JP3832330B2 - Outer cylinder rotary concentrator and sludge separation and concentration method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to an outer cylinder rotary type concentrator and a sludge separation and concentration method, and in particular, an outer cylinder rotary type concentrator and sludge separation and concentration for concentrating and discharging sewage sludge that has been polymer-agglomerated in a pretreatment by a filtration separation method It is about the method.
[0002]
[Prior art]
As a concentrator used for concentrating sewage sludge, etc., a screw is concentrically placed on an outer cylinder composed of a screen (filter medium) on the cylindrical circumference, and the sludge placed in a horizontally arranged outer cylinder is rotated by the screw. Is known to be concentrated and discharged by a filtration separation method while being transferred in the axial direction of the outer cylinder (Japanese Utility Model Laid-Open No. 7-9406).
[0003]
In addition, an outer cylinder constituted by a screen on a cylindrical peripheral surface and a screw arranged concentrically in the outer cylinder rotate in opposite directions to each other and sludge placed in the outer cylinder arranged horizontally is screwed into the axis of the outer cylinder. An outer cylinder rotary type concentrator (Japanese Patent Application Laid-Open No. 2001-179492) is known which concentrates and discharges by a filtration separation method while being transferred in the direction.
[0004]
[Problems to be solved by the invention]
The outer cylinder rotary type concentrator has the feature that the outer cylinder and the screw rotate in the reverse direction, so that the sludge is sent out well and the concentration efficiency is high. The sludge inlet and the sludge outlet for discharging sludge from the inside of the outer cylinder to the outside of the outer cylinder are formed on the peripheral surface of the cylindrical central axis of the screw, so the size of the sludge inlet and sludge outlet can be increased. In addition, since the sludge flow is not linear, the concentrated sludge discharge resistance is large, and in the case of sewage sludge that has been polymer agglomerated in the pretreatment, there is a risk of destroying the polymer condensation flocs in the sludge. Can not do. In addition, there is a problem that sludge is easily clogged.
[0005]
Moreover, the conventional outer cylinder rotary type concentrator is difficult to adjust the sludge residence time in the outer cylinder, and lacks the adjustability of the sludge concentration process.
[0006]
The present invention has been made to solve the above-described problems, and has a low concentration resistance of concentrated sludge, there is no possibility of destroying the polymer flocs in the sludge, and a stable concentration treatment can be performed. The sludge flows smoothly and is not easily clogged, and the sludge residence time in the outer cylinder can be easily adjusted. The object is to provide a method for separating and concentrating sludge.
[0007]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, an outer cylinder rotary type concentrator according to the present invention has an outer cylinder in which both ends are closed by disk-shaped flange plates and the cylindrical peripheral surface is constituted by a screen made of a metal filter medium (punching metal) or the like. And a screw arranged concentrically in the outer cylinder, wherein the outer cylinder and the screw are driven to rotate in directions opposite to each other. A polymer central sludge which is a material to be treated on a shaft peripheral surface of a portion where the cylindrical central axis is located at one end side in the outer cylinder from the hollow cylindrical portion of the cylindrical central axis. An inlet opening to be introduced into the outer cylinder is provided, an outlet opening is formed in the flange plate on the other end side of the outer cylinder, and an outlet opening degree adjusting mechanism for adjusting the opening area of the outlet opening is increased or decreased. Provided in The Der substantially the same position opening edge of the outer tube outer peripheral side when viewed in the radial direction of the outer cylinder and the cylindrical circumferential surface by the screen of the outlet opening is, without the polymer flocs are broken, the concentrated sludge is the outlet It is characterized by being discharged out of the outer cylinder without receiving a discharge resistance larger than the opening .
[0008]
According to the outer cylinder rotating type concentrator having the above-described configuration, the concentration of the polymer agglomerated sludge to be treated introduced into the outer cylinder from the inlet opening of the cylindrical central shaft is increased by the reverse rotation of the outer cylinder and the screw. Concentrated sludge and the like are discharged outside the outer cylinder without receiving a larger discharge resistance than the outlet opening formed in the flange plate located in front of the transfer direction by the screw rotation (axial direction of the outer cylinder). In addition, the sludge residence time in the outer cylinder can be adjusted by adjusting the opening area of the outlet opening. Furthermore, the opening edge on the outer cylinder outer peripheral side of the outlet opening is substantially at the same position as seen in the radial direction of the cylindrical peripheral surface by the screen and the outer cylinder, and sludge does not accumulate in the outer cylinder after the operation is completed. Easy to clean.
[0009]
The outlet opening degree adjusting mechanism includes a shutter plate that is disposed so as to overlap with the flange plate formed with the outlet opening and can be rotationally displaced with respect to the flange plate, and the rotational displacement position of the shutter plate with respect to the flange plate Accordingly, the amount of closing of the outlet opening by the shutter plate can be increased or decreased.
[0010]
In order to achieve the above object, the method for separating and concentrating sludge according to the present invention has a substantially horizontal self-contained outer cylinder having both ends closed by disk-shaped flange plates and a cylindrical peripheral surface constituted by a screen. And rotating the screw concentrically arranged in the outer cylinder in the direction opposite to the rotation direction of the outer cylinder, and the polymer agglomerated sludge as the object to be treated is made into the cylindrical central axis of the screw. A mode in which the sludge is left in the outer cylinder from the inlet opening provided on the axial peripheral surface of the portion where the cylindrical central axis is located on one end side in the outer cylinder. The cleaning liquid is sprayed from the upper outside of the outer cylinder toward the cylindrical peripheral surface of the outer cylinder, and is provided on the outer peripheral surface of the cylindrical central shaft while continuously or intermittently cleaning the screen. On the screw blades In the process of transferring the sludge in the outer cylinder from one end side of the outer cylinder to the other end side and discharging it from the outlet opening formed at the flange position on the other end side of the outer cylinder, In addition, the sludge retention time in the outer cylinder is adjusted by increasing or decreasing the opening area of the outlet opening , the polymer flocs floc is not destroyed, and the concentrated sludge has a larger discharge resistance than the outlet opening. It is characterized by being discharged out of the outer cylinder without receiving .
[0011]
In the sludge separation and concentration method according to the present invention, the sludge filling rate in the outer cylinder is set to 50% or more and 90% or less in order to maintain the sludge separation and concentration efficiency and improve the cleaning recovery of the screen.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
[0013]
1 to 4 show one embodiment of an outer cylinder rotary type concentrator according to the present invention.
[0014]
The gantry 1 has left and right side plates 3 and 5, and a bearing sleeve 7 and a bearing bracket 9 are fixed to the side plates 3 and 5 on one horizontal axis X. The bearing sleeve 7 and the bearing bracket 9 rotatably support the outer cylinder 15 by bearing members 11 and 13.
[0015]
The outer cylinder 15 is composed of a metal screen 21 made of punched metal or the like with its both ends closed by disk-shaped flange plates 17 and 19 and its cylindrical peripheral surface. The short shaft sleeve 23 is fixed to one (left side) flange plate 17, and the bearing member 11 is attached to the inner peripheral side of the short shaft sleeve 23. A long shaft sleeve 25 is fixed to the other (right) flange plate 19, and a bearing member 13 is attached to the outer peripheral side of the long shaft sleeve 25.
[0016]
As shown in FIGS. 2 and 3, the cylindrical metal screen 21 has a half shape and is fixed at both ends to two semicircular members 27 </ b> A and 27 </ b> B fastened to each other by bolts and nuts 29. The left and right semi-annular members 27A and 27B are fastened to the flange plates 17 and 19 by bolts and nuts 31, respectively. A plurality of tie bars 33 are spanned between the left and right semi-annular members 27A, 27B, and a plurality of axially intermediate portions of the metal screen 21 are auxiliary-supported from the outside to the intermediate portions of the tie bars 33 in the axial direction. A single support ring 35 is attached.
[0017]
A sprocket 37 for rotating the outer cylinder is fixed to the long shaft sleeve 25. The sprocket 37 is drivingly connected to an electric motor for rotationally driving an outer cylinder (not shown), and rotationally drives the outer cylinder 15 in, for example, a counterclockwise direction (see FIG. 5).
[0018]
A screw 39 is concentrically disposed in the outer cylinder 15 so as to be rotatable. The screw 39 is concentrically connected to a cylindrical central shaft 41, a helical screw blade 43 provided on the outer peripheral surface of the cylindrical central shaft 41, and a closed end (right end) of the cylindrical central shaft 41. And a drive shaft 45.
[0019]
The cylindrical central shaft 41 is in the outer cylinder 15, and one end side (left side) extends into the bearing sleeve 7, and the extending shaft portion 47 is rotatably supported by the long shaft sleeve 7 by the bearing member 49. Yes. The front end surface of the extending shaft portion 47 is open, and the open end is an inlet 51 for sludge (object to be processed).
[0020]
The sludge of the object to be processed is placed in the outer cylinder 15 from the hollow cylinder portion 53 of the cylindrical central shaft 41 on the shaft peripheral surface of the portion where the cylindrical central shaft 41 is located on one end side (flange plate 17 side) in the outer cylinder 15. There are provided two inlet openings 55 to be introduced into the. The hollow cylindrical portion 53 of the cylindrical central shaft 41 has a closing plate 57 for preventing sludge of the object to be processed from entering the hollow cylindrical portion 53 to the right side in FIG. It is fixed.
[0021]
The rotary drive shaft 45 penetrates the long shaft sleeve 25 in the axial direction, and is rotatably supported by the long shaft sleeve 25. The rotary drive shaft 45 is drivingly connected to an electric motor for screw rotation drive (not shown). It is driven to rotate in the direction of rotation.
[0022]
The screw blades 43 transfer the sludge in the outer cylinder 15 from the left side (flange plate 17 side) to the right side (flange plate 19 side) in FIG. 1 by rotating the screw 39 in the clockwise direction. The outer peripheral edge of the screw blades 43 is opposed to the inner peripheral surface of the metal screen 21 with a minute gap so that the sludge does not short pass. If necessary, a scraper can be attached to the screw blade 43 and the metal screen 21 can be regenerated and recovered by scraping.
[0023]
A plurality of outlet openings 59 for discharging the concentrated sludge in the outer cylinder 15 to the outside of the outer cylinder 15 is formed in the flange plate 19. The outlet opening 59 is an arc-shaped opening concentric with the center of the outer cylinder 15, and the opening edge 61 on the outer peripheral side of the outer cylinder is seen in the radial direction of the cylindrical peripheral surface (inner peripheral surface) by the metal screen 21 and the outer cylinder 15. Are almost in the same position. This means that the metal screen 21 has no weir between the inner peripheral surface and the outlet opening 59. Thereby, after the operation is finished, the sludge does not accumulate in the outer cylinder 15 and cleaning becomes easy.
[0024]
As shown in FIG. 4, the flange plate 19 is arranged so as to overlap the outer surface of the flange plate 19 as an outlet opening degree adjusting mechanism for increasing or decreasing the opening area (effective area) of the outlet opening 59. The shutter plate 63 is fixed to the flange plate 17 by bolts 65 so as to be capable of rotational displacement. The shutter plate 63 has a blade shape portion 67 for each outlet opening 59, and the amount of closing of the outlet opening 59 by the blade shape portion 67 is uniform according to the rotational displacement position (fixed position in the rotation direction) with respect to the flange plate 19. Increase or decrease. The through hole 69 of the bolt 65 formed in the shutter plate 63 is an arc-shaped long hole concentric with the center of the outer cylinder 15, and the shutter plate 63 is moved by the bolt 65 within the range of the through hole 69. It can be fixed at an arbitrary rotational angle position with respect to the flange plate 19.
[0025]
A cleaning pipe 71 for jetting cleaning liquid is fixedly disposed above the outer cylinder 15 in such a manner as to span between the left and right side plates 3 and 5. The cleaning pipe 71 is disposed at a position slightly deviated from the position directly above the outer cylinder 15 toward the rotation direction of the outer cylinder 15 so that the cleaning liquid sprayed from the cleaning pipe 71 is efficiently applied to the metal screen.
[0026]
Next, a method for separating and concentrating sludge using the outer cylinder rotary concentrator having the above-described configuration will be described.
[0027]
The outer cylinder 15 is rotated in the counterclockwise direction and the screw 39 is rotated in the clockwise direction opposite to the rotation direction of the outer cylinder 15, respectively. The material is continuously charged into the hollow cylindrical portion 53 from the charging port 51 of the portion 47. This sludge enters the outer cylinder 15 through the inlet opening 55 through the hollow cylinder portion 53 and is transferred from one end side (left side) to the other end side (right side) of the outer cylinder 15 by the rotating screw blades 43. .
[0028]
In this transfer process, the liquid component (filtrate) in the sludge permeates the metal screen 21 and separates and flows out downward of the outer cylinder 15 to concentrate the sludge. The concentrated sludge is transferred in the transfer direction (axial direction). Without being changed, each outlet opening 59 is smoothly discharged to the outside of the outer cylinder 15.
[0029]
Thereby, concentrated sludge can be discharged | emitted out of the outer cylinder 15, without receiving large discharge resistance, and the floc which the polymer aggregated is not broken. Moreover, the sludge residence time in the outer cylinder 15 can be easily adjusted by increasing / decreasing the effective area of the outlet opening 59 by the shutter plate 63.
[0030]
In the above-described sludge concentration process, the cleaning liquid is sprayed onto the metal screen 21 forming the cylindrical peripheral surface of the outer cylinder 15 by the cleaning pipe 71 located above the outer cylinder 15, thereby cleaning the metal screen 21. As a result of the rotation, the entire outer cylinder filtering area (entire circumference) by the metal screen 21 acts effectively, and the processing capability is dramatically improved. In this case, in order to maintain the sludge separation / concentration efficiency at a good level and improve the recovery of the cleaning of the metal screen 21, as shown in FIG. % Or less is preferable.
[0031]
Concentrated sludge is continuously and efficiently concentrated due to the effect of conveying the concentrated sludge by rotating the screw and the effect of scraping the filter surface by the differential speed of the tip of the screw blade 43 rotating in the opposite direction to the outer cylinder filter surface (metal screen 21). Is done. The reverse rotational speed difference between the outer cylinder 15 and the screw 39 can be optimally set according to the sludge, and is preferably 4 RPM or more. Moreover, although washing | cleaning is always performed continuously, when filterability is good, you may make it perform intermittently instead of continuously. Furthermore, when the filterability is very good, it is possible to dispense with washing water.
[0032]
【The invention's effect】
As will be understood from the above description, according to the outer cylinder rotary concentrator and the sludge separation and concentration method according to the present invention, the polymer agglomerated sludge and the like to be treated introduced into the outer cylinder from the inlet opening of the cylindrical central shaft. Concentration of the material is performed with high efficiency by reverse rotation of the outer cylinder and the screw, and the concentrated sludge and the like are from an outlet opening formed in a flange plate located in front of the transfer direction by the screw rotation (axial direction of the outer cylinder). Because it is discharged outside the outer cylinder without receiving a large discharge resistance, there is no risk of destroying the polymer flocs in the sludge, stable concentration treatment can be performed, and the sludge flows smoothly and hardly clogs. Become. In addition, the sludge residence time in the outer cylinder can be adjusted by adjusting the opening area of the outlet opening. In the outer cylinder rotary concentrator according to the present invention, the opening edge of the outlet opening on the outer cylinder outer peripheral side is substantially in the same position when viewed in the radial direction of the cylinder outer surface by the screen and the outer cylinder, and after the operation is finished. The sludge does not accumulate in the outer cylinder, and cleaning becomes easy.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an embodiment of an outer cylinder rotary concentrator according to the present invention.
FIG. 2 is a front view of a metal screen portion of an outer cylinder rotary concentrator according to the present invention.
3 is a cross-sectional view taken along line III-III in FIG.
FIG. 4 is an end view of the outer cylinder of the outer cylinder rotary type concentrator according to the present invention.
FIG. 5 is an explanatory view showing a usage state of the outer cylinder rotary concentrator according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Stand 15 Outer cylinder 17, 19 Flange board 21 Metal screen 39 Screw 41 Cylindrical center axis 43 Screw blade 55 Inlet opening 59 Outlet opening 63 Shutter board

Claims (4)

An outer cylinder having both ends closed by disk-shaped flange plates and a cylindrical peripheral surface constituted by a screen, and a screw concentrically disposed in the outer cylinder, the outer cylinder and the screw being in opposite directions to each other In the outer cylinder rotary type concentrator that is rotationally driven, the screw has a cylindrical central axis having screw blades on the outer peripheral surface, and the cylindrical central axis is located at one end side in the outer cylinder. An inlet opening for introducing the polymer agglomerated sludge , which is an object to be processed, into the outer cylinder from the hollow cylinder portion of the cylindrical central shaft is provided on the peripheral surface, and an outlet opening is provided in the flange plate on the other end side of the outer cylinder. An outlet opening degree adjusting mechanism that is formed and adjusts the opening area of the outlet opening to be increased or decreased is provided in the outer cylinder, and an opening edge on the outer cylinder outer peripheral side of the outlet opening is a diameter of the cylindrical peripheral surface by the screen and the outer cylinder. Almost identical when viewed in the direction Der is, without the polymer flocs are broken, the concentrated sludge is external cylinder rotary concentrator, characterized in that it is discharged to the outside of the outer tube without being the outlet opening is greater than the discharge resistance.   2. The outer cylinder rotary type concentrator according to claim 1, wherein the outlet opening degree adjusting mechanism includes a shutter plate that is disposed so as to overlap with a flange plate in which the outlet opening is formed and is rotatable and displaceable with respect to the flange plate. An outer cylinder rotary type concentrator that increases or decreases the closing amount of the outlet opening by the shutter plate according to the rotational displacement position of the shutter plate with respect to the flange plate. Both ends are closed by disk-shaped flange plates, and the outer cylinder constituted by the screen with the cylindrical peripheral surface is rotated about its own central axis, and the screw disposed concentrically in the outer cylinder is Rotating in the direction opposite to the rotation direction of the outer cylinder, supplying the polymer agglomerated sludge as the object to be processed to the hollow cylinder portion of the cylindrical central axis of the screw, and the cylindrical central axis is inside the outer cylinder Introduced in such a manner that an upper space is left in the outer cylinder from an inlet opening provided on a shaft peripheral surface of a portion located on one end side of the outer cylinder, and cleaning liquid is introduced into the cylindrical peripheral surface of the outer cylinder from above the outer cylinder. The sludge in the outer cylinder is removed from the one end side of the outer cylinder by screw blades provided on the outer peripheral surface of the cylindrical central axis, while continuously or intermittently cleaning the screen. Transferred to the end side of the outer cylinder In the course of discharging from an outlet opening formed in the flange position of the end side, performs a filtering of the sludge by said screen, said increases or decreases adjusting the opening area of the outlet opening by adjusting the sludge residence time in the outer tube The method for separating and concentrating sludge, characterized in that the polymer coagulation floc is not destroyed and the concentrated sludge is discharged outside the outer cylinder without receiving a discharge resistance larger than the outlet opening .   4. The method for separating and concentrating sludge according to claim 3, wherein the sludge filling rate in the outer cylinder is 50% or more and 90% or less.

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