JPH0480728B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for economically storing and smoothly discharging slurry such as coal-water mixture (CWM) or coal-oil mixture (COM). The present invention relates to a slurry storage device that can store slurry.

[Prior Art] When attempting to use coal as an alternative fuel to petroleum, there is a problem in that coal is solid and therefore difficult to transport, store, and handle.
Therefore, a technology has been developed in which coal is crushed and mixed with water or oil and additives added as necessary to form a fluid (slurry). By the way, if such slurry is stored in a storage tank for a long period of time, the particles will settle and the lower layer will become thicker, making it impossible to supply slurry with an appropriate concentration, and the particles will accumulate near the outlet. This may cause problems such as accumulation, making it impossible to discharge smoothly, and further solidifying and blocking the discharge port. Therefore, a device to blow air into the storage tank or a mechanical stirring device is installed, and these devices stir the inside of the tank to disperse the coal particles.
Methods have been proposed, such as keeping the concentration of the slurry uniform, or scraping out the thickened slurry in the lower layer using a scraper or conveyor and circulating it to the upper part of the tank using a pump.

[Problems to be Solved by the Invention] However, in order to obtain sufficient effects in the above method, a large amount of energy is required to move the slurry having a high specific gravity, resulting in high operating costs.

Considering the characteristics of a non-Newtonian fluid such as coal slurry, it has a very high viscosity in the low shear rate region, so that there is little particle sedimentation in a static state, and the fluid transitions from a static state to a fluid state. During the process, a certain amount of energy is absorbed and the bonding state between the particles changes, resulting in a slurry with a low viscosity that is easier to transport. Therefore, if the slurry is allowed to flow excessively, its viscosity will decrease and its stability will decrease. This will lead to further sedimentation and sedimentation. Therefore, it can be said that the most appropriate method is to leave the slurry stationary in a storage tank to maximize its stability and store it without stirring or circulating the slurry as described above.

This invention was made with attention to these points, and it is possible to store a slurry having the characteristics of a non-Newtonian fluid, such as coal slurry, in a high viscosity state stably for a long time, and to perform high-speed stirring when discharging it. To provide a slurry storage device capable of smoothly and economically storing and discharging slurry while reducing the viscosity thereof, efficiently and easily discharging the slurry, and suppressing the flow of the slurry to the necessary minimum. The purpose is to

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a stirring chamber in the center by a partition member having circulation holes for free circulation of the slurry, and A cylindrical storage tank is formed with a stability chamber on the outer periphery of the tank, and a discharge port is provided at the bottom of the stirring chamber. A scraper that moves the slurry near the bottom plate upward and toward the center, a variable speed first drive device that rotates the scraper, a stirring blade rotatably provided in the stirring chamber, and the stirring The configuration includes a second drive device that rotates the blades.

[Function] In the slurry storage device of the present invention, when storing the slurry, the scraper is rotated at a slow speed by the first drive device for an appropriate period of time, thereby maintaining stability without changing the bonding state of the non-Newtonian fluid. The slurry can be stored for a long period of time while maintaining its stability while preventing the slurry particles from thickening and settling, allowing the slurry to stand still in the storage tank and maximizing its stability.

When discharging slurry, the rotation of the first drive device is increased to speed up the rotation of the scraper to promote slurry movement to the stirring chamber, and the second drive device rotates the stirring blades in the stirring chamber at high speed to reduce the viscosity of the slurry. Lower it and let it drain through the outlet.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

Figures 1 to 3 show an embodiment of the present invention. In these figures, 1 is a cylindrical storage tank with a bottom, and the bottom plate 2 is inclined in a funnel shape so that the center is lower. A stirring chamber 3 is provided in the center of the bottom plate 2, and the other portion serves as a stability chamber 1a. This stirring chamber 3 includes a funnel-shaped inclined bottom plate 4 having a larger slope than the bottom plate 2, and is erected from the upper end of the inclined bottom plate 4 toward the center so as to cover the upper space of the inclined bottom plate 4 in the shape of a truncated cone. It is composed of a plurality of plate-shaped supports (partition members) 5 and a top plate 6 supported on the upper end of the supports 5. A discharge port 7 is formed in the lower part of the inclined bottom plate 4, and a vertically elongated slit (flow hole) 5a with a widened lower part is formed between the adjacent supports 5 so that the slurry can flow therethrough. It's summery. A hollow cylindrical support tower 8 is erected on top of the top plate 6. A disk-shaped support plate 11 having a bearing part 10 in the center is fixed to the upper surface of the flange part 9 at the upper end of the support tower 8, and a shaft seal formed in the center of the top plate 6 and the bearing part 10 are fixed to the upper surface of the flange part 9 at the upper end of the support tower 8. Stirring shaft 1 by part 6a
2 is vertically and rotatably supported. The lower end of the stirring shaft 12 reaches the vicinity of the inclined bottom plate 4 of the stirring chamber 3, and a plurality of arms 13 extending radially from the stirring shaft 12 are provided in the portion of the stirring shaft 12 inside the stirring chamber 3. The first stirring blade 14a and the scraping blade 14b are connected to the lower end of the stirring shaft 12.
A stirring blade 15 is provided. The first stirring blade 1
4a is located at approximately the center of the height of the stirring chamber 3, and the second stirring blade 15 is located at approximately the same height as the discharge port 7, and these stirring blades 14a and 15 are in the shape of a vertical plate. . On the other hand, the scraping blade 14b is parallel to the inclined bottom plate 4 and has a suitable distance between it and the inclined bottom plate 4.
The scraper 34 has a shape that is inclined or arcuate with respect to the vertical plane, similar to the scraper 34 described later. The stirring shaft 12 is rotatably driven by a stirring drive motor (drive device) 16 installed on the support plate 11 via gears 17 and 18.

On the other hand, a support tower 8 is provided on the lower surface of the flange portion 9.
An annular inner rail 19 is laid along the outer surface of the inner rail 19, and a support ring 20 is rotatably suspended from the inner rail 19, as shown in FIG. This support ring 20 has a pair of wheels 22 attached to mutually opposing inner surfaces at appropriate locations in the circumferential direction of a ring member 21 having a U-shape with an upwardly open cross section, each with a shaft 23 thereof cantilevered. It is configured. The vertical portion 19a of the inner rail 19 is inserted between the wheels 22, so that the wheel 22 runs on the upper surface of the horizontal portion 19b of the inner rail 19. An inner annular member 24 is fixed to the lower surface of this support ring 20, beam members 25 are fixed radially to the outer periphery of this inner annular member 24, and the outer end of each beam member 25 is connected to the outer annular member 24.
It is fixed to 6. A wheel 28 is provided on the lower surface of the outer annular member 26 and runs on an annular outer rail 27 laid on the upper surface of the peripheral edge of the storage tank 1. 29 and a variable speed scraper drive motor (drive device) 31 that is rotationally driven via a belt 30.
is installed. Note that this scraper drive motor 31 may be installed on the floor 1c around the storage tank 1. On the lower side of the beam member 25 and the inner annular member 24, a plurality of vertical arms 3 are provided at appropriate locations in the radial direction.
2 is installed vertically, and the lower part of this vertical arm 32 is the storage tank 1.
They are connected and reinforced by a plurality of stages (three stages in the figure) of horizontal arms 33 extending in the radial direction. The lowermost horizontal arm 33 is provided parallel to the inclined bottom plate 2 of the storage tank 1, and a plurality of scrapers 34 close to the bottom plate 2 are attached to each horizontal arm 33. This scraper 34
As shown in FIG. 3, the front surface in the rotation direction is an inclined surface or a curved surface formed so that the lower side protrudes in the rotation direction, and the horizontal arm 33 is arranged so that the outer side in the radial direction of each scraper 34 protrudes in the rotation direction. is installed diagonally. And at the lower end there is a claw part 3.
5 is formed, and a scraper drive motor 31
is activated to rotate the beam member 25, and when the horizontal arm 33 rotates in the direction of arrow A, the slurry near the bottom plate 2 of the storage tank 1 is moved to the center of the storage tank 1 and upward. In addition, the scraper 34
The inclined surface may be an arcuate surface like a part of a sphere inclined so that the outer side and the front surface in the direction of rotation protrude. An inner scraper 34a is attached to the lower end of the vertical arm 32 at the upper part of the stirring chamber 3 along the support body 5, and this inner scraper 34a has a flat plate member attached at an angle with respect to the horizontal arm 33. When the beam member 25 rotates in the direction of arrow A, the slurry in the stable chamber 1a is sent to the stirring chamber 3.

At a position of the outermost vertical arm 32 facing the upper part of the inner wall 1b of the storage tank 1, there is a plate-shaped scraper that moves along the inner wall 1b as the vertical arm 32 rotates and prevents the slurry from sticking to the inner wall 1b. A mounting plate 41 is attached. An annular liquid supply groove 43 having an inner edge wall 42 with an extended inner wall 1b is formed at the upper edge of the storage tank 1, and slurry is supplied to the liquid supply groove 43 at positions that equally divide the circumference of the storage tank 1. A plurality of liquid pipes 44 are connected,
The slurry supplied through the liquid supply pipe 44 overflows the inner edge wall 42 from the liquid supply groove 43 and is evenly supplied into the storage tank 1. Further, a scraping plate 45 that prevents slurry from sticking to the liquid supply groove 43 is provided vertically from the beam member 25.

The space R above the storage tank 1 is the floor 1 around the storage tank 1.
It is covered with a peripheral wall 46 erected c and a roof (covering member) 47 placed on the peripheral wall 46 and fixed with bolts or the like, and this roof 47
It has a dome shape and is made of reinforced plastic or the like to be lightweight and strong so that the load can be supported only by the peripheral wall 46, and can be removed using a crane or the like. In addition,
The roof 47 does not have to be all integral; for example, it may be divided into two along a vertical plane including the center. Further, the peripheral wall 46 is partially or completely removable.

Air conditioning equipment 48 is installed outside the peripheral wall 46, and sensors 49 for measuring the temperature or humidity of the space R are installed at appropriate locations inside the peripheral wall 46 or the roof 47. This air conditioning equipment 48 blows outside air into a water tank (not shown) to increase the humidity through gas-liquid contact and sends it into the space R, or it sprays water droplets into the air, and the detected value of the sensor 49 is It is operated according to the above, and the humidity in the space R is adjusted to prevent moisture in the slurry from evaporating. Note that a temperature adjustment device may be incorporated into this air conditioning equipment 48 so that the temperature within the space R can be adjusted as necessary. Note that the roof 47 may be constructed as a bellows-like object that extends and contracts on a pair of rails and can be opened and closed to facilitate maintenance of the equipment in the storage tank 1, cleaning of the inside of the storage tank 1, etc. .

Next, the operation of the slurry storage device configured as described above will be described in the case of storing CWM.

CWM is generally produced by finely pulverizing coal and mixing it with water and additives to reduce the non-flammable components (ash). The CWM is sent through the liquid supply pipe 44 by a pump (not shown) and is supplied to multiple locations in the liquid supply groove 43.
The liquid overflows uniformly from the inner edge wall 42 of No. 3 to the entire inner wall 1b, flows into the storage tank 1, and is stored. The slurry that has flowed into the storage tank 1 changes over time and becomes a stable state with high viscosity, but the slurry in the lower part of the storage tank 1 thickens over time, albeit slightly.
That is, sedimentation and accumulation of slurry particles on the bottom plate 2 of the storage tank 1 occur at a slow rate, and if this is left for a long period of time, there is a risk that storage will be hindered. In this case, it is sufficient to prevent the slurry in a very limited range in contact with the bottom plate 2 from stagnation and accumulation, and the scraper drive motor 31 is operated at a low speed to rotate the outer annular member 26. scraper 34
slides the slurry near the bottom plate 2 of the storage tank 1 on the inclined surface, blows it upward and slightly toward the center, mixes it with the slurry near the top, and prevents the particles of the slurry near the bottom from settling and accumulating. . By setting this rotation speed to a low shear rate range that maintains the internal structure of the slurry and maintains its viscosity, for example, one rotation every 10 to 30 days, most of the slurry can be kept at a high viscosity, and the bottom plate By stirring only the vicinity of 2, deposition and solidification can be prevented while minimizing the required energy. In the stirring chamber 3, the stirring drive motor 16 is appropriately rotated at a rotation speed much faster than the rotation speed of the scraper 34, and the stirring blade 14 is
The slurry is made uniform by the blades a and 15 and the scraper blades 14b. The turbulent flow generated by this stirring is
The air is blocked by the agitation chamber 3 and remains within the stirring chamber 3, so that it does not significantly affect the stability of the stability chamber 1a.

When discharging the slurry, the slurry is sucked from the discharge port 7 by a pump (not shown), the scraper drive motor 31 is rotated at a higher speed than in the above case, and the stirring drive motor 16 is also rotated. Since the scraper 34 rotates at a higher speed than when it is stored, the action of scraping the slurry toward the center is strong, and the inner scraper 34a
is attached parallel to the conical side surface of the support body 5 and at an angle with respect to the horizontal arm 33, so that
The slurry is pushed down over the entire vertical height of the inner scraper 34a. Due to these actions and the flow accompanying the discharge from the discharge port 7, the slurry moves to the center of the bottom plate 2 and is sent into the stirring chamber 3.
The mixture is uniformly stirred by the stirring blades 14a and 15 and discharged from the discharge port 4. At this time, the scraping blade 14b
serves to scrape the slurry thickened on the inclined bottom plate 4 toward the center, mix it, and discharge it uniformly. The rotational speed of the scraper 34 at this time is
The stirring blades 14a, 15 and scraping blades 14b can be adjusted according to the amount and concentration of slurry to be discharged.
It is preferable to adjust the rotational speed to an appropriate speed by changing the speed of the stirring drive motor 16.

In the storage and discharge process described above, moisture from the slurry is removed by operating the air conditioning equipment 48 and controlling the humidity in the space R to be equal to or slightly higher than the saturated vapor pressure at that temperature. evaporation and changes in the properties of the slurry. Alternatively, the above objective may be achieved by operating the temperature adjustment mechanism of the air conditioner 48 to lower the temperature in the space R and lower the saturated vapor pressure.

In the slurry storage device of this example, stirring in the stirring chamber 3 destroys the internal structure of the slurry, making the slurry low in viscosity, allowing it to be easily discharged and preventing clogging. In addition, a stabilization chamber 1a and a stirring chamber 3 are provided, and each part performs separate functions of leaving the slurry still and storing it, and stirring and discharging it, thereby eliminating the influence of one from the other. It has little effect. In addition, separate drive mechanisms are provided for stirring each, so the rotation speed can be set and changed independently, making the above functional division more effective and allowing storage and storage to suit the properties of the slurry. Can be discharged. Then, the air conditioning equipment 48 adjusts the humidity in the space R and the temperature as necessary, prevents the evaporation of water from the slurry and maintains its quality constant, and prevents the sedimentation of powder due to the concentration of the slurry and further prevents the discharge port 7. The effect of preventing blockage is further enhanced.

Note that the above example is a device for storing non-volatile slurry, but in the case of slurry such as COM where the oil content is likely to volatilize and catch fire, the stirring drive motor 16, scraper drive motor 31, etc. Measures may be taken such as making it explosion-proof or installing it outside the roof 47.

[Effects of the Invention] As described in detail above, the present invention provides a stirring chamber in the center and a stabilization chamber in the outer periphery of the stirring chamber by means of a partition member having circulation holes that allow free circulation of the slurry. A cylindrical storage tank with a discharge port provided at the bottom of the stirring chamber, and a rotatable storage tank provided inside the stability chamber are rotated along the bottom plate of the storage tank to pump the slurry near the bottom plate upward. a scraper that moves the scraper toward the center and a variable speed first drive that rotates the scraper, a stirring blade that is rotatably provided in the stirring chamber, and a second drive that rotates the stirring blade. Since the structure is equipped with a device, it is possible to economically store the slurry in a uniform and stable dispersion state for a long period of time without the solid content in the slurry precipitating, thickening, or separating. , during discharge transfer,
This has the excellent effect of making it possible to fluidize the slurry and transfer it easily and efficiently without clogging.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the main part, and FIG. 3 is a perspective view of the main part. 1... Storage tank, 1a... Stability chamber, 2... Bottom plate, 3... Stirring chamber, 5... Support body (partition member), 5a... Slit (flow hole), 7... Outlet, 14a, 15... Stirring blade,
16, 31... Drive motor (drive device), 34... Scraper.

Claims (1)

[Claims] 1 A stirring chamber is formed in the center by a partition member having circulation holes that allow free circulation of the slurry, and a stability chamber is formed on the outer periphery of the stirring chamber, and a discharge port is provided at the bottom of the stirring chamber. a cylindrical storage tank, a scraper rotatably provided in the stable chamber and rotated along the bottom plate of the storage tank to move the slurry near the bottom plate upward and toward the center; A slurry storage device comprising: a variable speed first drive device for rotating; a stirring blade rotatably provided in the stirring chamber; and a second drive device for rotating the stirring blade.