JP2001347260A - Sewage purifying apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sewage purifying apparatus capable of being installed at any location, saving a space and purifying efficiently a large amount of sewage. SOLUTION: This sewage purifying device is provided with an aspirator 5 that mixes a coagulant solution 4 stored in a coagulant tank 2 and air from an air filter 3 with washing waste water 1 by a vacuum suction mechanism, an introduction pipe 17 that introduces the washing waste water 1a containing coagulate particles and the air into the inside or a cylindrical stirring chamber 18 in the tangential direction with respect to the horizontal cross section of the stirring chamber 18, a mixing cylinder 8 that sucks the washing waste water circling and going up along the inner wall of the stirring chamber 18, from the inlet part 8b of its upper end and makes the coagulate particles gravity-flow down as air bubbles are held in them, and a waste water collecting part 10 that stores the washing waste water 1d flowing out from the outlet part 8b of the lower end of the mixing cylinder 8 and discharges it together with the coagulate particles to the outside from an upper connection pipe 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewage purification apparatus, and more particularly, to a sewage purification apparatus for reducing the concentration of contaminants such as surfactants in laundry wastewater.

[0002]

2. Description of the Related Art Conventionally, washing wastewater from an electric washing machine is drained as it is, and anionic surfactants such as sodium linear alkylbenzenesulfonate (LAS) and alkylsulfate, which are the main components of the synthetic detergent, are relatively insoluble. Since it is difficult to biodegrade, it causes water pollution of rivers and the like as compared with soap.

[0003] Today, it is said that laundry wastewater discharged from homes has the greatest effect on water pollution. For this reason, it is desired from the viewpoint of environmental protection to reduce the concentration of contaminants such as surfactants contained in washing wastewater and drain clean water.

In response to such a demand, Japanese Patent Application Laid-Open No. 8-229
Japanese Patent Application Publication No. 543 proposes a wastewater treatment apparatus that efficiently and quickly floats and separates fine particles and the like in wastewater. The configuration of this conventional wastewater treatment apparatus will be described with reference to FIGS.

A throttle 158 which narrows a part of a flow path 156 through which the liquid to be treated 102 flows, and a gas inlet 1 provided downstream of the throttle 158 and having the same cross-sectional area in the direction of the flow path 156.
60, and a gas inlet 166 through which air is introduced from the outside into the gas inlet 160 is formed.
A widened portion 162 in which the flow path 156 is gradually widened is provided on the downstream side.

Downstream of the expanding section 162, there is provided a pressurizing and mixing section 108 for mixing the liquid to be treated 102 in the flow path 156 and the gas flowing in from the gas inlet 166 under pressure. A drug injecting unit 120 for injecting an aggregating agent is connected thereto, a drug mixing unit 122 is formed downstream thereof, and a nozzle unit 124 and a floating separation layer 128 are provided downstream thereof.

[0007]

However, although this conventional wastewater treatment apparatus is small, it mixes a gas and a coagulant into the suctioned liquid to be treated, and removes the liquid to be treated containing the aggregate formed by this. Since the respective processing steps leading to agitation and separation of aggregates are connected by a long pipe, the whole apparatus is bulky and the installation place is restricted. That is, in order to purify household wastewater such as washing wastewater and kitchen wastewater from home, it has been difficult to secure a sufficient installation space for such a device around water such as a washing machine or a sink.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a sewage purification apparatus capable of further saving space and efficiently purifying a large amount of sewage.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a sewage purification apparatus which collects coarse aggregate particles by mixing a flocculant with a sewage containing a pollutant such as a surfactant. And means for mixing air with the sewage together with mixing of the flocculant, and introducing the sewage containing the agglomerated particles and the air into a cylindrical stirring chamber at an angle that does not pass through the center of the stirring chamber. Means for sucking the sewage rising while rotating along the inner wall of the stirring chamber to retain bubbles in the agglomerated particles, and drainage collection for temporarily storing the sewage flowing out from the mixing means. And a means for purifying sewage.

According to this configuration, a mechanism for mixing aggregates and air into sewage water containing contaminants, forming aggregate particles of the contaminants, and coarsening and collecting the particles is concentrated in a compact space.

The present invention also relates to a sewage purifying apparatus for collecting agglomerated aggregated particles by mixing a flocculant into a sewage containing a pollutant such as a surfactant. And a means for introducing the sewage containing the aggregated particles and the air into a cylindrical stirring chamber so as to be tangential to a horizontal cross section of the stirring chamber. A mixing means for sucking the sewage rising while rotating along the inner wall from an inlet at an upper end and allowing the aggregated particles to flow naturally while holding bubbles, and the sewage flowing out from an outlet at a lower end of the mixing means. A wastewater collecting means for temporarily storing the wastewater and discharging it together with the aggregated particles to the outside from an upper outlet.

According to this configuration, the aggregate and air are mixed with the sewage containing the pollutant to form the agglomerate particles of the contaminant, collect the coarse particles, and discharge the sewage to the outside together with the aggregate particles. Mechanism to be integrated in a compact space.

Further, a filtration unit is provided which communicates with the wastewater collecting means through the discharge port to separate and collect the aggregated particles from the wastewater and drains purified water from which the aggregated particles have been removed. In addition, the aggregate particles separated by the filtration unit can be discarded as ordinary waste, and water pollution of rivers and the like due to drainage can be suppressed.

Further, by integrally forming the stirring chamber, the drainage collecting means and the filtration section, the apparatus itself becomes compact and space is saved.

In this case, the mixing of the coagulant into the sewage and the mixing of the air can be performed smoothly by a reduced-pressure suction mechanism. As the reduced pressure suction mechanism, for example,
An aspirator can be used, and this is a method in which a negative pressure section is generated by flowing pressurized water. Therefore, there is no need to install an air pump for mixing air, which is advantageous in terms of simplification of the system and cost reduction.

A spiral fin in which a pair of substantially square or substantially rectangular plate-like members twisted so as to form a predetermined angle between two opposite sides thereof is connected in series in the mixing cylinder. Is provided, the sewage naturally flows down in the mixing cylinder along the surface of the spiral spiral fin, so that the aggregated particles can retain bubbles and promote the coarsening thereof.

Further, a washing net can be used for separating and collecting the aggregated particles in the filtration section. In this case, a washing net used to prevent damage to laundry such as clothes during washing can be used in combination with filtration of aggregated particles.

By the way, if the surface of the inner wall of the drainage route of the sewage from the means for mixing air with the sewage together with the mixing of the flocculant is subjected to non-adhesive processing, the sewage is formed during the purification treatment of the sewage. Aggregate particles can be prevented from adhering to the inner wall of the drainage passage.

If the drainage collecting means is provided detachably with respect to the stirring chamber, the drainage collecting means can be removed as necessary to perform maintenance such as cleaning of the inside thereof.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> A first embodiment of the present invention
An embodiment will be described with reference to the drawings. First, the configuration of the sewage purification apparatus according to the present embodiment will be described. As shown in FIG. 1, the aspirator 5, which is a reduced-pressure suction mechanism, is connected through an introduction pipe 17 to a portion below a stirring cylinder 18 described below. Further, one end on the root side of a branch pipe 15 branched in a Y-shape is connected to the aspirator 5.
The other end of the branch pipe 15 is connected to a coagulant tank 2 for storing a coagulant solution 4 and an air filter 3 for filtering air sucked from outside air. Reference numeral 16 denotes a flow control valve for the coagulant solution 4.

Inside the stirring cylinder 18 whose upper surface is closed,
A stirring chamber 6, which is a cylindrical space, is formed. As shown in FIG. 2, the introduction pipe 17 is, for example, a stirring cylinder 18 so as to be tangential to a horizontal section of the substantially circular stirring chamber 6.
Is linked to Therefore, the washing drainage 1a introduced into the stirring chamber 6 via the introduction pipe 17 forms a swirling water flow f along the inner wall of the stirring chamber 6, and rises inside the stirring chamber 6 while being stirred.

Below the agitating cylinder 18, a cylindrical drainage collecting section 10 which is isolated and has a larger inner diameter than the agitating cylinder 18 is provided concentrically. A mixing tube 8 having a predetermined length and a relatively small inner diameter is inserted in a substantially central portion of the inside of the stirring tube 18 and the drainage collection unit 10 in the longitudinal direction. A spiral fin 7, which will be described later, is provided inside the mixing cylinder 8.

The spiral fin 7 is formed, for example, by twisting a plate having an aspect ratio of about 1.5: 1 or 1: 1 such that the angle between two opposing sides is 180 °.
The cells are spirally formed by connecting a plurality of cells in series. The number of cells in this case is not particularly limited. The material of the spiral fin 7 may be either a metal or a resin, but a resin is more preferable in terms of moldability.

The inlet 8a at the upper end of the mixing cylinder 8 is
The washing drainage 1b, which is in the vicinity of the upper surface and rises in the stirring chamber 6 as a swirling water flow f, flows through the inlet 8a through the mixing cylinder 8
And flows down the surface of the spiral spiral fin 7 naturally.

Reference numeral 19 denotes a filtering section formed in a box shape having an open upper surface, and 19a denotes a lid for opening and closing the upper opening. Inside the filtration unit 19, a dewatering basket 20 made of a wire mesh or the like shaped along the inner wall is detachably provided. Further, inside the dewatering basket 20, a bag-like washing net 21 having water permeability is held. Also,
A drain pipe 22 for draining purified water that has passed through the washing net 21 is provided below the side surface of the filtration unit 19.

Reference numeral 25 denotes a connecting pipe drawn from above the drainage collecting section 10, and the other end thereof is guided through the lid 19 a of the filtering section 19 into the washing net 21. Thus, the drainage collection unit 10 and the filtration unit 19 are connected to each other through the connection pipe 25. In addition, if the filtration part 19 is provided detachably with respect to the connection pipe 25, the filtration part 19 can be separated from the sewage purification device and maintenance such as cleaning can be performed as needed, so that shortening of the product life can be suppressed.

Next, the usage of the sewage purification apparatus having the above configuration will be described with reference to FIGS. First, when the washing drainage 1 is introduced into the aspirator 5 by pressurizing and supplying means (not shown) such as a pump, a negative pressure portion is generated by the water flow, and coagulation is connected to the branch pipe 15 communicating with the negative pressure portion. The coagulant solution 4 and air are mixed into the washing drainage 1 from the agent tank 2 and the air filter 3. The mixing amount of the coagulant solution 4 can be appropriately adjusted by adjusting the opening / closing state of the flow control valve 16 in accordance with the flow rate of the washing drainage 1.

As the coagulant to be added at this time, inorganic polyaluminum chloride, aluminum sulfate and the like generally used for sewage purification treatment can be suitably used. In order to further increase the size of the aggregate particles, For example, an organic polymer flocculant such as polyacrylamide may be used.
In the present embodiment, the washing drainage 1 to which the inorganic coagulant has been added is pumped into the aspirator 5 in a tank (not shown). Then, a polymer coagulant solution is prepared in the coagulant tank 2, and the air and the polymer coagulant are mixed into the washing drainage 1 by the suction action of the aspirator 5.

The washing wastewater 1a in which the coagulant solution 4 and the air are mixed is passed through the introduction pipe 17 through the introduction pipe 17 as described above.
The swirling water flow f is introduced into the stirring chamber 8 along the inner wall of the stirring chamber 6 and rises inside the stirring chamber 6 while being stirred. At this time, since the washing wastewater 1a is rapidly stirred, contaminants such as a surfactant and a dirt component separated from the laundry in the washing wastewater 1a are aggregated together with the action of the coagulant, and several tens to Aggregates coarsened to several hundred μm are formed. The washing wastewater 1b containing the aggregates thus coarsened flows into the mixing cylinder 8 from the inlet 8a, and flows down the surface of the spiral spiral fin 7 naturally.

When the washing drain 1a is swirled and stirred in the stirring chamber 6, light air is concentrated near the outer peripheral surface of the mixing cylinder 8 due to the action of centrifugal force. Since the air and the aggregate in the waste water 1b are uniformly mixed, the coarsening of the aggregate particles holding the bubbles in the mixing cylinder 8 is promoted.

Then, the washing wastewater 1c containing the aggregated particles falls from the outlet part 8b of the mixing cylinder 8 into the wastewater collecting part 10,
It is gradually stored here. At this time, washing drainage 1c
Becomes a jet due to gravity and drops vigorously. If it is attempted to separate the aggregated particles from the washing wastewater 1c using a filter or the like, the aggregated particles that have become coarser are crushed by the jet and become fine particles again. Would. Therefore, by temporarily storing the washing wastewater 1c in the wastewater collecting unit 10 and buffering the flow of the jet, the coarsened aggregate particles can be guided to the filtering unit 19 without being crushed.

When the water level of the washing wastewater 1c reaches near full water in the wastewater collecting part 10, the washing wastewater 1d overflows through the connecting pipe 25 and is guided into the filtering part 19 together with the waste aggregate 23. . Then, the waste aggregate 23 is filtered and separated by the washing net 21, and the washing net 21 is removed.
, The purified water 1e that has been naturally dehydrated is drained to the outside from the drain pipe 22 via the dehydrating basket 20.

When the waste agglomerates 23 accumulate in the washing net 21 to a certain extent, the lid 19a of the filtering unit 19 is opened and the washing net 21 is taken out.
Discard 3 At the same time, since the dewatering basket 20 can also be removed, the inside of the filtration unit 19 including the dewatering basket 20 can be maintained in a sanitary state by washing the washing net 21 and the dewatering basket 20 as necessary.

If the inner wall of the drainage passage from the aspirator 5 to the connecting pipe 25 is subjected to non-adhesive processing (for example, fluorine coating), the washing wastewater mixed with aggregate particles passes through the drainage passage. Since there is no danger of the aggregate particles sticking to the inner wall, the trouble of cleaning the drainage passage is unnecessary even in the repeated washing water purification treatment.

An example of a cleaning test for washing wastewater by the sewage purification apparatus according to the present invention will be described. The dimensions of the inner diameter and the height of each part of the used sewage purification apparatus were such that the stirring cylinder 18 was 50 mm × 200.
mm, the mixing cylinder 8 is 20 mm x 360 mm, and the drainage collecting section 10 is 6
It is 6 mm x 250 mm. Washing wastewater was supplied to such a sewage purification device at a supply flow rate of about 4.8 L / min and mixed with the washing wastewater at an air intake flow rate of 3.0 L / min.

Using Kao powder detergent Attack (trademark) as a surfactant, initial concentration 240 ppm, turbidity 100 NTU
The washing drainage was prepared so that The inorganic flocculants include poly aluminum chloride aqueous solution PAC300A manufactured by Taki Kagaku.
((Trademark), poly aluminum chloride concentration 33%), and 1.7 mL was added per 1 L of washing drainage.

Further, the flocculant tank 2 was filled with a 0.3% aqueous solution of a nonionic polymer flocculant N110 (trade name) manufactured by Toagosei Co., Ltd., and was prepared so that 4.0 mL was mixed with 1 L of washing wastewater. When the concentration of the surfactant in the purified water 1e drained from the drain port 22 was measured under such experimental conditions, the concentration was lowered from 240 ppm in the washing wastewater 1 before the treatment to about 8 ppm, and the turbidity which is an index of the transparency was measured. The degree is 1-2NT
It became U and sufficient purification treatment capacity was obtained.

<Second Embodiment> A second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a schematic sectional view of the sewage purification device according to the present embodiment. In this figure, the same members as those of the sewage purification device according to the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 3, a characteristic configuration of the present embodiment is that a filtering section 19 is provided outside the drainage collecting section 10 with a stirring cylinder 1.
8 is provided integrally with the sewage water purification apparatus in which all the steps of the wastewater purification treatment are integrated. The filtering unit 19 is detachable from the stirring tube 18 by a hook type clamp 26.

A packing 27 for preventing water leakage is provided between the upper surface of the filtration unit 19 and the bottom surface of the stirring tube 18 so as to avoid the portion where the mixing tube 8 is inserted. Further, the drainage collecting section 10 is fixed to the upper surface of the filtering section 19 by bonding or the like. Reference numeral 28 denotes a discharge pipe provided at an upper part of the side surface of the drainage collection unit 10.

Next, a usage mode of the sewage purification apparatus having the above configuration will be described with reference to FIG. First, when the washing drainage 1 is introduced into the aspirator 5 by pressurizing and supplying means (not shown) such as a pump, a negative pressure portion is generated by the water flow, and coagulation is connected to the branch pipe 15 communicating with the negative pressure portion. The coagulant solution 4 and air are mixed into the washing drainage 1 from the agent tank 2 and the air filter 3. The mixing amount of the coagulant solution 4 depends on the flow rate of the washing drainage 1 and the flow control valve 16.
It can be adjusted appropriately by adjusting the opening / closing degree of.

As the coagulant to be added at this time, inorganic polyaluminum chloride, aluminum sulfate and the like generally used for purification treatment of sewage can be suitably used. For example, an organic polymer flocculant such as polyacrylamide may be used.
In the present embodiment, the washing wastewater 1 to which the inorganic coagulant has been added is pumped into the aspirator 5 in a tank (not shown). Then, a polymer coagulant solution is prepared in the coagulant tank 2, and the air and the polymer coagulant are mixed into the washing drainage 1 by the suction action of the aspirator 5.

The washing wastewater 1a in which the coagulant solution 4 and the air are mixed is supplied to the stirring tube 1 via the introduction pipe 17 as described above.
The swirling water flow f is introduced into the stirring chamber 8 along the inner wall of the stirring chamber 6 and rises inside the stirring chamber 6 while being stirred. At this time, since the washing wastewater 1a is rapidly stirred, contaminants such as a surfactant and a dirt component separated from the laundry in the washing wastewater 1a are aggregated together with the action of the coagulant, and several tens to Aggregates coarsened to several hundred μm are formed. The washing wastewater 1b containing the aggregates thus coarsened flows into the mixing cylinder 8 from the inlet 8a, and flows down the surface of the spiral spiral fin 7 naturally.

When the washing drainage 1a is swirled and stirred in the stirring chamber 6, light air is concentrated near the outer peripheral surface of the mixing cylinder 8 by the action of centrifugal force. Since the air and the aggregate in the waste water 1b are uniformly mixed, the coarsening of the aggregate particles holding the bubbles in the mixing cylinder 8 is promoted.

Then, the washing drainage 1c containing the aggregated particles falls from the outlet 8b of the mixing cylinder 8 into the drainage collector 10,
It is gradually stored here. At this time, washing drainage 1c
Becomes a jet due to gravity and drops vigorously. If it is attempted to separate the aggregated particles from the washing wastewater 1c using a filter or the like, the aggregated particles that have become coarser are crushed by the jet and become fine particles again. Would. Therefore, by temporarily storing the washing wastewater 1c in the wastewater collecting unit 10 and buffering the flow of the jet, the coarsened aggregate particles can be guided to the filtering unit 19 without being crushed.

When the water level of the washing drainage 1c reaches near full water in the drainage collecting part 10, the laundry drainage 1d overflows through the discharge pipe 28 and is guided into the filtering part 19 together with the waste aggregate 23. . Then, the waste aggregate 23 is filtered and separated by the washing net 21, and the washing net 21 is removed.
, The purified water 1e that has been naturally dehydrated is drained to the outside from the drain pipe 22 via the dehydrating basket 20.

When the waste agglomerates 23 have accumulated in the washing net 21 to some extent, the filtration unit 19
Is released, and the washing net 21 is taken out from the removed filtration unit 19, and the accumulated waste aggregates 23 can be discarded. At the same time, since the dewatering basket 20 can also be removed, the inside of the filtration unit 19 including the dewatering basket 20 can be maintained in a sanitary state by washing the washing net 21 and the dewatering basket 20 as necessary.

In each of the above embodiments of the present invention, the case where washing wastewater is used as wastewater has been described. However, it is needless to say that the same effect can be expected with household wastewater such as wastewater from a dishwasher. is there.

[0049]

As described above, according to the present invention, there is provided a sewage purification apparatus which collects coarse aggregate particles by mixing a flocculant into a sewage containing a contaminant such as a surfactant.
Means for mixing air with the sewage together with mixing of the flocculant, and means for introducing the sewage containing the agglomerated particles and the air into a cylindrical stirring chamber at an angle which does not pass through the center of the stirring chamber. Mixing means for sucking the sewage rising while rotating along the inner wall of the stirring chamber to retain bubbles in the agglomerated particles, and wastewater collecting means for temporarily storing the sewage flowing out of the mixing means. With this configuration, the piping connecting each means can be omitted, and the wastewater purification device itself can be made more compact accordingly. Therefore, this sewage purification apparatus can be mounted in a small space in a home-use washing machine and the like, and a large amount of sewage can be efficiently purified and clean water can be drained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a sewage purification device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line xx in FIG.

FIG. 3 is a schematic sectional view of a sewage purification apparatus according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram showing a conventional wastewater treatment device.

FIG. 5 is a front view of the suction device of the wastewater treatment device (A).
And a longitudinal sectional view (B).

[Explanation of symbols]

 1, 1a, 1b, 1d Laundry drainage 1e Purified water 2 Coagulant tank 3 Air filter 4 Coagulant solution 5 Aspirator 6 Stirring chamber 7 Spiral fin 8 Mixing cylinder 10 Drain collection unit 15 Branch pipe 16 Flow control valve 18 Stirring cylinder 19 Filtration unit 20 Dehydration basket 21 Laundry net 22 Drain pipe 23 Waste aggregate 25 Connecting pipe 26 Hook clamp 27 Packing 28 Discharge pipe

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinya Takagi 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Co., Ltd. (72) Inventor Muheidaira 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka 4D037 AA12 AB02 AB16 BA01 BA06 BA07 BB03 BB04 BB07 BB08 BB09 CA02 CA08 4D062 BA19 BA22 BA29 BB09 BB12 CA07 DA04 DA05 DB02 DC02 DC06 EA03 EA08 EA33 FA02 FA16

Claims (9)

[Claims] 1. A sewage purification device for collecting flocculated particles which are made coarse by mixing a flocculant into a sewage containing a contaminant such as a surfactant, wherein air is mixed with the sewage together with mixing of the flocculant. A means for introducing the sewage containing the agglomerated particles and the air into the interior of the cylindrical stirring chamber at an angle that does not pass through the center of the stirring chamber; and while rotating along the inner wall of the stirring chamber. A sewage purification apparatus comprising: mixing means for sucking the rising sewage to retain bubbles in the aggregated particles; and drainage collecting means for temporarily storing the sewage flowing out of the mixing means. 2. A sewage purifying apparatus for collecting flocculent particles which are made coarse by mixing a flocculant into a sewage water containing a contaminant such as a surfactant, and mixing air with the sewage together with the flocculant. Means, means for introducing the sewage containing the aggregated particles and the air into a cylindrical stirring chamber so as to be tangential to a horizontal cross section of the stirring chamber, and along an inner wall of the stirring chamber. A mixing means for sucking the sewage that rises while swirling from the inlet at the upper end and allowing the aggregated particles to flow naturally while holding bubbles, and temporarily storing the sewage flowing out from the outlet at the lower end of the mixing means. Wastewater purifying apparatus, further comprising a drainage collecting means for discharging the aggregated particles together with the aggregated particles from an upper discharge port to the outside. 3. A filtration unit which communicates with the wastewater collecting means through the discharge port to separate and collect the aggregated particles from the wastewater and drain purified water from which the aggregated particles have been removed. The sewage purification apparatus according to claim 2, further comprising: 4. The apparatus according to claim 2, wherein the stirring chamber, the wastewater collecting means, and the filtration unit are integrally formed.
Or the sewage purification device according to claim 3. 5. The sewage purification apparatus according to claim 1, wherein the mixing of the coagulant into the sewage and the mixing of the air are performed by a reduced-pressure suction mechanism. 6. A spiral in which a pair of substantially square or substantially rectangular plate-like members twisted so that an angle formed by a pair of opposite sides thereof becomes a predetermined angle is connected in series inside the mixing means. The sewage purification device according to any one of claims 1 to 5, wherein fins are provided. 7. The sewage purification apparatus according to claim 3, wherein a net for washing is used for separating and recovering the aggregated particles in the filtration section. 8. A non-adhesive process is applied to a surface of an inner wall of a drainage path of the sewage from the means for mixing air to the sewage together with the mixing of the coagulant and the filtration section. The sewage purification device according to claim 7. 9. The sewage purification apparatus according to claim 1, wherein said drainage collecting means is provided detachably with respect to said stirring chamber.