JP2001025650A - Powder injection and dissolution apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder injection and dissolution apparatus capable of preventing troubles such as adhesion and clogging in the supply port part of a powder to a dissolution tank and stably and smoothly supplying the powder. SOLUTION: In a powder injection and dissolution apparatus for producing a solution or a slurry by dissolving a powder supplied through a transportation pipe 4 to a dissolution tank 5 in a liquid, the supply port part 9 of the dissolution tank 5 for a powder is made to have a double pipe structure composed of an inner pipe 11, which is the transportation pipe 4, and an outer cylinder 12 so installed around the inner pipe 11 as to be at an interval from the inner pipe 11 and as to be opened to the inside of the dissolution tank 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder injection melting apparatus, and more particularly to a structure of a powder supply port to a melting tank.

[0002]

2. Description of the Related Art There is known a powder injection and dissolution apparatus for transporting powder to a dissolution tank and dissolving the powder in a liquid in the dissolution tank to prepare a solution or slurry. In this powder injection melting apparatus, for example, as shown in FIG. 7, powder is supplied to a melting tank 101 through a transport pipe 102, and a separate melting tank 101 is supplied.
It is dissolved in a liquid supplied into the inside, for example, water, and stirred to produce a solution or slurry.

In such a powder injecting and dissolving apparatus, for example, when there is an upper lid 103 as shown in FIG. 7, water droplets from a stirrer (not shown) adhere to the upper lid 103, or water drops due to condensation. May occur. Similarly, dew condensation and water droplets may also occur around the powder transport pipe 102 and the powder supply port 104 directly attached to the upper lid 103. When the powder comes in contact with water drops in such a state, a lump of powder is formed,
In some cases, the powder supply port 104 may be blocked to hinder the supply of the powder or may be completely blocked. When such a state is reached, it is necessary to remove the transport pipe 102 to wash off the adhered substance, open the closed part by poking with a rod-shaped object, and further perform operations such as cleaning with a chemical. I have to stop. In particular, when the water temperature in the tank is high and the outside air temperature is low, dew condensation is likely to occur on the upper lid 103, and condensed water drops drips on the powder supply port 104 attached to the upper lid 103, causing the powder to become wet,
Adhesion is more likely to occur and blockage is more likely to occur.

In order to avoid such a problem, for example, as shown in FIG. 8, the tip of a supply port 113 of a transport pipe 112 for transporting powder into the melting tank 111 is placed inside the melting tank 111. The upper lid 114 may be protruded so that the powder is prevented from adhering to the inner surface of the upper lid 114 as much as possible. However, since water drops are conveyed to the opening of the transport pipe 112 which is suspended inward, the powder is moistened when the powder exits from the outlet, so that the wet powder adheres or adheres. It causes the obstruction of the tube.

Further, a method of preventing the powder from getting wet by introducing a dry gas directly into the transport pipe, particularly into the supply port, is conceivable. However, it is possible to prolong the time until blockage or the like. However, it has not reached a fundamental solution.

[0006] In the field of preparing a solution or slurry by supplying powder, for example, slaked lime (calcium hydroxide) slurry or activated carbon slurry is produced industrially. In the case of slaked lime, if it adheres, it reacts with carbon dioxide in the gas and changes into calcium carbonate to form a hard deposit. Therefore, it takes a lot of trouble and time to remove the deposit. Therefore, it is necessary to prevent such deposits from being generated as much as possible.

In recent years, in the supply of powder, the advent of a single-shaft screw pump or the like has made it easier to transport the powder little by little, thereby preparing the powder into a solution or slurry. Even in this case, the powder is often transported directly to the melting tank by a small-diameter transport pipe. In such a system, since the amount of air sent along with the powder transport is small, the outlet of the transport pipe, that is, the supply port, is easily affected by the moisture inside the tank,
It is also susceptible to the effects of condensation and the like, and the supply port is more likely to be clogged.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for adhering powder at a supply port to a melting tank while taking into account the above-described powder transport method which is currently becoming a general-purpose system. An object of the present invention is to provide a powder pouring and melting apparatus capable of preventing the occurrence of a blockage problem and capable of supplying a stable and smooth powder.

[0009]

In order to solve the above-mentioned problems, a powder injection and melting apparatus according to the present invention dissolves powder supplied to a melting tank through a transport pipe into a liquid to dissolve the powder. Alternatively, in a powder injection dissolution apparatus for preparing a slurry, a supply port to a dissolution tank for powder is provided with the transport pipe as an inner pipe, and is disposed around the inner pipe at an interval from the inner pipe. It has a double tube structure provided with an outer cylinder that opens inward.

The supply port can be provided on the side wall of the dissolving tank or the like. However, in the present invention, when the supply port is provided on the upper lid of the dissolving tank, that is, when powder is supplied from above to the inside of the dissolving tank. It is particularly suitable when supplied.

Although the supply port may be configured to have a simple double-pipe structure, a means for supplying a dry gas (for example, dry air) between the inner pipe and the outer cylinder is provided. It is more preferable that the outer cylinder is provided with a heat insulating material on the outer surface side, and that the outer cylinder is provided with a heating element on the outer surface side. Further, the tip of the double pipe may have a structure substantially flush with the inner surface of the dissolving tank, and the outlet of the powder may be further separated from the inner surface of the dissolving tank and more affected by water droplets dripping from the inner surface. In order to make it difficult, it is also possible to adopt a structure in which the distal end portions of the inner tube and the outer cylinder protrude into the inside of the melting tank from the inner surface of the melting tank.

The means for transporting the powder to the melting tank is not particularly limited. However, if a transport system using a screw pump, for example, a single screw pump, is used, the powder can be transported quantitatively little by little as described above. At the same time, the improved structure of the supply port according to the present invention can simultaneously prevent adhesion and blockage. In particular, the effect of the present invention is great when the powder is such as slaked lime or the like which easily forms hard deposits.

According to the powder injecting and dissolving apparatus of the present invention, the supply port to the powder dissolving tank has a double pipe structure, and the outer cylinder is provided at an interval from the inner pipe which is the powder transport pipe. As a result, water droplets and the like are prevented from directly flowing into the inner tube from the inner surface of the dissolving tank, and the air layer between the inner tube and the outer cylinder becomes a heat insulating layer, so that the inside of the inner tube is less likely to be condensed. As a result, the powder supplied into the dissolving tank through the inner tube is less likely to be moistened, and the generation of deposits due to the moisture and the problem of blockage of the tubes due to the deposits are eliminated.

In particular, if dry gas is supplied between the inner tube and the outer tube, the outer surface of the outer tube is kept warm, or a heating element is provided on the outer surface, the occurrence of problems can be suppressed more effectively. .

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 and FIG.
1 shows a powder pouring and dissolving apparatus according to an embodiment of the present invention, particularly a powder pouring and dissolving apparatus suitable when strict control of moisture such as slaked lime is required. In FIG. 1, a powder 1 is stored in a powder storage hopper 2 and is supplied by a powder supply pump 3 installed below the hopper 2.
It is supplied into the dissolving tank 5 via the transport pipe 4. As the powder supply pump 3, a single-shaft screw pump capable of supplying a fixed amount is used.

A liquid, in this embodiment, water, is supplied to the dissolving tank 5 through a liquid supply pipe 6. Powder 1 supplied
And water are stirred by the stirrer 7 to prepare a predetermined solution or slurry. The generated solution or slurry is sent to another process via the drawing pump 8.

A supply port 9 for supplying the powder 1 to the dissolving tank 5 is provided on the upper lid 10 of the dissolving tank 5, and the supply port 9 is connected to the transport pipe 4 as shown in FIG. Inner tube 11,
It is installed around the inner tube 11 with an interval from the inner tube 11,
It has a double pipe section (double pipe structure) with the outer cylinder 12 opening toward the inside of the dissolution tank 5.

In this embodiment, the inner pipe 1 of the double pipe section 9 is used.
A dry gas, particularly dry air, is supplied between the first cylinder 1 and the outer cylinder 12. The dry air supply means 13 includes a compressor 14, a dehumidifier 15 for dehumidifying the compressed air from the compressor 14, and an air storage tank 16 for retaining the dehumidified dry air.
Dry air is supplied into the outer cylinder 12 from the air storage tank 16 via the air supply pipe 17. In the dehumidifier 15, for example, dehumidification is performed so that the dew point becomes -20C to -60C.

As a more specific structure of the double pipe portion 9, for example, the diameter of the outer cylinder 12 (the lower end diameter) is as follows.
It is preferable that the diameter is in the range of 1.5 to 5 times the diameter of the inner tube 11 (the lower end diameter). If less than 1.5 times, the inner tube 11 is
2 reduces the effect of being isolated from the upper lid 10 and the inner pipe 11
The effect of reliably protecting the powder inside from water droplets and moisture diminishes. In addition, the flow rate of the supply air becomes too high, which may cause the powder to fly up. If it exceeds five times, the required air amount becomes too large, and the dry air supply means 13 may be unnecessarily large and expensive. The cross-sectional shape of the outer cylinder 12 may be circular or polygonal.

The height of the outer tube 12 is preferably in the range of 2 to 10 times the diameter of the inner tube 11. If it is less than twice, convection tends to occur between the inner tube 11 and the outer cylinder 12, and if convection occurs, moisture in the dissolution tank 5 tends to be entrained. Even if it exceeds 10 times, no further increase in the effect due to the double-pipe structure can be expected, and the size (height) of the outer cylinder 12 simply increases, which leads to an increase in cost.

The supply amount of the dry air is such that the air between the inner tube 11 and the outer tube 12 of the double tube portion 9 is reduced by one every few seconds.
An amount that can be replaced is sufficient. If the supply amount is too large, the air blown downward may wind up the powder.

When preparing the solution or slurry in the dissolving tank 5, a filter 19 is provided in the exhaust port 18 to prevent the powder from scattering from the exhaust port 18.

In the powder injection and dissolution apparatus configured as described above, the supplied powder 1 and water are mixed in the dissolution tank 5.
The mixture is mixed while being stirred by the stirrer 7 to prepare a solution or slurry having a predetermined concentration. Since the powder 1 is quantitatively supplied by the single screw pump 3, the powder 1 is precisely prepared into a target solution of a predetermined concentration or a slurry.

The powder 1 transported in the transport pipe 4 is supplied into the dissolving tank 5 through the inner pipe 11 at the supply port 9 to the dissolving tank 5. Since the dry air is supplied between the inner tube 11 and the outer tube 12 due to the double tube structure, dew condensation in the supply port portion 9 and its surroundings, in particular, the inner tube 11 is prevented. In addition, the inner pipe 1
Since the air layer between the outer cylinder 1 and the outer cylinder 12 functions as a heat insulating layer, dew condensation is more effectively prevented from this aspect.

Since the supply port 9 has a double-pipe structure, the lower end of the inner tube 11 is separated from the upper lid 10 at an opening, particularly at the opening. The attached water droplets and the moisture in the portions are not directly connected. Therefore,
The powder flowing in the inner tube 11 or the powder immediately before falling from the lower end opening of the inner tube 11 is prevented from getting wet.

As a result, it is possible to prevent the formation and adhesion of powder lumps due to moisture, and to prevent the attached matter from closing the inner tube 11. As a result of preventing the powder supply from being adhered and preventing the inner tube 11 from being blocked, stable operation can be performed for a long period of time. In particular, as described above, powders such as slaked lime
In the case of a substance which is liable to be adhered and which easily produces a hard adhered substance, a great effect can be obtained by the present invention.

In the above-described embodiment, dry air is supplied between the inner tube 11 and the outer tube 12. However, in the case where the humidity is relatively small and the powder hardly generates deposits, or In the case where the temperature difference between the inside and outside is relatively small, for example, as shown in FIG. 3, an effect can be obtained by merely providing the supply port 21 having a simple double tube structure without supplying dry air.

Further, as shown in FIG. 4, for example, a heat insulating material 33 is provided on the outer surface side of the outer cylinder 32 in the supply port portion 31 having a double pipe structure to reduce heat radiation in the double pipe portion and to form dew condensation. Can be suppressed. The heat insulating material 33 may be provided so as to cover a part or the entire surface of the upper lid 10 in addition to the supply port 31 having the double pipe structure. In particular, such installation of the heat insulating material 33 is effective when the frequency of reversal between the water temperature and the air temperature is small and the degree of dew condensation is relatively light.
In this case, the above-mentioned supply of dry air may be used in combination.

Further, as shown in FIG. 5, for example, a heating element 43 is provided on the outer surface side of an outer cylinder 42 in a supply port 41 having a double pipe structure so that the inside of the double pipe section is made higher than the water temperature. By doing so, it is also possible to suppress the occurrence of condensation. Generally, an electric heater can be used as the heating element 43. The temperature rise by the heating element 43 may be controlled to about plus 10 ° C. with respect to the water temperature of the melting tank 5. Also in this case, the supply of the dry air described above can be used together.

In each of the above embodiments, the position of the lower end of the supply port portion of the double tube structure is set to be substantially the same as the position of the upper lid. For example, as shown in FIG. The position of the lower end of the supply port 41, that is, the position of the lower end (tip) of the inner tube 52 and the outer cylinder 53 can be extended to a position hanging down below the inner surface of the upper lid 10. In this way, the outlet of the powder can be separated from the upper lid 10,
It is possible to minimize the adhesion of the powder to the upper lid 10 due to the winding of the powder from the outlet or the like. Further, when water is injected along the upper lid 10 for the purpose of cleaning the inner surface of the upper lid 10, water can be prevented from entering the double pipe, and the inside can be prevented from getting wet to prevent powder from adhering. Can be Also in this case, the supply of the dry air described above can be used together.

[0031]

As described above, according to the powder pouring and dissolving apparatus of the present invention, since the supply port of the powder to the dissolving tank is formed in a double pipe structure, it is caused by moisture and wetness. It is possible to prevent the powder from adhering and to prevent the powder supply tube from being blocked due to the adhesion, and to perform stable powder supply over a long period of time, and thus to prepare a stable solution or slurry.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a powder injection melting apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged schematic longitudinal sectional view of a powder supply port of the melting tank of FIG.

FIG. 3 is a schematic vertical sectional view of a powder supply port of a powder injection and melting apparatus according to another embodiment of the present invention.

FIG. 4 is a schematic longitudinal sectional view of a melting tank of a powder injection melting apparatus according to still another embodiment of the present invention.

FIG. 5 is a schematic longitudinal sectional view of a melting tank of a powder injection melting apparatus according to still another embodiment of the present invention.

FIG. 6 is a schematic longitudinal sectional view of a melting tank of a powder injection melting apparatus according to still another embodiment of the present invention.

FIG. 7 is a schematic vertical sectional view of a conventional dissolving tank.

FIG. 8 is a schematic longitudinal sectional view of another conventional dissolving tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Powder 2 Powder storage hopper 3 Powder supply pump (uniaxial screw pump) 4 Transport pipe 5 Dissolution tank 6 Liquid supply pipe 7 Stirrer 8 Extraction pump 9, 21, 31, 41, 51 Supply port part 10 Top lid 11, 52 Inner pipe 12, 32, 42, 53 Outer cylinder 13 Dry air supply means 14 Compressor 15 Dehumidifier 16 Air storage tank 17 Air supply pipe 18 Exhaust port 19 Filter 33 Heat insulator 43 Heating element

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Susumu Hoshi 1-2-8 Shinsuna, Koto-ku, Tokyo Organo Corporation F-term (reference) 4G035 AA19 AB43 AE13 AE15 AE19 4G037 AA03 CA11 DA30 EA02 4G068 AA01 AB22 AC16 AD21 AF12 AF20

Claims (8)

[Claims] In a powder injection dissolving apparatus for dissolving powder supplied into a dissolving tank via a transport pipe into a liquid to prepare a dissolving solution or slurry, a supply port for the dissolving tank for powder is provided. Wherein the transport pipe is an inner pipe, and is arranged around the inner pipe at an interval from the inner pipe, and has a double pipe structure provided with an outer cylinder opening toward the inside of the dissolving tank. Powder injection melting equipment. 2. The powder injection and melting apparatus according to claim 1, wherein the supply port is provided in an upper lid of the melting tank. 3. The powder injection and dissolution apparatus according to claim 1, further comprising means for supplying a dry gas between the inner tube and the outer tube. 4. The powder injection and dissolution apparatus according to claim 1, wherein a heat insulating material is provided on an outer surface side of the outer cylinder. 5. The powder injection and melting apparatus according to claim 1, wherein a heating element is provided on an outer surface of the outer cylinder. 6. The dissolving tank according to claim 1, wherein the distal ends of the inner tube and the outer cylinder protrude further into the dissolving tank than the inner surface of the dissolving tank.
A powder injection dissolution apparatus according to any one of the above. 7. The powder injection and dissolution apparatus according to claim 1, wherein a screw pump is used for transporting the powder to the dissolution tank. 8. The powder according to claim 1, wherein the powder is slaked lime.
A powder injection dissolution apparatus according to any one of the above.