JP2005095767A - Flow straightening member of sewage treating tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the flow straightening member of a sewage treating tank, by which the velocity component of the water to be conveyed from an underwater mixer in the rotational direction of the water is converted smoothly into the linear velocity component along the bottom surface of the sewage treating tank so that the circulation efficiency in the sewage treating tank is improved. <P>SOLUTION: The underwater mixer 12 is suspended downward in the sewage treating tank 11 at the position higher than the bottom surface of the sewage treating tank. The flow straightening member 10 is fixed to the bottom surface of the sewage treating tank 11 and arranged just under the underwater mixer 12. The flow straightening member 10 is composed of an almost conical projection 17 projecting upward and four guide blades 18 arranged almost radially in a plane view on the inclined plane of the projection 17. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rectifying member installed in a sewage treatment tank.

  2. Description of the Related Art Conventionally, a sewage treatment apparatus is known in which an axial flow pump or a diagonal flow pump is installed downward in a sewage treatment tank in a sewage treatment plant, a water storage, or the like. In this kind of sewage treatment apparatus, a circulating flow is generated in the entire sewage treatment tank when the pump conveys the sewage downward. Thereby, a water flow can be generated even near the bottom surface of the sewage treatment tank, and sedimentation of solid matter can be prevented. In addition, efficient sewage treatment can be performed without retaining sewage in the sewage treatment tank.

  By the way, the water conveyed downward from the pump once collides with the bottom surface of the sewage treatment tank, and then flows laterally along the bottom surface. Therefore, the flow direction of the water conveyed downward from the pump is abruptly changed near the bottom surface. Then, in order to smooth the direction change of a water flow, providing a rectifying member in the bottom face of a sewage treatment tank is proposed.

For example, as shown in FIG. 8, an apparatus is known in which a conical protrusion 101 is provided on the bottom surface of a sewage treatment tank 102 (see, for example, Patent Document 1). In the apparatus, the flow of water is smoothed by changing the direction of the water conveyed downward from the pump 100 along the protrusions 101.
JP 2003-181267 A

  However, the flow of water conveyed from the axial flow or mixed flow pump 100 is actually a spiral flow, not a simple downward flow. In the above apparatus, although the downward water flow can be changed in the horizontal direction, the swirl flow 103 from the pump 100 cannot be converted into a linear flow along the bottom surface.

  That is, the flow of water conveyed from the pump 100 includes not only a downward speed component along the axial direction of the pump 100 but also a rotational speed component. However, the conical protrusion 101 can convert the downward component into the horizontal component, but cannot convert the rotational component into the linear component. As a result, the conventional apparatus has not been able to fully utilize the rotational direction component of the water flow.

  The present invention has been made in view of such points, and the object of the present invention is to change the speed component in the rotation direction of the water conveyed from the pump into a linear speed component along the bottom surface of the sewage treatment tank. By smoothly converting, the circulation efficiency of the sewage treatment tank is improved.

  The rectifying member according to the present invention is a rectifying member that guides the flow of water in the sewage treatment tank, and in the sewage treatment tank, an axial-flow or mixed-flow submersible pump is located above the bottom of the tank. Installed in the downward direction. And the rectification | straightening member which concerns on this invention is provided with the some guide blade extended in planar view substantially radially, and is arrange | positioned directly under the said submersible pump.

  Thereby, the water conveyed downward from the submersible pump collides with the rectifying member located directly below the pump. Since the rectifying member is provided with a plurality of guide vanes extending substantially radially in a plan view, the water flow from the pump is guided by the guide vanes. As a result, the swirl direction component of the water flow is converted into a component in a radially expanding direction, and the linear component of the water flow increases. Therefore, the water from the pump flows smoothly in a substantially radial manner in plan view. Moreover, sewage circulates smoothly throughout the sewage treatment tank.

  In addition, substantially radial as referred to in the present specification means a state in which it is spread radially when viewed as a whole. In other words, it means a state of spreading from the center side toward the outside. Therefore, it is not necessary for all or part of the blades to be radial in a strict sense. Other shapes that spread outwardly, such as so-called spiral shapes, are also included in a substantially radial manner.

  The rectifying member is preferably fixed to the bottom surface of the sewage treatment tank.

  As a result, the swirl direction component of the water flow is converted into a component that spreads radially along the bottom surface of the sewage treatment tank. Therefore, the speed of the water flow along the bottom surface of the sewage treatment tank is increased, and sedimentation of solid matter can be more effectively prevented.

  The rectifying member may be attached to the submersible pump through a frame that is open at least on the side.

  Thus, since the rectifying member is attached to the submersible pump via the frame, the rectifying member can be installed together only by installing the submersible pump in the sewage treatment tank. Therefore, it is not necessary to fix the rectifying member in the sewage treatment tank in advance. Moreover, alignment with a rectifying member and a submersible pump becomes easy.

  It is preferable that the center side of each guide blade is formed in a spiral shape in a plan view and the outer side is formed in a radial shape in a plan view.

  As a result, in the central region where the swirl direction component of the water flow is relatively large, the guide vanes are formed in a spiral shape in plan view, so that the flow direction can be changed gently while suppressing the pressure loss of the water flow. it can. On the other hand, in the outer region where the swirl direction component of the water flow is relatively small, the guide vanes are formed radially in plan view, so that the water flow can be more effectively guided radially.

  It is preferable that the rectifying member includes a substantially conical protrusion protruding upward, and each guide blade is provided along a side surface of the protrusion from the top of the protrusion.

  Thus, the water conveyed downward from the submersible pump is guided radially by the guide vanes and is changed in the lateral direction along the projections. Therefore, the water flow can be guided more effectively, and the circulation efficiency of the sewage in the sewage treatment tank can be further improved.

  According to the present invention, the swirl direction component of the water flow from the submersible pump can be smoothly converted into a substantially radial component. Therefore, the pressure loss of the water flow can be reduced. Moreover, it becomes possible to increase the speed of the horizontal flow along the bottom face of the sewage treatment tank. As a result, the sewage circulation efficiency in the sewage treatment tank can be increased, and the sewage treatment can be made more efficient.

  If the rectifying member is attached to the submersible pump through a frame that is open at least at the sides, it is not necessary to fix the rectifying member in the sewage treatment tank in advance. Moreover, alignment with a rectifying member and a submersible pump becomes easy.

  If the center side of each guide vane is formed in a spiral shape in plan view and the outside is formed in a radial shape in plan view, the water flow can be guided more smoothly. Therefore, the pressure loss of the water flow can be further reduced, and the circulation efficiency of the sewage can be further improved.

  If a substantially conical protrusion projecting upward is provided and each guide vane is arranged along the side surface from the top of the protrusion, the flow in the swirling direction can be guided radially and at the same time downward Since the flow of the water can be directly changed in the horizontal direction, the circulation efficiency of the sewage can be further improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the rectifying member 10 according to the present embodiment is fixed to the bottom surface of the sewage treatment tank 11. In the present embodiment, the rectifying member 10 is installed at the central portion of the bottom surface of the sewage treatment tank 11. However, the installation position of the rectifying member 10 is not limited at all.

  A propeller-type underwater mixer 12 is provided directly above the rectifying member 10. The underwater mixer 12 is attached to a lower end portion of a frame (not shown) that is suspended from the upper end opening of the sewage treatment tank 11, and is installed in a downward posture above the bottom surface of the sewage treatment tank 11. Although the installation height of the underwater mixer 12 is not particularly limited, in the present embodiment, the underwater mixer 12 is disposed below the sewage treatment tank 11. In the figure, reference numeral 13 denotes a power supply cable to the motor 14 of the underwater mixer 12.

  As shown in FIG. 2, the underwater mixer 12 includes a motor 14, a propeller 15 attached to the rotating shaft of the motor 14, and a substantially annular cover 16 that covers the side of the propeller 15. The propeller 15 is located below the motor 14, and is installed downward so as to discharge the water sucked from above.

  As shown in FIGS. 2 to 4, the rectifying member 10 includes a substantially conical protrusion 17 protruding upward, and four guide blades 18 erected on the side surface of the protrusion 17. The top of the projection 17 is a flat surface 19. The guide blades 18 are arranged in a shape that opens from the center side toward the outside. That is, the guide blades 18 extend outward from the vicinity of the flat surface 19 of the projection 17 along the side surface of the projection 17 and are arranged in a substantially radial shape in plan view. More specifically, as shown in FIG. 4, each guide blade 18 is formed in a spiral shape at the center side and radially formed at the outer side. The outside of each guide vane 18 protrudes from the side surface of the protrusion 17 and is in contact with the bottom surface of the sewage treatment tank 11.

  The flow regulating member 10 is disposed directly under the underwater mixer 12. Here, the flat surface 19 of the projection 17 is located directly below the rotation axis of the underwater mixer 12, and the center positions of the rectifying member 10 and the underwater mixer 12 are aligned. A broken-line arrow in FIG. 4 represents the rotation direction of the propeller 15 of the underwater mixer 12. As can be seen from FIG. 4, the spiral direction of the guide vane 18 is set to a direction corresponding to the rotation direction of the propeller 15 so as to smoothly change the direction of the swirling flow from the underwater mixer 12.

  During the sewage treatment, the underwater mixer 12 is driven, and the sewage circulates in the sewage treatment tank 11 as shown in FIG. That is, the water sucked into the underwater mixer 12 from above is discharged downward and collides with the rectifying member 10. The flow direction of the water that has collided with the rectifying member 10 is changed as follows.

  That is, the water flow discharged from the underwater mixer 12 has a speed component in the turning direction along with a downward speed component. However, since the rectifying member 10 includes the conical protrusion 17, the water flow flows along the side surface of the protrusion 17, and the downward velocity component is smoothly converted into the horizontal velocity component by the protrusion 17. The Further, since the rectifying member 10 includes a plurality of substantially radial guide vanes 18, the water flow flows along the guide vanes 18, and the velocity component in the turning direction is converted into a linear velocity component by the guide vanes 18. .

  Thereby, the flow direction of the water flow from the underwater mixer 12 is smoothly changed without receiving a large resistance. As a result, the pressure loss of the water flow decreases, and the speed of the water flow along the bottom surface of the sewage treatment tank 11 increases. Therefore, the water flow along the bottom surface reaches the end of the sewage treatment tank 11, and good circulation can be generated throughout the sewage treatment tank 11 (see FIG. 1). Moreover, it is possible to prevent sediment from staying on the bottom surface of the sewage treatment tank 11.

  As described above, according to the present embodiment, the direction of the water flow that spirals downward from the underwater mixer 12 can be smoothly changed along the bottom surface of the sewage treatment tank 11. Therefore, the flow of water at the bottom of the sewage treatment tank 11 can be activated. Moreover, sewage can be circulated favorably throughout the sewage treatment tank 11, and the sewage can be efficiently stirred.

  The guide vane 18 of the rectifying member 10 has a structure in which the upper side is opened. Therefore, even if foreign matter is included in the sewage, the foreign matter is not easily entangled with the guide blade 18. Therefore, the rectifying member 10 can perform a sufficient rectifying action on sewage containing impurities and the like.

  In the present embodiment, the number of guide vanes 18 of the rectifying member 10 is four, but the number is not limited to four. The shape of the guide blade 18 is not particularly limited. The guide blades 18 may be formed in a substantially radial shape in plan view, and of course, the entire guide blade 18 may be formed in a strict radial shape. Further, the entirety may be formed in a spiral shape, an arc shape, an arc shape, or other curved shapes. Moreover, you may form substantially radial shape as a whole by combining various curve shape or linear shape.

  In the above embodiment, the rectifying member 10 is fixed to the bottom surface of the sewage treatment tank 11. However, as shown in FIG. 5, the rectifying member 10 may be attached to the underwater mixer 12 via the frame 20. In the modification shown in FIG. 5, a frame 20 made up of a plurality of bar-like members extending downward is fixed to the underwater mixer 12. And the rectification member 10 is being fixed to the lower end part of the flame | frame 20 in the state which contacted the bottom face of the sewage treatment tank 11. FIG. The frame 20 is not a member that guides the water flow, and the side thereof is largely open.

  The sewage treatment tank 11 is provided with a guide bar 21 extending in the vertical direction. The underwater mixer 12 is provided with an engaging member (not shown) that engages with the guide rod 21. When installing the submerged mixer 12 and the rectifying member 10 in the sewage treatment tank 11, the engaging member and the guide rod 21 are engaged, and the submerged mixer 12 until the rectifying member 10 contacts the bottom surface of the sewage treatment tank 11. Is suspended along the guide bar 21. Thereby, the underwater mixer 12 and the rectifying member 10 can be easily installed.

  According to this modification, it is possible to obtain the same effect as in the above embodiment. Moreover, since it is not necessary to fix the rectifying member 10 in the sewage treatment tank 11 in advance and the underwater mixer 12 is installed, the rectifying member 10 is also installed, so that the rectifying member 10 can be easily installed. Can do.

  In the embodiment shown in FIGS. 1 to 4, it is needless to say that a guide rod for guiding the raising and lowering of the underwater mixer 12 may be provided in the sewage treatment tank 11.

  In the embodiment and the modification, the rectifying member 10 is provided on the bottom surface of the sewage treatment tank 11. However, a gantry may be provided on the bottom surface of the sewage treatment tank 11 and the rectifying member 10 may be installed on the gantry. It is also possible to suspend and support the flow regulating member 10 at a position slightly above the bottom surface of the sewage treatment tank 11. In the modification of FIG. 5, the underwater mixer 12 and the rectifying member 10 may be suspended and supported at a slightly higher position.

  The rectifying member 10 is composed of the protrusion 17 and the guide vane 18, but the protrusion 17 may be omitted when the purpose is to exclusively convert the swirl direction component of the water flow into a radial component. . For example, as shown in FIG. 6, guide vanes 18 may be provided directly on the bottom surface of the sewage treatment tank 11.

  In the said embodiment and modification, the rectification | straightening member 10 was provided in the center part of the sewage treatment tank 11 (refer Fig.7 (a)). However, the rectifying member 10 can be provided at any position of the sewage treatment tank 11. For example, as shown in FIG. 7B, the rectifying member 10 can be provided near the corner of the sewage treatment tank 11. In such a case, in order to efficiently circulate sewage throughout the sewage treatment tank 11, it is preferable to appropriately change the length, shape, and the like of the guide blade 18 according to the installation position of the rectifying member 10. For example, the guide blade 18 on the center side of the sewage treatment tank 11 may be formed longer than the guide blade 18 on the end side. Further, the blade intervals of the guide blades 18 may be unequal intervals.

  The submersible pump is not limited to the propeller type submersible mixer 12, but may be another axial pump or mixed flow pump.

  As described above, the present invention is useful for rectification of sewage in a sewage treatment tank in a sewage treatment plant, a water storage plant or the like.

It is sectional drawing of a sewage treatment tank. It is a side view of a flow regulating member and an underwater mixer. It is a perspective view of a rectifying member. It is a top view of a baffle member. It is sectional drawing of the sewage treatment tank which concerns on a modification. It is a figure explaining the rectification | straightening member which concerns on a modification, (a) is a perspective view, (b) is a top view, (c) is a side view. (A) And (b) is a figure which shows the installation position of a rectifying member, respectively. It is sectional drawing of the conventional sewage treatment tank.

Explanation of symbols

10 rectifying member 11 sewage treatment tank 12 submersible mixer (submersible pump)
13 Feeding cable 14 Motor 15 Propeller 16 Cover 17 Projection 18 Guide vane 19 Flat surface 20 Frame 21 Guide rod

Claims (5)

A rectifying member for guiding the flow of water in the sewage treatment tank,
In the sewage treatment tank, an axial-flow or mixed-flow submersible pump is installed downward above the bottom of the tank,
A rectifying member for a sewage treatment tank, comprising a plurality of guide vanes extending substantially radially in a plan view and disposed immediately below the submersible pump.   The rectifying member for a sewage treatment tank according to claim 1, which is fixed to a bottom surface of the sewage treatment tank.   The rectifying member for a sewage treatment tank according to claim 1, wherein the rectifying member is attached to the submersible pump through a frame that is open at least at a side.   The rectifying member for a sewage treatment tank according to any one of claims 1 to 3, wherein a center side of each guide blade is formed in a spiral shape in a plan view and an outer side is formed in a radial shape in a plan view. Provided with a substantially conical protrusion protruding upward,
Each said guide blade is a rectification | straightening member of the wastewater treatment tank as described in any one of Claims 1-4 provided along the side surface of the said protrusion from the top part of the said protrusion.

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