JP2005270900A - Lifting device for diffuser in aeration tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lifting device for a diffuser capable of stably lifting the diffuser in an aeration tank with a simple device. <P>SOLUTION: The diffuser 10 is provided on the bottom surface 2 of the aeration tank 1. The diffuser 10 is connected with a flexible riser tube 3 for supplying diffused air. The diffuser 10 is provided with an air bag 12, where air is supplied/discharged thereto/from through an air supply tube 13 branched from the riser tube 3. The amount of air in the air bag 12 is reduced or increased, thereby adjusting the acting buoyancy; as a result, the diffuser 10 is liftable through a space between the bottom surface 2 and a liquid level 15 in the aeration tank 1. In this time, the shape, size, and other structure of the aeration tank and diffuser are not limited specially. Moreover, the supply of air to the air bag 12 is possible by flowing the air for aeration, thereby enabling the lifting of the diffuser with this simple device. Furthermore, when a stationary frame 5 is provided in the diffuser 10, a workspace is secured in levitation, thus bringing about convenience. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a device for raising and lowering a diffused gas in an aeration tank.

  In general, aerobic treatment in which sludge is biologically treated with aerobic microorganisms is performed by providing a diffused gas along the bottom surface of the aeration tank in a horizontal state and sending air to the diffused gas. Aerated air is supplied into the aeration tank from the provided ejection holes for aeration.

  In the aeration tank that performs the aerobic treatment, if the treatment is continued, clogging or the like may occur in the diffused gas ejection holes, and smooth aeration may not be performed. For this reason, maintenance of diffused gas, such as cleaning an ejection hole, is needed regularly. However, if the water inside the tank is drained for this maintenance, the water treatment will stop during that time, so that this kind of aeration tank can be cleaned, inspected and replaced without draining conventionally. Further, an elevating device for raising the diffused gas from the tank bottom to the vicinity of the upper surface opening is provided.

  Conventionally, the lifting device is generally one that lifts the diffused gas with a wire. As the lifting mode, for example, as shown in FIG. 3, the diffused gas 20 in the aeration tank 1 is pulled with the wire 22. Therefore, the diffused gas 20 rotates from the horizontal state to the vertical state via the hinge 21 and is suspended by the wire 24 or the like in that state (for example, see Patent Document 1). Further, the air supply pipe communicating with the diffused gas from the outside of the tank is also used as a lifting member, and the air supply pipe can be rotated by a joint part via a swivel joint or the like, and the air supply pipe is swung (folded) via the joint part. Thus, there is one that can raise and lower the diffused gas connected to the lower end of the air supply pipe (for example, see Patent Document 2).

Also disclosed is a technique in which the diffused gas is made up of a synthetic resin or the like to reduce the weight, so that the diffused gas is raised from the bottom of the tank to the vicinity of the water surface by the buoyancy of the air supplied into the diffused gas. (For example, see Patent Document 3).
JP 2001-246394 A Japanese Patent Publication No. 50-23546 JP-A-53-144154

  However, in the lifting device described in Patent Document 1, as shown in FIG. 3, it is necessary to separately provide a lifting and winding mechanism such as a wire leading to the diffused gas 20 outside the aeration tank 1. Increase in size and complexity. An increase in size and complexity of the apparatus is not preferable because the apparatus is expensive and increases the cost burden, and is not preferable because maintenance frequency is further increased and maintenance becomes complicated.

  Furthermore, in the lifting device described in Patent Document 2, the air supply pipe that leads to the diffused gas has a complicated structure, and the movable space of the air supply pipe that swings through the joint portion can be sufficiently secured in the aeration tank. There must be. For this reason, this apparatus may not be used when the width of the aeration tank is narrow.

  Further, in the lifting device described in Patent Document 3, since the diffused gas is light, even when the diffused gas is operating at the bottom of the aeration tank, buoyancy is generated by the air supplied into the diffused gas and floats. Try to go up. For this reason, in order to stabilize the diffused gas at the bottom of the tank, it is necessary to provide a means for preventing the floating from being separately provided on the diffused gas and the tank bottom. It must be wider than necessary. Furthermore, in order to produce a stable buoyancy that can raise the diffused gas, the shape is limited, and the diffused gas must be supplied with a large amount of air and maintained inside. The volume is too large compared to the aeration capacity. Moreover, since the supplied air is always discharged from the ejection holes, there is also a problem that the buoyancy during ascent is not stable.

  Accordingly, an object of the present invention is to make it possible to stably move up and down the diffused gas with a simple device and to prevent the shape and structure of the diffused gas from becoming large.

  In order to solve the above-described problems, the present invention attaches an airbag to the diffused gas and causes buoyancy to act on the diffused gas. Since the diffused gas moves up and down in the aeration tank by increasing or decreasing the buoyancy, it does not require large and complicated lifting equipment.

  Specifically, a diffused gas is provided on the bottom surface of the aeration tank, a flexible riser pipe for supplying diffused air is connected to the diffused gas, and an airbag is provided in the diffused gas. By supplying and discharging air, the diffused gas can be raised and lowered between the bottom surface and the liquid surface of the aeration tank.

  In this way, the buoyancy acting on the diffused gas can be adjusted by increasing or decreasing the amount of air intervening in the airbag. Therefore, if the buoyancy is increased, the diffused gas will rise and the buoyant force will be increased. Since the diffused gas sinks and stabilizes on the bottom of the aeration tank due to its own weight, there is no need to provide fixing means or the like on the bottom of the diffused gas and the aeration tank. Moreover, since there is no particular limitation on the shape and size of the aeration tank or the shape, size, and other configurations of the aeration tank in order to provide this lifting device, the lifting device using this airbag can be aerated by any configuration. It can be used for tanks and diffused gas.

  The air supply / discharge to the airbag may be performed via an air supply pipe branched from the flexible riser pipe and connected to the airbag. In this way, the air supplied from the air supply means (blower, etc.) is supplied to the diffused gas via the riser pipe when the aeration tank is operating, and to the airbag via the air supply pipe during maintenance. Since it can be selectively supplied to both of them, it is possible to use a simple device that also serves as an air supply means by diverting aeration air without adding another air supply means for the airbag. It is possible to raise and lower the diffused gas.

  Further, the configuration of the diffused gas may be that a diffuser tube is attached on a stationary frame, and the airbag may be provided below the stationary frame. In this way, when the diffused air rises, the stationary frame is also located on the water surface, so that it is possible to walk on the frame. For this reason, it is convenient because it is not necessary to newly provide a work space for cleaning, checking, replacing, or the like on the aeration tank.

  Since the present invention is configured as described above, the diffused gas can be moved up and down stably with a simple device, and the shape and structure of the diffused gas are not increased.

One embodiment is shown in FIGS. The device for raising and lowering the diffused gas in the aeration tank of this embodiment is
A diffused gas 10 consisting of a stationary frame 5 placed on the bottom surface 2 in the aeration tank 1 and an air diffuser pipe 6 stretched over the frame 5, and the bottom surface 2 and the liquid surface 15 in the aeration tank 1. It is a device that moves up and down.

  As shown in FIG. 1, a header pipe 3 ′ drawn from the lower end of the riser pipe 3 is fixed on the stationary frame 5, and a diffuser pipe 6 is appropriately branched from the header pipe 3 ′, and each pipe 3 ′, 6 is fixed at a height of a predetermined distance from the upper surface of the stationary frame 5 through a pipe support or the like. The diffuser pipe 6 is provided with a small-sized diffuser hole 11 so that the air fed through the riser pipe 3 is discharged into the aeration tank 1. Below the stationary frame 5, the airbag 12 is attached over the entire lower surface. The airbag 12 is made of a bag made of resin or the like, and is inflated by being filled with air, and the air is maintained when the filling port is closed. In addition, although the free material can be used for the stationary frame 5, in order to reduce the resistance of water when the diffused gas 10 moves up and down, a mesh-like material such as grating is preferable.

  The riser pipe 3 is connected to an air supply means (not shown) such as a blower provided outside the aeration tank 1 via an air pipe 16, and the riser pipe valve 7 is opened to open the riser pipe from the air supply means. When air is fed into the air pipe 3, air is supplied from the header pipe 3 'to the diffuser pipe 6 so that the water in the aeration tank 1 is aerated. At this time, the air bag 12 is not filled with air, and even if it is filled, it has a small amount of air that does not produce buoyancy that raises the dead weight of the diffused gas 10. You can think of it. For this reason, the diffused gas 10 is in a state of being stably placed near the bottom surface 2 of the aeration tank 1.

  When it is desired to float the diffused gas 10, the riser pipe valve 7 is closed, the air supply means is once stopped, and then the airbag valve 8 shown in the figure is opened. At this time, the air vent valve 9 is closed.

  When the air supply means is activated again, air is supplied from the air supply means to the air supply pipe 13 via the air pipe 16, and the airbag 12 is filled with air. When the amount of the filled air reaches a predetermined amount that generates buoyancy in the diffused gas 10, the air supply means is stopped, and if the airbag valve 8 is closed, the diffused gas 10 is liquid before and after the operation. Ascend toward the surface 15. At this time, since the riser tube 3 has flexibility, the riser tube 3 bends and follows as the diffused gas 10 rises, and does not obstruct the raising and lowering.

  When the diffused gas 10 rises to the vicinity of the liquid level 15, the hook 4 provided in the diffused gas 10 and the hook 14 provided near the upper opening of the aeration tank 1 are locked so that the diffused gas 10 does not move easily. To. If locked in this way, it is possible to prevent the diffused gas 10 floating on the liquid surface 15 from shaking and to stabilize the work such as maintenance, and in the unlikely event that the air in the airbag 12 leaks out. Even if the buoyancy becomes insufficient, the diffused gas 10 does not sink, so it is safe.

  When maintenance of the diffused gas 10 is completed and the diffused gas 10 is operated again, the hooks 4 and 14 are first removed in order to sink the diffused gas 10. Next, the air vent valve 9 provided in the discharge pipe 17 branched from the air supply pipe 13 is slightly opened. This is to prevent the diffused gas 10 from abruptly sinking.

  When the diffused gas 10 sinks and reaches the bottom surface 2 of the aeration tank 1, the air vent valve 9 is closed, and thereafter, the work of sending air to the diffuser pipe 6 through the riser pipe 3 is performed. At this time, it is desirable to provide a known shock absorber for absorbing shock between the diffused gas 10 and the bottom surface 2 of the aeration tank 1. This is because the impact is reduced when the diffused gas 10 lands on the bottom surface 2.

  In this embodiment, the riser tube 3 having the equivalence is used. However, the present invention is not limited to this embodiment, and a rigid riser tube 3 having no flexibility may be used. In this case, it is only necessary to maintain the connection between the riser pipe 3 and the air pipe 16 as the diffused gas 10 moves up and down. Further, the air in the airbag 12 may be exhausted by the air supply means connected to the air pipe 16 without providing the exhaust pipe 17 and the air vent valve 9 used in this embodiment.

  Further, in the present embodiment, the airbag 12 is made of a bag made of resin or the like. For example, another embodiment of the airbag 12 is a rigid body having a downward concave air reservoir. The airbag 12 may be configured. In this configuration, the downward concave air reservoir can be secured so that air does not escape upward and laterally, so that the same effect as the bag-like airbag 12 can be obtained. Moreover, since the lower surface is open | released in the water in the aeration tank 1, release | releasing of the air of an air reservoir part is comparatively easy.

  In addition, the airbag 12 may be attached below the stationary frame 5 as in this embodiment, or depending on the case, above the stationary frame 5 or above the header pipe 3 ′ or the air diffuser pipe 6 or the like. The air bag 12 may be directly attached regardless of the downward direction, and the attachment position in the vertical direction with respect to the diffused gas 10 of the airbag 12 is arbitrary. However, the mounting position of the airbag 12 in the plane direction with respect to the diffused gas 10 is desirably the entire plane direction of the diffused gas 10 or symmetrically disposed with respect to the center position (the center of gravity in the plane direction). . This is because the diffused gas 10 can float and sink while moving in parallel along the bottom surface 2 of the aeration tank 1.

  In this embodiment, the stationary frame 5 is provided in the diffused gas 10 so that a working space can be secured when the diffused gas 10 floats on the liquid surface 15. However, the stationary frame 5 is omitted if necessary. May be. Moreover, the diffused gas 10 may adopt the one configured from the diffuser tube 6 as in this embodiment, or other types having a similar aeration function configured by a diffuser panel or the like, for example. A diffused gas 10 may be employed.

Perspective view of one embodiment Cut front view of the same embodiment Cutting front view of conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aeration tank 2 Aeration tank bottom face 3, 23 Riser pipe 3 'Header pipe 4,14 Hook 5 Stationary frame 6 Air diffuser pipe 7 Riser pipe valve 8 Air bag valve 9 Air vent valve 10, 20 Air diffuser 11 Air diffuser hole 12 Air Bag 13 Air supply pipe 15 Liquid level 16 Air pipe 17 Discharge pipe

Claims (3)

  A diffused gas 10 is provided on the bottom surface of the aeration tank 1, a flexible riser pipe 3 for supplying diffused air is connected to the diffused gas 10, and an airbag 12 is provided in the diffused gas 10. An apparatus for raising and lowering the diffused gas in the aeration tank, wherein the diffused gas 10 can be raised and lowered between the bottom surface 2 and the liquid level 15 of the aeration tank 1 by supplying and discharging air.   The supply and discharge of air to and from the airbag 12 is performed via an air supply pipe 13 that branches from the flexible riser pipe 3 and is connected to the airbag 12. lift device.   The aeration tank according to claim 1 or 2, wherein the diffused gas (10) has a diffuser pipe (6) mounted on a stationary frame (5), and the airbag (12) is provided below the stationary frame (5). For raising and lowering the diffused gas.

Images