Sedimentation and sedimentation separation apparatus and sedimentation and sedimentation separation method

Abstract

To provide an apparatus for sand settlement and sedimentation separation and a method for sand settlement and sedimentation separation.SOLUTION: An apparatus for sand settlement and sedimentation separation includes: a cylindrical tank 11 which has a hopper part 11a; an inner cylinder 13 which is inserted and arranged in a vertical axial direction in the cylindrical tank 11 and is rotated and driven by an external driving device 12; spiral separators 14 which are arranged around the inner cylinder 13, have therebetween a conical spiral plate 14b in which a spiral flow passage 14a is formed, and separate sludge 31b in sewage 31a; a sewage introduction part 15 which introduces the sewage 31a containing organic matter and earth and sand into the inner cylinder 13; a sediment collection part 16 which is provided at a lower part of the hopper part 11a and collects sediment 21 settled by its own weight when the introduced sewage 31a falls; a sludge collection passage 20 which is formed in an inner periphery of the hopper part 11a and collects the sludge 31b containing organic matter that falls from an outer peripheral edge 14c of the conical spiral plate 14b; and a sludge discharge pipe 20a which discharges the sludge 31b from a lower end side of the sludge collection passage 20 to the outside.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a sand sedimentation and separation device and a sand sedimentation and separation method.

Background Art

[0002] In sewage treatment to date, in sand sedimentation tank facilities (sand sedimentation, sand collection, sand lifting, sand washing), primary treatment sedimentation tank facilities, and gravity thickening facilities in sludge thickening facilities, separation facilities by gravity sedimentation have been required (Patent Document 1).

[0003] Therefore, conventional facilities have a large floor area and require a water tank made of a large concrete structure, resulting in high civil engineering costs and equipment costs, and also requiring time and cost for maintenance.

[0004] In addition, due to the frequent floods expected due to recent climate change and the huge earthquakes expected to occur within 30 years, when the sewage treatment plant function is lost, the construction of technology applicable to temporary simple treatment facilities is also desired.

[0005] The sand sedimentation tank facilities in sewage treatment to date are sand scraping and lifting facilities using buckets or sand collection and lifting facilities using high-pressure pumps. Since the machines and piping facilities are complex and costly, the development of facilities with a simple configuration is desired.

[0006] In addition, since a large amount of sewage is treated, a large civil engineering structure is required, resulting in high civil engineering costs. Therefore, low-cost sewage treatment technology is required when reconstructing facilities. Furthermore, due to the shortage of maintenance personnel caused by the decrease in the working population, labor-saving in operation and maintenance is required.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

[0008] This invention was made to solve the problems of the prior art, and its objective is to provide a sedimentation and sludge separation apparatus and a sedimentation and sludge separation method that can efficiently separate sediment and sludge within a single apparatus. [Means for solving the problem]

[0009] To achieve this objective, the first invention is: A cylindrical tank having a hopper section that tapers downwards, An inner cylinder is inserted and positioned in the vertical axis direction within the cylindrical tank and is rotationally driven by an external drive device, A spiral separator is provided, which has multiple conical spiral plates arranged around the inner cylinder, with spiral flow channels formed between them, and separates the sludge from the wastewater. The cylindrical tank includes a wastewater introduction section for introducing wastewater containing organic matter and sediment, A sediment recovery unit is provided at the lower part of the hopper section to recover sediment that settles due to its own weight when the introduced wastewater falls, A sludge recovery passage is formed along the hopper section and collects sludge containing organic matter that falls from the outer edge of the conical spiral plate, A key feature of this sedimentation and sedimentation separation device is the inclusion of a specific feature.

[0010] The second aspect of the present invention is characterized in that, in the first aspect of the present invention, the sludge recovery passage has an opening that hangs vertically downward from the outer peripheral edge of the conical spiral plate, or is located on the axis of rotation of the inner cylinder. separation It was made into a device.

[0011] The third aspect of the present invention is, in the first or second aspect of the present invention, an overflow section provided on the upper inner side of the cylindrical tank for overflowing separated water, which contains sludge containing some organic matter that has floated near the liquid surface, An overflow water discharge pipeline for discharging the separated water that overflows in the overflow section to the outside as discharged water, The sand sedimentation and settling system is characterized by comprising a sludge discharge pipeline that discharges sludge to the outside from the lower end side of the sludge collection passage. separation It was made into a device.

[0012] The fourth aspect of the present invention relates to the first or second aspect of the present invention, The sand sedimentation and sedimentation system is characterized by comprising a microbubble generating device that ejects microbubbles from a nozzle into the cylindrical tank. separation It was made into a device.

[0013] The fifth aspect of the present invention is: The first or second sand sedimentation / sedimentation separation apparatus of the present invention Using, As the introduced wastewater falls as a downward flow, it is collected as sediment in the sediment collection section, The sedimentation and sedimentation separation method is characterized by the recovery of the sediment, the reversal of the upward flow, the rotation of the spiral separator separating the sludge containing organic matter from the separated water, and the settling of the sludge containing organic matter into the sludge recovery passage for collection. The sixth aspect of the present invention is, in the fifth aspect of the present invention, The sedimentation and sedimentation separation method according to claim 5 is characterized by ejecting fine bubbles from an ejection nozzle into the cylindrical tank to wash away organic matter contained in the sediment. [Effects of the Invention]

[0014] According to the present invention, when treating sewage, both sand sedimentation and sludge treatment can be separated in a single device, thus saving space in the facility. Furthermore, it can also function as a temporary treatment for sand sedimentation and sedation in the event of a disaster. [Brief explanation of the drawing]

[0015] [Figure 1] This is a partially cutaway perspective view showing a first embodiment of the sand sedimentation apparatus of the present invention. [Figure 2] This is a schematic diagram showing a first embodiment of the sand sedimentation apparatus of the present invention. [Figure 3] It is a schematic diagram of the inside of the sand and sediment settling device of the present invention. [Figure 4] It is a schematic diagram showing a second embodiment of the sand and sediment settling device of the present invention.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, an embodiment of the present invention will be described. Note that this embodiment is merely one embodiment of the present invention and is not to be construed as being in any way limiting, and design changes can be made as appropriate within the scope of the present invention. 「First Embodiment」

[0017] FIG. 1 is a partially cut-away perspective view of the sand and sediment settling device of the first embodiment. FIG. 2 is a schematic diagram of the sand and sediment settling device. FIG. 3 is a schematic diagram of the inside of the device. As shown in FIGS. 1 and 2, the sand and sediment settling device 100A of this embodiment includes a cylindrical tank 11 having a vertical hopper portion 11a that gradually tapers downward at the lower part, an inner cylinder 13 disposed in the cylindrical tank 11 and rotationally driven by an external drive device 12, a plurality of conical spiral plates 14b disposed around the inner cylinder 13 with a spiral flow path 14a formed therebetween, a spiral separator 14 that separates sludge 31b containing organic matter from sewage 31a into separated water 31c, a sewage introduction portion 15 that introduces sewage 31a containing organic matter and sediment into the inside of the inner cylinder 13, a sand collection portion 16 provided at the lower part of the hopper portion 11a that collects sand 21 that has settled by its own weight when the introduced sewage 31a descends, a sand transfer device 17 that transfers the sand 21 collected by the sand collection portion 16 to the outside, a sludge collection passage 20 formed along the inner peripheral surface of the hopper portion 11a that collects sludge containing organic matter falling from the outer peripheral edge portion 14c of the conical spiral plate 14b, and a sludge discharge pipe 20a that discharges sludge 31b to the outside from the sludge collection passage 20 on the lower end side of the hopper portion 11a.

[0018] The cylindrical tank 11 is a vertical cylindrical water tank into which wastewater 31a is introduced, with a hopper section 11a integrally formed on its lower side, and is installed on an installation frame (foundation, etc.) not shown. The material can be steel plate or concrete, and is selected appropriately depending on the installation location and size, and is not limited to any particular material.

[0019] The inner cylinder 13 is rotationally driven by an external drive device 12, and is rotated at a low speed. The rotational speed of the inner cylinder 13 is, for example, 0.5 to 5 revolutions per minute, more preferably 1 to 3 revolutions per minute.

[0020] In this embodiment, wastewater 31a is introduced through an introduction section 15 inserted from the lower part of the inner cylinder 13 upwards. However, the present invention is not limited to this, and wastewater 31a may also be introduced from the upper part of the inner cylinder 13. In this embodiment, the introduction tip 15a of the wastewater introduction section 15 is installed above the uppermost mounting position of the conical spiral plate 14b of the spiral separator 14, but this is not limited to this.

[0021] Here, wastewater 31a refers to wastewater that includes, for example, domestic wastewater flowing into sewers, sediment recovered in sedimentation basins from rainwater, dredged sludge accumulated in pipeline facilities, separated sand separated by liquid cyclones from sedimentation basin sludge and human waste / septic tank sludge, and dredged sediment from construction sites, rivers, coastlines, lakes, etc.

[0022] The wastewater 31a ejected from the inlet 15a of the wastewater inlet section 15 is discharged to the outside as treated water 31e in the same amount as the amount introduced. As a result, the introduced wastewater 31a is drawn into the inner cylinder 13 and then pulled towards the bottom, becoming a downward flow F1 that descends along the inside of the inner cylinder 13. During this descent, heavier impurities such as sand settle into the sediment collection section 16 at the bottom due to their own weight, becoming sediment 21.

[0023] Here, the spiral separator 14 is equipped with a conical spiral plate 14b with a spiral channel 14a formed in between, and since the conical spiral plate 14b rotates in accordance with the inflow rate, the shape of the cylindrical tank 11 is circular.

[0024] This spiral separator 14 rotates a conical spiral plate 14b, on which a spiral channel 14a is formed, around a rotation axis perpendicular to its axis, using a rotary drive device 12.

[0025] By forming a spiral separator 14 with a helical channel 14a without folds, organic matter does not clog, and the sludge 31b containing organic matter is collected along the slope toward the outer edge 14c side along with the settling fine sand 21a. The inclination angle of this conical spiral plate 14b is preferably, for example, 45° or more and less than 90° with respect to the horizontal, preferably around 60°. The spacing between the conical spiral plates 14b in the group of conical spiral plates (rotating inclined plates) is preferably, for example, 75 to 150 mm.

[0026] The rotation of the spiral separator 14 causes a portion of the downward flow F1 passing through the lower end 13a side of the inner cylinder 13 to become a reverse flow F2. This reverse flow F2 becomes an upward flow F3 due to the rotation of the conical spiral plate (rotating inclined plate) 14b and rises to the liquid surface.

[0027] As this upward flow F3 rises, the sludge (including organic matter) 31b in the wastewater 31a is separated on the back and front sides of the conical spiral plate (rotating inclined plate) 14b, and as it rotates, it moves from the surface of the conical spiral plate (rotating inclined plate) 14b towards the outer peripheral edge 14c of the end, and falls and drains from the outer peripheral edge 14c as sludge 31b.

[0028] In other words, as shown in the schematic diagram of the inside of the sedimentation and settling apparatus in Figure 3, the rotation of the conical spiral plate 14b of the spiral separator 14 causes the sludge particles 31b to separate from the surface side. As the separated sludge 31b falls through the drop passage 11d formed between the inner wall 11a and the outer edge 14c of the tank, a gentle shear force acts between the inner wall 11e and the outer edge 14c, promoting the concentration of the falling sludge 31b.

[0029] The separated water 31c, from which sludge 31b has been separated from wastewater 31a, rises to the liquid surface side of the cylindrical tank 11 and overflows the overflow section 18 installed near the liquid surface. The overflow water 31d that exceeds the overflow section 18 is discharged to the outside as treated water 31e via the overflow water discharge pipeline 18a.

[0030] The overflow section 18 is formed along the inner circumferential surface of the upper part of the cylindrical tank 11, and temporarily stores the overflow water 31d that flows over it, before discharging it to the outside as treated water 31e via the overflow water discharge pipeline 18a. Sludge and other debris accumulate inside the overflow section 18, so it is collected and removed periodically.

[0031] Alternatively, the wastewater may be discharged directly to the outside without installing an overflow section 18. Furthermore, the overflow section 18 may be installed in at least one location.

[0032] The sediment recovery section 16 is an area for temporarily recovering sediment 21. The recovered sediment is then transported by a sediment transfer device 17, and driven water 17a, such as high-pressure water, is used to discharge sediment contaminants 17c to the outside via a sediment contaminant discharge pipeline 17b.

[0033] According to the sand sedimentation and separation device 100A of this embodiment, the wastewater 31a introduced into the inner cylinder 13 becomes a downward flow F1 after introduction, and during this downward flow, the large sand particles in the wastewater 31a settle as sediment 21 towards the sediment recovery section 16.

[0034] Subsequently, as the wastewater 31a passes near the lower end 13a of the inner cylinder 13, a portion of the downward flow F1 of the wastewater 31a reverses to become a reverse flow F2, which rises as an upward flow F3, synchronized with the conical spiral plate 14b rotating within the spiral channel 14a of the spiral separator 14. As this upward flow F3 rises, the rotation of the spiral separator 14 separates the sludge 31b containing organic matter from the wastewater 31a, resulting in separated water 31c.

[0035] The spiral separator 14 separates the organic matter and sludge 31b, which consists of fine sand, contained in the wastewater 31a. The separated water 31c, from which the sludge 31b has been separated, rises due to the rotational action of the spiral separator 14, and this rising water passes over the overflow section 18 to become overflow water 31d, which is then discharged to the outside as treated water 31e. Since the discharged treated water 31e has had the fine sand and organic matter separated, it can reduce the load on the treatment facility installed downstream of the sand settling / sedimentation unit 100A.

[0036] In this way, when the spiral separator 14 rotates, an upward flow F3 is generated, and during this upward movement, the solid sludge 31b falls and is separated as separated water 31c, thereby obtaining an effective settling capacity due to rotation. In other words, the fall of the sludge 31b due to the rotation of the spiral separator 14 is like the settling of an umbrella being slowly swung around. Therefore, when the sludge 31b falls through the drop passage 11d formed between the inner wall 11a and the outer edge 14c of the tank, the sludge 31b does not simply fall in the vertical axis direction as is, but rather the sludge 31b is concentrated by shear force as it falls into the sludge recovery passage 20, thereby improving the concentration effect of the sludge 31b.

[0037] Furthermore, the sludge 31b that falls from the outer peripheral edge 14c of the conical spiral plate 14b of the spiral separator 14 falls into the sludge recovery passage 20, which has an opening 20b at a position hanging down from the outer peripheral edge 14c of the conical spiral plate 14b, and accumulates as sludge on the lower end side of this passage. This sludge 31b is discharged to the outside as sludge 31b from the sludge discharge pipeline 20a via the sludge transfer pump P.

[0038] In other words, the sludge recovery passage 20 is formed between the hopper section 11a and the hopper passage 11b installed inside it, and its opening 20b is located at a position that hangs down in the vertical axis direction from the outer peripheral edge 14c of the conical spiral plate 14b. As a result, the fallen sludge 31b is reliably collected in the sludge recovery passage 20 and is prevented from flowing into the sediment recovery section 16.

[0039] The sand and sedimentation separation device 100A according to this embodiment can separate both sand 21 and sludge 31b, possessing the function of separating both, thus enabling space-saving of the equipment. Furthermore, it can also function as a temporary treatment for sand and sediment in the event of a disaster.

[0040] In recent years, the cost of civil engineering structures has been rising, but by realizing a grit chamber and a sedimentation tank within the same facility, cost and space savings can be achieved. Normally, the sediment discharged from a grit chamber is treated as industrial waste after passing through washing equipment. A typical grit chamber is rectangular and equipped with facilities for accumulating the sand, but this can also be omitted, thereby reducing treatment costs.

[0041] Conventional sedimentation tanks require equipment to concentrate the settled sludge in a subsequent stage. However, with the sand and sedimentation separation device 100A according to this embodiment, sludge 31b concentrated to approximately 3-4% by weight can be discharged. Therefore, cost savings can be achieved.

[0042] In this embodiment, the sedimentation and sedimentation separation method using the sedimentation and sedimentation separation device 100A involves the following process: when wastewater 31a introduced from the wastewater inlet 15 falls as a downward flow F1 inside the inner cylinder 13, it is collected as sediment 21 by gravity in the sedimentation and sedimentation recovery section 16. The upward flow F3, which reverses after the collected sediment 21 has fallen, rotates the spiral separator 14 to separate the sludge 31b containing organic matter from the separated water 31c. The sludge 31b containing organic matter is then allowed to settle by gravity and collected in the sludge recovery passage 20. Thus, this method allows for the separation of sediment and sedimentation in a single device, and each can be recovered within a single device. "Second Embodiment"

[0043] Figure 4 shows a second embodiment of the present invention, which is another form of the sand sedimentation apparatus. The sand sedimentation separation apparatus 100B according to this embodiment is equipped with a microbubble generator 42 that ejects microbubbles 41a from an ejection nozzle 41 provided in a cylindrical tank 11. Since the other configurations and effects are the same as in the first embodiment, the description of the first embodiment will be used as a reference, and a detailed explanation will be omitted here.

[0044] The size of the microbubbles 41a generated by the microbubble generator 42 is, for example, 1 mm or less, and to enhance the cleaning effect, it is, for example, 0.01 to 0.5 mm. If the size exceeds 1 mm, bubbles will not adhere easily to organic matter, and the rate at which the bubbles rise will increase, causing upward flow deviation and reducing the separation efficiency and the recovery rate of soil and sediment.

[0045] According to the sedimentation and sedimentation separation apparatus 100B of this embodiment, fine bubbles 41a are ejected from the ejection nozzle 41 into the cylindrical tank 11 to wash away organic matter contained in the sediment 21. These fine bubbles 41a can separate the sediment and organic matter in the sediment. Moreover, by attaching the fine bubbles 41a to the organic matter, the buoyancy of the organic matter is increased, and the separation of organic matter from sediment in the spiral separator 14 can be improved. [Industrial applicability]

[0046] This invention is applicable to all types of sand settling and sedimentation equipment. [Explanation of symbols]

[0047] 100A, 100B Sedimentation and Separation System 11a Hopper section 11 Cylindrical tank 12 Drive unit 13 Inner cylinder 14a Spiral channel 14b Conical spiral plate 14c Outer edge 14 Spiral Separator 15. Wastewater inlet 16. Sedimentation Recovery Section 17 Sand transfer device 18 Overflow section 18a Overflow water discharge pipe 20 Sludge collection passage 20a Sludge discharge pipeline 21 Sediment 31a Wastewater 31b Sludge 31c Separated water 31d Overflow water 31e Treated water 41 Spray nozzle 41a Microbubbles 42 Microbubble Generator F1 downdraft F2 reverse flow F3 Upward Flow

Claims

1. A cylindrical tank having a hopper section that tapers downwards, An inner cylinder is inserted and positioned in the vertical axis direction within the cylindrical tank and is rotationally driven by an external drive device, A spiral separator is provided, which has multiple conical spiral plates arranged around the inner cylinder, with spiral flow channels formed between them, and separates the sludge from the wastewater. The cylindrical tank includes a wastewater introduction section for introducing wastewater containing organic matter and sediment, A sediment recovery unit is provided at the lower part of the hopper section to recover sediment that settles due to its own weight when the introduced wastewater falls, A sludge recovery passage is formed along the hopper section and collects sludge containing organic matter that falls from the outer edge of the conical spiral plate, A sedimentation and sedimentation separation device characterized by the inclusion of a sedimentation and sedimentation system.

2. The sludge recovery passage is characterized in that its opening is located at a position where it hangs down in the vertical axis direction from the outer peripheral edge of the conical spiral plate, or on the side of the rotational axis direction of the inner cylinder, as described in claim 1.

3. An overflow section is provided on the upper inner side of the cylindrical tank, which allows separated water, containing some organic matter that has floated to the surface of the liquid, to flow over. An overflow water discharge pipeline for discharging the separated water that overflows in the overflow section to the outside as discharged water, A sludge discharge pipeline that discharges sludge to the outside from the lower end side of the sludge collection passage, A sand sedimentation and separation apparatus according to claim 1 or 2, characterized by comprising the following:

4. The sand sedimentation and separation apparatus according to claim 1 or 2, characterized in that it is equipped with a microbubble generating device that ejects microbubbles from an ejection nozzle into the cylindrical tank.

5. Using the sand sedimentation and separation apparatus described in claim 1 or 2, As the introduced wastewater falls as a downward flow, it is collected as sediment in the sediment collection section, A sedimentation and sedimentation separation method characterized in that the sediment is collected, the reversed upward flow separates the sludge containing organic matter from the separated water by the rotation of the spiral separator, and the sludge containing organic matter is allowed to settle and collected in the sludge collection passage.

6. The sedimentation and sedimentation separation method according to claim 5, characterized in that fine bubbles are ejected from a nozzle into the cylindrical tank to wash away organic matter contained in the sediment.

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