JP2006192330A - Agitation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an agitation device which is suitable for agitation of a sewage tank, and consumes a small amount of energy. <P>SOLUTION: The agitation device has a delivery pipe 21 which keeps one end connected to a pump 19 feeding sewage 13 to the sewage tank 12 and the other end disposed in the sewage 13 in the sewage tank 12. A diffuser 27 is attached to the end of the delivery pipe 21, disposed in the water in the sewage tank 12. An ejector 25 sucking the sewage 13 in the sewage tank 12 into the delivery pipe 21 is installed in the delivery pipe 21 at a position corresponding to the liquid surface in the sewage tank 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a stirring device that stirs a liquid in a water tank and promotes mixing, reaction, and the like of the liquid. The present invention relates to a stirring device particularly suitable for stirring a liquid in an anaerobic tank.

  As a stirring device that stirs the liquid in order to promote mixing, reaction, etc. of the liquid in the water tank, a mixer type equipped with a stirring blade, an aerator type that combines mechanical stirring and aeration with the stirring blade, and a water tank An air diffuser type that supplies air is known. Patent Document 1 describes a circulation type stirring device that circulates liquid in a water tank with a submersible pump arranged in the water tank.

  When the water tank is an anaerobic tank, an aerator type or a diffused type stirring device cannot be used, and a mixer type must be used. However, fine flocs called activated sludge exist in a sewage tank, which is a kind of anaerobic tank, and when using a mixer type, activated sludge may be destroyed by rotating stirring blades. The destruction of activated sludge leads to a decline in the function of the sewage tank. Further, any of the mixer type, aerator type, air diffusion type, and circulation type requires a dedicated power source for stirring, and energy consumption of only the stirring device is required during operation.

Registered Utility Model No. 3018877

  An object of the present invention is to provide an agitation apparatus that is suitable for agitation of an anaerobic tank, particularly a sewage tank, and that consumes less energy.

  The present invention is a stirring device for stirring a liquid in a water tank, wherein one end is connected to a pump that supplies the liquid to the water tank, and the other end is disposed in the liquid in the water tank. A stirrer provided with a pipe and a diffuser provided at an end of the discharge pipe disposed in the liquid in the water tank and diffusing a flow of liquid discharged from the pump through the discharge pipe into the water tank provide.

  The flow of the liquid discharged from the discharge pipe into the liquid in the water tank through the diffuser spreads over the entire area of the water tank, thereby stirring the liquid in the water tank.

  The inside of a water tank is stirred with the liquid which the pump for supplying a liquid to a sewage tank discharges. Therefore, there is no need for a dedicated drive source for the stirring device, and no energy is consumed only for stirring. Specifically, it is effectively used for stirring the liquid in the water tank without wasting the dynamic pressure of the liquid discharged from the pump for supplying the liquid to the water tank.

  The diffuser is provided at an end of a discharge pipe disposed in the liquid in the water tank, and the liquid supplied from the pump is discharged through the diffuser. Therefore, even when the water tank is an anaerobic tank, it is possible to prevent air from being mixed into the liquid in the anaerobic tank when the liquid is discharged from the discharge pipe.

  Since there is no rotating part like a stirring blade, there is no possibility that the activated sludge is destroyed even when the water tank is a sewage tank.

  The water tank is connected to an upstream water tank and a downstream water tank, and it is preferable that a liquid flow from the upstream water tank toward the downstream water tank exists in the water tank.

  As described above, the end of the discharge pipe provided with the diffuser is disposed in the liquid in the water tank. Due to the flow of the liquid from the upstream water tank to the downstream water tank in the water tank, the vicinity of the diffuser at the end of the discharge pipe disposed in the water tank becomes a low pressure, and a siphon that draws the liquid in the discharge pipe into the water tank is formed. Therefore, a pump with a low head can be used as a pump for supplying liquid to the water tank, and the shaft driving force required to drive the pump can be reduced.

  Preferably, the stirring device further includes an ejector that is provided at a position corresponding to the liquid level in the water tank of the discharge pipe and sucks the liquid in the water tank into the discharge pipe.

  Floating matter existing in the vicinity of the liquid level in the water tank is sucked into the discharge pipe by the ejector and discharged again from the diffuser into the water tank. Therefore, by providing the ejector, the suspended matter existing near the liquid surface can be effectively stirred.

  Specifically, the ejector causes the inside of the discharge pipe to communicate with the inside of the water tank at the end of the throttle side where the diameter of the discharge pipe is reduced from the pump side toward the diffuser side. And a suction port.

  The liquid flow in the discharge pipe is depressurized when passing through the throttle. The suction port provided at the end of the restrictor on the diffuser side is at a low pressure, and the liquid and suspended matter near the liquid surface of the water tank are sucked into the discharge pipe.

  As an alternative, the ejector is disposed in the discharge pipe, and communicates between the water wheel rotating by the flow of the liquid from the pump side to the diffuser side, and the inside of the water tank on the diffuser side with respect to the water wheel. A suction port and an impeller disposed at a position corresponding to the suction port in the discharge pipe and rotating in conjunction with the water wheel.

  The water turbine is preferably at a high specific speed (low head). The water wheel is rotated by the flow of liquid from the pump side to the diffuser side in the discharge pipe, and the impeller rotates in conjunction with the rotation of the impeller, so that the suction port becomes a low pressure, and the liquid and suspended matter near the liquid level in the water tank enter the discharge pipe. Inhaled. Since the suction port is made low by rotating the impeller by the water wheel, even if the pressure difference between the pump side (upstream side) and the diffuser side (downstream side) is relatively smaller than the suction port, Liquid and suspended matter are sucked into the discharge pipe from the suction port.

  In the stirring device of the present invention, the liquid discharged by the pump for supplying liquid to the water tank is discharged into the water tank from the diffuser disposed in the liquid in the water tank through the discharge pipe, and spreads throughout the water tank, thereby The liquid in the water tank is agitated. Therefore, there is no need for a dedicated drive source for the stirring device, and no energy is consumed only for stirring. In addition, the liquid in the water tank is not aerated for stirring, and the liquid supplied from the pump is discharged into the water tank from the diffuser arranged in the liquid in the water tank, so that air is mixed into the liquid in the water tank. Can be prevented. Furthermore, there is no rotating part like a stirring blade, and the activated sludge in the liquid is not destroyed. Therefore, the stirring device of the present invention consumes less energy and is suitable for stirring an anaerobic tank, particularly a sewage tank.

  By providing the ejector, the floating substance near the liquid level in the water tank can be sucked into the discharge pipe and discharged from the diffuser, so that the liquid containing the floating substance can be stirred more effectively like the liquid in the sewage tank. .

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

(First embodiment)
The stirrer 11 according to the first embodiment of the present invention shown in FIGS. 1 and 2 stirs sewage 13 in a sewage tank 12 that is a kind of anaerobic tank. The dirty water tank 12 is connected to an upstream water tank (for example, an aerobic tank) 16 via a connecting pipe 15A connected to the side wall 14A. Moreover, the sewage tank 12 is connected to the downstream water tank (for example, aerobic tank) 17 via the connection pipe 15B connected with the other side wall 14B. In the vicinity of the bottom wall 18 in the stirring device 11, there is a flow of sewage 13 from the upstream water tank 16 toward the downstream water tank 17 as indicated by an arrow A.

  The stirring device 11 has one end connected to a pump 19 that supplies the sewage 13 to the sewage tank 12 via a connecting pipe 15C, and the other end disposed in the sewage 13 in the sewage tank 12. 21 is provided. As for the pump 19, the suction inlet 19a is connected to the other water tank 20C, and the discharge outlet 19b is connected to the connection pipe 15C. The pump 19 sucks the sewage 13 from the water tank 20 </ b> C and discharges it into the sewage tank 12 through the connecting pipe 15 and the discharge pipe 21.

  The discharge pipe 21 includes an elbow 23 having one end connected to the connecting pipe 15C and curved from the horizontal direction to the vertical direction. The elbow 23 is provided with a normally closed valve 24 for venting air. An ejector 25, a straight pipe 26, and a diffuser 27 are connected to the other end of the elbow 23 in this order. The ejector 25, the straight pipe 26, and the diffuser 27 extend in the vertical direction.

  1 and 2, the ejector 25 has an upper end connected to an elbow 23 and a lower end connected to a straight pipe 26 in the figure. Further, the ejector 25 includes a throttle portion 31 that decreases in diameter from the upper end side (the pump 19 side) toward the lower end side (the diffuser 27 side). Further, the ejector 25 includes a suction port 32 at an end portion on the lower end side of the throttle portion 31. The suction port 32 includes an upper wall 33 and a lower wall 34 that extend radially outward, and a support wall 35 that connects the upper wall 33 and the lower wall 34. A gap between the upper wall 33 and the lower wall 34 opens in the circumferential direction to allow communication between the inside of the discharge pipe 21 and the inside of the sewage tank 12. The suction port 32 is provided at a position corresponding to the water surface of the sewage 13. Specifically, the suction port 32 is preferably provided so that the upper end of the gap between the upper wall 33 and the lower wall 34 is located slightly below the water surface.

  The straight pipe 26 has an upper end connected to the ejector 25 and a lower end connected to the diffuser 27 in the drawing. The lower end of the straight pipe 26 is disposed near the bottom wall 18 of the sewage tank 12.

  The diffuser 27 has an upper end connected to the straight pipe 26 and a lower end facing the bottom wall 18 of the sewage tank 12 with a gap. The diffuser 27 expands from the upper end side toward the lower end side. The discharge end 27 a of the diffuser 27 is located near the bottom wall 18 of the sewage tank 12. A cone 37 is disposed on the bottom wall 18 of the sewage tank 12. The cone 37 and the bottom wall 18 and the inside of the discharge end 27 a of the diffuser 27 are connected by a plurality of support plates 38.

  Next, operation | movement of the stirring apparatus 11 is demonstrated. The sewage 13 sucked from the water tank 20C by the pump 19 flows into the discharge pipe 21 of the stirring device 11 from the connecting pipe 15C. The sewage 13 flowing into the discharge pipe 21 is discharged from the discharge end 27a of the diffuser 27 through the ejector 25 and the straight pipe 26. Since the flow of the sewage 13 is diffused when discharged from the diffuser 27, the flow of the discharged sewage 13 spreads over the entire area of the sewage tank 12 as indicated by reference numeral B, and thereby the sewage in the sewage tank 12. Is stirred. Specifically, the flow B of the sewage 13 flows in the horizontal direction along the bottom wall 18 toward the side walls 14A and 14B, and rises toward the water surface of the sewage 13 along the side walls 14A and 14B. Thus, since the inside of the sewage tank 12 is agitated by the sewage 13 discharged from the pump 19 for supplying the sewage 13 to the sewage tank 12, a dedicated drive source for the agitator 11 is not necessary and only for agitation. Does not consume energy.

  If the lower end of the discharge pipe 21 that discharges the sewage 13 from the pump 19 to the sewage tank 12 is located above the water surface of the sewage tank 12, the dynamic pressure of the sewage 13 discharged from the discharge pipe 21 is It is not used at all and discarded. On the other hand, in the present embodiment, the lower end of the discharge pipe 21 is disposed in the sewage 13 in the sewage tank 12 so that the dynamic pressure (discharge pipe dynamic pressure) of the sewage 13 discharged from the diffuser 27 of the discharge pipe 21 is reduced. It is used for stirring the sewage 13 in the sewage tank 12. In other words, the agitation device 11 of the present embodiment includes the sewage tank 12 in the sewage tank 12 without wasting the discharge pipe dynamic pressure in the entire head of the pump 19 for feeding the sewage 13 from the water tank 20C to the sewage tank 12. It is effectively used for stirring the sewage 13.

  The agitation device 11 of this embodiment does not aerate the sewage 13 into the sewage tank 12 for agitation, unlike an aerator type or aeration type agitation device. The sewage 13 supplied from the pump 19 to the sewage tank 12 is discharged from a diffuser 27 that is disposed near the bottom wall 18 in the sewage tank 12 and is submerged in the sewage 13. Therefore, no air is mixed into the sewage tank 12 when sewage is discharged from the discharge pipe 21. For these reasons, the stirring device 11 of this embodiment can reliably prevent air from being mixed into the sewage 13 in the sewage tank 12.

  Furthermore, the stirring device 11 of the present embodiment does not include a rotating portion such as a stirring blade provided in a mixer-type stirring device, and therefore, activated sludge contained in the sewage 13 in the sewage tank 12 may be destroyed. Absent.

  As described above, the diffuser 27 provided at the lower end of the discharge pipe 21 is disposed near the bottom wall 18 of the sewage tank 12. Further, in the vicinity of the bottom wall 18 in the stirring device 11, there is a flow A of the sewage 13 from the upstream water tank 16 toward the downstream water tank 17. Therefore, the vicinity of the diffuser 27 becomes a low pressure, and a siphon that draws the sewage 13 in the discharge pipe 21 into the sewage tank 12 is formed. Due to this siphon effect, a pump having a low head can be used as the pump 19 for supplying the sewage 13 to the sewage tank 12, and the shaft driving force required to drive the pump 19 can be reduced.

  The sewage 13 discharged by the pump 19 is decompressed when passing through the throttle portion 31 of the ejector 25. Therefore, the suction port 32 of the ejector 25 has a low pressure, and the sewage 13 near the water surface of the sewage tank 12 is sucked into the ejector 25 from the suction port 32. In addition to the sewage 13 near the water surface, floating matter (scum) near the water surface is sucked into the ejector 25 from the suction port 32. The sewage 13 and the suspended matter sucked into the ejector 25 flow into the diffuser 27 through the straight pipe 26 and are discharged again into the sewage tank 12 near the bottom wall of the sewage tank 12. By providing the ejector 25 in this way, suspended matter near the water surface can be effectively stirred.

(Second Embodiment)
The stirring device 11 according to the second embodiment of the present invention shown in FIGS. 3 to 5 is different from the first embodiment in the structure of the ejector 25.

  The ejector 25 includes a high specific speed (low drop) water turbine 45 disposed in the discharge pipe 21. Bearings 46 </ b> A and 46 </ b> B are arranged near the upper end and the lower end inside the ejector 25. A rotary shaft 47 extending in the vertical direction is rotatably supported by the bearings 46A and 46B. Retaining stoppers 48 </ b> A and 48 </ b> B are attached to the upper and lower ends of the rotating shaft 47. The water wheel 45 is fixed to the upper end side of the rotating shaft 47. The ejector 25 includes a suction port 49 on the lower end side (diffuser 27 side) of the water wheel 45. The suction port 49 includes an upper wall 50 and a lower wall 51 that extend radially outward, and a support wall 52 that connects the upper wall 50 and the lower wall 51. A gap between the upper wall 50 and the lower wall 51 opens in the circumferential direction to allow communication between the inside of the discharge pipe 21 and the inside of the sewage tank 12. The suction port 49 is provided at a position corresponding to the water surface of the sewage 13. Further, an impeller 53 is disposed at a position corresponding to the suction port 49 in the ejector 25. The impeller 53 includes a blade 55 fixed to the rotary shaft 47 by a rod 54. The ejector 25 at the portion where the impeller 53 is disposed has an increased diameter, and the diameter is reduced from the lower end side of the impeller 53 toward the lower end of the ejector 25.

  The water wheel 45 is rotated by the flow of the sewage 13 from the pump 19 side to the diffuser 27 side in the discharge pipe 21, and the impeller 53 is rotated in conjunction therewith. Liquid and suspended matter are drawn into the discharge tube. Since the suction port 49 is set to a low pressure by rotating the impeller by the water wheel, the sewage tank even when the pressure difference between the pump 19 side (upstream side) and the diffuser 27 side (downstream side) is relatively smaller than the suction port 49. 12 near the water surface and the suspended matter are reliably sucked into the diffuser 27 from the suction port 49. The sewage 13 and the suspended matter sucked into the ejector 25 sucked into the diffuser 27 are again discharged into the sewage tank 12 near the bottom wall 18.

  Since other configurations and operations of the second embodiment are the same as those of the first embodiment, the same elements are denoted by the same reference numerals and description thereof is omitted.

  Although the present invention has been described by taking a sewage tank as an example, the present invention is applicable to other anaerobic tanks and aerobic tanks other than the sewage tank.

The typical longitudinal section showing the stirrer concerning a 1st embodiment of the present invention. Sectional drawing in the II-II line of FIG. Typical sectional drawing which shows the stirring apparatus which concerns on 2nd Embodiment of this invention. Sectional drawing in the IX-IX line of FIG. Sectional drawing in the XX of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Stirring device 12 Sewage tank 13 Sewage 14A, 14B Side wall 15A, 15B, 15C Connecting pipe 16 Upstream water tank 17 Downstream water tank 18 Bottom wall 19 Pump 20 Water tank 21 Discharge pipe 23 Elbow 24 Normally closed valve 25 Ejector 26 Straight pipe 27 Diffuser 31 throttle part 32 suction port 33 upper wall 34 lower wall 35 support wall 37 cone 38 support plate 45 water wheel 46A, 46B bearing 47 rotary shaft 48 retaining 49 suction port 50 upper wall 51 lower wall 52 support wall 53 impeller 54 rod 55 Feather

Claims (5)

A stirring device for stirring the liquid in the water tank,
One end is connected to a pump that supplies liquid to the water tank, and the other end is a discharge pipe disposed in the liquid in the water tank,
A stirrer provided with a diffuser provided at an end of the discharge pipe disposed in the liquid in the water tank and diffusing a flow of liquid discharged from the pump through the discharge pipe into the water tank.   The agitation apparatus according to claim 1, wherein the water tank is connected to an upstream water tank and a downstream water tank, and a liquid flow from the upstream water tank toward the downstream water tank exists in the water tank.   The stirring device according to claim 1 or 2, further comprising an ejector that is provided at a position corresponding to the liquid level in the water tank of the discharge pipe and sucks the liquid in the water tank into the discharge pipe. The ejector includes a throttle portion that reduces the diameter of the discharge pipe from the pump side toward the diffuser side,
The stirrer according to claim 3, further comprising a suction port that communicates the inside of the discharge pipe with the inside of the water tank at the end of the throttle portion on the diffuser side. The ejector is
A water wheel disposed in the discharge pipe and rotated by a liquid flow from the pump side toward the diffuser side; and
A suction port that connects the inside of the discharge pipe and the inside of the water tank on the diffuser side of the water wheel;
The stirring device according to claim 3, further comprising an impeller disposed at a position corresponding to the suction port in the discharge pipe and rotating in conjunction with the water wheel.

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