JP2007029803A - Apparatus for dispersing insoluble matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for shearing insoluble matter in wastewater in a simple unit without adding any chemical solution of an emulsifier etc. so that insoluble matter has the grain diameter suitable for biological treatment and dispersing the sheared insoluble matter in wastewater. <P>SOLUTION: The apparatus for dispersing insoluble matter is provided in a water tank 1 for retaining wastewater 4 with: an agitator blade 5 to be revolved in wastewater 4; a drive part 6 for driving the agitator blade 5; a casing 12 for covering a negative pressure portion to be generated by the revolution of the agitator blade 5; and a suction pipe 9 to be communicated with the inside of the casing 12 for sucking wastewater 4 by means of the negative pressure from the outside of the casing 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for treating wastewater containing insoluble substances, and more particularly to an apparatus for enabling smooth treatment of wastewater without separating and collecting insoluble substances contained in wastewater. is there.

  It is considered preferable to separate and remove insoluble substances before wastewater containing insoluble substances (for example, oils and fats, gel substances such as proteins and starches). However, in order to separate and remove insoluble substances in wastewater, a large-scale apparatus such as a pressure levitation device is required, and it takes time, labor and cost to operate the apparatus and to process the separated insoluble substances. The operation of wastewater treatment facilities is often disturbed.

  Regarding the treatment of fats and oils, which are representative of insoluble substances in conventional wastewater, a method of biological treatment by dispersing oils and fats without removing the fats and oils (Patent Document 1, pages 1 to 3, first) (See the figure). In this method, as shown in FIG. 9, a treatment tank 100 for temporarily storing wastewater, and an inlet opening is provided at a position slightly lower than the surface of the treatment liquid inside the treatment tank 100, and sequentially descends from the inlet opening, A pipe body 101 having a pipe passage bent so as to be inclined upward toward an outlet opening located in the processing liquid, and an air blowing means in which an air pipe 102 is connected to a relatively low position in the upward inclination of the pipe body 101 103 and a blower 104 for sending air to the air blowing means 103.

  When the air is blown into the tubular body 101 by the air blowing means 103, the processing liquid is sucked from the inlet opening near the water surface of the tubular body 101, and the processing liquid is discharged from the outlet opening. Inside the tube body 101, the fats and oils sucked together with the treatment liquid are mixed and stirred by the air bubbling action.

  On the other hand, regarding the particle size distribution of fats and oils, a method of reducing the particle size of fats and oils and dispersing them in wastewater is studied in order to be well decomposed by microorganisms such as activated sludge in wastewater treatment facilities (Patent Document 2 , See pages 1-5). According to this study, the emulsifier is continuously or intermittently added to the waste water, and the fats and oils are dispersed so that the particles having a particle size in the range of 1 to 100 μm are contained in an amount of 80% or more of the fats and oils. It is understood that biological treatment is performed, and the method is disclosed.

Japanese Patent Publication No. 6-77755 JP 2001-259673 A

  However, in the apparatus of Patent Document 1, since only mixing and stirring of air bubbling is performed locally, the degree of dispersion of fats and oils in the wastewater is low and hardly dispersed or emulsified, and the fats and oils in the wastewater are caused by organisms. There is a problem that it is difficult to be decomposed.

  In order to solve such problems, in the method of Patent Document 2, an emulsifier is added to adjust the particle size suitable for biological treatment in order to promote emulsification and dispersion of fats and oils. As a result, the running cost is increased and the operating cost is increased.

  The present invention has been made in view of the problems of the prior art as described above, and with a simple apparatus, without adding a chemical solution such as an emulsifier, the particle size suitable for biological treatment of insoluble substances in wastewater. An object of the present invention is to provide an apparatus for shearing and dispersing.

The present invention provides a dispersion apparatus that rotates a stirring blade in waste water containing an insoluble substance and disperses the insoluble substance in the waste water by using a shearing force generated in the stirring blade. A stirring blade, a drive unit that drives the stirring blade, a casing that covers a negative pressure generating portion generated by the rotation of the stirring blade, and a suction that communicates with the casing and sucks the wastewater from the outside of the casing by a negative pressure The following structure is included as a preferable aspect.
A communication pipe that draws gas from the outside of the waste water to the center of the stirring blade by using the negative pressure generated by the rotation of the stirring blade is provided.
The other end of the suction pipe is opened near the water surface of the waste water.
The other end of the suction pipe is opened near the bottom of the waste water.
The other end of the suction pipe is branched and one is opened near the water surface of the waste water and the other is opened near the bottom of the waste water.

  The present invention is configured as described above, and the following excellent effects are obtained.

  (1) Since insoluble substances can be effectively sucked up to the stirring blade by the negative pressure generated by the rotation of the stirring blade, the oil droplets have a median diameter of about 9 μm due to the shearing force generated by the rotation of the stirring blade. It is emulsified and dispersed to an extent, and biological treatment of fats and oils can be performed well.

  (2) Since the opening position of the suction tube can be provided at an arbitrary position, it is possible to deal with substances of any specific gravity, such as when the specific gravity is lighter than water or when the specific gravity is heavier than water.

  (3) Furthermore, since the gas can be sucked together from the outside, the dissolved oxygen concentration in the wastewater can be kept high.

  In the present invention, the median diameter is a particle diameter corresponding to a cumulative 50% in the particle diameter distribution. It is suitable for biological treatment when the median diameter is 1 to 100 μm, but the smaller the median diameter, the better. In the present invention, fats and oils are insoluble liquids such as animal and vegetable oils and mineral oils.

  Furthermore, the gas drawn from the outside of the wastewater is mainly assumed to be air, but is not limited to air, and gases such as ozone and nitrogen may be used depending on the application.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings, but it goes without saying that the present invention is not limited to the embodiments. FIG. 1 is a schematic view showing a first embodiment of the present invention. FIG. 2 is a schematic diagram showing the stirring blade in FIG. FIG. 3 is a schematic view showing a second embodiment of the present invention. FIG. 4 is a schematic view showing a third embodiment of the present invention. FIG. 5 is a schematic view showing a fourth embodiment of the present invention.

[Embodiment 1]
In FIG. 1, 1 is a water tank in which waste water 4 containing insoluble substances is retained, and 10 is a side wall in the water tank 1. Above the water tank 1, an introduction pipe 2 for introducing the waste water 4 into the water tank 1 is arranged, and the transfer pipe 3 for transferring the treated water is provided on the lower side so as to keep the water level in the water tank 1 constant. It is communicated. A stirring blade 5 is provided at the bottom of the water tank 1. The volume of the water tank 1 is set in advance so as to maintain a residence time necessary for shearing the insoluble material contained in the waste water 4 with the stirring blade 5 and dispersing and emulsifying the waste water 4.

  A drive unit 6 for rotating the stirring blade 5 is a submersible motor type drive unit connected to the stirring blade 5 so that the stirring blade 5 can rotate. The stirring blade 5 is fixed to a rotating shaft (not shown) at the lower part of the drive unit 6. In addition, a drive unit 6 is provided outside the lower part of the water tank 1, the rotation shaft of the drive unit 6 is sealed with a mechanical seal or the like, and a stirring blade 5 is connected to the rotation shaft so that it can be directly driven by the drive unit 6. It may be configured. Furthermore, the drive unit 6 may be fixed on the water surface, and the rotating shaft may be extended to the stirring blade 5 in the waste water 4, and is not particularly limited.

  As shown in FIG. 2, the stirring blade 5 and the surrounding configuration have a hollow stirring member 5 having a rotating shaft 13 for fixing to the drive unit 6. A fixed wing 15 is provided at a portion sandwiched between the upper and lower rectifying plates 14 so that the rectifying plate 14 covers and the discharged waste water 4 does not rotate together and exits horizontally. A casing 12 is provided in the negative pressure generating portion of the stirring blade 5, and a suction pipe 9 is connected to the casing 12 so that the waste water 4 can be sucked from an arbitrary place in the water tank 1 by the negative pressure transmitted into the casing 12. is doing.

  In the present embodiment, the stirring blade 5 is a hollow stirring body, but it is not particularly limited as long as a negative pressure can be generated at the center of rotation.

  By configuring as described above, the following operation occurs. Waste water 4 is introduced into the water tank 1 from the introduction pipe 2 to fill the water tank 1. The waste water 4 introduced by the introduction pipe 2 is moved in the direction away from the stirring blade 5 by the rotation of the stirring blade 5, moved toward the side wall 10 of the water tank 1, and moved to the side wall 10. Along with this, it becomes an upward flow 11 and moves to the vicinity of the water surface. On the other hand, a negative pressure is generated in the central portion of the stirring blade 5 as the waste water 4 moves toward the side wall 10, and the inside of the casing 12 provided in the rotation central portion becomes a negative pressure. By comprising in this way, the waste water 4 of arbitrary places can be sucked in by the suction pipe 9 using the negative pressure in the casing 12. In this embodiment, the suction pipe 9 is arranged so as to suck insoluble substances near the water surface. By arranging in this way, insoluble substances having a small specific gravity with respect to the wastewater 4 (for example, fats and oils) are efficiently sent to the stirring blade 5, so that they are finely sheared by the shearing force generated at the tip of the stirring blade 5, Can be refined and dispersed. In addition, the material refined and dispersed in this way is suitable for biological treatment.

[Embodiment 2]
FIG. 3 shows a second embodiment of the present invention. In FIG. 3, reference numeral 7 denotes a communication pipe for introducing air, which is a gas, from the outside into the water tank 1, one end communicating with the hollow portion of the stirring blade 5 and the other end opened on the water surface of the waste water 4. . Reference numeral 8 denotes fine bubbles introduced into the waste water 4 by the air introduced from the communication pipe 7 being sheared by the stirring blade 5. Since other parts are the same as those of the first embodiment, description thereof is omitted.

  Next, the operation of this embodiment will be described. In the present embodiment, the waste water 4 in the vicinity of the stirring blade 5 is moved in the direction away from the stirring blade 5 by the stirring blade 5 rotated by the driving unit 6, and moves toward the side wall 10 of the water tank 1. Along with this, it becomes an upward flow 11 and moves to the vicinity of the water surface. Due to the movement of the waste water 4, a negative pressure is generated at the center of the stirring blade 5. Due to the negative pressure generated in the central portion of the stirring blade 5, the pressure inside the communication pipe 7 having one end opened to a position where the negative pressure is generated is lowered, and air is supplied from the other end opened in the air of the communication pipe 7. The air is sucked and discharged from the one end opened at the center of the stirring blade 5. The discharged air reaches the stirring blade 5 together with the waste water 4, is finely sheared by the shearing force generated by the rotation of the stirring blade 5, forms fine bubbles 8, and is sent out into the waste water 4.

  In this way, air is mixed into the waste water 4 introduced into the stirring blade 5, the air is sheared by the stirring blade 5 to form fine bubbles 8, and the fine bubbles 8 are flown by the rotation of the stirring blade 5 in the water tank. As a result, the momentum of the upward flow 11 of the waste water 4 near the side wall 10 of the aquarium 1 increases due to the rising action of the fine bubbles 8. Then, by forming a strong upward flow 11 in the vicinity of the side wall 10 of the water tank 1, a constant flow direction is formed in the water tank 1, and substances with low specific gravity such as fats and oils of the waste water 4 are efficiently raised and sucked again. It reaches the tube 9, is introduced up to the stirring blade 5, is further finely dispersed under the influence of the rotational shearing force, and is emulsified in the waste water 4. Further, since the fine bubbles 8 introduced into the stirring blade 5 and sheared have a small bubble diameter, the dissolved oxygen in the waste water 4 can be increased in a short time, and the dissolved oxygen concentration can be kept high. The particle size of the insoluble substance in the waste water 4 dispersed in this manner is suitable for biological treatment.

[Embodiment 3]
FIG. 4 shows a third embodiment of the present invention. In FIG. 4, reference numeral 9 denotes a suction pipe provided in the waste water 4 in the water tank 1. In this embodiment, the suction pipe 9 is opened near the bottom of the water tank 1 so that the insoluble substance 16 having a higher specific gravity than the waste water 4 can be sucked. Since the rest is the same as in the second embodiment, a description thereof will be omitted.

  Next, the operation of this embodiment will be described. Since the movement of the waste water 4 near the stirring blade 5 and the suction of air, which is a gas, are the same as in the second embodiment, the description thereof is omitted.

  On the other hand, the suction pipe 9 opened near the bottom of the water tank 1 sucks the insoluble substance 16 having a higher specific gravity than the water accumulated in the bottom of the water tank 1 together with the waste water 4, and the insoluble having a higher specific gravity than the waste water 4 and water. The substance 16 and air both reach the stirring blade 5 and are finely sheared by the shearing force generated by the rotation of the stirring blade 5 to form fine substances and fine bubbles 8, which are sent out into the waste water 4.

  If the insoluble substance 16 having a higher specific gravity than the wastewater 4 is sucked in this way, the insoluble substance 16 having a higher specific gravity than the wastewater 4 can be used as long as the protein or starch is gelled. The gel-like material is finely dispersed by being sheared by, so that it floats in the waste water 4. On the other hand, the insoluble substance 16 having a high specific gravity that has been sent into the waste water 4 without being finely dispersed is again deposited on the bottom of the water tank 1 and taken into the stirring portion by the suction tube 9 and introduced again into the stirring blade 5. Then, it is further finely dispersed under the influence of the shearing force due to the rotation and dispersed in the waste water 4. In addition, since the fine bubbles 8 introduced and sheared into the stirring blade 5 have a small bubble diameter, the dissolved oxygen in the waste water 4 can be increased in a short time, and the dissolved oxygen concentration can be kept high. The substance dispersed in this way is suitable for biological treatment because it has a size that is easily taken up by microorganisms.

[Embodiment 4]
FIG. 5 shows a fourth embodiment of the present invention. In FIG. 5, 9 is a suction tube provided in the waste water 4 in the water tank 1, and in this embodiment, the insoluble substance 16 having a higher specific gravity than the waste water 4 and the lighter specific gravity can be sucked together. The suction pipe 9 is opened near the bottom of the water tank 1 and near the water surface of the waste water 4 in the water tank 1. Since the rest is the same as in the second or third embodiment, the description is omitted.

  By configuring in this way, it is possible to incorporate insoluble substances 16 having a specific gravity lighter than that of waste water 4 such as fats and oils and substances that are gelled such as proteins and starch, and have a specific gravity higher than that of waste water 4. It is possible to refine both the precipitate and the floated material and disperse them in the waste water 4, so that the waste water 4 can be treated without separating and removing insoluble substances from the waste water 4 and waste can be reduced. Become. Since such a dispersed substance has a small particle size, it is easily taken up by microorganisms and is suitable for biological treatment.

  Next, an emulsification / dispersion test of fats and oils was performed using the apparatus of the second embodiment of the present invention. The results are shown below. In addition, it tested using the apparatus of patent document 1 as a comparative example. The schematic diagram of the fats and oils dispersion apparatus of a comparative example is shown in FIG. In this test, tap water is used as raw water and waste oil containing simulated oil and fat mixed with salad oil, which is often used in the food industry, is used to measure the particle size distribution of dispersed particles at that time, and the median diameter is calculated from the particle size distribution. Calculated. A measuring apparatus and a test method are shown below. The median diameter here refers to a particle diameter corresponding to 50% cumulative in the particle diameter distribution.

(Measurement device for particle size distribution and median size of oil droplets)
HORIBA, Ltd .: Laser diffraction / scattering particle size distribution analyzer (LA-910W)
Measurement principle: Light source based on Mie scattering theory: Combined use of He-Ne laser and tungsten lamp

〔Test method〕
200 L of tap water was put into a water tank, 200 ml of salad oil (commercial product) was added thereto, and after operating for a predetermined time, a simulated oil / fat-containing wastewater was obtained and measured with the above-mentioned equipment.

  Table 1 shows the median diameter of dispersed particles when salad oil is dispersed for 5 minutes, 10 minutes, and 30 minutes in the examples. Moreover, the graph which showed the particle size distribution of the dispersion | distribution particle | grains when making it disperse | distribute to FIG.6, FIG.7, FIG.8 for 5 minutes, 10 minutes, and 30 minutes was represented.

  As shown in Table 1, in the examples, the median diameter when dispersed for 5 minutes was about 9 μm. Further, as shown in FIG. 6, 99.6% was distributed when the particle diameter was 20 μm or less, and 60.4% was distributed when the particle size was 10 μm or less. Further, the median diameter when dispersed for 10 minutes was about 8.3 μm, which was slightly finely dispersed. Further, looking at the particle size distribution from FIG. 7, 99.7% was distributed when the particle size was 20 μm or less, and 65.7% was distributed when the particle size was 10 μm or less. Furthermore, the median diameter when dispersed for 30 minutes was 7.04 μm, which resulted in a finer dispersion. However, it was only about 2 μm smaller than the dispersion for 5 minutes. In this apparatus, the dispersion was almost completed within a few minutes. Further, from FIG. 8, it was found that 99.7% was distributed in a particle size of 20 μm or less after dispersion for 30 minutes, and 77% was distributed in a particle size of 10 μm or less.

  On the other hand, in the comparative example, even when dispersed for 5 minutes and 10 minutes, the salad oil was not emulsified at all, and the cloudiness phenomenon indicating that the tap water was also emulsified was not obtained. Also, when dispersed for 30 minutes, the oil did not disperse finely in tap water and did not emulsify, but when measured intentionally, it did not fall within the measurement range at 200 μm or more.

  Next, the result of the activated sludge treatment of the dispersed salad oil and the undispersed salad oil is shown.

[Measurement equipment for residual oil]
Measuring device: HORIBA, Ltd. Oil concentration meter OCMA-305
Measuring method: H-997 extraction non-dispersive infrared absorption method

〔Test method〕
In the test, activated sludge was collected in a 200 ml Erlenmeyer flask, salad oil dispersed so as to have an oil load of 600 mg / L was added thereto, and the culture was rotated for 20 hours. Then, the entire activated sludge was centrifuged, and the oil concentration The concentration of residual oil was measured with a total. As a comparative example, salad oil that was not dispersed was added.

  The results of measuring the residual oil concentration contained in the supernatant water after centrifugation after the test are shown in Table 1. From this result, it can be seen that the processing is good in the embodiment. On the other hand, in the comparative example, although it was processed, it was a result that did not reach 30 mg / L, which is a standard for discharge into a general water area.

  By using the present invention, it is possible to perform wastewater treatment of substances that are difficult to disperse in water, and since it can be treated together with what was normally separated and discarded, waste can be reduced and wastewater treatment is also good Therefore, it can greatly contribute to prevention of environmental pollution. It can also be used as a device for dispersing a gel substance in a liquid such as food processing industry. Further, it can be used as a reaction device for gas and liquid.

It is a schematic diagram which shows schematic structure of the 1st Embodiment of this invention. It is the schematic diagram which showed schematic structure of the stirring blade in FIG. It is a schematic diagram which shows schematic structure of the 2nd Embodiment of this invention. It is a schematic diagram which shows schematic structure of the 3rd Embodiment of this invention. It is a schematic diagram which shows schematic structure of the 4th Embodiment of this invention. It is a graph showing the particle size distribution after the process for 5 minutes in an Example. It is the graph showing the particle size distribution after the process for 10 minutes in an Example. It is the graph showing the particle size distribution after the process for 30 minutes in an Example. It is a schematic diagram which shows schematic structure of the test apparatus of a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Water tank 2 Introducing pipe 3 Transfer pipe 4 Waste water 5 Stirring blade 6 Drive part 7 Communication pipe 8 Fine bubble 9 Suction pipe 10 Side wall 11 Upflow 12 Casing 13 Rotating shaft 14 Rectifying plate 15 Fixed blade 16 Heavy insoluble substance 100 Water tank 101 Tubing body 102 Air pipe 103 Air blowing means 104 Blower

Claims (5)

  In a dispersion apparatus that rotates a stirring blade in waste water containing an insoluble substance and disperses the insoluble material in the waste water using shearing force generated in the stirring blade, the stirring blade that rotates in the waste water; A drive unit that drives the stirring blade, a casing that covers a portion where negative pressure is generated by the rotation of the stirring blade, and a suction pipe that communicates with the casing and sucks the wastewater from outside the casing by negative pressure. An insoluble substance dispersing apparatus characterized by that.   2. The insoluble substance dispersing apparatus according to claim 1, further comprising a communication pipe that draws gas from outside the waste water to the center of the stirring blade by using a negative pressure generated by the rotation of the stirring blade.   The insoluble substance dispersing apparatus according to claim 1 or 2, wherein the other end of the suction pipe is opened near the water surface of the waste water.   3. The insoluble substance dispersing device according to claim 1, wherein the other end of the suction pipe is opened near the bottom of the waste water.   3. The dispersion device for insoluble substances according to claim 1, wherein the other end of the suction pipe is branched and one is opened near the water surface of the waste water and the other is opened near the bottom of the waste water.

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