.

  In addition, since the stirring blade in this invention is a low power compaction prevention blade, it can be used not only for dehydration but also for cooling powder that is easily compacted including hydrate.

It is a schematic block diagram of the gas hydrate dehydration apparatus which has a stirring blade concerning this invention. It is a stirring blade front view of the gas hydrate dehydrator concerning the present invention. It is an AA arrow line view of FIG. It is BB sectional drawing of FIG. It is the C section enlarged view of FIG. It is a front view of other embodiment of the stirring blade of the gas hydrate dehydrator which concerns on this invention. It is a front view of other embodiment of the stirring blade of the gas hydrate dehydrator which concerns on this invention. It is a front view at the time of unitizing the stirring blade of the gas hydrate dehydrator concerning this invention. It is an AA arrow line view of FIG. It is a cross-sectional view which shows other embodiment of the stirring blade of the gas hydrate dehydrator concerning this invention. It is a principal part side view of the scraper which concerns on this invention. It is a front view of other embodiment of the scraper which concerns on this invention. It is a front view of other embodiment of the scraper which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas hydrate dehydrator 2 Gas hydrate dehydrator 3 Blower 4 Cooler 5 Brine unit 6 Drive device 7 Jacket 8 Inlet 9 Outlet 10 Horizontal tank 11 Rotating shaft 12 Transfer screw 13 Hammer blade 14 Stirring blade 15 Discharge blade 16 Inclined Plate 17 Movable weir 18 Fixed part 19 Movable part 20 Screw shaft 22 Leg body 23 Wings body 24, 25, 26 Pipe 27 Mixing part 28 Unit stirring blade body 29 Unit tube body 30, 38 Notch part 31 Projection part 32 Reinforcement member 33 Presser plate 34 Bolt 35 Scraper 36 Inclined surface 37 Blade

Claims (9)

Introduce gas hydrate into the tank and stir with a low power consolidation prevention blade, introduce reaction gas such as methane and natural gas into the tank and react with water adhering to the gas hydrate, In the gas hydrate dehydrator in which water adhering to the gas hydrate is removed by generating new gas hydrate by this reaction, the low power consolidation prevention blade is disposed along the inner wall surface of the tank. An agitating blade structure of a gas hydrate dehydrator comprising a blade body extending in the direction of the rotation shaft and a leg for attaching the blade body to the rotation shaft. The stirring blade structure of the gas hydrate dehydrator according to claim 1, wherein a plurality of low power consolidation prevention blades composed of the leg body and the blade body are arranged in the rotation direction and the axial center direction of the rotation shaft. A plurality of low power consolidation prevention blades composed of the legs and wings are arranged on a boss that can be fixed to a rotating shaft to form a stirring unit, and a plurality of the stirring units are arranged in the axial direction of the rotating shaft. Item 3. A stirring blade structure of a gas hydrate dehydrator according to item 1 or 2. The stirring blade structure of the gas hydrate dehydrator according to any one of claims 1 to 3, wherein the cross-sectional shape of the leg is configured to project in the rotational direction. The stirring blade structure of the gas hydrate dehydrator according to any one of claims 1 to 3, wherein a rake face is provided on the blade body. The stirring blade structure of a gas hydrate dehydrator according to claim 1, 2, 3, or 5, wherein a scraper is provided on the blade body. The stirring blade structure of a guy hydrate dehydrator according to claim 6, wherein a blade portion is formed on the outer edge of the scraper. The stirring blade structure of a gas hydrate dehydrator according to claim 6 or 7, wherein a plurality of notches are provided at the outer edge of the scraper. The gas hydrate according to any one of claims 6 to 8, wherein a plurality of scrapers are provided, and the positions of the notches are shifted in the axial direction of the rotation shaft so that the notches provided on the outer edge of each scraper do not overlap. Agitation blade structure of dehydrator.

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