JPH0724215A - Method and device for preparing aqueous high molecular electrolyte solution - Google Patents

Abstract

PURPOSE:To industrially and easily prepare a homogeneous high molecular electrolyte soln. by diluting a water-in-oil type high molecular electrolyte emulsion with water. CONSTITUTION:A high molecular electrolyte emulsion and water are supplied to a mixing chamber 3, the pressure difference between the outside and inside of the mixing chamber is controlled to >=0.5kg/cm<2> to mix the emulsion and water, and the liq. mixture is forced out under pressure from an orifice 5 provided at a part of the mixing chamber during or immediately after mixing to prepare an aq. high molecular electrolyte soln.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a preparation method for adding water to a water-in-oil type polyelectrolyte emulsion used in a water treatment facility and the paper and pulp industry to finally prepare an aqueous polyelectrolyte solution. The present invention relates to a preparation device.

[0002]

2. Description of the Related Art In a water treatment facility or the like, various chemicals, such as a flocculant, a flocculation aid, and a pH adjuster, are added to various polluted wastewater to treat the polluted water. The drug is added to the liquid to be treated after the drug is diluted to prepare an aqueous solution having an appropriate concentration so as to be uniformly mixed with the liquid to be treated. For example, in the case of polymer flocculant,
After being diluted and prepared in a stirrer / stirring tank, the sludge is uniformly mixed with the sludge, and the sludge flocculation / dewatering process is performed.

As a method for diluting these drugs, a diluting liquid such as water is introduced into a drug preparation tank, and the diluting liquid is added little by little while stirring with a stirrer and mixed and dissolved in a predetermined time. Was adopted. However, for example, when diluting a polymer coagulant, the ratio of the diluent to the drug is as high as 1: 1000 to 1:20, and long-term mixing is required to obtain a uniform polymer coagulant. Moreover, when the stirring power is weak, the dissolution of the drug may be incomplete.

When a liquid water-in-oil type polymer electrolyte emulsion type polymer flocculant is prepared by diluting it in an aqueous solution state, phase inversion is involved, so that an initial shearing force for the diffusion of the polymer electrolyte into water is particularly high. And shearing force is required. For this reason, a high level of energy must be added to the preparation of the aqueous solution of the polyelectrolyte in consideration of the dispersing action of the polyelectrolyte, and the introduction of a high shearing force device such as a homomixer or the shift zone or shearing of these devices. There is a problem that it becomes necessary to pass through the zone a plurality of times and the dilution / preparation time becomes long. If the initial shearing force or shearing force is small, gelation or aggregation of emulsion particles occurs when the emulsion undergoes phase inversion, and the surface area of the polymer electrolyte particles increases,
In some cases, efficient preparation of an aqueous polyelectrolyte solution may not be possible.

[0005]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems, and it is possible to efficiently dilute a water-in-oil type polymer electrolyte emulsion useful as a polymer flocculant with water to obtain a uniform emulsion. It is an object of the present invention to provide a method and a device for preparing an aqueous solution of a molecular electrolyte by industrially simple operations.

[0006]

The method for preparing an aqueous solution of a polymer electrolyte according to the present invention, which has solved the above-mentioned problems, is a method for preparing a water-in-oil type polymer electrolyte emulsion containing a polymer electrolyte in an amount of 10 to 50% by weight. In the method of adding the emulsion to form a polymer electrolyte aqueous solution, first, the emulsion and water are supplied to a mixing chamber, and then the pressure difference between the outside of the mixing chamber and the inside of the mixing chamber is 0.5 kg / cm ² or more. The point is that the mixed solution is squeezed out from an orifice provided in a part of the mixing chamber while mixing the emulsion and water or immediately after the mixing. Further, it has a plurality of tubes for supplying liquid, a mixing chamber for mixing two or more kinds of liquid substantially instantaneously, and a pressure gauge for measuring a differential pressure between the outside of the mixing chamber and the mixing chamber, The present invention also includes an apparatus for preparing a polymer electrolyte aqueous solution having an orifice having a gap capable of maintaining a differential pressure between the outside of the mixing chamber and the inside of the mixing chamber when the mixed solution is squeezed out to be 0.5 kg / cm ² or more.

[0007]

In the present invention, each of the water-in-oil type polymer electrolyte emulsion (hereinafter sometimes simply referred to as an emulsion) and water is supplied to the mixing chamber to form a mixed liquid. Simultaneously with or immediately after mixing the obtained mixed liquid so that it does not substantially stay in the mixing chamber, through an orifice provided in a part of the mixing chamber to a treatment tank provided with a stirrer outside the mixing chamber. Press out. The mixed solution may be extruded into the atmosphere and then introduced into the stirring treatment tank, or directly into the diluting solution in the stirring treatment tank. By a short mixing / diluting operation from the supply to the mixing chamber to the pressurization, the emulsion is phase-shifted from the oil phase continuous phase state to the water phase continuous phase, diluted with water, and further stirred in the stirring treatment tank. Is added to obtain a uniform polymer electrolyte aqueous solution. In the present invention, since a series of mixing and diluting operations are efficiently performed in a short time, gelation that tends to occur when the emulsion undergoes phase inversion and aggregation / coalescence of emulsion particles can be reliably prevented.

In the present invention, when the mixed liquid is forced out of the mixing chamber through the orifice provided in a part of the mixing chamber, the differential pressure (ΔP) between the outside of the mixing chamber and the mixing chamber is set to 0.5 kg / cm ² or more. Keeping is an essential requirement. More preferably the differential pressure is 1 kg
/ Cm ² ≦ ΔP <15 kg / cm ² If the differential pressure is less than 0.5 kg / cm ² , the emulsion will be insufficiently diluted and dissolved, and the effect of shortening the preparation time will be difficult to manifest. On the other hand, when the pressure difference is 15 kg / cm ² or more, the disadvantage becomes larger considering the investment resistance such as the pressure resistance of the emulsion supply pump and the supply pressure of the dilution water. By maintaining this differential pressure to 0.5 kg / cm ² or more, the Reynolds number (Re) of the mixed liquid near the orifice is 3 × 10 ³ <Re <
A so-called turbulent flow region of 3 × 10 ⁵ is obtained, and the polymer electrolyte aqueous solution can be rapidly and uniformly prepared.

In the present invention, the gap between the orifices through which the mixed liquid is forced out is not particularly limited as long as the differential pressure inside and outside the mixing chamber can be maintained within the above range, but the preparation time of the polymer electrolyte aqueous solution is shortened, and From the viewpoint of making the aqueous solution uniform, the range of 0.05 to 20 mm is preferable. Further, one or a plurality of orifices are provided in a part of the mixing chamber, and their installation positions are set so that the mixed liquid does not stay in the mixing chamber. For example, the vicinity of the position where the emulsion and the water supplied through the supply pipe meet is preferable.

A preferable residence time of the emulsion and water supplied to the mixing chamber in the mixing chamber is substantially within 1 second, more preferably within 0.5 seconds, and mixing is performed so as to attain the appropriate residence time. The size of the chamber is appropriately selected. If the residence time in the mixing chamber exceeds 1 second, the dilution and dissolution of the emulsion will be insufficient. Typical mixing chamber volume is 0.0
The capacity is preferably in the range of 01 to 0.5 liter. The weight ratio of the water-in-oil type polyelectrolyte emulsion and water supplied into the mixing chamber may be appropriately determined according to the concentration of the desired polyelectrolyte aqueous solution, but in general, the emulsion 1
The proportion of water is preferably 20 to 1000 parts by weight with respect to parts by weight.

The water-in-oil type polyelectrolyte emulsion used in the present invention includes, for example, a copolymer of quaternary dimethylaminoethyl (meth) acrylate and acrylamide, a chaotic polymer such as polyethyleneimine or polyethyleneimine graft polymer. An electrolyte or anionic polyelectrolyte such as carboxymethyl cellulose or sodium polyacrylate is contained in the range of 10 to 50% by weight, and these polyelectrolyte aqueous solutions become droplets and are immiscible with water, kerosene, naphthene and isoparaffin. Examples thereof include emulsions finely dispersed in an oily liquid, and various emulsion products are commercially available as flocculants for pollutants and dehydrating agents for sludge.

[0012]

The present invention will be described in more detail with reference to the following examples, but the following examples do not limit the present invention.
All modifications and implementations that do not depart from the spirit of the description below are included in the technical scope of the present invention.

Embodiment 1 FIG. 1 shows a schematic explanatory view of the device of the present invention. Using this device, in the following steps, a water-in-oil emulsion type polymer flocculant (dimethylaminoethyl methacrylate quaternary salt homopolymer) having a concentration of 25% by weight was diluted with water to a concentration of 0.2% by weight (mixing / mixing). The dilution ratio was 1: 125) to obtain an aqueous polymer flocculant solution. The polymer electrolyte emulsion of the polymer flocculant is supplied from the emulsion storage tank 11 to the liquid delivery pump 9
Is sent to the preparation apparatus A of the present invention via the supply pipe 1. On the other hand, the dilution water is supplied from the dilution water tank 12 to the flow meter 10
It is pressure-fed to A via the supply pipe 2 while the flow rate is controlled by.

FIG. 2 shows an enlarged view of the polymer electrolyte aqueous solution preparation apparatus A of the present invention. The polymer electrolyte emulsion supply pipe 1 penetrates through the central portion of the cylindrical mixing chamber 3 and has an opening near an orifice 5 provided at the lower end of the mixing chamber. The water supply pipe 2 has an opening on the upper side surface of the mixing chamber 3, and a pressure gauge 4 for measuring the differential pressure inside and outside the mixing chamber is attached to the mixing chamber.

The volume of the mixing chamber 3 was 56 × 10 ^-6 m ³ . The flow rates of the emulsion and the dilution water were 4.8 × 10 ⁻⁶ m ^{3 / s} and 607 × 10 ⁻⁶ m ^{3 / s} , respectively. Further, the gap between the orifices was adjusted to about 0.5 mm so that the differential pressure before and after the orifice 5 was 1 kg / cm ^2, and the pressure of the pressure gauge 4 was controlled to ² kg / cm ² . The residence time of the mixed liquid in the mixing chamber was calculated from the flow rate and was 0.0
It was 9 seconds.

The polymer electrolyte aqueous solution that has passed through the orifice 5 and is squeezed out into the atmosphere is introduced into a treatment tank 6 provided below the aqueous solution preparation apparatus A. The treatment tank 6 is provided with a stirrer 7 with stirring power of 0.2 kw / m ³ until the aqueous solution squeezed out through the orifice 5 reaches a predetermined electric conductivity (mS / cm). Stir-mixed to achieve complete dissolution. The predetermined electric conductivity is the electric conductivity of the polymer electrolyte aqueous solution obtained when the whole amount of the polymer emulsion charged into the apparatus is completely dissolved, and is determined by the kind of the polymer electrolyte and the concentration of the aqueous solution. For example, in the case of the dimethylaminoethyl methacrylate quaternary salt homopolymer used in this example, the electrical conductivity of a 0.2 wt% aqueous solution is 0.86 mS / cm.

Therefore, when the electric conductivity in the stirring treatment tank reaches this predetermined electric conductivity, it is considered that the water-in-oil emulsion type polymer coagulant is completely converted into the polymer electrolyte aqueous solution. You can Further, the shorter the stirring time (hereinafter referred to as required stirring time) in the treatment tank required to reach the predetermined electric conductivity, the higher the mixing effect of the preparation apparatus A of the present invention. The electric conductivity is measured by measuring the electric conductivity (mS / c) of the sampling liquid in the treatment tank.
m) was read by an electric conductivity meter, and the required stirring time is shown in Table 1. Further, with respect to the present Example 1, Example 2 to be described later, and Comparative Example 1, changes with time of the electric conductivity of the solution in the treatment tank were measured, and the results are shown in FIG. It can be seen that the required stirring time of Examples 1 and 2 according to the method of the present invention is considerably shortened as compared with Comparative Example 1.

Examples 2 to 3 Using the same polymer flocculant and aqueous solution preparation apparatus as in Example 1, aqueous polymer electrolyte solutions were obtained. However, the flow rate of the polymer coagulant emulsion and the flow rate of the diluting water were set as shown in Table 1, the clearance of the orifice was adjusted, and the pressure gauge 4 was operated while being adjusted as shown in Table 1. In addition, in the same manner as in Example 1, the required stirring time in the processing tank 6 until reaching a predetermined electric conductivity was measured, and the results are also shown in Table 1.

Comparative Example 1 An aqueous polymer electrolyte solution was obtained using the same polymer flocculant and aqueous solution preparation device as in Example 1. However, the flow rate of the polymer coagulant emulsion and the flow rate of the diluting water are set as shown in Table 1, and the baffle plate T at the lower end surface of the mixing chamber for forming the orifice 5 is removed to adjust the differential pressure before and after the orifice. It was set to 0 kg / cm ² . The indication of pressure gauge 4 is 1.0 kg / cm ²
Met. Also, the required stirring time was measured and the results are shown in Table 1.
Also described in.

Comparative Example 2 An aqueous polymer electrolyte solution was obtained using the same polymer flocculant and aqueous solution preparation device as in Example 1. However, the flow rate of the polymer coagulant emulsion and the flow rate of the diluting water were set as shown in Table 1 so that the residence time of the emulsion and the diluting water in the mixing chamber was 2 seconds. Also, the gap between the orifices was adjusted so that the differential pressure before and after the orifice 5 was maintained at 1 kg / cm ^2, and the indication of the pressure gauge 4 was controlled at ² kg / cm ² . The required stirring time is also shown in Table 1.

[0021]

[Table 1]

[0022]

According to the present invention, when a water-in-oil type polyelectrolyte emulsion useful as a polymer flocculant is used as a polyelectrolyte aqueous solution having a desired concentration, gelation or emulsion during phase inversion of the emulsion It was possible to prevent aggregation and coalescence of particles and shorten the dissolution time. Therefore, a uniform polymer electrolyte aqueous solution can be easily prepared in a short time by a quick and simple operation. Therefore, it becomes possible to prepare an aqueous solution of the polymer electrolyte in the treatment tank even if a stirrer having inferior ability to the stirrer used conventionally is used or the stirrer is omitted.

[Brief description of drawings]

FIG. 1 is a schematic side view showing the configuration of an apparatus for preparing a polymer electrolyte aqueous solution according to the present invention.

FIG. 2 is an enlarged explanatory view of a mixing chamber and an orifice in FIG.

FIG. 3 is a graph showing a required stirring time in Examples and Comparative Examples.

[Explanation of symbols]

 1 Emulsion supply pipe 2 Dilution water supply pipe 3 Mixing chamber 4 Pressure gauge for differential pressure measurement 5 Orifice 6 Processing tank 7 Stirrer 8 Preparation liquid delivery pump 9 Emulsion delivery pump 10 Dilution water flow meter 11 Emulsion storage tank 12 Dilution Water Tank A Polymer Electrolyte Aqueous Solution Preparation Device M Motor T Baffle Plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomohiko Sasaki 2-1-6 Nishijima Nishiyodogawa-ku, Osaka-shi, Osaka Prefecture Kubota Shin-Yodogawa Plant (72) Inventor Tokuni Toshi, Nishijima Nishijima-ku, Osaka-shi, Osaka 2 -1-6 Kubota Co., Ltd. Shin-Yodogawa Factory

Claims (2)

[Claims] 1. A method for adding water to a water-in-oil type polyelectrolyte emulsion containing a polyelectrolyte in a range of 10 to 50% by weight to prepare the emulsion as a polyelectrolyte aqueous solution. This mixture is supplied to the mixing chamber and then, while the emulsion and water are being mixed or immediately after mixing, so that the pressure difference between the outside of the mixing chamber and the inside of the mixing chamber becomes 0.5 kg / cm ² or more. A method for preparing an aqueous polymer electrolyte solution, which comprises pressurizing from an orifice provided in the. 2. A plurality of pipes for supplying liquid, a mixing chamber for substantially instantaneously mixing two or more kinds of liquids, and a pressure gauge for measuring a differential pressure between the outside of the mixing chamber and the mixing chamber. An apparatus for preparing a polymer electrolyte aqueous solution, having an orifice having a gap capable of maintaining a differential pressure between the outside of the mixing chamber and the inside of the mixing chamber at 0.5 kg / cm ² or more when the mixed solution is squeezed out.