JP2001026650A - Continuous dissolving apparatus for polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact apparatus for continuous dissolution of polymers which continuously produces a uniform polymer solution having a high degree of solubility without any undissolved residue, prevents the deterioration of handleability of charge stocks, etc., at dissolution operation or the deterioration of the solution, shortens the dissolution time and inhibits the generation of unmixed lumps. SOLUTION: A continuous dissolving apparatus for polymers 10 is equipped with a supply device 11 which supplies particulate polymers, a pulverizing device 12 which pulverizes the polymers supplied from the supply device 11, a dispersion device 14 which drops the powders pulverized in the pulverizing device 12 onto a liquid flow of a solvent and disperses and mixes the polymer into the solvent, a dissolution tank 15 which stirs and dissolves a mixture of the polymer and the solvent sent from the dispersion device 14, and a solution- dispensing device 16 which continuously dispenses the solution from the solution tank 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous polymer dissolution apparatus for dissolving a granular polymer in a liquid serving as a solvent to continuously generate a solution.

[0002]

2. Description of the Related Art Conventionally, high-molecular weight water-soluble polymers have been used for dewatering sludge and treating various wastewaters in paper mills, building plants, sewage treatment plants, large-scale groundwater treatment plants, small-scale human waste and sewage treatment plants, and the like. (For example, Diafloc Co., Ltd.). This flocculant neutralizes the surface charge of colloids and fine particles suspended in water, agglomerates the particles, forms a large floc by its adsorption and crosslinking action, and separates and removes suspended substances by sedimentation or floating. To facilitate.

[0003] In the prior art, as a polymer melting device,
A batch type as shown in FIG. 3 is used. In this polymer dissolving apparatus, a desired amount of a liquid (solvent) such as water is supplied to and stored in a dissolving tank 1 from an injection port 2, and while a polymer 3 is charged, a screw stirrer 4 or the like is used to supply the polymer.
Stir at about 0 RPM for 30 minutes to 1 hour to dissolve. When the dissolution is completed, the entire amount of the dissolving solution 5 is discharged from the discharge valve 6, and then the dissolving tank 1 is filled with the liquid from the injection port 2 again, and the next preparation is started.

[0004]

However, the prior art has the following problems. Since the dissolving device is of a batch type, it is necessary to dissolve a required amount of the dissolving solution all at once, so that the device has a large capacity. Also, when using the lysis solution continuously,
It is necessary to arrange two dissolving devices side by side or to prepare a storage tank for the dissolving solution, which increases the installation space for the devices.

[0005] From the viewpoint of handling properties such as preparation in the dissolving operation, the polymer is charged into the dissolving tank with a large particle size and has poor solubility. That is, if the particle size of the polymer is large,
The swelling time of the polymer particles (the dissolution process in which the particles gradually expand while absorbing liquid from the surface toward the center and swelling and expanding, is called swelling) is long, and as a result, the dissolution time is long. Excessive agitation (high speed, high shear) of polymer particles with insufficient swelling will degrade the solution, so in the conventional apparatus, low-speed, long-time agitation must be performed to avoid this. From this point, the dissolution time is long.

[0006] When the polymer is supplied in the form of fine powder, a part of the polymer flies as dust at the time of charging, which hinders the working environment. When the polymer is fine powder, moisture in the air is absorbed at the time of charging. The polymer adheres to a powder path such as a hopper or a dissolving tank, or the polymers adhere to each other to form a bridge at the outlet of the hopper, thereby impairing fluidity.

[0007] Since a large amount of the polymer is injected at a time in a large particle size, the dispersion of the powder in the solvent becomes insufficient, and the powder easily floats on the solvent, resulting in a powder residue (mamako). Once generated, the flour cannot be easily dissolved, and adheres and grows in a melting tank or a stirrer, causing errors in solubility and non-uniformity.

[0008] An object of the present invention is to continuously dissolve a polymer to make the apparatus configuration compact, to shorten the dissolving time without deteriorating the handling properties such as preparation in the dissolving operation and the degradation of the dissolving solution, An object of the present invention is to continuously generate a uniform and high-solubility solution without dissolution while suppressing generation.

[0009]

According to the present invention, there is provided a supply apparatus for supplying a granular polymer, a pulverizing apparatus for pulverizing the polymer supplied from the supply apparatus, and a liquid film flow of a solvent. A powder dispersing device for dispersing and mixing the polymer in the solvent by dropping the powder pulverized by the pulverizing device, a dissolving tank for stirring and dissolving the mixed solution of the polymer and the solvent sent from the dispersing device, and a dissolving solution in the dissolving tank. And a dissolving solution delivery device capable of continuous delivery.

According to a second aspect of the present invention, in the first aspect of the present invention, the dissolving tank further stirs the mixed liquid by a liquid stream generated by circulating the mixed liquid of the polymer and the solvent. It is something to do.

According to a third aspect of the present invention, in the second aspect of the present invention, the circulation of the mixed solution, the dissolution of undissolved matter, and the solubility It is equipped with an in-line mixer for promoting uniformity of (solution concentration).

According to a fourth aspect of the present invention, in the third aspect of the present invention, the inline mixer further includes a dissolving liquid outlet through a screen on a side wall of the impeller chamber, and the dissolving liquid outlet is connected to the dissolving liquid outlet. A solution delivery device is connected.

[0013]

According to the first aspect of the present invention, the following effects are obtained. Since the dissolving apparatus is of a continuous type capable of continuously sending out the dissolving solution, the capacity of the apparatus can be reduced, the installation space of the apparatus can be reduced, and the apparatus can be compact.

Since the granular polymer supplied from the supply device is pulverized by a pulverizer immediately before mixing with the solvent,
Handling problems that occur when using finely pulverized powder in advance, such as being apt to fly out as dust during preparation, absorbing moisture in the air and adhering to a hopper, etc., or causing polymers to stick together to form a bridge, etc. Can be prevented.

[0015] Since the polymer particles finely pulverized by the pulverizer are mixed with the solvent, the swelling time for absorbing the liquid from the surface to the center of the polymer particles is shortened, whereby the dissolution time can be shortened, and the compact device can be used. Enables continuous dissolution. In other words, if the powder particle size is crushed to 1/4,
It divides into individual, the individual volume is 1/64, the total surface area is almost quadrupled, and the swelling time for absorbing the liquid from the surface to the center of the particle can be shortened. In the dissolution tank, since the swelling is sufficient to agitate the polymer particles, a short-term agitation can produce a solution without deterioration without applying excessive agitation (high speed, high shear).

The finely pulverized powder is dropped by a dispersing device little by little on a uniformly flowing liquid film, dispersed and mixed well, and put into a dissolving tank. It is hard to float and the generation of flour can be suppressed. As a result, it is possible to avoid concentration errors and non-uniformity of the solution caused by the generation of flour.

According to the present invention, the following effects are obtained. The stirring of the dissolving tank is performed by the water flow (
The water flow of the diluent added to the dissolving tank can also contribute), and it is possible to prevent the polymer dissolving solution from clinging to the rotating shaft and deteriorating the dissolving solution due to the shearing action of the screw generated by the conventional screw stirrer.

According to the third aspect of the present invention, the following operations are provided. The solution is circulated by the in-line mixer arranged in the circulation path of the solution, and at the same time, the solution can be homogenized by the stirring action of the rotor of the in-line mixer.

According to the present invention, the following effects are obtained. The delivery of the solution is performed by a solution delivery device (metering pump) via a screen provided on the side wall of the impeller chamber in the inline mixer. At this time, the undissolved matter is ground between the impeller and the screen, and the solution that has passed through the screen, that is, the undissolved matter that has been filtered through the screen, is sent out. Therefore, it is possible to generate a solution containing no undissolved matter such as flour.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view showing a continuous polymer dissolution apparatus, FIG. 2 is a half sectional view showing an in-line mixer,
FIG. 3 is a schematic diagram showing a conventional device.

As shown in FIG. 1, a continuous polymer dissolution apparatus 10 includes a polymer supply apparatus 11, a polymer pulverization apparatus 12,
It has a solvent supply device 13, a dispersion device 14, a dissolution tank 15, and a solution delivery device 16.

The polymer supply device 11 is constituted by a hopper 21 and supplies a granular polymer 22 such as a polymer flocculant intermittently, for example, once a day. Hopper 21
A cone shape having a volume corresponding to the discharge amount of the polymer 22 is formed.
A bridge prevention device such as a hot air supply device can be provided.
The polymer supply device 11 includes a fixed amount feeder 24 below the hopper 21 so that a required amount of the polymer 22 can be supplied quantitatively. As the quantitative feeder 24,
For example, a rotary feeder can be used, and the number of rotations can be changed by the motor 25 according to the required amount.

The polymer pulverizing device 12 is provided with a polymer 22 supplied from a quantitative feeder 24 of the polymer supplying device 11.
Crush. The particle size of the commercially available polymer 22 supplied from the supply device 11 is, for example, 0.4 to 0.7 mm (maximum 2 mm or more) when it is a polymer flocculant. The pulverizing device 12 enables the polymer 22 to be pulverized to a range of 0.15 to 0.25 mm. The crusher 12 is, for example, a roll mill 2
6 is driven by a motor 27 via gears to change the rotation direction and peripheral speed of the two grinding rolls. The roll mill 26 can adjust the gap (clearance) between the rolls according to the type, particle size, and the like of the polymer 22. Since the number of rotations required for crushing is low, the crushing device 12 can be operated continuously. In addition, since the processing is continuously performed from the hopper 21 to the crushing device 12, the operation can be performed without causing the powder to wind up and affecting the surrounding environment.

The solvent supply device 13 temporarily stores a liquid (eg, water) serving as a solvent in a solvent liquid tank 30 via a solvent liquid inlet 28 and an electromagnetic valve 29, and quantitatively stores the liquid by a liquid supply pump 31. Supply. 32 is a pump drive motor. At this time, liquid is supplied from the solvent liquid inlet 28 by the interlocking of the electromagnetic valve 29 and the liquid level detecting device 33 of the tank 30.

The liquid supplied from the liquid supply pump 31 of the solvent supply device 13 is distributed by a valve 34 to a liquid supply nozzle 35 and a diluent supply port 39. The liquid supplied from the liquid supply nozzle 35 spreads uniformly on the inclined surface of the shooter 36 and forms a liquid film flow below the crushing device 12. The dispersing device 14 drops the polymer 22 finely pulverized by the pulverizing device 12 as it is onto a liquid film flow uniformly flowing on the shooter 36, mixes the polymer 22 in a good dispersion state with the solvent, and enters the dissolving tank 15. And send.

The dissolving tank 15 stirs and retains the mixed liquid fed from the shooter 36 of the dispersing device 14 to further disperse and swell, thereby promoting dissolution in a short time. In the dissolving tank 15, a dissolving solution (mixed solution) is supplied to a dissolving solution
The mixed solution in the tank is stirred by the water flow generated by further circulation and the water flow generated from the diluent supply port 39, and the polymer solution is clung to the rotating shaft as seen in a conventional screw stirrer. Without causing
It is easy to clean the inside of the container.

A liquid level detecting device 40 is provided in the dissolving tank 15, and based on a detection result of the liquid level detecting device 40, a fixed amount feeder 24 of the polymer supply device 11, a roll mill 26 of the crushing device 12, and a liquid supply of the solvent supply device 13. The drive of the pump 31 is controlled so that the liquid level in the dissolution tank 15 can be controlled.

Dissolution liquid (mixture) circulation path 3 in dissolution tank 15
8A is provided with an in-line mixer 41. 4
1A is a mixer drive motor. The in-line mixer 41 circulates the dissolved liquid (mixed liquid) to the dissolving tank 15 and promotes dissolution of undissolved substances (such as joint powder) and uniformity of solubility of the dissolved liquid. In addition, the inline mixer 41
As shown in FIG. 2, a circulation suction port 42, a circulation discharge port 43, and an impeller chamber 45 containing a flexible impeller 44 made of rubber or the like are connected to the circulation path 38A. Further, the in-line mixer 41 includes a solution sending port 47 through a screen 46 on a side wall of the impeller chamber 45.

The solution delivery device 16 is constituted by a positive displacement metering pump 48 connected to the solution delivery port 47 of the in-line mixer 41, and discharges the solution in the solution tank 15 from the solution discharge port 49 quantitatively. . 50 is a pump drive motor. The solution to be withdrawn from the solution tank 15 by the pump 48 of the solution delivery device 16 is supplied to the in-line mixer 4.
Since it is constantly rubbed by the side surface of the impeller 44 and drawn through the screen 46 in the cleaning state, it does not include undissolved matter. The deposits on the screen 46 are crushed by the pressing rotation of the side surface of the impeller 44. In addition, since the pump 48 of the solution delivery device 16 is of a positive displacement type and is of a discharge type in which the solution is pumped out with a fixed mass, the solution is not sheared by the rotor and the solution is not deteriorated.

Therefore, in the polymer continuous dissolution apparatus 10, a solution is generated as follows.

(1) In the polymer supply device 11, after the polymer 22 is charged into the hopper 21 with the particle size generally marketed and distributed, stable supply by the quantitative feeder 24 can be ensured. Then, the polymer 22 is finely pulverized by the pulverizing device 12, and the polymer 22 is dropped and dispersed and mixed on a uniformly flowing liquid film flow of the dispersing device 14.
In the dissolution tank 15, a water flow of the diluent supplied stably,
Stirring the mixture of polymer 22 in a circulating flow of the dissolving solution;
Swell the particles. The polymer 22 obtains a stirring action by circulation of the solution in the dissolving tank 15 and a grinding effect of undissolved material between the impeller 44 and the screen 46, and further dissolves the solution containing no undissolved material into the screen 46.
, A uniform dissolving solution containing no undissolved substances can be produced in a short time.

(2) The solution produced in the dissolving tank 15 is continuously discharged by the pump 48 of the dissolving solution delivery device 16, and the quantitative supply of powder and liquid is performed by the liquid level of the dissolving tank 15. Automatic continuous dissolution of the polymer can be realized by controlling the operation and the stop in conjunction with.

According to the present embodiment, the following operations are provided. Since the dissolving apparatus 10 is of a continuous type capable of continuously delivering the dissolving solution, the capacity of the apparatus can be reduced, the installation space of the apparatus can be reduced, and the apparatus can be made compact.

Since the granular polymer supplied from the supply device 11 is pulverized by the pulverization device 12 immediately before mixing with the solvent, it occurs when using finely pulverized powder in advance. This can prevent adverse effects in handling, such as absorbing moisture from the hopper 21 and adhering to the hopper 21 or the like, or causing polymers to adhere to each other to easily form a bridge.

Since the polymer particles finely pulverized by the pulverizer 12 are mixed with the solvent, the swelling time for absorbing the liquid from the surface to the center of the polymer particles can be shortened, and the dissolution time can be shortened. enable. That is, if the powder particle size is crushed to 1/4, one is divided into 64, the volume of each is 1/64, the total surface area is almost quadrupled, and the liquid is absorbed from the surface to the center of the particles. The swelling time can be shortened. In the dissolving tank 15, since the swelling is sufficient to agitate the polymer particles, it is possible to generate a dissolving solution without deterioration by short-time agitation without applying excessive agitation (high speed, high shear).

The finely pulverized powder is dispersed by a dispersing device 14
Since the powder is dropped little by little on a uniformly flowing liquid film, dispersed and mixed well, and put into the dissolving tank 15, the powder is unlikely to float on the surface of the liquid, and the generation of a powder residue can be suppressed. As a result, it is possible to avoid concentration errors and non-uniformity of the solution caused by the generation of flour.

The stirring of the dissolving tank 15 is performed by a water flow due to the circulation of the mixed liquid (in addition, the water flow of the diluting liquid added to the dissolving tank 15 can also contribute), and the rotation of the polymer dissolving liquid generated by a conventional screw stirrer is performed. Deterioration of the solution due to clinging to the shaft and shearing action of the screw can be prevented.

The solution is circulated by the in-line mixer 41 arranged in the circulation path of the solution and, at the same time, the solution can be homogenized by the stirring action of the impeller 44 of the in-line mixer 41.

The delivery of the solution is performed by using an in-line mixer 4
Screen 4 provided on the side wall of impeller chamber 45 in 1
6 through the dissolving solution delivery device 16 (metering pump 48). At this time, the undissolved material is impeller 44
Between screen and screen 46, screen 4
6, ie, a solution without any undissolved matter that has been filtered by the screen 46 is sent out. Therefore,
A solution containing no undissolved substances such as flour can be generated.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and the design can be changed within the scope of the present invention. The present invention is also included in the present invention. For example, the dissolution tank of the present invention may be provided with a moderate (low speed, low shear) stirrer.

[0041]

As described above, according to the present invention, the polymer is continuously dissolved to make the apparatus compact, and the dissolving time can be reduced without deteriorating the handling properties such as charging in the dissolving operation and the deterioration of the dissolving solution. It is possible to shorten the length, suppress generation of flour, and continuously produce a uniform and highly soluble solution without undissolution.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a continuous polymer dissolution apparatus.

FIG. 2 is a half sectional view showing an in-line mixer.

FIG. 3 is a schematic view showing a conventional device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 dissolving device 11 supply device 12 crushing device 14 dispersing device 15 dissolving tank 16 dissolving solution sending device 38A dissolving solution circulation path 41 in-line mixer 44 impeller 45 impeller room 46 screen 47 dissolving solution outlet

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoshiyuki Ikeya 2-1-1 Mitoshima, Fuji-shi, Shizuoka Prefecture F-term in Kobayashi Manufacturing Co., Ltd. (reference) 4F070 AA71 AB13 CA11 CB02 DA41

Claims (4)

[Claims] 1. A supply device for supplying a granular polymer, a pulverization device for pulverizing the polymer supplied from the supply device, and a powder pulverized by the pulverization device dropped on a liquid film flow of a solvent to convert the polymer. A dispersion device for dispersing and mixing in a solvent, and stirring a mixed solution of the polymer and the solvent sent from the dispersion device,
A continuous polymer dissolving apparatus comprising: a dissolving tank for dissolving; and a dissolving solution sending device capable of continuously sending the dissolving solution in the dissolving tank. 2. The polymer continuous dissolving apparatus according to claim 1, wherein the dissolving tank agitates the mixed liquid by a liquid stream generated by circulating the mixed liquid of the polymer and the solvent. 3. An in-line mixer for circulating the mixed solution, dissolving undissolved matter, and promoting uniformity of solubility (dissolved solution concentration) in a path of circulating the mixed solution in the dissolving tank. Item 4. A continuous polymer dissolution apparatus according to item 2. 4. The continuous polymer dissolving apparatus according to claim 3, wherein said in-line mixer is provided with a solution sending port through a screen on a side wall of said impeller chamber, and a solution sending device is connected to said solution sending port.