JP2007237094A - Air float for collecting scum and scum collecting method using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air float for collecting scum which can separate water and scum as much as possible, and efficiently collect only the scum to perfectly remove it outside a system, and a scum collecting method using the air float. <P>SOLUTION: The air float for collecting scum comprises a frame-shaped float part 2 consisting of an air injection type float 4, and a net part 3 disposed so as to cover the frame surface of the frame-shaped float part 2. The float part 2 is made expandable and contractable by injection or discharge of air to or from the float 4. When it expands, the entire air float is made to float to the water surface by the buoyancy, and when it contracts, the entire air float is made to sink into water by the self-weight. In using the air float, air is exhausted to sink the air float to a prescribed depth below the water surface, and after passing a prescribed period of time in such a state, air is injected again to float the air float to the water surface. During the floating up, the net part stretched on the float part skims and collects scum floating on the water surface. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a scum recovery air float for scooping and recovering floating scum generated at a sewage treatment plant, wastewater treatment facility, and the like, and a scum recovery method using the scum recovery air float.

  For example, in sewage treatment plants, wastewater treatment facilities, etc., in sedimentation ponds, sewage reservoirs, and human waste digesters, film-like or bubble-like floating debris, so-called scum, is generated on the surface of the sewage. If the amount of this scum increases too much, it may generate a bad odor or adversely affect the purification process. Therefore, it is necessary to remove scum regularly or irregularly and collect it.

  Conventionally, as a method for collecting the scum, a method as shown in FIG. 6 has been employed (see Patent Document 1). That is, in the conventional scum recovery method, as shown in FIGS. 6A and 6B, for example, a hollow having a predetermined thickness so as to be orthogonal to the flow of sewage W slowly flowing down in the settling basin 51. A pipe 52 is provided so as to be able to rotate at a water surface height position of the sewage W, and a scum recovery hole 53 having a predetermined hole width is formed on the peripheral surface of the hollow pipe 52 along the axial direction.

  When the amount of scum S generated is small and there is no need for recovery, the rotational position of the hollow pipe 52 is set so that the scum recovery hole 53 faces upward as shown in FIG. When the scum S has accumulated to the extent that recovery is necessary, the hollow pipe 52 is rotated 90 degrees toward the scum side so that the scum recovery hole 53 faces the scum S as shown in FIG. Set. As a result, the scum S floating on the water surface flows into the scum recovery hole 53 together with the sewage W, and is discharged out of the system through the recovery pipe 54 connected to the end of the hollow pipe 52.

JP-A-11-128916 (all pages, all figures)

  However, in the case of the above-described conventional method, in order to collect the scum, the scum S must be put on the sewage W and poured into the scum collection hole 53, and only the scum S cannot be collected. For this reason, in the conventional processing system, actinomycetes other than the scum collected by the scum collecting device of FIG. 6 are currently returned to the pretreatment side, and could not be completely eliminated outside the system. .

  The present invention has been made in order to solve the above-described problem, and separates water and scum as much as possible, efficiently recovers only the scum and completely eliminates it out of the system. It is an object of the present invention to provide a float and a scum recovery method using the float.

  In order to achieve the above object, the present invention employs the following scum recovery air float. That is, the air float for scum recovery of the present invention comprises a frame-like float portion made of an air injection type float, and a net portion arranged so as to cover the frame surface of the frame-like float portion. The part can be freely expanded and contracted by injecting and discharging air into the air-injected float, and the entire air float floats on the water surface due to its buoyancy during expansion, and the entire air float sinks into the water due to its own weight during contraction. It is what I did. In addition, a mooring rope for mooring the air float at a fixed position during use can be provided. The net part can be exchangeable.

  Furthermore, in order to achieve the above object, the present invention employs the following scum recovery method. That is, the scum recovery method of the present invention uses the scum recovery air float, floats the scum recovery air float in a state of being inflated by injecting air on the water surface to be scum recovered, and then removes a predetermined amount of air. The scum recovery air float is submerged to a predetermined depth below the surface of the water, and after a predetermined time has passed in this state, air is again injected into the scum recovery air float to float to the water surface. The scum that floats on the surface of the water is scooped up and collected at the net part stretched on the part.

  According to the scum recovery air float and the scum recovery method of the present invention having the above-described configuration, during normal times when scum is not recovered, the air in the float portion is drawn out so that the entire air float is submerged below the water surface. At the time of recovery, air is injected into the float part to float the entire air float to the water surface. Thereby, only the scum is scooped up by the net part stretched on the frame surface of the float part, and the sewage is filtered by the net. For this reason, unlike the prior art, only the scum can be efficiently recovered from the sewage, and the recovered scum can be completely excluded from the system.

Embodiments of the present invention will be described below with reference to the drawings.
1 and 2 show an embodiment of an air float for collecting scum according to the present invention. 1A is a plan view of a scum recovery air float according to the embodiment, FIG. 1B is a right side view thereof, FIG. 1C is a front view thereof, and FIG. 2 is II-II in FIG. It is line sectional drawing.

  A scum recovery air float (hereinafter abbreviated as “air float”) 1 of the present invention includes a float portion 2 and a net portion 3 placed on the float portion 2. The float unit 2 generates buoyancy for sinking the entire air float 1 below the surface of the water, or for floating up to the surface of the water. The net part 3 scoops and collects the scum floating on the water surface at the net part when the air float 1 is lifted.

  The float portion 2 is formed by forming an air injection type float 4 having a cylindrical cross section or the like in a rectangular frame in plan view. The air injection type float 4 has a side surface at an appropriate position in the air injection type float 4. An air injection port (with a check valve) 5 for injecting air and an air discharge port 6 for extracting air from the air injection type float 4 are provided. This air injection type float 4 is made of a waterproof material (for example, a waterproof woven fabric, rubber, etc.) that can be freely inflated or deflated by injecting and discharging air.

  The net part 3 is a frame body 7 having a ladder shape in plan view, and a net 8 having a predetermined mesh width (for example, about 50 mesh) is pasted on the upper surface of the float part 2 by a fastener such as a rope 9. It is fixed. Further, mooring ropes 10 having a predetermined length for mooring the entire air float at a fixed position are attached to the four corners of the net portion 3. The net 8 may be a net or braided string or wire, or a net or punched hole in a metal plate or plastic plate. Furthermore, in order to be able to replace the net part 3 according to the difference or change in the properties of the scum generated in each unique facility, or the damage or deterioration of the net part, for example, the net part 3 can be attached to and detached from the float part 2. A flexible slide frame structure may be used, and a replaceable cartridge type may be used.

The air float 1 having the above configuration is used as shown in FIG. 3, for example.
First, prior to the start of use, as shown in FIG. 3A, an air supply compressor 11 is connected to the air inlet 5 of the float section 2, and an exhaust valve or an exhaust pump 12 is connected to the air outlet 6. Set so that air can be freely injected and discharged.

  After connecting the compressor 11 and the exhaust valve or the exhaust pump 12, the compressor 11 is operated to inject air into the air injection type float 4, and the air injection type float 4 is expanded. Then, the air float 1 is floated in the settling basin 51 in a state where the air injection type float 4 is inflated, and is moored by using the mooring rope 10 at an appropriate position in the settling basin 51, for example, a position closer to the downstream in the settling basin 51. To do. The mooring rope 10 also serves as a stopper for ensuring the fixed position of the air float 1 and preventing the air float 1 from sinking deeper than necessary. That is, although not shown in the drawings, usually, the bottom of the sedimentation basin 51 or the like is equipped with ancillary equipment such as a sludge scraper, so that the air float 1 does not touch and break. is there.

  When the exhaust valve or the exhaust pump 12 is opened in the moored state and the air in the air injection type float 4 is extracted, the air injection type float 4 is deflated, and the air float 1 gradually enters the sewage W by its own weight. It will sink. Then, as shown in FIG. 3 (b), the exhaust valve or the exhaust pump 12 is closed when it sinks to a predetermined depth regulated by the length of the mooring rope 10 (for example, about 5 to 30 cm from the water surface), and the air float 1 Is stopped at that depth. In this settling state, the air-injected float 4 is actually in a deflated state as much as the air has been removed, but in FIG. 3 (b) it remains inflated for ease of illustration. It is drawn.

  A weight may be hung from the bottom of the air float 1 in order to adjust the balance between buoyancy and its own weight. Further, the frame body 7 with the net 8 stretched may be made of a hollow pipe or the like, and sand or the like may be put in the pipe instead of the weight.

  When the sewage treatment of the sedimentation basin 51 proceeds and scum S is generated on the surface of the water as shown in FIG. To start. As a result, the air-injection float 4 swells, its buoyancy increases gradually, and the air float 1 rises toward the water surface.

  Then, the air float 1 scoops up the scum S floating on the water surface with the net 8 stretched on the upper surface of the float and lifts it together with the air float 1 during the ascent. Then, as shown in FIG. 4B, when the air float 1 completely floats on the surface of the water, the sewage lifted together with the scum S is spilled from the mesh of the net 8 and filtered. Only scum S (including impurities) remains.

  When only the scum S is scooped off by the net 8, for example, as shown in FIG. 5, the scum S on the net 8 is sucked by the vacuum device 13 or the like and sent to the dehydrator or dryer 14 and further dehydrated or dried to reduce the weight. After that, it is completely discharged out of the system. The dehydrated water may be discharged out of the system as it is, or may be returned to the settling basin 51 again. When returning to the sedimentation basin, it should be returned after removing anything that adversely affects water treatment, such as actinomycetes, without returning as it is. Note that a volume reduction device having a drying function may be arranged in place of the dehydrator 14 to reduce the amount of scum discharged out of the system.

  When the scum recovery process is completed as described above, the exhaust valve or the exhaust pump 12 is opened to evacuate the air from the air injection type float 4, and the air float 1 is again put into the sewage W as shown in FIG. Sink and prepare for the next scum collection process.

  In the scum recovery process, when there is a concern that the scum S collected in the sedimentation basin 51 flows out from the sewage discharge port of the sedimentation basin to the subsequent water treatment apparatus, as shown in FIGS. The scum overflow prevention net 15 may be attached to the sewage discharge port of the settling basin 51 to prevent the scum S from flowing out. The scum overflow prevention net 15 is desirably a replaceable cartridge type.

  As described above, according to the air float 1 of the present invention, water and scum can be separated as much as possible, and only the scum can be efficiently recovered.

  In the above-described embodiment, the net portion 3 for scooping the scum S is disposed on the upper surface side of the float portion 2, but may be disposed on the lower surface side. However, in this case, when the air float 1 is floated up to the water surface, the net 8 of the net portion 3 arranged on the lower surface of the float portion is still immersed in the sewage W. Then, the mooring rope 10 or the like may be used to pull up the entire air float 1 from the water surface by a predetermined height, thereby filtering the sewage on the net so that only the scum remains.

  Moreover, although the planar view shape of the air injection type float 4 was made into the rectangular frame body, it is not restricted to a treasure shape, It should be set as arbitrary planar view shapes according to the shape of the sedimentation basin etc. to be processed. Can do. Furthermore, the cross-sectional shape of the air-injection float 4 is not limited to a cylindrical shape, and may be an arbitrary cross-sectional shape such as a rectangular shape or an elliptical shape.

1 shows an embodiment of an air float for collecting scum according to the present invention, in which (a) is a plan view, (b) is a right side view thereof, and (c) is a front view thereof. It is the II-II sectional view taken on the line of Fig.1 (a). The example of the installation to the sedimentation basin of the scum collection | recovery air float is shown, (a) is a top view of a sedimentation basin, (b) is the longitudinal cross-sectional view. (A) (b) is explanatory drawing of scum collection | recovery operation | movement. It is a figure which shows the process example of a scum suction | inhalation. (A)-(c) is explanatory drawing of the conventional scum collection | recovery method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air float for scum collection 2 Float part 3 Net part 4 Air injection type float 5 Air inlet 6 Air outlet 7 Frame 8 Net 9 Rope 10 Mooring rope 11 Compressor 12 Exhaust valve or exhaust pump 13 Vacuum device 14 Dehydrator or Dryer 15 Scum overflow prevention net 51 Sedimentation basin W Sewage S Scum

Claims (4)

It consists of a frame-like float part made of an air injection type float and a net part arranged so as to cover the frame surface of the frame-like float part,
The float part can be freely expanded and contracted by injecting and discharging air into the air-injecting float, and when inflated, the entire air float floats on the water surface due to its buoyancy. An air float for collecting scum, characterized by being sinking.   The scum recovery air float according to claim 1, further comprising a mooring rope for mooring the air float at a fixed position during use.   The scum recovery air float according to claim 1 or 2, wherein the net portion is replaceable.   A scum recovery method using the scum recovery air float according to any one of claims 1 to 3, wherein the scum recovery air float inflated by injecting air is floated on a water surface to be scum recovered. Next, a predetermined amount of air is extracted and the scum recovery air float is submerged to a predetermined depth position below the surface of the water. After a predetermined time has elapsed in this state, air is again injected into the scum recovery air float to rise to the water surface. A scum collecting method comprising scooping up and collecting the scum floating on the water surface at the net portion stretched on the float portion during the ascent.

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