JP6835364B2 - Powder mixer and powder mixing method - Google Patents

Description

The present invention relates to a powder mixer and a powder mixing method.

Conventionally, as a powder mixer, one in which powder discharged from a hopper is supplied to a slurrying mixer via a vertical chute to form a slurry is known (see, for example, Patent Document 1). In this powder mixer, slurry formation is promoted by spraying water on the unslurried escaped powder that has escaped into the spray nozzle cylinder.

By the way, in the powder mixer, air may be mixed in the powder in advance in order to smoothly flow the powder until the slurry formation is started. Therefore, when the powder is slurried, it is necessary to exhaust the supplied air.

However, in the conventional powder mixer, there is no mention of mixing a gas with a powder. Further, when the mixed air is exhausted, dust is generated there, so it is necessary to slurry this, but this point is not mentioned either.

Jikken Sho 62-16179

An object of the present invention is to provide a powder mixer and a powder mixing method capable of effectively slurring generated dust while removing gas when supplying powder.

The present invention provides means for solving the above problems.
A mixing tank in which powder and liquid are supplied, the powder and the liquid are mixed to form a slurry, and a discharge passage for the slurry is connected to the lower part.
A detour passage connected to the space above the mixing tank and
It is provided with an injection means for injecting a liquid into a slurry of dust contained in a gas entering the detour passage from the mixing tank.
Provided is a powder mixer characterized by supplying the slurry obtained in the mixing tank and the slurry slurried in the detour passage to the same supply destination.

With this configuration, the gas in the space above the mixing tank can be exhausted through the bypass passage. At this time, even if the gas contains dust, the liquid injected from the injection means can mix the dust and the liquid contained in the gas, so that the slurry can be reliably formed.

The injection means is preferably provided in the detour passage.

With this configuration, the liquid can be injected from the space above the mixing tank to the gas (dust) that has entered the detour passage, so it is effective to mix the dust and liquid contained in the gas in the detour passage. Can be made into a slurry.

The injection means is preferably provided in the vicinity of the connecting portion between the mixing tank and the detour passage.

With this configuration, the liquid can be injected to the gas (dust) flying (drifting) in the upper space of the mixing tank or the gas (dust) trying to enter the detour passage from the upper space of the mixing tank. Before the (dust) invades the detour passage, the dust contained in the gas and the liquid can be mixed and effectively made into a slurry.

The detour passage has a first passage portion that goes upward from the space above the mixing tank.
The injection means preferably has a first injection unit that injects a liquid from above the first passage portion toward the mixing tank.

With this configuration, it is possible to effectively slurry the dust generated in the space above the mixing tank by directly injecting the liquid.

The detour passage has a second passage portion extending downward toward the discharge passage on the side of the mixing tank.
It is preferable that the injection means further includes a second injection portion that injects a liquid downward from above toward the second passage portion.

With this configuration, dust that cannot be slurried by the first injection section and has flowed into the second passage section can be reliably slurried by the second injection section and guided to the discharge passage.

The detour passage has a first passage portion that goes upward from the space above the mixing tank and a second passage portion that extends downward toward the discharge passage on the side of the mixing tank, and is the first passage. The section and the second passage section merge at the upper confluence,
The injection means is preferably composed of a single injection unit capable of injecting a liquid into the first passage portion and the second passage portion via the upper merging portion.

With this configuration, even with a single injection portion, dust can be slurried in both the first passage portion and the second passage portion, and the configuration can be simplified.

The mixing tank is
A hopper that gradually becomes smaller as the opening cross section goes downward,
A stirring unit that is connected to the lower end opening of the hopper and extends downward to stir the supplied powder and liquid.
A liquid supply unit that supplies liquid into the hopper to generate a swirling flow,
It is preferable to provide.

With this configuration, the powder supplied into the hopper can be smoothly moved downward by the swirling liquid and stirred by the stirring unit to form a slurry.

It is preferable to provide a gas mixing section for mixing the gas with the powder supplied to the mixing tank.

With this configuration, the fluidity of the powder can be improved, so that the powder can be smoothly moved to the mixing tank without causing clogging or the like.

The present invention provides means for solving the above problems.
A powder mixing method in which powder and liquid are supplied into a mixing tank and mixed to form a slurry, and the slurry is discharged from a discharge passage at the bottom.
When the gas in the space above the mixing tank is discharged through the detour passage, a liquid is sprayed onto the dust contained in the gas to form a slurry, and the slurry obtained in the mixing tank and the detour passage Provided is a powder mixing method characterized by supplying the obtained slurry to the same supply destination.

According to the present invention, it is possible to effectively discharge the gas contained in the powder which had been supplied to the bypass passage from the upper space of the mixing tank. Further, even if dust is contained in the gas, it can be effectively made into a slurry by the liquid injected by the injection means.

It is a schematic front sectional view of the powder mixer which concerns on this embodiment. It is a schematic plan view of the hopper of FIG. It is an enlarged sectional view of the powder supply part of FIG. It is the schematic front view of the hopper part of the powder mixer which concerns on another embodiment. It is the schematic front view of the hopper part of the powder mixer which concerns on another embodiment. It is the schematic front view of the hopper part of the powder mixer which concerns on another embodiment.

Hereinafter, embodiments according to the present invention will be described with reference to the accompanying drawings. It should be noted that the following description is essentially merely an example and is not intended to limit the present invention, its application, or its use.

FIG. 1 shows a schematic front sectional view of the powder mixer according to the present embodiment. This powder mixer includes a mixing tank 1, an exhaust pipe 2 which is a detour passage, and a powder supply unit 3 for supplying powder to the mixing tank 1, and these are housed in a housing (not shown). However, the exhaust pipe 2 extends in the vertical direction along the outer surface of the housing.)

The mixing tank 1 is composed of a hopper 4 on the upper side and a stirring unit 5 extending downward following the opening at the lower end thereof.

The hopper 4 is formed in a funnel shape in which the opening area gradually decreases as the opening area decreases downward. However, the upper part of the hopper 4 has a cylindrical shape, and as shown in FIG. 2, nozzles 6 for allowing liquid (here, water) to flow in are provided in three equal parts. The nozzle 6 is for swirling the liquid supplied to the inner surface of the hopper 4. As shown in FIG. 1, a discharge pipe 7 is connected to the lower end opening of the hopper 4. The upper opening of the hopper 4 is closed by the lid 8. A powder supply pipe 9 for supplying powder (here, dry powder activated carbon) is connected to the lid 8 at the center, and an exhaust pipe 2 is connected to the outer peripheral side. A powder supply unit 3 is provided above the powder supply pipe 9.

The stirring unit 5 is composed of a static mixer in which the screw 11 is housed in the communication pipe 10 connected to the lower end opening of the hopper 4.

The exhaust pipe 2 includes a first passage portion 12 connected to an opening formed in the lid 8 and extending vertically upward, and a second passage portion 13 provided on the side of the mixing tank 1 and connected to the discharge pipe 7. To be equipped. The first passage portion 12 and the second passage portion 13 are communicated with each other by connecting the communication portions 12a and 13a branched from the first passage portion 12 and the second passage portion 13. The first passage portion 12 is provided with a first injection portion 14. The first injection unit 14 is configured to inject a liquid (here, water) into the hopper 4 in the form of a shower. As a result, the dust generated in the upper space in the hopper 4 flows down to the stirring unit side by the liquid injected from the first injection unit 14. The second passage portion 13 is composed of a tube 13b made of a flexible resin material except for the upper portion. The lower end of the tube 13b is connected to a communication portion 7a extending from the discharge pipe 7. A second injection portion 15 is provided in an upper portion of the second passage portion 13. The second injection unit 15 is configured to inject a liquid (here, water) into the second passage unit 13 in the form of a shower. As a result, some of the liquid injected from the first injection unit 14 cannot flow down, and the dust that has entered the second passage portion 13 can flow down to the discharge pipe 7.

As shown in FIG. 3, the powder supply unit 3 includes a first tubular portion 16 and a second tubular portion 17 on the upper portion of the powder supply pipe 9.

The first tubular portion 16 is composed of a ferrule short pipe extending vertically downward. The first tubular portion 16 and the pipe 19 are integrally formed by welding. The upper end of the second tubular portion 17 is connected to the pipe 19 on the upper side by a ferrule clamp 18.

The second tubular portion 17 includes a first gas supply unit 20 and a second gas supply unit 21 arranged below the first gas supply unit 20.

The first gas supply unit 20 includes a first outer cylinder 22 and a first inner cylinder 23, and the annular opening at the upper end is closed by the upper lid 24, and the annular opening at the lower end is covered with the partition plate 25, whereby the first interior is provided. The space 26 is partitioned. An air supply pipe 27 is connected to the upper side of the first outer cylinder 22, and the gas (here, air is used, but may be an inert gas such as argon gas or nitrogen) is the first. It is supplied into the internal space 26. The first inner cylinder 23 extends downward so as to form a tubular space 28 with the outer peripheral surface of the first tubular portion 16. The first inner cylinder 23 is composed of a sintered filter so that the gas supplied into the first inner space 26 can be uniformly ejected into the tubular space 28 on the inner diameter side.

The second gas supply unit 21 includes a second outer cylinder 29 and a second inner cylinder 30, and the annular opening at the upper end is covered with the partition plate 25, and the bottom plate 31 is arranged in the intermediate portion to form the second internal space. 32 is partitioned. The partition plate 25 has a disk shape, and through holes 33 are formed at a plurality of locations in the circumferential direction on the inner peripheral side thereof, and the first internal space 26 and the second internal space 32 are communicated with each other. The second outer cylinder 29 is located on the outer diameter side of the first outer cylinder 22, and is formed inside a predetermined dimension with respect to the outer peripheral edge of the partition plate 25. The second inner cylinder 30 extends continuously downward from the first inner cylinder 23 and terminates below the lower end of the first tubular portion 16. The bottom plate 31 is composed of a sintered filter so that the gas flowing into the second internal space 32 is uniformly ejected downward.

The powder supply pipe 9 penetrates the central portion of the lid 8 that covers the upper opening of the hopper 4 and projects into the hopper 4. The upper end opening of the powder supply pipe 9 is closed by the upper lid 35 fixed by the ferrule clamp 34. The liquid supply space 36 is partitioned by the powder supply pipe 9, the upper lid 35, the first outer cylinder 22 of the second tubular portion 17, and the partition plate 25. Liquid (here, water) can be supplied to the liquid supply space 36 via the liquid supply pipe 37 connected to the upper lid 35. An annular gap is formed between the inner peripheral surface of the powder supply pipe 9 and the outer peripheral surface of the partition plate 25. The liquid supplied into the liquid supply space 36 flows down along the inner surface of the powder supply pipe 9 through the gap. As a result, the inner surface of the powder supply pipe 9 can be washed away with liquid (water), and the powder adhering to the inner surface of the powder supply pipe 9 can be recovered and efficiently made into a slurry. The inner peripheral surface of the powder supply pipe 9 is coated with Teflon (registered trademark) to prevent powder and the like from adhering to the inner peripheral surface.

Although not shown, the powder contains dry gas (air is used here, but an inert gas such as argon gas or nitrogen may be used) on the upstream side of the powder supply unit 3. A gas mixing section for allowing the gas to be mixed and a uniaxial eccentric screw pump following the gas mixing section are provided.

The gas mixing portion has a funnel-shaped passage, and its wall surface is made of a porous material so that dry gas can be supplied to the internal space. When the powder passes through the gas mixing section, the dry gas flowing from the entire wall surface is mixed and then supplied to the powder supply section 3. The fluidity of the powder is improved by mixing the dry gas, and the powder can be conveyed in fixed amounts by the uniaxial eccentric screw pump.

Next, the operation of the powder mixer having the above configuration will be described.
In the powder supply, the fluidity is improved by passing through a funnel-shaped passage and mixing the dry gas. Then, the powder mixed with the dry gas is conveyed to the powder supply unit 3 by the uniaxial eccentric screw pump.

In the powder supply unit 3, the gas is made to flow into the first internal space 26 through the air supply pipe 27 before the powder is supplied. A part of the gas that has flowed into the first internal space 26 is ejected into the tubular space 28 between the first tubular portion 16 and the second tubular portion 17. The rest of the gas that has flowed into the first internal space 26 flows into the second internal space 32 and is ejected downward. Further, the liquid is made to flow into the liquid supply space 36 through the liquid supply pipe 37. The liquid that has flowed into the liquid supply space 36 flows downward along the inner peripheral surface of the powder supply pipe 9.

When the powder is conveyed to the powder supply unit 3 in this state, the powder flows down the first tubular portion 16 and falls from the lower end opening thereof. At this time, the gas ejected into the tubular space 28 is a parallel flow that flows downward in the same downward direction as the powder flows, and the powder supplied from the first tubular portion 16 is first due to humidity or the like. It exhibits a function as a so-called air curtain that prevents the lower end opening of the tubular portion 16 and the inner peripheral surface of the second inner cylinder 30 from adhering to the opening. Therefore, the powder that has fallen from the lower end opening of the first tubular portion 16 does not adhere to the inner peripheral surface of the second inner cylinder 30, but falls from the lower end opening as it is.

Further, around the powder that has fallen from the second inner cylinder 30, the flow of gas ejected from the bottom plate 31 of the second gas supply unit 21 can prevent the powder from spreading to the surroundings. Further, this gas flow prevents the liquid flowing down along the inner peripheral surface of the powder supply pipe 9 from entering the second inner cylinder side. At this time, the second outer cylinder 29, which protrudes downward from the bottom plate 31 and is arranged on the inner diameter side of the outer peripheral edge of the partition plate 25, also prevents the liquid from entering the second inner cylinder 30 side. Therefore, the powder does not adhere to the inner surface of the second inner cylinder 30, and is less likely to adhere to the inner surface of the powder supply pipe 9. Further, since the liquid flows down on the inner surface of the powder supply pipe 9, the powder flows down to the hopper 4 together with the liquid without adhering.

In the hopper 4, as shown in FIG. 1, a liquid is supplied through the nozzle 6 to generate a swirling flow. As a result, the dropped powder moves to the lower stirring unit 5 together with the liquid. In the stirring unit 5, the powder and the liquid are agitated by the screw 11 to form a slurry, which flows out to the discharge pipe 7. When the powder falls into the hopper 4, dust is generated, and the liquid is injected from the first injection portion 14 provided in the first passage portion 12 of the exhaust pipe 2. As a result, the dust in the hopper 4 flows down to the stirring unit 5.

Further, in the space above the hopper 4, when the powder falls into the hopper 4, the gas (dry gas) mixed in the gas mixing portion (not shown) and the powder are separated, so that the powder is separated. The gas mixed in the inflow. Then, this gas goes from the first passage portion 12 of the exhaust pipe 2 to the discharge pipe 7 via the second passage portion 13. As a result, it is possible to prevent the gas from entering the stirring unit 5 together with the powder and the liquid. That is, when the powder and the liquid are slurried, it is possible to prevent the bubbles from being formed and popped by the discharge pipe 7 to scatter the dust. Further, dust that could not flow down with the liquid injected from the first injection unit 14 flows into the second passage portion 13 via the communication portions 12a and 13a. A second injection portion 15 is provided in the second passage portion 13, and a liquid is injected. Therefore, the dust that has flowed into the second passage portion 13 flows downward and is guided to the discharge pipe 7.

In the discharge pipe 7, the powder slurried in the stirring unit 5 is flowing down, so even if dust remains in the gas flowing into the discharge pipe 7 from the second passage portion 13, here It is completely removed. Then, the slurried powder (here, the activated carbon slurry) is supplied to the landing well and the activated carbon contact pond.

As described above, according to the mixing tank 1 having the above configuration, the powder supplied into the hopper 4 can be smoothly guided to the stirring unit 5 by the swirling flow of the liquid. Since the powder is mixed with gas, it is necessary to discharge it, but it can be discharged to the discharge pipe 7 via the exhaust pipe 2. Further, the dust generated in the hopper 4 can be first flowed down to the stirring unit 5 by the first injection unit 14. Then, the dust that has entered the exhaust pipe 2 without being able to flow down can be guided to the discharge pipe 7 by flowing down the second passage portion 13 by the second injection portion 15. Further, the dust that has flowed out from the exhaust pipe 2 to the discharge pipe 7 can be removed by the slurry powder from the stirring unit 5. Therefore, it is possible to surely remove the generated dust while realizing the exhaust of the gas mixed with the powder.

The present invention is not limited to the configuration described in the above embodiment, and various modifications can be made.
In the above embodiment, the exhaust pipe 2 is composed of a first passage portion 12 and a second passage portion 13, and a first injection portion 14 and a second injection portion 15 are provided in each of the exhaust pipe 2, as shown in FIG. In addition, the injection unit 38 can be configured to be shared. That is, the upper portions of the first passage portion 12 and the second passage portion 13 are inclined so as to approach each other, and the injection portion 38 is arranged at the upper confluence portion thereof. According to this, a single injection portion 38 can be formed only by devising the piping structure to form the upper confluence portion, and it can be manufactured easily and inexpensively.

In the above embodiment, the first passage portion 12 is provided at only one place, but it is also possible to provide two or more places. FIG. 5 shows a configuration in which the exhaust pipes 2 are provided at two symmetrical positions. The first passage portion 12 of each exhaust pipe 2 is provided with the first injection portion 14, and the second passage portion 13 is provided with the second injection portion 15. As a result, the liquid can be injected into the space above the hopper 4 via each of the first passage portions 12. That is, the liquid injection region can be widened, and the dust generated in the space above the hopper 4 can be effectively flowed down to the stirring unit side. Further, the dust that has entered each of the second passage portions 13 can be allowed to flow down to the discharge pipe 7 by the second injection portion 15.

In the above embodiment, the first inner cylinder 23 and the bottom plate 31 are made of a sintered filter, but may be made of a punching metal or the like. All you need is.

In the above embodiment, the injection means is provided in the middle of the exhaust pipe 2, but it may be provided in the lid 8 of the hopper 4. In FIG. 6, the injection portion 39 is provided near the connection position of the first passage portion 12 to the lid body 8. Then, the liquid injected from the injection unit 39 can be sprayed onto the gas to flow into the first passage unit 12. As a result, the dust contained in the gas can flow down into the hopper 4.

In the above embodiment, the position of the second outer cylinder 29 is arranged on the outer diameter side of the first outer cylinder 22, so that the second inner space 32 is expanded on the outer diameter side of the first inner space 26. However, the first outer cylinder 22 and the second outer cylinder 29 may be arranged at the same or substantially the same outer diameter position.

In the above embodiment, the first internal space 26 and the second internal space 32 are partitioned by the partition plate 25 and communicated only by the through hole 33, but these are one continuous internal space without the partition plate 25. It may be configured by.

In the above embodiment, the second outer cylinder 29 is configured to extend vertically downward from the partition plate 25, but it may be configured to approach or separate from the powder supply pipe 9 side as it goes downward. ..

In the above embodiment, the first tubular portion 16 and the second tubular portion 17 have a cylindrical shape, but the tubular portion may have a polygonal cross section.

1 ... Mixing tank 2 ... Exhaust pipe (detour passage)
3 ... Powder supply unit 4 ... Hopper 5 ... Stirring unit 6 ... Nozzle 7 ... Discharge pipe (discharge passage)
8 ... Lid body 9 ... Powder supply pipe 10 ... Communication pipe 11 ... Screw 12 ... First passage 13 ... Second passage 14 ... First injection (injection means)
15 ... Second injection unit (injection means)
16 ... 1st tubular part 17 ... 2nd tubular part 18 ... Ferrule clamp 19 ... Piping 20 ... 1st gas supply part 21 ... 2nd gas supply part 22 ... 1st outer cylinder 23 ... 1st inner cylinder 24 ... Top lid 25 ... Partition plate 26 ... First internal space 27 ... Air supply pipe 28 ... Cylindrical space 29 ... Second outer cylinder 30 ... Second inner cylinder 31 ... Bottom plate 32 ... Second internal space 33 ... Through hole 34 ... Ferrule clamp 35 ... Top lid 36 ... Liquid supply space 37 ... Liquid supply pipe 38 ... Injection unit 39 ... Injection unit

Claims (9)

A mixing tank in which powder and liquid are supplied, the powder and the liquid are mixed to form a slurry, and a discharge passage for the slurry is connected to the lower part.
A detour passage connected to the space above the mixing tank and
It is provided with an injection means for injecting a liquid into a slurry of dust contained in a gas entering the detour passage from the mixing tank.
A powder mixer characterized by supplying the slurry obtained in the mixing tank and the slurry slurried in the detour passage to the same supply destination. The powder mixer according to claim 1, wherein the injection means is provided in the detour passage. The powder mixer according to claim 1, wherein the injection means is provided in the vicinity of a connecting portion between the mixing tank and the detour passage. The detour passage has a first passage portion that goes upward from the space above the mixing tank.
The powder mixer according to claim 1 or 2, wherein the injection means has a first injection unit that injects a liquid from above the first passage portion toward the mixing tank. The detour passage has a second passage portion extending downward toward the discharge passage on the side of the mixing tank.
The powder mixer according to claim 4, wherein the injection means further includes a second injection unit that injects a liquid downward from the upper side toward the second passage portion. The detour passage has a first passage portion that goes upward from the space above the mixing tank and a second passage portion that extends downward toward the discharge passage on the side of the mixing tank, and is the first passage. The section and the second passage section merge at the upper confluence,
The powder according to claim 1, wherein the injection means is composed of a single injection unit capable of injecting a liquid into the first passage portion and the second passage portion via the upper merging portion. Mixer. The mixing tank is
A hopper that gradually becomes smaller as the opening cross section goes downward,
A stirring unit that is connected to the lower end opening of the hopper and extends downward to stir the supplied powder and liquid.
A liquid supply unit that supplies liquid into the hopper to generate a swirling flow,
The powder mixer according to any one of claims 1 to 6, wherein the powder mixer is provided. The powder mixer according to any one of claims 1 to 7, further comprising a gas mixing unit for mixing a gas with the powder supplied to the mixing tank. A powder mixing method in which powder and liquid are supplied into a mixing tank and mixed to form a slurry, and the slurry is discharged from a discharge passage at the bottom.
When the gas in the space above the mixing tank is discharged through the detour passage, a liquid is sprayed onto the dust contained in the gas to form a slurry, and the slurry obtained in the mixing tank and the detour passage A powder mixing method characterized by supplying the obtained slurry to the same supply destination.

Images