JP2007268406A - Depressurization device and apparatus for producing gas hydrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a depressurization device the structure of which is made simple, the depressurizing operation of which is also made simple and through which a granular substance can be conveyed stably and surely. <P>SOLUTION: The depressurization device 51, which is arranged between a high pressure zone 41 and a low pressure zone 42 for conveying the granular substance 43 from the former to the latter, is provided with a rotating body 50 having a communicative hole 44 for communicating the high pressure zone 41 with the low pressure zone 42 and a piston 45 arranged to be reciprocated in the communicative hole 44. The rotating body 50 is rotated to one direction to change the course of the communicative hole 44 so that the high pressure zone 41 is successively in the states communicated, non-communicated and again communicated with the low pressure zone 42. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a depressurization device and a gas hydrate manufacturing device provided between the high pressure region and the low pressure region so as to send powder particles.

  In gas hydrate, gas molecules such as hydrocarbons such as methane, ethane, propane, and butane, which are natural gas components, and carbon dioxide are taken into the interior of the three-dimensional structure formed by combining water molecules. It is a general term for clathrate hydrates (hydrates) formed in this way. In other words, gas hydrate is an ice-like solid substance composed of source gas molecules and water molecules, and is a kind of stable inclusion compound in which source gas molecules are included inside a three-dimensional cage structure formed by water molecules. It is. This gas hydrate has a relatively large gas storage capacity, and has characteristic properties such as large generation / decomposition energy and selectivity of hydrated gas. For example, transportation and storage of natural gas, etc. Various applications such as means, heat storage systems, actuators, and separation and recovery of specific component gases are possible, and research is actively conducted.

  Gas hydrate is usually generated under high pressure and low temperature conditions. The following methods are well known as generation methods. By spraying cooled water from the top of the reaction vessel filled with raw material gas at high pressure, so-called "water spray method", in which gas hydrate is generated on the surface of the water droplet when the water droplet falls in the raw material gas, reaction A so-called “bubbling method” or the like is performed such that gas hydrate is generated on the surface of the bubbles when the bubbles of the source gas rise in the water by introducing the source gas into the water in the container as bubbles.

  The gas hydrate produced by the above production method is an ice granule having a gas hydrate content increased to about 90 wt% or pelletized, and brought to a supercooled state and brought to atmospheric pressure by a depressurizer. The pressure is usually reduced and stored in a storage tank (Patent Document 1).

A conventional depressurization apparatus is configured by providing an intermediate chamber between a high pressure region and a low pressure region, and providing a high pressure side valve and a low pressure side valve between the intermediate chamber and the high pressure region and between the low pressure region, respectively. ing.
The actual depressurization procedure will be described. First, both valves are closed and the intermediate chamber is made into a high pressure atmosphere with a compressor or the like. And the granular material in a high voltage | pressure area | region is moved to an intermediate chamber by opening a high voltage | pressure side valve | bulb. Subsequently, the high pressure side valve is closed, and the intermediate chamber is depressurized to atmospheric pressure by a known depressurization means in a sealed state. Then, the low pressure side valve is opened, and the granular material is transferred to the low pressure region (atmospheric pressure).

JP 2005-263675 A

  As described above, a conventional depressurization apparatus is configured by providing an intermediate chamber, and a high-pressure side valve and a low-pressure side valve on both sides of the intermediate chamber, and the depressurization procedure is performed through a number of processes. Since the transfer can be performed, there is a problem that the structure is complicated, the number of equipment is large, the decompression process takes a long time, and further, the granular material forms a bridge and the transfer is unstable.

  An object of the present invention is to provide a depressurization apparatus and a gas hydrate manufacturing apparatus that have a simple structure, a simple depressurization operation, and that can stably and reliably transfer powder particles.

  In order to achieve the above object, a first aspect of the present invention is a depressurization device provided between the high pressure region and the low pressure region to send the granular material from the high pressure region to the low pressure region. A rotating body including a communication hole capable of communicating with the region and a piston provided in the communication hole so as to be reciprocally movable; and by rotating the rotating body in one direction, the direction of the communication hole The high pressure region and the low pressure region can be sequentially switched to a communication state, a non-communication state, and a communication state again. Here, “powder and granular material” is used to include both powder and granular material. The particle size is typically 2 mm to 50 mm in diameter.

  According to the depressurization apparatus according to the first aspect of the present invention, by rotating the rotating body in one direction, the high-pressure region and the low-pressure region are sequentially communicated, non-communication state as the direction of the communication hole, The pressure in the high-pressure region is changed from the initial position to the opposite position when the piston provided in the communication hole reaches the re-communication state through the non-communication state. And move. Thereby, the granular material which entered the communication hole is surely pushed out to the low pressure region by the movement of the piston.

Therefore, even if the rotating body is rotated, the high pressure region and the low pressure region are always kept in a disconnected state by the piston, and each time the rotating body is rotated, the granular material that has entered the communication hole is always in the low pressure region. The pressure is released to the side and pushed out by the piston. Therefore, it is possible to automatically perform the depressurization and the transfer of the granular material while keeping the two regions in a state of being blocked from each other.
When the rotating body continuously rotates, the piston moves in the communication hole from the high pressure side to the low pressure side each time, and the above operation is repeated, and the granular material is depressurized from the high pressure region to the low pressure region through the communication hole. While being transported.

  If two or more systems are used to connect the high pressure region and the low pressure region, continuous depressurization and granular material transfer can be realized by phasing the rotation of each rotating body in each system. can do.

According to a second aspect of the present invention, in the decompression device according to the first aspect, there is provided closed chamber communication means for communicating the closed chambers on both sides of the piston in the non-communication state. To do.
According to the decompression device according to the second aspect of the present invention, since the closed chamber communication means for communicating the closed chambers on both sides of the piston in the non-communication state is provided, the high pressure region and the low pressure region are in the non-communication state. The pressure on both sides of the piston in the communication hole can be balanced, and the rotating body further rotates in this state, and the high pressure region and the low pressure region communicate with each other through the communication hole. The impact and pulsation due to can be suppressed.

According to a third aspect of the present invention, in the depressurization apparatus according to the second aspect, the closed chamber communication means includes a communication path that connects the two closed chambers, and an on-off valve provided in the communication path. It is characterized by this.
Since the on-off valve is provided in this way, the timing for balancing the pressures on both sides of the piston can be controlled. Therefore, depending on the shape and size of the opening at both ends of the communication hole, depending on the rotation angle of the rotating body, the high pressure region and the pressure resistant region may be short-circuited by the communication hole and the sealed chamber communication means. Can be easily eliminated with a valve.

  In addition, a fourth aspect of the present invention includes a generation apparatus that generates a gas hydrate by reacting a raw material gas and water at low temperature and high pressure, and a gas hydride that is provided at a subsequent stage of the generation apparatus and is under high pressure. A gas hydrate production apparatus comprising: a depressurization device for transferring rate particles to low pressure, wherein the depressurization device is any one of the first to third aspects. It is characterized by comprising the described depressurization device.

  ADVANTAGE OF THE INVENTION According to this invention, in the gas hydrate manufacturing apparatus, the gas hydrate particle | grains produced | generated under high pressure can be stably transferred to a low pressure area | region, decompressing.

  According to the present invention, by rotating the rotating body in one direction, the high-pressure region and the low-pressure region can be sequentially switched between a communication state, a non-communication state, and a communication state as the direction of the communication hole. In addition, when the piston provided in the communication hole reaches the re-communication state through the non-communication state, the piston moves from the initial position to the opposite position under the pressure of the high pressure region. Thereby, the granular material which entered the communication hole is surely pushed out to the low pressure region by the movement of the piston. Therefore, even if the rotating body is rotated, the high pressure region and the low pressure region are always kept in a disconnected state by the piston, and each time the rotating body is rotated, the powder particles that have entered the communication hole are in the low pressure region each time. It is depressurized to the side and pushed out by the piston. Therefore, it is possible to automatically perform the depressurization and the transfer of the granular material while keeping the two regions in a state of being cut off from each other.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 is a cross-sectional view of a main part of a depressurization apparatus according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a main part showing an initial state of rotation of the rotating body of the depressurizing apparatus, and FIG. FIG. 4 is a fragmentary cross-sectional view showing a state in which the pressure balance on both sides of the piston is balanced, and FIG. 4 is a fragmentary cross-sectional view showing a state in which the rotating body is rotated 180 degrees from the state of FIG.

  The depressurization device 51 according to the present embodiment is provided between the high pressure region 41 and the low pressure region 42 in order to send the powder particles 43. The depressurizing device 51 is a substantially cylindrical body provided with a cylindrical communication hole 44 capable of communicating the high pressure region 41 and the low pressure region 42 and a piston 45 provided in the communication hole 44 so as to be capable of reciprocating. A rotating body 50 having a structure is provided. Then, by rotating the rotating body 50 in one direction, clockwise in FIG. 1, the high pressure region 41 and the low pressure region 42 are sequentially communicated with each other as the direction of the communication hole 44 (FIGS. 1 and 2). The communication state (FIG. 3) and the communication state (FIG. 4) can be switched again.

  However, although the communication hole 44 is located in the direction of the communication state in FIG. 1, since the piston 45 is provided in the communication hole 44, the communication hole 44 is not actually communicated and is blocked. Ribbed stoppers 53A and 53B are provided at both ends of the communication hole 44 to prevent the piston 45 from falling off. Closed chamber communication means is provided for communicating the closed chambers 46 and 47 on both sides of the piston 45 in the non-communication state (FIG. 3). The closed chamber communication means includes a communication passage 48 that connects the two closed chambers 46 and 47, and an open / close valve 49 provided in the communication passage 48.

Next, the operation of the decompression device according to the above embodiment will be described.
By rotating the rotating body 50 in one direction, the high-pressure region 41 and the low-pressure region 42 can be sequentially switched between a communication state, a non-communication state, and a communication state as the direction of the communication hole 44. When the piston 45 provided in the communication hole 44 reaches the recommunication state through the non-communication state, the piston 45 moves from the initial position to the opposite side position under the pressure of the high pressure region. Thereby, the granular material 43 that has entered the communication hole 44 is reliably pushed out to the low pressure region by the movement of the piston 45.

Therefore, even if the rotating body 50 is rotated, the high pressure region 41 and the low pressure region 42 are always kept in a disconnected state by the piston 45, and the powder particles that have entered the communication hole 54 simply by rotating the rotating body 50. Each time the body 43 is depressurized to the low pressure region side, it is pushed out by the piston 45. Therefore, it is possible to automatically perform the depressurization and the transfer of the granular material while the two regions 41 and 42 are maintained in the mutually disconnected state.
Since closed chamber communication means for communicating the closed chambers 46 and 47 on both sides of the piston 45 in a non-communication state is provided, both sides of the piston 45 in the communication hole 44 are in a non-communication state with the high pressure region 41 and the low pressure region 42. The pressures 46 and 47 can be balanced, and in this state, the rotating body 50 further rotates and the high pressure region 42 and the low pressure region 41 communicate with each other through the communication hole 44. Impact and pulsation can be suppressed.

  If two or more systems of the decompression device 51 are used to connect the high pressure region 41 and the low pressure region 42, continuous decompression and powder particles can be achieved by phasing the rotation of each rotating body 50 of each system. Body transfer can be realized.

  FIG. 5 is a schematic configuration diagram showing a gas hydrate manufacturing apparatus according to an embodiment of the present invention provided with the above depressurization apparatus 51. The gas hydrate manufacturing apparatus according to the present embodiment includes a first generator 1 that is a first generation unit that generates a primary gas hydrate 6 by reacting a raw material gas and water under low temperature and high pressure, The gravity dehydration device 2 for dehydrating the generated primary gas hydrate 6, the pulverizer 3 for pulverizing the dehydrated primary gas hydrate 7 to a uniform size, the pulverized primary gas hydrate 8 and the raw material gas react again. And a second generator 4 that is a second generation unit that generates a high-concentration secondary gas hydrate 9. The crusher 3 is provided in a cylindrical connecting pipe 5 in the present embodiment, which is a connecting portion between the gravity dehydrator 2 and the second generator 4.

  First, the first generator 1 and the first generation process will be described. The inside of the first generator 1 is adjusted to a predetermined temperature and pressure by a known method, and raw material gas and raw water are supplied to the first generator 1, where the production reaction of the primary gas hydrate 6 proceeds. In this embodiment, the temperature is 1 ° C. to 5 ° C., the pressure is 4 MPa to 8 MPa, preferably the temperature is 2 ° C. to 4 ° C., and the pressure is 5 MPa to 6 MPa.

  Since the specific gravity of the primary gas hydrate 6 is smaller than that of water, the primary gas hydrate 6 floats in water and is slurried. The generated primary gas hydrate 6 is extracted out of the first generator 1 in the slurry state and is subjected to a subsequent dehydration step by the gravity dehydrator 20. The slurry-like primary gas hydrate 6 contains a large amount of moisture, and the gas hydrate content is about 20 wt%.

Next, the gravity dehydrator 20 and the dehydration process will be described.
The primary gas hydrate 6 in the slurry state extracted from the first generator 1 is introduced into the dehydration tower 2 of the gravity dehydrator 20. This dehydration tower 2 is provided with a slurry introduction part 21 at the lower part, a drain port 22 for discharging water in the slurry to the outside is provided at the middle part, and a dehydration take-out part 23 is provided at the upper part. It has a vertically long shape. Slurry of the primary gas hydrate 6 is fed from the first generator 1 through the line 25 to the slurry introduction unit 21 using a slurry pump 24 at a constant feed rate. The water flowing out from the drain port 22 is returned to the first generator 1 through the line 26.

  In the present invention, a bed moving means 31 for moving the bed 30 formed by the gas hydrate which is solid content in the slurry in the dehydration tower 2 is provided. In the present embodiment, the bed moving means 31 is provided in the dehydration tower 2, and can move from the lower part to the upper part in the dehydration tower 2 and can pass water, and the piston 32. And a drive mechanism 33 that moves the bet 30 at a set speed, and after the bet 30 exceeds the position of the drain port 22, the piston 32 moves the bet 30 upward at a set constant speed. Has been. Here, the drive mechanism 33 includes a rack and pinion structure 34 and a power source (not shown).

The bed 30 of the primary gas hydrate 7 (hereinafter referred to as dehydrated primary gas hydrate) dehydrated by raising the dehydration tower 2 is pushed up to the take-out portion 23 at the top of the dehydration tower 2. The gas hydrate content of the dehydrated primary gas hydrate 7 is about 50 wt%.
The dehydrated primary gas hydrate 7 is further brought into contact with the gas in the second generator 4 at the subsequent stage to react with the gas, thereby increasing the gas hydrate content and increasing the gas storage amount and the high concentration secondary gas hydrate. 9 can be obtained.

  Next, the crusher and the crushing process will be described. The crusher 3 used in the crushing step is provided in the connecting pipe 5 between the dehydration tower 2 and the second generator 4, and is provided in the vicinity of the inlet 11 to the second generator 4. And a scraping portion 15 having a scraping action plate 14 at the tip of the shaft 13. The mesh portion 12 is provided immediately before the introduction port 11 to the second generator 4. The mesh of the mesh portion 12 is preferably 2 to 5 mm.

  The scraping action plate 14 passes through the take-out portion 23 of the dehydration tower 2 and is configured to be capable of reciprocating in the axial direction between the mesh portion 12. The shaft 13 has a structure that can be operated from the outside of the connecting pipe 5 manually or by a known power unit (not shown).

The crushing process will be described.
First, the dehydrated primary gas hydrate 7 pushed up to the take-out part 23 of the dehydration tower 2 is collected by sliding the collecting action plate 14 of the collecting part 15 along the bottom of the connecting pipe 5, Push to the mesh part 12 side. The dehydrated primary gas hydrate 7 is crushed to a uniform particle size by passing through the mesh portion 12. By repeating this crushing operation, the pulverized primary gas hydrate 8 having a uniform particle size is supplied to the second generator 4.

Next, the second generator 4 and the second generation process will be described.
The pulverized primary gas hydrate 8 crushed by the pulverization step is supplied to the second generator 4 from the inlet 11 on the downstream side of the mesh portion 12. In the second generator 4, the raw gas is blown and fluidized into the pulverized primary gas hydrate 8 having a gas hydrate content of about 50 wt%, and the residual water and raw material of the pulverized primary gas hydrate 8 are supplied. A second generation step is performed in which the gas is re-reacted to generate a high concentration secondary gas hydrate 9.
By the second generation step, a high concentration secondary gas hydrate 9 having a gas hydrate content of about 90 wt% can be obtained. The generated secondary gas hydrate 9 is sent to the pelletizer 35 of the next process by the screw conveyor 17. It is formed into pellets of about 20 mm by the pelletizer 35 and sent to the supercooling device 36. The subcooling device 36 cools to −20 ° C.

  Subsequently, it is sent to the decompression device 51 through the line 38. Pellets (powder particles 43) depressurized to atmospheric pressure by the depressurizer 51 are sent to the storage tank 37 through the line 39. The storage tank 37 is at −20 ° C. and atmospheric pressure.

  Thereby, in the gas hydrate production apparatus, the gas hydrate particles generated under high pressure (about 5 MPa) can be stably transferred to the low pressure region while depressurizing.

  INDUSTRIAL APPLICABILITY The present invention can be used for a depressurization apparatus and a gas hydrate manufacturing apparatus provided between the high pressure region and the low pressure region to send powder particles.

It is principal part sectional drawing of the decompression apparatus which concerns on embodiment of this invention. It is principal part sectional drawing which shows the state at the time of the rotation body rotation of the said decompression device. It is principal part sectional drawing of the state by which the pressure balance of the both sides of a piston was achieved in the middle of rotation of a rotary body. It is principal part sectional drawing which shows the state which the rotary body rotated 180 degrees from the state of FIG. It is a schematic block diagram which shows the manufacturing apparatus of the gas hydrate which concerns on one embodiment of this invention provided with the decompression apparatus which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 1st generator, 2 Dehydration tower, 3 Crusher, 4 Second generator, 5 Connection pipe, 6 Primary gas hydrate, 7 Dehydrated primary gas hydrate, 8 Crush primary gas hydrate, 9 Secondary gas hydrate Rate, 11 inlet, 12 mesh part, 13 shaft part, 14 scraping action plate, 15 scraping part, 18 screw conveyor, 20 gravity dehydrator, 21 slurry introducing part, 22 drainage port, 23 takeout part, 24 slurry pump 25, 26 line, 30 bed, 31 bed moving means, 32 piston, 33 drive mechanism, 34 rack and pinion structure, 35 pelletizer, 36 supercooling device, 37 storage tank, 38, 39 line, 41 high pressure area, 42 low pressure Area, 43 powder, 44 communication hole, 45 piston, 46, 47 Closed chamber, 48 Communication path, 49 Open / close valve, 50 Rotating body, 51 Depressurization device

Claims (4)

A depressurization device provided between the two regions to send the granular material from the high pressure region to the low pressure region,
A rotating body including a communication hole capable of communicating the high pressure region and the low pressure region, and a piston provided in the communication hole so as to be reciprocally movable;
By rotating the rotating body in one direction, the high-pressure region and the low-pressure region can be sequentially switched to a communication state, a non-communication state, and a communication state as the direction of the communication hole. Depressurization device.   2. The depressurization apparatus according to claim 1, further comprising closed chamber communication means for communicating closed chambers on both sides of the piston in the non-communication state.   3. The depressurization apparatus according to claim 2, wherein the closed chamber communication means includes a communication path that connects the two closed chambers, and an on-off valve provided in the communication path. A generator for reacting a raw material gas and water under low temperature and high pressure to generate gas hydrate, and a gas hydrate powder under high pressure that is provided downstream of the generator to move to low pressure A gas hydrate production apparatus comprising:
The said depressurization apparatus consists of the depressurization apparatus described in any one of Claim 1 to 3, The manufacturing apparatus of the gas hydrate characterized by the above-mentioned.

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