JPS63294933A - Slurry storage vessel - Google Patents

Abstract

PURPOSE:To prevent the particles of slurry from settling and to smoothly discharge the slurry by providing the driving unit which drives a scraper both in ordinary direction and in reverse direction and forming a scrape-hoisting surface which moves the slurry upward when the scraper is rotated in the ordinary direction and a scrape- gathering surface which moves the slurry to the center of bottom plate when the scraper is rotated in the reverse direction. CONSTITUTION:A scraper driving mechanism 29 is put into operation in order to prevent the particles of slurry in a storage vessel 1 from settling to a bottom plate 2 with the lapse of time. That is, when a variable speed reversible unit 31 is set in the ordinary direction side and a scraper driving motor 30 is put into low speed operation, the scrape-hoisting surface of the scraper 24 moves the slurry of the vicinity of bottom plate to slide upward to mix with the slurry of upper part. The revolving velocity is kept in a low shearing velocity range, such as one revolution per 10-30 days, so that the slurry is agitated keeping high viscosity to prevent the particles of slurry from settling. And in the case of discharging the slurry, the unit 31 is changed over to the reverse direction side and the motor 30 is put into high speed operation, so that the slurry near the bottom plate 2 is moved to the vicinity of center by the scraping surface of the scraper 24.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention applies to coal-water mixtures (CWM) or coal-water mixtures (CWM) or coal-water mixtures (CWM).
The present invention relates to a slurry storage tank for storing slurry such as oil mixture (COM).

[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, when such a slurry is stored for a long period of time, as a result of the particles settling, the lower layer becomes thicker and further solidifies, making it impossible to discharge smoothly. Therefore, the coal particles are dispersed by blowing air into the storage tank or mechanically stirred to maintain a uniform slurry concentration, or the thickened slurry in the lower layer is scraped out using a scraper or conveyor. Methods have been proposed, such as using a pump to circulate the water to the top of the tank.

[Problems to be solved by the invention] However, in order to obtain a sufficient effect of preventing deposition and solidification by the method described above, a large amount of energy is required to move the slurry with a large specific gravity, and the operation is slow. The cost will increase.

Generally, since the internal structure of a non-Newtonian fluid such as a slurry changes as it flows, its viscosity properties change depending on the deformation rate. In other words, it exhibits a very high viscosity in the low shear rate region, forming a stable slurry with no particle sedimentation, and the internal structure consisting of bonds between particles is destroyed in the process of transitioning from a static state to a fluid state. This creates a low-viscosity slurry that is easier to transport. Therefore, if the slurry is made to flow excessively, such characteristics will be lost and sedimentation and deposition will be promoted instead.

Therefore, it can be said that the most appropriate method is to let the slurry stand still in the tank without stirring or circulating the slurry as described above, and to maximize its standing stability and store it.

This invention was made with attention to these points,
It is an object of the present invention to provide a slurry storage tank that can store slurry smoothly and economically by suppressing the flow of slurry to the necessary minimum and using a device with a relatively simple configuration.

Means for Solving Problems] This invention provides a bottomed cylindrical storage tank having a discharge port in the center of the bottom plate, a scraper rotatable along the bottom plate,
The scraper is provided with a drive device that rotates the scraper in forward and reverse directions, and the scraper has a scraping surface that is inclined or curved so as to move the slurry upward when the scraper rotates in the forward direction, and a drive device that rotates the scraper in the forward and reverse directions. In some cases, an inclined or curved scraping surface is formed to move the slurry to the center of the bottom plate.

[Function] When storing slurry, the scraper is rotated in the normal direction at a very slow speed, and the scraping surface creates a flow that moves the slurry near the bottom plate upward, mixing the slurry near the bottom plate of the storage tank with the slurry in the upper layer. Prevent accumulation and solidification and store statically. In addition, 1. When discharging slurry, the scraper is reversed at a higher speed, and the scraping surface creates a flow near the bottom plate that moves the slurry to the center of the bottom plate, allowing the slurry to be discharged from the discharge port. Make it.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

In these drawings, l is a cylindrical storage tank with a bottom,
The bottom plate 2 is formed to be inclined in a funnel shape so that the center is lower, and the upper part of the bottom plate 2 inside the inner wall 1a is a stationary chamber 1b. A cylindrical stirring chamber 3 is provided. This stirring chamber 3 also has a funnel-shaped inclined bottom plate 3a, a discharge port 4 is formed in the center thereof, and an annular convex wall 3b projecting slightly upward is provided at the upper edge. The stationary chamber 1b and the stirring chamber 3 are partitioned to prevent the influence of stirring in the stirring chamber 3 from affecting the stationary chamber 1b.

A support structure 5 is installed on the upper surface of the storage tank l, spanning the storage tank l, and a hole 5a is formed in the center of this support part 5, and a rotating shaft 6 is vertically inserted into this hole 5a. . This rotary shaft 6 has a support part 6a formed in the shape of a flange at its upper end, and is supported by an elevating support mechanism 7'' installed on the upper surface of the support part 5, and is also installed near the hole 5a. By being rotated by the stirring mechanism 8, stirring blades 39, which will be described later, are rotated and the slurry in the stirring chamber 3 is stirred. The lifting support mechanism 7 includes a plurality of hydraulic jacks 7a installed around the hole 5a on the support portion 5, and the hydraulic jacks 7a.
a ring body 7b connecting the movable ends of the ring body 7b;
and the support portion 6a to rotatably support the rotary shaft 6; and the hydraulic jack 7a.
The hydraulic motor 7d drives the hydraulic motor 7d. The stirring mechanism 8 includes a stirring drive motor 8a installed on the support part 5, and a gearbox 8b that transmits the rotational force of the stirring drive motor 8a to the rotating shaft 6. The rotary shaft 6 is connected to the rotary shaft 6 in a state where the rotary shaft 6 is movable in the axial direction.

A stirring structure 9 for stirring the stationary chamber 1b is rotatably attached to the rotating shaft 6. That is, a cylindrical member IO is rotatably mounted on the upper part of the rotating shaft 6, a plurality of beam members 11 are attached radially to the outer surface of the cylindrical member IO, and the outer end of each beam member 11 is a ring member. 12, and this ring member 12 has a rail 1 laid in an annular shape on the floor 1c around the storage tank (2).
A plurality of wheels 14 are provided to run on the vehicle.

A mounting member 15 having a vertical through hole 15a is attached to a position slightly inside the storage tank inner wall 1a of each of the beam members 11, and a vertical arm 16 is inserted into the through hole 15a. At the same time, a fixture 17 provided at the upper end of the vertical arm 16 is supported by abutting against the mounting member 15.

In addition, stoppers I 8 and 19 are fixed at a position slightly below the vertical center of the rotating shaft 6 and near the lower end, and cylindrical members 2 and 19 are respectively fixed to the rotating shaft 6 above the stoppers 18 and 19.
0.21 is rotatably and slidably mounted on the exterior. Between the outer surfaces of these cylindrical members 20 and 21 and the vertical arm 16, lower first arms 22 and upper second arms 23 extend radially and extend from the bottom plate 2.
A plurality of scrapers 24 are attached to each first arm 22 at a small distance from the bottom plate 2, and a plurality of ailerons 25 are attached to each second arm 23. . As shown in FIG. 3 (the left side of the figure is the center side of the storage tank 1, and the same is true for FIG. 4), the scraper 24 has a scraping surface formed in the forward rotation direction as an arcuate surface or an inclined plane with the lower side protruding. 26 and a wavy claw portion 27 is formed at the lower end thereof, while the front surface in the reverse direction is a scraping surface 28 formed as an inclined plane with the outer side protruding. Therefore, when the scraper 24 rotates in the normal direction, the slurry flows upward, and when the scraper 24 rotates in the reverse direction, it flows toward the center. In addition, the aileron 25
As shown in FIG. 4, a flat plate-like member is attached to the second arm 23 with its lower and inner sides protruding in the normal rotation direction, and during normal rotation, the slurry is transferred upward and outward. When the rotation is reversed, the flow is made to flow downward and inward.

These cylindrical members to, 20.21. The beam member 11, the first arm 22, the scraper 24, the second arm 23, the ailerons 25, and the vertical arm 16 together constitute the stirring structure 9, and there is a gap between the floor lc and the ring member 12. It is designed to be rotated by a scraper drive mechanism 29 installed at. This scraper drive mechanism 29 includes a scraper drive motor 30 installed on the floor lc.
, a variable reversible device 31 provided on the output shaft of this scraper drive motor 30, a pinion 32 attached to the output shaft of this variable reversible device 31, and teeth attached to the outside of the ring member 12 and meshing with the pinion 32 on the upper surface. The stirring structure 9 can be rotated reversibly in either forward or reverse directions and at different speeds.

Note that the fixing metal fitting 17 at the upper end of the vertical arm 16 is positioned so that the scraper 24 has an appropriate distance from the bottom plate 2, and at this time, the stopper 18 of the rotating shaft 6.
19 and the cylindrical member 20.21 are set to have an appropriate interval. Therefore, in the state shown in FIG. 1 when the lifting support mechanism 7 is not operating, the vertical arm 16 and the first
The loads of the arm 22, scraper 24, second arm 23, and aileron 25 are supported by the beam member 11 via the fixture 17 and the mounting member 15.

A scraping plate 34 is attached to the vertical arm 16 at a position facing the upper part of the inner wall 1a of the storage tank 1, which moves along the inner wall 1a as the vertical arm 16 rotates and prevents slurry from sticking to the inner wall 1a. has been done.

Further, at the upper edge of the storage tank 1, an annular liquid supply groove 35 having an inner edge wall 35a formed by extending the upper edge of the inner wall 1a of the storage tank 1 is provided.
A slurry supply pipe 3 is formed in this liquid supply groove 35.
6 are communicated at a plurality of locations, and the slurry supplied through the liquid supply pipe 36 flows from the liquid supply groove 35 to the inner edge wall 35a.
The supply liquid W! is designed to evenly overflow and be supplied into the storage tank L, and this supply liquid W! A scraping plate 37 is provided vertically from the beam member 11 to prevent slurry from sticking to the t35.

As shown in FIG. 5, a stirring blade 39 having a cylindrical drum 38 on the outside and blades 40 on the inside is attached to the portion of the rotating shaft 6 inside the stirring chamber 3. As shown in FIG. In addition, the side wall 4 of the stirring chamber 3
A screw member 42 is screwed into the screw member 1, and an arc plate-shaped steadying member 43 is pivotally attached to the tip of each screw member 42, and by rotating the screw member 42, the above-mentioned A steadying member 43 is brought into contact with the drum 38 to fix the rotating shaft 6. Note that this steadying member 43 may be inserted into the stirring chamber 3 using a spring or the like, and this spring may be automatically activated by a signal from a seismometer or the like. A bottom plate 3a is provided below the stirring blades 39 of the rotating shaft 6.
Vertical wings 44 are attached in a cross shape along the slope. Further, these stirring blades 39 and vertical blades 44 rotate together with the rotating shaft 6, and are slidably attached in the axial direction of the rotating shaft 6, so that the rotating shaft 6 can be moved up and down. The position in the height direction does not change.

The upper space R of the storage tank 1 is airtightly covered by a peripheral wall 45 and a dome-shaped roof 46 that are erected on the floor IC so as to surround the storage tank 1. This roof 46 is integrally manufactured from a lightweight and high-strength material such as reinforced plastic, and can be lifted and removed using a crane or the like.
This makes it easier to remove adhering slurry in the storage tank and perform maintenance and inspection of each machine. Additionally, a sensor 47 that measures the humidity and temperature of this space R, and an air conditioning system 48 that adjusts the humidity and temperature of the space R as necessary to prevent the moisture in the slurry from evaporating and increasing the concentration of the slurry are installed. has been done. This air conditioning equipment 48 is one that blows outside air into the aquarium, increases humidity through gas-liquid contact, and sends it into the space R, or one that sprays water droplets into the space R. Additionally, a device equipped with a temperature adjustment mechanism may be used if necessary. Note that the roof 46 may be configured as a bellows-shaped member that extends and contracts on a pair of rails so that it can be opened and closed to facilitate maintenance and inspection.

Next, we will explain the action of the slurry storage tank configured as above by C.
The case of storing WM will be described.

CWM is generally produced by finely pulverizing coal and mixing it with water and additives to reduce non-flammable components. The liquid supply pipe 36 is connected by a pump (not shown).
C that is sent through the liquid supply groove 35 and supplied to multiple locations in the liquid supply groove 35.
WM evenly overflows from the inner edge wall 35a of the liquid supply groove 35 to the entire inner wall 1a, 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 of high viscosity, but the lower part tends to become slightly bromised over time. In other words, near the bottom plate 2 of storage tank 1, slurry particles do not settle or accumulate at all, but they gradually accumulate and solidify, albeit at a very slow rate, and if this is left for a long period of time, it will interfere with storage. There is a risk that this may occur. Therefore, the standing room t of the storage tank l
The scraper drive mechanism 29 is operated in order to prevent the slurry from stagnation and particle accumulation in a very limited area in contact with the bottom plate 2 of b. That is, the variable reversible device 3
1 is set to the forward rotation side, scraper drive motor 3
0 is operated at low speed, its rotation is controlled by the variable reversible device 31.
, pinion i2, and rack 33 to the ring member 12, and integrally rotates the stirring structure 9 in the normal direction. Due to this rotation, the scraping surface 26 of the scraper 24 is brought into contact with the bottom plate 2 of the storage tank 1.
The slurry in the vicinity is allowed to slide up to the vicinity above and mixed with the slurry in the vicinity above. At this time, the aileron 20 further transfers the slurry scraped up by the scraper 24 to the storage tank 20.
to help prevent particles from settling and accumulating. At this time, the rotation speed of the stirring structure 9 is set to 10, for example.
By setting the stirring speed to a low speed such as one rotation every ~30 days, the stirring speed is set to a low shear rate range that maintains the internal structure of the slurry, which is a non-Newtonian fluid, and maintains high viscosity, and prevents excessive flow. In addition to maintaining the stability of the slurry, it also reduces the energy required and reduces operating costs. Note that the second arm 23 of the aileron 25. The attachment angle may be made variable using a screw or the like so that the action of the aileron 25 can be adjusted.

On the other hand, in the stirring chamber 3, it is desirable to ensure the fluidity of the slurry, especially when transporting, and the stirring mechanism 8 is operated as appropriate to stir the slurry in the stirring chamber 3 and make it uniform. put. That is, when the stirring drive motor 8a is operated, its rotation is transmitted to the rotating shaft 6 via the gear box 8b, and the stirring blades 39 and vertical blades 44 attached to the lower part of the stirring drive motor 8a are moved much further than the stirring structure 9. Rotate at high speed. This rotation uniformly stirs the slurry in the stirring chamber 3, and the turbulence caused by this stirring is suppressed from being transmitted upward by the convex wall 3b provided at the upper edge of the stirring chamber 3, so that the slurry in the stilling chamber 1b is prevented from being transmitted upward. Effects that disturb the static condition are kept to a minimum.

When discharging the slurry, a discharge pump (not shown) is operated, the variable reversible bag E31 is switched to the reverse rotation side, the scraper I drive motor 30 is operated at a much higher speed than normal rotation, and the slurry is further stirred. Drive motor 8a
Activate. The rotation of the scraper drive motor 30 integrally reverses the stirring structure 9, and due to this rotation, the scraping surface 28 of the scraper 24 causes the slurry near the bottom plate 2 of the storage tank 1 to flow near the center, and the gap above the convex wall 3b. More stirring chamber 3
send to Additionally, the ailerons 20 also send the slurry downward and inward to assist the slurry transporting action of the scraper 24. In the stirring chamber 3, the slurry sent from above is further stirred by the blades 40 and the vertical blades 44, and is discharged from the discharge port 4. The rotational speeds of the stirring structure 9 and the rotating shaft 6 at this time are adjusted according to the amount and concentration of the slurry to be discharged. Due to the stirring by the blades 40 and the vertical blades 44, the internal structure of the slurry in the stirring chamber 3 is destroyed and the viscosity becomes low.
This prevents blockage and facilitates drainage.

For example, because only storage was performed without transportation,
When the amount of particles settling on the bottom plate 2 of the storage tank 1 increases, the viscosity increases, and the load on the scraper drive motor 30 becomes excessive, the lifting support mechanism 7 is operated to raise the stirring structure 9. That is, when the hydraulic motor 7d is operated to drive the hydraulic jack 7a and the support portion 6a of the rotating shaft 6 is pushed up via the ring body 7b and the bearing 7C, the rotating shaft 6
rises, and the stopper 18.19 fixed to the rotating shaft 6 pushes up the cylindrical member 20.21, raising the scraper 24, the ailerons 25, and the vertical arm 16 via the first arm 22 and the second arm 23. . When the scraper drive mechanism 29 is operated, the scraper 24 rotates in the slurry at a low temperature, so the load is reduced and stirring can be performed smoothly. Then, the slurry near the bottom plate 2 is scraped up and thinned by the stirring of the scraper 24, and the lifting support mechanism 7 is operated to gradually lower the scraper 24.

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. Further, if necessary, 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.

When removing deposits or carrying out repair work, the roof 46 is suspended and removed using a crane, and if necessary, the surrounding wall 45 is removed, allowing a crane vehicle or the like to approach the storage tank 1 and remove the roof 46 from inside the tank 1. You can work freely. In this case, since the structure is such that the roof 46 is supported only by the peripheral wall 45, there are no obstructive supports inside the storage tank l, making the work easier. As a method of supporting the roof 46, the air pressure in the space R may be made slightly higher than the outside pressure to push up the roof 46 and reduce the load on the peripheral wall 45.

In such a slurry storage tank, a scraper 24 installed near the bottom of the storage tank 1 is used to scrape up only a small amount of the slurry at the bottom of the tank to prevent the thickened slurry from accumulating and solidifying. without impairing the static stability of the slurry. Furthermore, each scraper 24 is formed with a scraping surface 26 and a scraping surface 28, which perform two functions by forward and reverse rotation of the rotating shaft 6, compared to the case where these two surfaces are provided separately. The device can be simplified and costs can be reduced. In addition, a standing chamber 1b and a stirring chamber 3 are provided, and each part performs separate functions of standing and storing the slurry, and stirring and discharging the slurry, thereby eliminating the influence of one from the other. It has little effect on 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. Roof 46 and surrounding wall 45
The space R above the storage tank 1 is airtightly covered, and the air conditioning equipment 4
Since the humidity and, if necessary, the temperature of this space R are adjusted by 8, evaporation of moisture from the slurry is prevented and the properties of the slurry do not change. In addition, in the event of an earthquake, the vibration prevention member 43 provided on the side wall 41 of the stirring chamber 3 engages with the drum 38 of the stirring blade 39, so that the rotating shaft 6, the first arm 22, and the second arm 23 Damage caused by excessive vibration can be prevented.

Note that the above example is a device for storing non-volatile coal slurry, but in the case of slurry such as COM where the oil content is likely to volatilize and catch fire, the scraper drive motor 30, stirring drive motor 8a, etc. make it explosion-proof,
Alternatively, measures such as installing it outside the roof 46 (in that case, make it a fixed roof) may be taken.

[Effects of the Invention] As detailed above, the present invention includes a bottomed cylindrical storage tank having a discharge port in the center of the bottom plate, a scraper that is rotatable along the bottom plate, and a scraper that can be rotated in forward and reverse directions. The scraper has an inclined or curved scraping surface that moves the slurry upward when the scraper rotates in the normal direction, and a scraper that moves the slurry to the center of the bottom plate when the rotation shaft rotates in the reverse direction. Since the slurry is formed with an inclined or curved scraping surface, it suppresses the flow of the slurry to the necessary minimum, suppresses the accumulation and solidification of particles, and allows smooth storage and discharge of the slurry. This has the excellent effect of simplifying the device.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is an enlarged perspective view of the main parts, Fig. 4 is an enlarged perspective view of the main parts, and Fig. 5 is the same. FIG. 2 is a view taken along the arrows ■-■, and FIG. 6 is an enlarged view of the main parts. ■・・・Storage tank, 2...Bottom plate, 4...
...Discharge port, 7... Lifting support mechanism, 24...
... Scraper, 26... Scraping surface, 28...
... Scraping surface, 29 ... Scraper drive mechanism, 31 ... Variable reversible device, lO ... Lifting motor, 17 ... Arm, 18 ...Scraper, 18a... Scraping surface, 18b... Scraping surface.

Claims (2)

[Claims] (1) A bottomed cylindrical storage tank with a discharge port in the center of the bottom plate;
a scraper rotatably provided along the bottom plate;
The scraper is equipped with a drive device that rotates the scraper in forward and reverse directions, and the scraper has an inclined or curved scraping surface that moves the slurry upward when the scraper rotates in the forward direction, and a drive device that rotates the scraper in the forward and reverse directions. A slurry storage tank characterized in that a sloping or curved scraping surface is formed to sometimes move the slurry to the center of the bottom plate. (2) The slurry storage tank according to claim 1, further comprising means for moving the scraper up and down.