JP3014998B2 - Multistage apparatus and method for continuous wastewater filtration - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an apparatus and a method for purifying water. More particularly, the present invention relates to low cost, multi-stage clarification of sewage and drinking water, providing a solution to the problem of filter clogging, and enabling continuous operation of the device.

[0002]

BACKGROUND OF THE INVENTION With the growing population and the growing shortage of fresh water, great efforts have been directed to the development of methods and apparatus for water purification that are not suitable for irrigation, industrial or household consumption. The water purification efforts are usually directed to seawater, saltwater or sewage wastewater. While contaminated freshwater is not as infinitely available as seawater, its purification is less costly because free solids are more easily removed therefrom than the 3.5% dissolved salt present in seawater. Can be done. Furthermore, there are few places where sewage wastewater can be discharged without causing any pollution problems. Such wastewater
Plants that treat wastewater effectively use available water as fertilizer or feed.
Together with food products to prevent groundwater or coastal pollution.

[0003] The first step of a clarification, or wastewater treatment, usually requires at least one filtration step. Collection
Intermediate filters must be periodically cleaned or replaced to prevent clogging. Replacement is a viable option in applications where only small amounts of solids are removed, for example in oil filters used in industrial and automotive applications. However, in large scale applications such as water purification, filter cleaning is required. Even when inexpensive and abundant filter media such as sand is used, the replacement is a major undertaking and there are disposal issues with contaminated filter media. Furthermore, the filtered solids have some value, either as such or after further processing, but are lost upon disposal of the filter material.

[0004] The usual method of cleaning the filter is to stop the filtration process and remove the filter for cleaning or treatment by chemical or ultrasonic means. Another method of cleaning the filter is to periodically reverse the flow in the filter to remove and remove accumulated sludge
Includes making Compressed air may be used for the same purpose as it foams and causes the solids particles to drain into the fluid stream. Settling tanks have the advantage that they are clogged and require minimal energy to operate, but such tanks require a large amount of land area to be effective for all but the largest particles, and clean tanks. To do so, the process must eventually be stopped. Particles smaller than the fluid to be removed
The sedimentation tank is not suitable for removing small particles , except when is heavy .

[0005] Centrifuges are considerably more expensive to build and operate than sedimentation tanks , but are used to filter on less land area than is possible with said tanks. Centrifugal force acts on solids heavier than water, which pushes against the perforated centrifugal ball wall lined with the filter material, and clarified water is collected from the center of the ball. However, filters are often clogged and require replacement or cleaning. The above-described method further has the disadvantage that there is no continuous water clarification and that large machines such as air compressors and pumps that use significant energy to operate are required to perform filter cleaning. It has the disadvantage.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus and a method for the purification of waste water or drinking water, which operates continuously and avoids the problem of filter clogging. It is a further object of the present invention to provide an apparatus for the purification of wastewater that is operated by reasonably sized machinery and is reliable in operation and saves energy and can be constructed and operated at a reasonable cost. Is the purpose.

[0007]

SUMMARY OF THE INVENTION The present invention achieves the above-identified object by providing a multi-stage apparatus for continuous wastewater filtration, the apparatus comprising a system for supplying wastewater containing free solids. A first tank provided with an inlet pipe for wastewater, a means for adding a coagulant to the wastewater, and an outlet pipe; and wherein the sedimentation is large enough to precipitate relatively large free solids. A second port for receiving said mixture of wastewater and coagulant from said outlet pipe, said second port having an openable lower port for discharging the free solids removed and an upper weir for discharging the semi-clarified water. Tank and said
A continuously driven, non-tensioned, perforated belt having a surface positioned to receive a stream of semi-finished and discharged water at a first position, wherein the non-tensioned perforated belt comprises
Form a depression on the surface to hold a lump of water,
The front of the belt for discharging the belt at the second position.
Retains fine solids condensed on the surface and clarifies
Sized to allow the passage of
And belt being in contact with said belt, to determine the combined weight of the water retained the belt and on its controls the motor and its speed of the belt as a function of said weight,
As a result, a cake of fine matter having a thickness of 1 mm or less, which is formed of a condensed fine solid content, is formed and held on the surface of the belt , whereby the filtration performance of the belt is reduced.
A load sensor for improving the force, a water collector provided under the first position for water passing through the holes of the belt, and for collecting particles falling off the belt at the second position. And a solids collecting container provided at the second position.

In a preferred embodiment of the present invention, there is provided a multistage apparatus for continuous wastewater filtration as described above, wherein the second tank has the shape of an inverted truncated prism. In a highly preferred embodiment of the present invention, there is provided a multi-stage apparatus for continuous wastewater filtration as described above, wherein the perforated belt passes through a tub at a second location. In a particularly preferred embodiment of the present invention, the continuous wastewater filtration wherein the second tank is further provided with a debris weir to remove free solids floating from the surface of the water contained therein. A multi-stage apparatus is provided. In another preferred embodiment of the present invention, the multi-stage apparatus further comprises a metering pump for mixing a coagulant into wastewater introduced into the first tank, wherein the first tank further comprises the wastewater. Equipped with an impeller submerged in the

The present invention further provides a method for continuous wastewater filtration comprising the steps of: (a) delivering wastewater containing free solids to a first tank; feed and adding a coagulant to b) the waste water, to the (c) the steps of mixing a coagulant to the wastewater in a first tank, (d) is tilted and the resulting mixture bottom of the second tank (E) periodically discharging the solids deposited from the second tank by opening a lower door; and (f) semi-clarified water is removed from the upper part of the second tank. Arranged to overflow from a weir and drop onto a continuously driven, non-tensioned, perforated belt having a surface positioned to receive the flow of the semi-clarified and discharged water at a first location. and the step, the belt Holes, followed by the second position
Fine solids condensed on the surface for draining
To allow the passage of clarified water
The belt is formed in a non-tensioned state on the surface of the belt to hold a mass of water, and (g) in contact with the belt, and cake retained water and the motor of the belt to determine the combined weight of the control their speed as a function of said weight, whereby 1mm or less of the thickness of the fines consisting of fine solids condensed on Is formed on the surface of the belt
To be retained, thereby allowing the filtration capacity of the belt
Providing a load sensor to improve the following : (h) collecting water filtered by the movable belt; and (i) removing solids particles from surfaces and holes of the movable belt. Consists of

In a preferred embodiment of the invention, the water mass has a depth between 2 cm and 10 cm in the largest depression area. In a particularly preferred embodiment of the invention,
The cake of the fine object is about 0.04 mm to 0.06 mm
Up to thickness is maintained. The novel apparatus and method of the present invention form a thin cake layer of fines formed from finely condensed solids retained on the surface of the movable belt.
The belt by the flocculated floc.
It will be seen that the partial clogging improves the filtration capacity of the system.

The present invention further provides a method for continuous wastewater filtration, comprising the steps of: (a) delivering wastewater containing free solids to a first tank; the step of adding to the waste water (b) a coagulant, a step for feeding to (c) a step of causing mixing of coagulant to said waste water, (d) a second tank of the inclined bottom of the resulting mixture, (E) periodically opening the solids deposited from the second tank by opening the lower door; and (f) dropping the semi-clarified water onto the perforated movable belt. in order to so the filtration is performed, the step of configuring to overflow the upper weir of said second tank, the step of collecting water filtered by (g) the movable belt, (h) the movable Belt surface and holes Comprising a step of removing the solids particles.

No. 5,178,173 to Kerlin et al., US Pat. No. 5,080,806 to Balzano, and Fulton.
on) U.S. Patent No. 3,959,133 and British Patent No. 2,172,216 describe a coagulation / coagulation sedimentation and filtration chain, but these references are performed by belt filters. No filtration step is taught or suggested. MacDonald (MacDona)
U.S. Pat. No. 3,537,584 to J. Id. and U.S. Pat. No. 2,173,256 to Jordan describe belt filters, but the reference is semi-finished and discharged. having position to have a surface to receive a flow of water that is in the first position, there by perforated belt untensioned condition being continuously driven
Te, untensioned state forms a recess for holding a mass of water on the surface, the discharge the belt hole is continued in a second position
Holds fine solids condensed on the surface for release
Large enough to allow clarified water to pass through
Been of come, and being in contact with said belt, to determine the combined weight of the water retained the belt and on its controls the motor and its speed of the belt as a function of said weight, Thereby, a cake of fine material having a thickness of 1 mm or less consisting of a fine solid content condensed is formed and held on the surface of the belt.
It does not teach or suggest a belt in combination with a load sensor to increase the filtration capacity of the belt.

The entire system for water purification is a reservoir used as a buffer, equipment for drying and treating solid waste, a chlorination station, an injector for adding oxygen to water, and softening by cold lime treatment. Additional optional equipment, such as equipment for processing and other equipment required to match the effective quality standards of the particular water to the purpose for which the treated water is needed. It contains various components. Such components are known in the art and are not part of the present invention.

In US Pat. No. 5,167,821, a step of adding a coagulant to the sludge is provided.
A step of mixing the mixture, a step of filtering the aggregated particles Movable filtration bed, and moving the filtered water, a step of cleaning the filtration bed by spraying, and removing the agglomerated particles from the belt by the scraper A method for thickening and dewatering a slurry sludge is disclosed. U.S. Pat. No. 4,707,272
No. 4,358,381, No. 4,078,12
No. 9, 4,110, 209, 4, 309, 2
Nos. 91 and 2,361,283 all describe a method for filtering slurry and a method for purifying wastewater, but the patent does not teach or suggest a particular method and apparatus of the present invention. .

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described with respect to certain preferred embodiments and will be more fully understood by reference to the following illustrative drawings, in which: FIG. DETAILED DESCRIPTION OF THE INVENTION Referring now particularly to the drawings, wherein the details shown are by way of illustration only and for the purpose of illustration of a preferred embodiment of the invention, the most informative, It is provided to provide the one believed to be the most easily understood description of the conceptual form. In this regard, no attempt is made to show structural details of the invention in more detail than necessary for a basic understanding of the invention, and the description provided in the drawings is illustrative of some aspects of the invention. There are those reveal to those skilled in the art or in fact to be carried out in any way is.

A multi-stage apparatus 10 for continuous wastewater filtration is shown in FIG. The first tank 12 is provided with a wastewater inlet side pipe 14 arranged to supply wastewater 16 containing free solids. The first tank 12 is further provided with a metering pump 18 for mixing the coagulant 20 with the wastewater 16 introduced here. The addition of the coagulant 20 improves the efficiency of the following stages of operation. The coagulant 20 is alum, ferric chloride, ferric sulfate, ferrous sulfate, titanium dioxide, lime, and polyacrylamide (PAM) cation, polyamine cation, amine resin cation, polyacrylamide (PAM) It may be suitably selected from the group consisting of polyacrylates such as anions.

The first tank 12 is provided submerged in waste water 16 .
The impeller 22 is provided with sufficient power to be applied to the impeller 22 by the motor 24 to ensure even distribution of the coagulant 20. The first tank 12 is provided with an outlet pipe 26 for feeding the produced mixture 28 to the next stage. The second tank 30 receives the mixture 28 from a long distributor outlet 32 attached to the end of the outlet pipe 26. The second tank 30 is large enough to cause the settling of a relatively large solids 34. Small volume mixture 2
8 are both of these solids 34 to periodically discharge a short time, at least one openable bottom port 36
Is provided. The weight of the mixture 28 compressing the solids 34 facilitates flushing of the door 38 covering the port 36 and drainage through the port 36. It is important to note that this discharging operation is performed using only the small amount of energy required to open and close the door. The second tank 30 has an upper weir 40 for discharging semi-clarified water 42. Such drainage could alternatively be provided by an outlet port or sieve mesh, but with the important advantage that the weir 40 would not be clogged, and under conditions where moderate flow rates were used, free solids could be reduced. They tend to retain and prevent their discharge to the next stage.

A continuously driven perforated belt 44
Has a surface 46 positioned to receive a stream of semi-finished and drained water 42 at a first location 48. Semi-clear
The clarified water 42 may come directly from the weir 40, but in the embodiment shown a fluid flow channel 50 is provided for this. Advantageously, belt 44 is driven by pulley 54 in the direction shown, causing belt slack 52 at first position 48. The water 42 discharged to the belt 44 at the first position 48 is thus retained on a large belt area and filtered.

As can be seen more clearly in FIG. 2, the belt 44 forms a depression 120 on the surface 46 for holding the water mass 122 in a non-tensioned state. Load sensor 124
Is in contact with the belt 44, mass of water 122 retained therein and a portion of the belt 44, as well as to determine the combined weight of the solids 60 on the belt 44. Load sensor 124
Is functionally connected to a motor controller 126, which sets the speed of the motor 128 as a function of the weight. The speed of the motor is thus such that it favors the formation of a cake 130 of less than 1 mm in thickness consisting of condensed fine solids ,
Arranged. The surface 46 of the belt thus covered
Improves the filtration capacity of the belt 44.

The belt of holes 56 as seen in Figure 3, seen in detail in FIG. 4, in this embodiment, the first position 48
The fine solids 6 that have become fine cakes 130 on the surface 46 for subsequent discharge at a second location 62 located below.
Together hold the 0, are sized to allow passage of clear water through the hole 56. Water collection tank 64
Are provided below the first location 48 for water 58 passing through the holes 56 in the belt. Three suitably sized idler pulleys 66 are shown in FIG. 1, which determine the path of travel of the belt. If a large diameter pulley (not shown) is used, one
An idler pulley is sufficient. The solids collection container 68
Provided below the second location 62 for collection of the cake 130 of fines falling from the belt 44.

FIG. 3 shows an enlarged view of one of the belt holes 56 as seen when the belt is in the first position 48. As can be seen, the entrance 70 to the hole 56 is slightly reduced on the side of the surface 46 due to the slack 52 of the belt, and thus the solids particles 6 having approximately the same diameter as the hole 56.
0 is prevented. This configuration is such that in the second position 62 shown in FIG. 4, the slack 52 of the belt is then pointing downwards.
This should be compared to configurations where there is a tendency to open the hole entrance 70. As a result, solids particles 60 already trapped at the entrance 70 to the hole tend to be released at the second location 62.

A further means of removing waste solids particles from belt 44 is described below with respect to FIG. Referring again to FIG. 2, the main body of water, ie, the water mass 122, is measured in the largest depression area and has a depth between 2 cm and 10 cm. Cake 130 of fine particles
Is advantageously maintained in the range from 0.04 mm to 0.06 mm.

Referring now to FIG. 5, a preferred embodiment of the second tank 72 is shown, which has the shape of an inverted oblique truncated triangular prism. The second tank 72 receives the mixture 28 from the long distributor outlet 32 attached to the end of the outlet pipe 26, thereby reducing the flow rate and preventing disturbing the sedimentation effect occurring in the second tank 72 . Distributor outlet 32 is lower inclined wall 7
4 are arranged to discharge in one direction. The water inside the second tank 72 flows slowly upward along the lower inclined wall 74, and the relatively large solids 34 formed by the action of the coagulant 20 slide down toward the door 76.

FIG. 6 shows a preferred embodiment of a perforated belt 44 provided with cleaning means. Two scrapers 77 are in contact with belt 44 to remove waste solids from surface 46. The row of spray jets 78a includes solids 60 from holes 56, as seen in FIG.
The inner surface 80 of the belt 44 is positioned to be sprayed with a fluid, air stream or water for removal of the fluid. An optional second row of spray jets 78b is shown below pulley 54. The spray jet 78b still moves the belt 4 after the belt 44 has passed the second position 62.
It acts to remove solids particles that remain attached to 4 and do not separate . The spray jets 78a, 78b require considerable energy to operate, and are intended to be used only in situations where other provided means , such as a bathtub 82, cannot adequately clean the holes 56. Be done
It is .

The perforated belt 44 is exposed to water at a second location 62.
Pass through bathtub 82. Advantageously, the water 84 in the tub 82
Are exchanged continuously. The water 84 may be heated and / or a detergent may be added to increase its effect. At least one ultrasonic generator 86 is submerged in a water bath 82 to separate the solid particles from the holes 56.
Be killed .

FIG. 7 is similar to the multi-stage apparatus 10, but
For example, such water for irrigation human consumption crops, is purified
7 depicts a multi-stage device 88 for continuous wastewater filtration configured to produce waste water. The multi-stage device 88 further comprises water 5 already filtered by the perforated belt 44.
8 is provided with a settling tank 90 arranged to receive the same. Where better quality water is required, such as that required for domestic applications, the sedimentation tank 90 pumps water that has already settled solids into a fine sand filter 92. The fine sand filter 92 can be used for a long period of time without requiring replacement since almost all contained solids have already been removed.

FIG. 8 is a diagrammatic view of a second tank 94 which is provided with a descaling device 96 for removing free solids 98 floating from the surface of the water 42 contained therein. Have been. A descaling device 96 is suspended above the second tank 94, and the descaling weir device 96 includes at least one floating sludge cutting blade 100, which partially removes the water 42. , And is driven horizontally by a chain 102, which is driven by an electric drive unit 104. In the embodiment shown, the drive unit 104 operates continuously in the same direction and has several sludge cutting blades 100, the sludge cutting blades 100 moving beyond the wall 106 of the second tank 94. The suspended solids 98 are moved to the receiver 110.

In a further embodiment (not shown), the drive unit is configured to reciprocate the chain, and reciprocation control is provided by a limit switch located near the tank wall. A sludge pump 112, such as the screw conveyor shown, transports sludge 114 deposited from the sludge receiver 110 to further processing steps . Dregs-up device 96 is greatly reduced continuously driven perforated load <br/> solid according to the belt 44 minutes to receive a flow of water 42 which is semi clarified discharged from the second tank 94 . Thereby, the perforated belt 44 improves the water treatment capacity , and the belt 44 can easily be kept in a clean state.

The present invention is not limited to the details of the embodiments described above, but may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. It will be clear to those skilled in the art that Therefore, the present embodiment should be considered in all respects as illustrative and not restrictive, and the scope of the present invention is to be defined not by the above description but by the appended claims. , All modifications that come within the meaning and range of equivalency of the claims are considered to be embraced.

[Brief description of the drawings]

FIG. 1 is a diagram of a preferred embodiment of the device according to the invention.

FIG. 2 is a diagram of a belt speed control system used in the embodiment of FIG.

FIG. 3 is an enlarged view of the perforated belt as seen in a first position.

FIG. 4 is an enlarged view of the perforated belt as seen in a second position.

FIG. 5 is a diagrammatic view of a beveled truncated prismatic tank used for the separation of relatively large solids.

FIG. 6 is a front sectional view of a perforated belt provided with various cleaning means.

FIG. 7 is a diagram of an apparatus configured to produce high quality water.

FIG. 8 is a diagrammatic view of a second tank provided with a debris weir for removing suspended solids.

DESCRIPTION OF SYMBOLS 10 ... Multi-stage device 12 ... First tank 14 ... Inlet pipe 16 ... Wastewater 18 ... Metering pump 20 ... Coagulant 22 ... Impeller 26 ... Outlet pipe 28 ... Mixture 30 ... Second tank 34 ... solids 36 ... port 38 ... door 40 ... top weir 42 ... water 44 ... perforated belt 46 ... surface 48 ... first position 52 ... slack 56 ... hole 58 ... filtered water 60 ... solids 62 ... second Position 64 ... Water tank for water collection 68 ... Solid content collection container 72 ... Second tank 74 ... Lower inclined wall 76 ... Door 78a ... Spray jet 78b ... Spray jet 82 ... Water bath 84 ... Water 86 ... Ultrasonic generator 88 ... Multistage Type device 90 ... settling tank 92 ... fine sand filter 94 ... second tank 98 ... free solids 120 ... depression 122 ... water 124 ... load sensor 126 ... motor controller 128 ... Motor 130: cake of fine objects

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 36/00-36/04 B01D 33/00-33/82 C02F 1/00

Claims (16)

(57) [Claims] 1. A first tank comprising a wastewater inlet pipe for supplying wastewater containing free solids, a means for adding a coagulant to the wastewater, and an outlet pipe. Large enough to precipitate large free solids, having an open bottom port for the discharge of the precipitated free solids and an upper weir for the discharge of semi-clarified water A second tank for receiving the mixture of wastewater and coagulant from the outlet pipe; and a surface positioned to receive a stream of the semi-clarified and discharged water at a first location; A non-tensioned perforated belt to be driven , wherein the non-tensioned
Forming a depression on the surface to hold a mass of water
The belt holes are subsequently ejected at the second position.
While retaining the fine solid content condensed on the surface,
Sized to allow passage of clarified water
A belt are in contact with the belt, to determine the combined weight of the water retained the belt and on its controls the motor and its speed of the belt as a function of said weight, whereby condensation A cake of fine material having a thickness of 1 mm or less made of a fine solid content is formed and held on the surface of the belt.
To improve the filtration capacity of the belt
A load sensor for causing water to pass through the holes in the belt, a water collector provided below the first location, and a second sensor for collecting particles falling off the belt at the second location. The solid provided in two positions
A multi-stage device for continuous wastewater filtration, comprising a shape collection container . 2. The method according to claim 1, wherein said water mass is at the largest depression area.
The multi-stage device for continuous wastewater filtration of claim 1 having a depth between cm and 10 cm. 3. The multi-stage apparatus for continuous wastewater filtration of claim 1, wherein the cake of fines is maintained at a thickness of about 0.04 mm to 0.06 mm. 4. The multi-stage apparatus for continuous wastewater filtration according to claim 1, wherein the second tank has the shape of an inverted oblique truncated prism. 5. The multi-stage apparatus for continuous wastewater filtration according to claim 1, wherein at least one scraper for removing waste solids is in contact with the belt. 6. A method for removing waste solids from said belt.
At least one spray jet to inject fluid
The multi-stage apparatus for continuous wastewater filtration according to claim 1, wherein a belt is disposed on the belt . 7. A method for removing waste solids from said belt.
At least one sprayer for injecting compressed air
A multi-stage apparatus for continuous wastewater filtration according to claim 1, wherein a jet is disposed on the belt . 8. A method for removing waste solids from said belt.
At least one spray jet to inject airflow
The multi-stage apparatus for continuous wastewater filtration according to claim 1, wherein a belt is disposed on the belt . 9. The perforated belt in the second position
The multi-stage apparatus for continuous wastewater filtration of claim 1, passing through a water bath . 10. The multi-stage apparatus for continuous wastewater filtration according to claim 9, wherein the water in the tub is continuously displaced therefrom. 11. The method according to claim 11, wherein at least one ultrasonic generator is provided.
The multi-stage device for continuous wastewater filtration according to claim 9, provided submerged in a water bath . 12. The continuous wastewater filtration of claim 1, wherein the second tank further comprises a debris weir to remove free solids floating from the surface of the water contained therein. For multi-stage equipment. 13. is added to the first tank by the coagulant metering pump, said first tank precipitation in the wastewater
The multi-stage apparatus for continuous wastewater filtration according to claim 1, further comprising an impeller provided at a predetermined position. 14. The multi-stage apparatus for continuous wastewater filtration according to claim 1, further comprising a settling tank arranged to receive water already filtered by the belt. 15. The solid content already set by the settling tank.
Further comprising a fine sand filter for receiving the settled water,
15. A multi-stage apparatus for continuous wastewater filtration according to claim 14. 16. A step of: (a) feeding wastewater containing free solids to a first tank; (b) adding a coagulant to said wastewater; (c) said wastewater in said first tank. in the step of mixing the coagulant, by opening the steps of delivering into the second tank bottom inclined mixture is (d) generating, (e) a lower portion of the door, deposited from the second tank Periodically discharging solids; and (f) semi-clarified water overflows from an upper weir of the second tank and receives a flow of the semi-clarified discharged water at a first location. Arranging to drop onto a continuously driven, non-tensioned, perforated belt having a surface located at
Fine solids condensed on the surface for draining
To allow the passage of clarified water
Been sized, the belt forms a recess for holding a mass of water on the belt surface in a non-tensioned state, is in contact with (g) said belt, said belt and on its cake retained water and the motor of the belt to determine the combined weight of the control their speed as a function of said weight, whereby 1mm or less of the thickness of the fines consisting of fine solids condensed on Is formed on the surface of the belt
To be retained, thereby allowing the filtration capacity of the belt
Providing a load sensor to improve the following : (h) collecting water filtered by the movable belt; and (i) removing solids particles from surfaces and holes of the movable belt. A method for continuous wastewater filtration comprising: