JP4217115B2 - Fluid nozzle structure and sludge removal method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluid nozzle structure and a sludge removal method.
[0002]
[Prior art]
Examples of sludge concentration and dehydration treatment apparatuses that efficiently concentrate and dehydrate high water content sludge generated in water treatment such as clean water, sewage, and industrial water include those shown in FIGS.
[0003]
In FIG. 5, the sludge concentration and dehydration apparatus 1 includes a sludge storage tank 3 for storing mixed sludge 2 (which may be only raw sludge and excess sludge), and the mixed sludge 2 from the sludge storage tank 3 to the other. A sludge supply means 4 comprising a pump, a supply pipe, etc., a flocculant supply section 5, a mixed sludge 2 supplied from the sludge supply means 4 and a polymer flocculant 6 supplied from the flocculant supply section 5 are motorized. Agitation tank 9 for agitation and mixing by driving agitation means 7 to agglomerate sludge particles of mixed sludge 2 to generate flocified sludge 8 and natural agitation tank 9 through natural dropping means 10 such as a pipe line A sludge concentrating section 11 for filtering and concentrating the floc sludge supplied downstream, and a concentrated sludge supplying means for supplying the concentrated sludge 12 generated by the sludge concentrating section 11 to a dehydrator 13 such as a rotary press by natural downstream supply. 14. Reference numeral 15 denotes a motor-driven stirring means provided in the sludge storage tank 3.
[0004]
As shown in FIG. 6, the sludge concentrating unit 11 includes a concentration tank 16 for gravity filtration and concentration of the flocked sludge 8 supplied from the natural dropping means 10, and a disk for filtering the flocked sludge 8 in the concentration tank 16. Connected to a honeycomb screen 17a having an appropriate thickness (thickness where sludge residue does not entangle and wrap around and a necessary and sufficient strength is obtained) and a horizontal shaft 17c fixed to the honeycomb screen 17a. Filtration means 17 provided with a motor 17b rotated by the filter, a separation liquid storage tank section 19 connected to the concentration tank 16 so as to store the separation liquid 18 filtered and produced by the honeycomb screen 17a of the filtration means 17, and the filtration means 17 Compressed air supply means 20 for blowing compressed air to the downstream side (back side) of the honeycomb screen 17a in the separated liquid flow direction, and compressed air supply Blowing of compressed air from the means 20 consist (compressed air outlet part) 21..
[0005]
The natural dropping means 10 is connected substantially horizontally to one side of the concentrating tank 16, and the inflow direction of the flocked sludge 8 introduced from the natural dropping means 10 into the concentrating tank 16 is a honeycomb screen 17a in plan view. It is comprised so that it may become substantially parallel to the rotation direction D.
[0006]
The honeycomb screen 17a of the filtering means 17 shown in an enlarged manner in FIGS. 7 and 8 is a disk-shaped metal honeycomb strainer having a diameter of 700 to 1000 mm and made of a highly corrosion-resistant metal member such as SUS304, SUS316, or Ti. The central horizontal shaft 17c is supported by the concentration tank 16, and the inside of the tank can be rotated at a slow speed of about 20 rpm at the maximum. The honeycomb screen 17a includes a strong outer ring having a width of about 20 mm, a metal foil flat plate and a metal foil corrugated plate having a width of 20 mm and a thickness of 50 microns (any thickness of 20 to 100 microns can be used) in the outer ring. Are stacked alternately.
[0007]
In the concentration dehydration apparatus 1 described above, the mixed sludge 2 stored in the sludge storage tank 3 is supplied to the coagulation tank 9 by the sludge supply means 4, and the polymer coagulant 6 coagulates from the coagulant supply unit 5. It is supplied to the tank 9.
[0008]
In the agglomeration tank 9, the mixed sludge 2 and the polymer flocculant 6 are agitated and mixed by the agitation means 7, and the sludge particles agglomerate to generate flocked sludge 8. Thus, the feed direction is supplied to the front surface of the honeycomb screen 17a rotating at a low speed in the rotation direction D from the side to the concentration tank 16 of the sludge concentration unit 11 so that the supply direction is substantially parallel to the rotation direction D.
[0009]
The floc sludge 8 introduced into the concentration tank 16 is filtered by the honeycomb screen 17a rotating at a low speed in the rotation direction D, and the separation liquid 18 passing through the honeycomb screen 17a from the upstream side to the downstream side in the separation liquid flow direction is separated liquid storage tank. It flows into the part 19. Further, when the concentrated sludge 12 is accumulated in the concentration tank 16, the sludge adhering to the honeycomb screen 17 a is scraped by the concentrated sludge 12 and supplied into the concentration tank 16, and the concentrated sludge 12 is accumulated in the concentration tank 16. If it is not scraped off by the concentrated sludge 12, it is transported from the liquid to the air by the honeycomb screen 17a and blown off by the compressed air blown from the compressed air blowing portion 21 and removed. It falls into the concentration tank 16. Therefore, the sludge in the concentration tank 16 is concentrated to obtain the concentrated sludge 12, and the concentrated sludge 12 is fed from the lower hopper 16a provided at the lower part of the concentration tank 16 to the dehydrator 13 by the concentrated sludge supply means 14. Is done.
[0010]
However, in the sludge concentrating part 11 of the above-described concentration dehydration processing apparatus 1, the concentrated sludge 12 is placed on the side opposite to the connecting part of the natural dropping means 10 in the concentrating tank 16, as shown in FIGS. There is a tendency to accumulate. However, in the sludge concentrating part 11, the concentrated sludge 12 is pulled out from the lower part of the lower hopper 16a provided in the lower part of the concentrating tank 16 to the concentrated sludge supplying means 14, so that the concentrated sludge 12 is difficult to pull out. Accordingly, liquid is mixed in the concentrated sludge 12 to be withdrawn. As a result, the concentration of the concentrated sludge 12 is lowered, and a part of the flocified sludge 8 supplied to the concentration tank 16 is also concentrated with the concentrated sludge 12. It will be pulled out to the supply means 14. For this reason, the dewatering process of the concentrated sludge 12 by the dehydrator 13 cannot be performed efficiently.
[0011]
Therefore, the applicant of the present application is to provide a sludge concentrating part structure capable of reliably delivering the concentrated sludge having a high concentration obtained by dehydrating floc sludge in the concentrating tank of the sludge concentrating part, An application was filed (prior application 1).
[0012]
[Prior Application 1]
Japanese Patent Application No. 2003-78623 Specification
In the sludge concentrating part structure of the prior application 1, as shown in FIGS. 9 and 10, the natural dropping means 10 is substantially the same as the sludge concentrating part 11 shown in FIGS. The inflow direction of the floc sludge 8 that is connected horizontally and introduced from the natural dropping means 10 to the concentration tank 16 is configured to be substantially parallel to the rotation direction D of the honeycomb screen 17a in plan view. However, the lower part of the concentration tank 16 is not provided with a lower hopper portion 16a (see FIGS. 7 and 8) to which the concentrated sludge supply means 14 is connected at the lower part. On the other hand, it is connected substantially horizontally to the other side opposite to the connection part of the natural fall means 10. That is, the connection portion of the concentrated sludge supply means 14 to the concentration tank 16 is on the downstream side in the rotational direction D below the honeycomb screen 17a.
[0014]
In the sludge concentrating part 11 shown in FIGS. 9 and 10, the liquid in the flocked sludge 8 supplied from the natural dropping means 10 to the concentration tank 16 passes through the honeycomb screen 17a from the one surface side to the other surface side to be flocked. It is separated from the sludge 8 and flows into the separated liquid storage tank 19 as a separated liquid 18. The sludge separated from the floc sludge 8 adheres to the honeycomb screen 17a, and the sludge adhering to the honeycomb screen 17a is scraped by the concentrated sludge 12 when the concentrated sludge 12 is accumulated in the concentration tank 16. When the concentrated sludge 12 is not collected in the thickening tank 16 or is not scraped off by the concentrated sludge 12, it is transported from the liquid to the air and compressed as shown in FIG. It is blown off by the compressed air blown from the air blowing section 21 and removed, and falls into the concentration tank 16. For this reason, the sludge of the concentration tank 16 is concentrated and the concentrated sludge 12 is obtained.
[0015]
The concentrated sludge 12 is supplied at the lower end side of the honeycomb screen 17a in the rotational direction D by the honeycomb screen 17a, and the concentrated sludge is supplied on the other side of the concentration tank 16 opposite to the side to which the natural dropping means 10 is connected. As a result, the concentrated sludge 12 is smoothly delivered to the concentrated sludge supply means 14. For this reason, in the sludge concentration part 11, the dehydration of the floc sludge 8 is performed reliably and the concentrated sludge 12 with a high density | concentration can be obtained. Accordingly, the concentrated sludge 12 shown in FIG. 5 can be supplied through the concentrated sludge supply means 14 with the concentrated sludge 12 containing a small amount of liquid and not containing the flocked sludge 8, and the dehydration in the dehydrator 13 is efficient. To be done.
[0016]
[Problems to be solved by the invention]
When the sludge adhering to the honeycomb screen 17a in the filtering means 17 is blown off by compressed air in the air, the compressed air is supplied from the compressed air supply means 20 of FIG. To the honeycomb screen 17a. At this time, the water impregnated in the honeycomb screen 17a by the action of the surface tension is pushed away by the compressed air and blown to the one surface side of the honeycomb screen 17a together with the compressed air. For this reason, the sludge adhering to the honeycomb screen 17a is efficiently peeled off by the cooperative action of water and air.
[0017]
However, in the honeycomb screen 17a, the peripheral speed on the radially outer peripheral side is higher than the peripheral speed on the inner peripheral side, so the amount of sludge that must be blown off per unit time is on the inner peripheral side of the honeycomb screen 17a. More than the circumference.
[0018]
Therefore, the amount of compressed air blown from the compressed air blowing portion 21 to the honeycomb screen 17a per unit time must be larger on the radially outer side than the center side of the honeycomb screen 17a. In this respect, no particular consideration is given, and the sludge adhering to the honeycomb screen 17a cannot be blown off uniformly.
[0019]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a fluid nozzle structure and a sludge removal method that can uniformly and uniformly blow off sludge adhering to a honeycomb screen.
[0020]
[Means for Solving the Problems]
The fluid nozzle structure according to claim 1 is a fluid nozzle structure including a hollow cylindrical fluid nozzle, and the fluid nozzle is disposed on the downstream side in the separated liquid flow direction of a rotatable honeycomb screen that filters flocified sludge. The honeycomb screen is arranged so as to extend from the center side of the honeycomb screen to the outer peripheral side on the side rotating from the upper side to the lower side, and on the side facing the honeycomb screen of the fluid nozzle, the circumferential width is the center of rotation of the honeycomb screen. A slit is formed which is narrow on the side and gradually widens toward the outer peripheral side of the honeycomb screen.
[0021]
In the fluid nozzle structure of claim 2, a pad that can be pressed against the surface of the honeycomb screen is fixed around a slit formed in the fluid nozzle.
[0022]
In the fluid nozzle structure according to claim 3, a fluid nozzle is attached to an arm that can move close to and away from the downstream surface of the honeycomb screen in the separation liquid flow direction, and a pressing unit that presses the fluid nozzle against the honeycomb screen is provided. Yes.
[0023]
In the fluid nozzle structure of claim 4, the pressing means is a weight, and in the fluid nozzle structure of claim 5, the pressing means is an elastic body.
[0024]
In the sludge removal method according to claim 6, sludge adhered to the honeycomb screen by blowing compressed air from the fluid nozzle of the fluid nozzle structure according to any one of claims 1 to 5 during the sludge concentration operation. In the sludge removal method of claim 7, at the end of the sludge concentration operation, the cleaning water is sprayed from the fluid nozzle of the fluid nozzle structure according to any one of claims 1 to 5 and adheres to the honeycomb screen. Wash the sludge.
[0025]
Since the honeycomb screen has a higher peripheral speed on the outer peripheral side than the rotation center side, the amount of sludge per unit time that must be blown off from the honeycomb screen, or the remaining sludge per unit time that must be cleaned with the honeycomb screen The amount increases gradually from the center of rotation of the honeycomb screen toward the outer periphery.
[0026]
However, since the width of the slit honeycomb screen rotation center side is narrow and the width of the honeycomb screen outer peripheral side is wide, the amount of compressed air sprayed per unit time, or the amount of washing water injected per unit time, The number is small on the honeycomb screen rotation center side of the slit and is large on the outer periphery side of the slit honeycomb screen.
[0027]
Therefore, the sludge adhering to the honeycomb screen is blown off and removed almost uniformly by the compressed air as a whole, and the remaining sludge adhering to the honeycomb screen is washed and removed by the washing water. The
[0028]
According to the present invention, the sludge adhered to the honeycomb screen can be reliably blown off and washed, and when the fluid nozzle is pressed against the honeycomb screen through the pad, the fluid nozzle is prevented from being worn. And leakage of compressed air and washing water can be reduced.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 to 3 show an example of an embodiment of a fluid nozzle structure and a sludge removal method of the present invention.
Thus, in the illustrated example, a honeycomb screen 17a in which a hollow cylindrical fluid nozzle 22 is housed in the concentration tank 16 (see FIGS. 9 and 10) instead of the compressed air blowing portion 21 shown in FIG. 1 is located on the downstream side in the separated liquid flow direction (the flocked sludge supply side opposite to the honeycomb screen 17a), and the fluid nozzle 22 is, as shown in FIG. The honeycomb screen 17a is rotated and arranged horizontally in the radial direction of the honeycomb screen 17a at a position slightly above the position where the horizontal shaft 17c is attached from the upper side to the lower side.
[0030]
The end of the fluid nozzle 22 on the outer peripheral side of the honeycomb screen 17a is closed, and its length is approximately the radius of the honeycomb screen 17a. On the opposite side of the fluid nozzle 22 to the honeycomb screen 17 a, a slit 23 extending in the longitudinal direction is formed substantially over the entire length of the fluid nozzle 22. The width of the slit 23 in the circumferential direction of the fluid nozzle 22 is narrow at the end of the honeycomb screen 17a on the rotation center side, and is gradually increased gradually toward the outer end of the honeycomb screen 17a.
[0031]
Thus, the fluid nozzle 22 has a length of about 300 to 400 mm, an inner diameter of about 30 mm, a width W1 of the slit 23 at the end of the honeycomb screen 17a on the rotation center side is about 1 mm, and the slit 23 at the end of the honeycomb screen 17a on the outer peripheral side. The width W2 is about 4 mm.
[0032]
A urethane rubber-based soft pad 24 is attached to the outer periphery of the fluid nozzle 22 along the edge of the slit 23. When the fluid nozzle 22 is installed at a predetermined position, the front surface of the pad 24 is the honeycomb. When installed on the floc sludge supply side of the screen 17a, it is pressed against the surface of the honeycomb screen 17a with a predetermined force.
[0033]
A pipe 27 for supplying the compressed air 25 or cleaning water 26 to the fluid nozzle 22 is connected to the end of the fluid nozzle 22 on the rotation center side of the honeycomb screen 17a. An automatic or manual three-way switching valve 28 is connected to the end opposite to the connection side. Thus, by switching the three-way switching valve 28, the compressed air 25 supplied through the pipe line 29 or the cleaning water 26 supplied through the pipe line 30 is sent from the pipe line 27 to the fluid nozzle 22. Can be paid.
[0034]
In FIG. 2, reference numeral 31 is installed above the upstream side (surface side) of the separation liquid flow direction of the honeycomb screen 17a so that the cleaning water 32 can be jetted to the upstream side of the honeycomb screen 17a in the separation liquid flow direction during operation. This is a cleaning nozzle.
[0035]
Next, the operation of the illustrated example will be described with reference to FIGS.
During the sludge concentration operation, the flocated sludge 8 introduced into the concentration tank 16 is filtered by the honeycomb screen 17a rotating at a low speed in the rotation direction D, and the separation liquid 18 that has passed through the honeycomb screen 17a from the upstream side to the downstream side in the separation liquid flow direction. Flows into the separated liquid storage tank 19. Further, the sludge adhering to the upstream surface of the honeycomb screen 17a in the flow direction of the separated liquid is scraped by the concentrated sludge 12 and supplied into the concentrated tank 16 when the concentrated sludge 12 is accumulated in the concentrated tank 16. When the concentrated sludge 12 is not accumulated in the concentration tank 16 or when it is not scraped off by the concentrated sludge 12, it is conveyed from the liquid to the air by the honeycomb screen 17a.
[0036]
On the other hand, since the three-way switching valve 28 is switched so that the compressed air 25 flows, the compressed air 25 from the pipe line 29 is introduced into the fluid nozzle 22 through the three-way switching valve 28 and the pipe line 27, and from the slit 23 to the honeycomb. It is sprayed on the downstream side (back side) of the separation liquid flow direction of the screen 17a, and flows out to the upstream side (front side) of the separation liquid flow direction of the honeycomb screen 17a. For this reason, the sludge adhering to the honeycomb screen 17a is blown off and removed. Since the pad 24 is stuck around the slit 23, the compressed air 25 blown to the honeycomb screen 17a does not leak around the pad 24, and the honeycomb screen 17a is moved from the downstream side in the cleaning liquid flow direction to the upstream side. Pass through to be exhausted. Further, since the fluid nozzle 22 does not directly contact the 17a, wear of the fluid nozzle 22 is prevented.
[0037]
Since the peripheral speed of the honeycomb screen 17a is faster on the outer peripheral side than the rotation center side, the amount of sludge that must be blown off from the honeycomb screen 17a gradually increases from the rotation center side of the honeycomb screen 17a toward the outer peripheral side. To be more.
[0038]
However, since the slit 23 has a narrow width W1 on the rotation center side of the honeycomb screen 17a and gradually increases to the width W2 toward the outer peripheral side of the honeycomb screen 17a, the amount of sprayed compressed air 25 per unit time is The number of slits 23 on the honeycomb screen 17a rotation center side is small, and the number of slits 23 on the honeycomb screen 17a outer peripheral side is large.
[0039]
Therefore, the sludge adhering to the honeycomb screen 17 a is blown off and removed almost uniformly by the compressed air 25 and falls into the concentration tank 16. For this reason, the sludge in the concentration tank 16 is concentrated to obtain the concentrated sludge 12, and the concentrated sludge 12 is supplied by the concentrated sludge supply means 14 connected to the side of the concentration tank 16 opposite to the natural dropping means 10 connection side. It is fed to the dehydrator 13 and dehydrated.
[0040]
The pressure of the compressed air 25 blown from the slit 23 to the honeycomb screen 17a is about 10 KPa.
[0041]
Since the cleaning water 32 is jetted from the cleaning nozzle 31 to the upstream surface of the honeycomb screen 17a in the separation liquid flow direction, the honeycomb screen 17a is not subjected to the sludge concentration operation or at the end of the sludge concentration operation. It is possible to more efficiently remove and clean the attached sludge.
[0042]
When the sludge concentration operation is completed, the honeycomb screen 17a is washed with water. That is, the three-way switching valve 28 is switched automatically or manually, and the cleaning water 26 is introduced from the pipe 30 to the fluid nozzle 22 via the three-way switching valve 28 and the pipe 27, and the cleaning water 26 passes from the slit 23 to the honeycomb screen 17a. Injected onto the downstream surface in the separated liquid flow direction. For this reason, the residual sludge adhering to the honeycomb screen 17a is washed. Since the pads 24 are adhered around the slits 23, the cleaning water 26 sprayed onto the honeycomb screen 17a does not leak to the surroundings, and passes through the honeycomb screen 17a from the downstream side in the separation liquid flow direction to the upstream side. And discharged.
[0043]
Since the honeycomb screen 17a has a higher peripheral speed on the outer peripheral side than the rotational center side, the amount of residual sludge per unit time that must be cleaned and removed increases from the rotational center side of the honeycomb screen 17a toward the outer peripheral side. Gradually increase.
[0044]
However, in this case as well, the slit 23 has a narrow width W1 on the rotation center side of the honeycomb screen 17a and gradually increases to a width W2 toward the outer peripheral side of the honeycomb screen 17a. The injection amount is small on the rotation center side of the honeycomb screen 17a of the slit 23 and increases on the outer peripheral side of the honeycomb screen 17a of the slit 23.
[0045]
Therefore, the remaining sludge adhering to the honeycomb screen 17a is cleaned and removed almost uniformly by the cleaning water 26 to be jetted. The pressure of the cleaning water 26 sprayed from the slit 23 to the honeycomb screen 17a is about 100 to 200 KPa.
[0046]
When cleaning from the back side of the honeycomb screen 17a with the cleaning water 26 from the fluid nozzle 22, it is more effective to perform cleaning from the front side of the honeycomb screen 17a with the cleaning water 32 from the cleaning nozzle 31. Can be cleaned.
[0047]
According to this example of illustration, the sludge adhering to the honeycomb screen 17a can be reliably removed by blowing off or washing.
[0048]
FIG. 4 shows another example of the embodiment of the fluid nozzle structure and the sludge removal method of the present invention. In this illustrated example, the separation liquid flow of the honeycomb screen 17a is applied to the pad 24 adhered to the fluid nozzle 22 with a predetermined pressing force. This is an example in which the surface is brought into contact with the downstream surface. That is, an arm 33 that extends upward is fixed to the top end of the fluid nozzle 22, and the upper end of the arm 33 is a beam that horizontally protrudes from a support member such as a side plate of the concentration tank 16 toward the honeycomb screen 17 a. The member 34 is pivotally supported via a horizontal pin 35 arranged in parallel with the fluid nozzle 22.
[0049]
A weight 37 is mounted on a pedestal 36 provided in the middle of the height direction of the arm 33 so as to give a rotational moment to the arm 33 in order to bring the fluid nozzle 22 close to the honeycomb screen 17a side. By moving the weight 37 in the direction of arrow A, the pressing force of the pad 24 against the honeycomb screen 17a can be adjusted.
[0050]
In this example, the pressing force of the pad 24 against the honeycomb screen 17a is adjusted by moving the weight 37, but the present invention can also be implemented by changing the weight of the weight 37. Instead of 37, an elastic / repellent means such as a spring may be provided.
[0051]
In the illustrated example, the pad 24 of the fluid nozzle 22 is pressed against the surface of the honeycomb screen 17a with a predetermined pressing force. Therefore, even if a shake occurs when the honeycomb screen 17a rotates (usually a shake of about 1 to 3 mm occurs). ) When the sludge is blown off and washed, the compressed air 25 and the washing water 26 do not leak to the surroundings, and the removal of the honeycomb screen 17a by blowing off and washing can be performed more reliably. Moreover, since the fluid nozzle 22 is not in direct contact with the honeycomb screen 17a as in the illustrated example described above, wear at the pressing portion of the fluid nozzle 22 can be prevented.
[0052]
In the fluid nozzle structure and the sludge removal method of the present invention, the case where the fluid nozzle 22 has a hollow cylindrical shape has been described. However, the fluid nozzle 22 is not limited to a cylindrical shape, and may be an elliptical cylindrical shape or a polygonal cylindrical shape. In addition, although the case where the width of the slit 23 of the fluid nozzle 22 gradually increases linearly from W1 to W2 has been described, the present invention can be implemented without linearly increasing (the width of the slit and the compressed air). Of course, the amount of blowout or the amount of spray of washing water is not necessarily directly proportional), and other various modifications can be made without departing from the scope of the present invention.
[0053]
【The invention's effect】
As described above, according to the fluid nozzle structure and the sludge removing method according to claims 1 to 7 of the present invention, the sludge attached to the honeycomb screen can be reliably blown off and washed, and the fluid nozzle can be used. When pressed against the honeycomb screen through the pad, it is possible to achieve an excellent effect that the wear of the fluid nozzle can be prevented.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a state in which fluid nozzles used in a fluid nozzle structure and a sludge removal method of the present invention are arranged on the back side of a honeycomb screen.
FIG. 2 is a view taken in the direction of arrows II-II in FIG.
FIG. 3 is an enlarged perspective view of a fluid nozzle used in the fluid nozzle structure and sludge removal method of the present invention.
4 is a view showing another example in which the fluid nozzle used in the fluid nozzle structure and the sludge removing method of the present invention is arranged on the back surface side of the honeycomb screen, and corresponds to a view taken in the direction of arrows II-II in FIG. It is.
FIG. 5 is a block diagram of a general concentration dehydration apparatus.
6 is a view taken in the direction of arrows VI-VI in FIG.
7 is a perspective view of an example of a sludge concentration unit structure in the concentration and dehydration processing apparatus shown in FIG.
FIG. 8 is a schematic plan view of FIG.
FIG. 9 is a perspective view of an example of a sludge concentrating portion structure disclosed in a prior application.
10 is a schematic plan view of FIG. 9. FIG.
[Explanation of symbols]
17a Honeycomb screen 22 Fluid nozzle 23 Slit 24 Pad 25 Compressed air 26 Cleaning water 33 Arm 37 Weight W1 Width W2 Width

Claims (7)

A fluid nozzle structure having a hollow cylindrical fluid nozzle, wherein the honeycomb screen rotates from the upper side to the lower side in the separated liquid flow direction downstream of the rotatable honeycomb screen that filters floc sludge. On the side facing the honeycomb screen of the fluid nozzle, the width in the circumferential direction is narrow on the rotation center side of the honeycomb screen, and the outer peripheral side of the honeycomb screen A fluid nozzle structure characterized in that a slit is formed so that it gradually becomes wider as it goes to. The fluid nozzle structure according to claim 1, wherein a pad that can be pressed on the surface of the honeycomb screen is fixed around a slit formed in the fluid nozzle. The fluid nozzle structure according to claim 1 or 2, further comprising a pressing means for attaching a fluid nozzle to an arm that can be moved close to and away from a downstream surface of the honeycomb screen in the separated liquid flow direction, and pressing the fluid nozzle against the honeycomb screen. . 4. The fluid nozzle structure according to claim 1, wherein the pressing means is a weight. The fluid nozzle structure according to claim 1, 2 or 3, wherein the pressing means is an elastic body. The sludge removal characterized by blowing compressed air from the fluid nozzle of the fluid nozzle structure in any one of Claims 1-5 at a honeycomb screen at the time of sludge concentration operation, and blowing off the sludge adhering to a honeycomb screen. Method. At the end of the sludge concentration operation, the sludge adhering to the honeycomb screen is washed by injecting cleaning water from the fluid nozzle of the fluid nozzle structure according to any one of claims 1 to 5. .

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