JPH11290663A - Powder dispersion dissolution and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To introduce a powdery composition into a treatment liquid, complete the treatment reaction in a short time while keeping the powdery composition under the stronger agitating state and then separate easily a turbid content, in a method and a device therefor introducing a powdery turbid liquid treatment agent having liquid-soluble or liquid-dispersible properties. SOLUTION: When powder having liquid-soluble or liquid-dispersible properties is dispersed or dissolved in a liquid in a flowing-down line, powder is formed preliminarily into the dispersed or roughly dissolved state through an agitation cushion unit 2 forming an agitation basin and then flowed forcibly. The positive mixture of the powder with a fluid and the effective utilization of forcible movement energy of the fluid can be carried out, and the desirable mixture agitation can be carried out by the agitation flowing-down operation accompanying the powerful shearing force and eddy flows by the arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for charging a powdery substance into a liquid. More specifically, the present invention relates to a technique for directly applying a fine powdery flocculant composition to a liquid to be treated, performing a flocculation reaction in a short time under a strong stirring state, and facilitating solid-liquid separation.

[0002]

2. Description of the Related Art Conventionally, in most coagulation treatments and the like, an inorganic electrolyte typified by a sulfuric acid band, polyaluminum chloride, or the like is added as a coagulant to wastewater containing a target pollutant, and then the pH is adjusted. It is established as a mainstream technology to generate small flocs, further inject a suitable liquid natural or synthetic polymer flocculant as needed, and stir to separate pollutants from wastewater as large flocs. I have.

[0003] These methods often require a large amount of equipment in a system in which a treatment target is achieved by utilizing drugs having different functions for each purpose.
In addition, recently, a technology has been developed in which a flocculant composition in the form of a powder is directly poured into wastewater and stirred to generate floc and solid-liquid separation, thereby simplifying the treatment process and improving the installation space. It is reported to be useful for such purposes.

However, when a chemical such as a powder coagulant to be used is directly applied to an object to be treated, there are technically many problems pointed out in terms of powder charging means, unlike the conventional liquid injection method. That is, establishment of stable quantitative supply technology of powder, establishment of uniform continuous supply technology of powder, selection of suitable conditions for agglutination reaction with target processing liquid, measures against secondary agglomeration of drug powder itself, moisture absorption during storage There are many issues such as prevention measures and work measures in handling powder.

[0005] As a method of putting these powders into water, for example, Japanese Patent Application Laid-Open No. 7-8771 proposes a method of dissolving a powder mixed therein by dissolving a powder coagulant in water. As a method for improving the disadvantage that the powder cannot be stably supplied due to the adhesion of the powder to the inner surface of a supply cylindrical body such as a hopper, there is a proposal of a method of supplying a constant amount while rotating the powder in a spiral. It is known that the second fluid is supplied to the negative pressure portion of the ejector and used as a gas-liquid mixing means. However, Japanese Patent Application Laid-Open No. 7-256071 discloses that A solid-liquid mixing means is shown in which powder is sucked and dropped from above the negative pressure section of the ejector via a supply device and a hopper and mixed into raw water.

[0006]

However, in the conventional target technology, a practical agglomeration method based on a reaction system between the powder composition and the target liquid has not been completed, and in particular, the unique behavior of the powder. As an appropriate technique for catching the image, it is not yet in a satisfactory state and is not practical. In view of such current situation, the present inventors firstly as a first important issue accurately and quantitatively distribute the applied powder composition, and then how efficiently disperse or dissolve in the target liquid, There was an immediate need to complete a rapid agglutination reaction. In particular, in the first problem, as a condition for performing a prompt agglutination reaction,
The main purpose of this study was to investigate the necessity of rapid stirring with strong shear force and vortex in a short time.

Further, as a second important problem, a method for precisely distributing a quantitative amount while maintaining a desired uniform state of the composition was examined. In particular, since the composition is not a single composition but a uniform powder composition consisting of multiple components, the composition design may be destroyed by the form movement after quantitative distribution, and the expected composition state is stably maintained. We examined mainly the means of supply.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above first problem, and as a result, supplied powder into a separately provided variable amount of cushion bath liquid separately provided in advance. Then, the liquid was temporarily changed from a dispersed state to a coarsely dissolved state, and then forcedly fed into the target liquid body within a short time. By this means, the active mixing with the target liquid fluid and the forced transfer energy of the fluid can be effectively utilized, and the ideal mixing and stirring have been successfully performed under the stirring flow with strong shearing force and vortex. Furthermore, in order to supply a precise quantitative distribution while maintaining a uniform state as an intended composition, which is the second problem, the powder composition should be adjusted to fine particles having a uniform particle size as much as possible. This was achieved by moving and supplying under an atmosphere of dry air during the transfer.

That is, the gist of the present invention is to provide a stirring cushion unit for forming a stirring flow area in advance in at least one place of the flow path when dispersing or dissolving the powder in the liquid in the flow path. And a method for dispersing and dissolving the powder, which is characterized by temporarily dispersing or coarsely dissolving and then forcibly sending the solution, and a processing apparatus incorporating these means.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A stirring cushion unit used in the present invention to excite a powder into a reaction state is mainly prepared when a powder composition is charged into a liquid to be treated. In the stirred flow area, the solution is once dispersed or coarsely dissolved and then sent into a liquid to be treated to complete the final reaction. This point is extremely important in performing the technique of the present invention.

In this case, the powder composition to be charged can be strictly in a liquid dispersion state. However, in the present invention, in order to always obtain a stable reaction state, the powdery coagulant composition is directly applied to the target liquid. The aim is to put it inside. However, it is extremely important that the main reaction is transferred into the target liquid in as short a time as possible because the composition is in a reactive state even in the preceding liquid.

Thus, in the present invention, since a self-contained powdery flocculant composition is used, once it is put into a liquid as described above, a partial reaction is started to be in a reaction state. It is extremely important to control the residence time in the coarsely dissolved state.

Here, within a short period of time, the reaction activity of the powdery coagulant composition is basically unchanged, and the coagulation properties for the target liquid are not impaired at all. Although a short time is related to the temperature of the reaction liquid in the stirring cushion unit, it is preferably at most 10 minutes. or,
The preceding liquid introduced into the unit may be a single liquid to be treated, a single non-target liquid, or a mixed liquid thereof.

In the present invention, as a typical example of the method of managing the residence time in the stirring cushion unit, the method can be easily implemented by a combination of an inflow liquid adjusting tank and a pump. That is, even if the existing equipment is added or installed in parallel, a plurality of appropriate windows for liquid inflow are provided on the upper surface of the semi-open tubular container where there is no liquid inflow from the bottom, and appropriate pumping is performed at the bottom of the tubular container. A pump is assembled into a unit, and these units are fixed in the raw water tank.

The pump is automatically operated according to the water level, and is automatically operated by the natural flow of the liquid into the stirring cushion unit according to the water level in the raw water tank. On the other hand, a powdery coagulant composition is supplied by operating an apparatus for automatically feeding a fixed amount of powder only during operation. At this time, while the liquid sent from the pump is refluxed by an appropriate method as necessary, the reaction is adjusted to the official reaction state required in the present invention. In this case, if the method of the present invention is adopted, a sufficient effect is exhibited under stability, and the powder and the liquid are once dispersed or coarsely dissolved in the stirring flow area, and are quantitatively contained in the liquid to be treated while maintaining the active state. Can be sent automatically.

In order to apply the dispersion or coarse solution of the powder coagulant composition obtained by the method of the present invention to, for example, other untreated contaminated liquids moving in a tube, at least the main pipe route must be used. What is necessary is just to inject and merge into the said liquid from the injection port provided in one place. The installation location and the number of the injection ports are not particularly limited and can be freely selected. When connecting to a pipe, it is usually preferable to connect directly to the main pipe using a cheese for piping, and usually to provide a check valve on the connection pipe side.

Further, the injection port is preferably provided in at least one place of the main pipe in consideration of the stirring time during the flow in the pipe, and can be connected as necessary or provided with a time difference. In this case, depending on the properties of the target contaminated liquid and the reaction characteristics with the coagulant composition to be injected, it is important to select appropriate ones after examining appropriate conditions such as single-stage aggregation or multi-stage aggregation.

In the present invention, the coagulant composition which is a powder is once supplied in advance to the liquid in the stirring cushion unit to be dispersed or coarsely dissolved and then sent to the contaminated liquid for post-processing. The liquid sending means is not particularly limited. That is, all known means such as suction or press-fitting can be adopted.

In particular, in the present invention, in order to dissolve the powdery coagulant composition in the target processing liquid, the coagulant composition once dispersed or coarsely dissolved by the preceding liquid in the intermediate tank is used. It is preferable that the contained liquid is guided to the suction side of a more powerful pump, and pressed into the target pipe in an active state while maintaining agitation by eddy energy in the pump body and the discharge pipe. Here, the pump to be used is not particularly limited, but a corresponding pump discharge head is required for press-fitting into the tube.

The coagulant liquid obtained by dispersing or coarsely dissolving the powder coagulant composition of the present invention in a liquid is sent to a target liquid fluid containing pollutants, and is then basically stirred during the fluid transfer. The flocculation reaction is completed and flocs are formed. However, in some cases, it may be more efficient to further stir.In such a case, after the coagulant composition-containing liquid is sent to the target liquid fluid, a static mixer or the like is provided in the tube in line and the stirring is performed. To strengthen.

Further, in order to supply the flocculant composition as a powder into the liquid in the stirring cushion unit, basically any commercially available powder quantitative supply apparatus can be employed. The preceding liquid is introduced into the stirring cushion unit simultaneously with the introduction of the powder. The method of introducing the preceding liquid into the stirring cushion unit does not need to be particularly limited, and can be freely selected, such as natural inflow in the processing step or supply by a pump.

In the present invention, since the flocculant composition which is a powder is stored or held in a large amount in a hopper, sufficient consideration must be given to moisture absorption. It is highly desirable to provide protection. For this reason, in the present invention, the path before the liquid is poured into the liquid of the stirring cushion unit is protected by air blown by a compressor or a blower. At this time, it is preferable to take measures after dehumidifying as much as possible the moisture in the air with an aftercooler or the like, and then sending the air, and stirring only at a fixed portion of the powder such as a hopper at regular intervals.

As described above, in the present invention, when the powder coagulant is injected into the target treatment liquid fluid containing the pollutant, the powder is once dispersed or coarsely dispersed in the preceding liquid in the stirring cushion unit. After a short period of time, it is injected within a short period of time. Substantially more excellent coagulation effect can be obtained than directly injecting the powder coagulant into the liquid fluid to be treated. A reaction regime can be achieved. As a result, direct treatment of the high-concentration contaminated liquid is easy, and an extremely efficient agglutination reaction can be achieved. The powder dispersing and dissolving method and the apparatus of the present invention, when performing the wastewater treatment by directly charging the powdery flocculant composition, compared with the conventional batch reaction agglomeration reaction method by batch powder addition, It provides an innovative new method that can be called continuous precision addition.

The novel method of the present invention is not fundamentally limited to the scope of use. For example, turbid water regeneration treatment during earth and sand washing used at civil engineering construction sites, coagulation and dewatering of excess sludge from biological treatment processes, recycled circulating water recovery equipment at ready-mixed concrete manufacturing plants, other oil-containing wastewater, steel rolling wastewater, water-soluble cutting oil It is extremely useful for applying a powder coagulant to the treatment of general factory wastewater such as wastewater.

Further, the present invention can be applied to fields such as dewatering of scum and the like discharged from the processing steps of various other industrial wastewaters with a powder coagulant. As described above, it is a very useful technology in a wide range of fields, and greatly contributes to global environmental protection. Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

[0026]

【Example】

Example 1 In order to confirm the effect of the present invention using model wastewater,
A kaolin 2500 mg / L colloidal suspension containing sodium pyrophosphate 200 mg / L as a stabilizer was prepared as test raw water. Collect this in a beaker,
Super Namit TN400L, a commercially available nonionic powder coagulant composition (manufactured by Tomen Construction)
The addition amount of was changed and the state of aggregation was examined with a jar tester. A good floc was formed after about 30 seconds by adding about 100 to 120 mg / L. Preliminary tests confirmed that, after stirring was stopped, the floc was allowed to settle for 1 minute and completely clear supernatant water was obtained.

Next, this raw water was used as a continuous test apparatus and executed based on the flow sheet shown in FIG. In FIG. 1, reference numeral 1 denotes the entire powder feeder, 1a denotes a powder holder tank, which holds powder 1b inside the tank.
This powder holder tank is directly connected to the powder fixed amount supply unit 1c. The powder is supplied quantitatively by a powder feeder motor 1d attached to the supply unit, and falls into the stirring cushion unit 2. Further, the mixture was mixed with raw water and stirred in running water to form a powder dispersion or coarse solution in a running water state. The amount of water supplied into the stirring cushion unit 2 was adjusted by the flow rate adjusting valve 10. 11 is a raw water regulating valve,
Reference numeral 12 denotes a raw water valve.

The stirring cushion unit 2 will be described in detail with reference to FIG. In FIG. 2, the agitation cushion unit 2 provided in the raw water tank 4 is mainly an inflow liquid adjusting tank 2 having a liquid opening 2b at the top which is semi-open and has no liquid inflow from the bottom.
and a submersible pump 3 installed at the bottom. The submersible pump 3 has a float switch 3b (entering a suitable water level) and a switch 3c (appropriate water level turning off) for automatically turning on and off the power according to the level of the inflowing liquid into the inflowing liquid adjusting tank 2a. 3a indicates a pipe on the discharge side from the submersible pump 3;
Reference numeral 6 denotes a submersible pump power cord.

The prepared dispersion or coarse solution of the powder coagulant is mixed in-line with the test raw water (RW) of the raw water tank 4 supplied by the raw water pump 5 by the transfer submersible pump 3 in the water supply pipe. The mixture was further stirred by the static mixer 6 and fed to the thickener 7 under pressure. The above test raw water (R
W) In the water pipe, the dispersion liquid of the powder coagulant injected by the transfer pump 3 reacted with the contaminants in the raw water, and was stirred and transferred to the thickener 7 while growing coagulated flocs. Reference numeral 15 denotes a sample water sampling valve. The thickener 7 has a rake 9 and a rake rotating motor 14 and separates into treated water (TW) and sludge (S). The sludge (S) is transferred to a separately provided dehydrating device by a sludge pump 8 via a sludge valve 13 and a series thereof. Has been completed.

An experiment was carried out with test raw water using a test apparatus according to the flow described in detail above. At this time, the continuous water flow per hour by the pump was 1 cubic meter, and SuperNamit TN which is a commercially available nonionic powder coagulant composition was used.
400 L (manufactured by Tomen Construction) was supplied into the small mixing tank 2 while changing the effective concentration as shown in Table 1 below, and the agglutination reaction experiment of the present invention was performed. Thereafter, the treated water containing the generated floc was collected into a graduated cylinder from the sample water sampling valve 15 at the thickener entrance, and the sedimentation of the floc was observed. The results were as shown in Table 1 below.

[0031]

[Table 1]

As is clear from the results in Table 1, good results were obtained in Experimental Examples 1 to 3. These experimental examples are in agreement with the results of preliminary tests, and clearly show that the agglomeration method of the present invention has extremely good reproducibility and is an industrially practical agglutination method. Next, a comparative example of the present invention will be presented.

Comparative Example 1 For comparison, the powder coagulant composition was directly charged into a raw water tank without using a stirring cushion tank, and the entire raw water tank was returned by a raw water pump. The coagulation treatment was performed under exactly the same conditions as in Example 1 with the amount of coagulant added as shown. The results were as shown in Table 2 below.

[0034]

[Table 2]

As compared with the result of Example 1, although the processability is somewhat recognized, the transparency of the supernatant water is lacking in that the growth of formed flocs is not so good. Furthermore, a difference is also observed in terms of sedimentation. This can be observed that the flocculation cannot be generated because the aggregating reaction progresses at an early stage due to insufficient stirring power.

Example 2 In order to treat the actual wastewater from the ready-mixed concrete factory, the SS amount was 50,0 min.
The method of the present invention was applied using raw water containing 00 mg / L and 1.2 mg / L of hexavalent chromium. First, by a beaker test, it was confirmed in a preliminary experiment that a treatment could be achieved by adding 600 mg / L of a commercially available cationic powder coagulant Super Namit TN315C (manufactured by Tomen Construction) to raw water and stirring the raw water.

Then, the raw water was continuously passed at 2 cubic meters per hour by a pump using the same test apparatus used in Example 1, and the effective concentration of the Super Namit TN315C powder flocculant composition was increased to 600 mg / L. In addition, the mixture was supplied into the stirring cushion tank 2 and an agglutination reaction experiment of the present invention was performed. Thereafter, the treated water containing the generated floc at the end of the reaction was collected in a measuring cylinder in the same manner as in Example 1, and the sedimentation of the floc was compared and observed. The results were as shown in Table 3 below.

[0038]

[Table 3]

From the results shown in Table 3, the same coagulation effect as in Example 1 was confirmed, and no total chromium was detected in any of the treated waters of Experimental Examples 4 to 6. Thus, it was confirmed that harmful metals could be removed at the same time. In particular, the factory wastewater is a strong alkali and usually requires a neutralization step for the coagulation treatment. However, the method of the present invention is simple and requires a simple automatic addition and movement of the powder coagulant composition and a moving step. It was convinced that the method was excellent in practicality in that the coagulation treatment could be completed only through the process.

[0040]

The method and apparatus for dispersing and dissolving a powder according to the present invention are a part of a technique for introducing a water-reactive powder coagulant composition into a target liquid to be treated, and achieve the object reliably and stably. It was developed for the purpose. Conventionally, there was a treatment agent that can complete the reaction by a simple basic operation of directly adding powder and stirring to the target treatment liquid, but it is mainly a batch addition reaction system, and a continuous reaction form to the target liquid is not.

That is, it is difficult to obtain a direct and efficient reaction of the powder with the liquid in handling the powder, and such technical fields have hardly been developed. In the present invention, a reactive powder in a liquid is converted into an unfinished liquid that is dispersed or coarsely dissolved and retains the reaction activity, and then continuously injected into the target processing liquid while maintaining the stirring state to complete the reaction. It was completed as a practical technique to be performed.

Further, in the water treatment using a powder flocculant, highly concentrated polluted water can be directly treated, which is extremely advantageous. Is required. According to the present invention, in response to this, the shearing force at the time of stirring is strengthened, and a practical powder dispersion mixing method that can be easily incorporated into a continuous processing step is an innovative technology in the field of water treatment. The effect can be shown. from now on,
We are convinced that there is a great deal of industrial contribution in the fields of various types of water recycling, wastewater, and sewage treatment.

[0043]

[Brief description of the drawings]

FIG. 1 shows a flow sheet employed in an embodiment of the present invention.

FIG. 2 is a view for explaining in detail a stirring cushion unit 2 in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 powder feeder 1a powder holder tank 1b powder 1c powder quantitative supply unit 1d powder feeder motor 2 stirring cushion unit 2a influent liquid adjusting tank 2b 3 transferred underwater pump 3a discharge side pipe 3b float switch 3c float switch 4 Raw water tank 5 Raw water pump 6 Static mixer 7 Thickener 8 Sludge pump 9 Rake 10 Flow control valve 11 Raw water control valve 12 Raw water valve 13 Sludge valve 14 Rake rotation motor 15 Sample water sampling valve 16 Underwater pump power cord

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masujiro Arita 4-1003, 558-oka, Shinanomachi, Totsuka-ku, Yokohama-shi (72) Shunji Yanagisawa 50-74, Nishino Umemotocho, Yamashina-ku, Kyoto-shi, Kyoto (72) ) Inventor Mamoru Kitamura 5-22-11 Hannan-cho, Abeno-ku, Osaka-shi (72) Inventor Minoru Matsumura 3-17-11 Hiyoshidai, Otsu-shi, Shiga

Claims (11)

[Claims] When a powder is dispersed or dissolved in a liquid in a flow-down path, a stirring cushion unit for previously forming a stirring flow area for the powder is provided in at least one place in the flow path, and the powder is once dispersed or coarsely dissolved. And then forcibly sending the powder. 2. The method according to claim 1, wherein the forced liquid supply is performed in a separately formed fluid.
The method for dispersing and dispersing a powder according to claim 1, wherein the stirring is performed in a merged state. 3. The method for dispersing and dissolving a powder according to claim 1, wherein the merged state is a divided liquid flow state, and a forced stirrer is further provided in the merged state. 4. The method according to claim 1, wherein said powder is continuously supplied quantitatively. 5. The method according to claim 1, wherein the stirring cushion unit comprises a combination of an inflow liquid adjusting tank and a pump. 6. The method according to claim 1, wherein a submersible pump is used as the pump. 7. The method for dispersing and dispersing powder according to claim 1, wherein a peripheral closed type tank provided with an inflow liquid amount adjusting function is used as the falling liquid adjusting tank. 8. The powder dispersing and dissolving method according to claim 1, wherein, as the function of adjusting the amount of the inflowing liquid, the discharge liquid of the pump is sent out of the system while refluxing the inside of the closed tank once. Method. 9. An undiluted solution to be treated and / or
The method for dispersing and dissolving a powder according to any one of claims 1 to 8, wherein a non-target treatment liquid is used. 10. The method for dispersing and dispersing a powder according to claim 1, wherein the powder is held in an atmosphere of dry air until the powder is supplied into the liquid in the intermediate tank. 11. An apparatus incorporating the method for dispersing and dispersing a powder according to any one of the above claims.