JP2004298936A - Supporting structure of dehydration plate for sludge treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a dehydration plate supporting structure which can suppress increase of friction resistance by supporting a movable dehydration plate with bearings and can reduce driving energy, in the dehydration plate supporting structure equipped with a sludge treatment mechanism having the movable dehydration plate. <P>SOLUTION: A sludge concentration apparatus is equipped with a concentration mechanism which applies gravitational natural dehydration to remove water from the sludge and concentrates it. The concentration mechanism is composed of a plurality of dehydration plate groups each of which has a plurality of vertical dehydration plates 2, 3 set parallel to each other at a designated interval, and has the dehydration plate supporting structure. The upper face of each dehydration plate group of the concentration mechanism has an upward slope toward an exit side. One group of a plurality of dehydration plates 2, 3 is made movable while the other are made stationary. Sludge transfer elements 4 are formed on the upper face of the movable dehydration plates 3, and a driving unit is attached to give each motion of upward, forward, downward and backward in series to the movable dehydration plates 3. The dehydration plate supporting structure is constituted by connecting a movable shaft 3x with a crank shaft 13, and the movable shaft 3x composed of a center shaft 3xa and a hollow shaft 3xb. The center shaft 3xa is connected to the crank shaft 13 while the hollow shaft 3xb supports the movable dehydration plates 3 rotationally so that the friction of the movable shaft 3x is reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a dewatering plate support structure that rotatably supports a dewatering plate group of a sludge treatment device that concentrates or dewaters sludge water.
[0002]
[Prior art]
Decreasing the water content of the sludge is performed by concentrating the sludge in a human waste treatment facility or the like, and then dehydrating the water from the concentrated sludge, and performing solid-liquid separation into a separated liquid and a dewatered cake. This is a necessary process in the processing step. A typical example of a dehydrator for dewatering sludge is a filter dehydrator using a filter cloth. Examples of the dehydrator include a pressurized container type filter, a rotary vacuum type filter, and a centrifugal type dehydrator. And a belt press. As an example of the belt press, a “sludge dewatering device” of Patent Document 1 is known. In this sludge dewatering device, a suction chamber for sucking moisture is provided in contact with an endless screening belt that filters moisture in sludge, and a suction unit is connected to the suction chamber to set the inside of the suction chamber to a negative pressure state. Is configured.
[0003]
In addition to the filter cloth type, there is also a punch plate type, and as a modified example thereof, a “dehydrating device” of Patent Document 2 is known. The dewatering device includes a slurry supply unit that supplies slurry, a dewatering unit that dewaters the slurry, a cake discharge unit that discharges cake after dewatering, and a cake that is arranged above the dewatering unit and that is being dewatered and is pressed against the dewatering unit. A pressurizing unit, and the dewatering unit includes a plurality of dewatering plate groups each including a plurality of flat plates whose plate surfaces are arranged in parallel at predetermined intervals in a vertical direction, and each flat plate of each dewatering plate group is alternately and Adjacent flat plates are arranged at a predetermined distance from each other, and at least one of the dehydrating plate groups sequentially performs ascending, advancing, descending, and retreating so that the phases of the dehydrating plate groups are relatively shifted. It comprises a part.
[0004]
In the above dewatering device, a method of dewatering by dropping water by gravity through the respective gaps of the dewatering plate group, from sludge thrown on a plate-shaped dewatering plate group vertically arranged at predetermined intervals. Has been adopted. On the other hand, as a method of condensing sludge, generally, sludge is put into a sedimentation tank or a concentration tank, and gravity is used to separate the liquid into an upper layer and a lower layer of concentrated sludge. A flotation method or the like is employed in which fine bubbles are generated by stirring or blowing air under pressure, and sludge is attached to the bubbles to float and separate.
[0005]
[Patent Document 1]
JP-A-58-17810 [Patent Document 2]
JP-A-6-155090
[Problems to be solved by the invention]
By the way, reducing the water content of sludge by several percent significantly reduces the volume of surplus sludge. For example, the operation of transporting surplus sludge and the like generated in agricultural settlement drainage treatment plants to human waste treatment facilities and the disposal cost of sludge are reduced. Since it is advantageous in reduction and the like, sludge concentration treatment is required for sludge that has undergone such treatment. In particular, although the reduction of the volume is effective in transporting excess sludge, the above-mentioned dewatering device is of a type that is installed in a human waste treatment facility or the like. The required power is also large. Therefore, these devices cannot be used for a simple thickening treatment of sludge such as a thickening treatment for transporting sludge generated in an agricultural settlement, and there is no example in which such a proposal has been made.
[0007]
Therefore, the sludge dewatering device described in Patent Literature 2 as a sludge concentrating device meeting such a demand is to omit the pressurizing section and to make one of the two movable dewatering plate groups a fixed dewatering plate group. Thus, it is conceivable to obtain a sludge concentrating apparatus which is compact, omitted, reduced in weight, and economical in cost. However, when such a device is configured, the movable dewatering plate group is rotatably supported by a movable shaft connected via a bearing provided at an eccentric position of the crankshaft, and the movable shaft is caused to circularly move by rotation of the crankshaft. Configuration.
[0008]
When such a drive mechanism is adopted, when the crankshaft is rotated, the self-aligning action of the bearing causes the movable shaft to pry in the bearings on both sides, increasing the friction and increasing the wear of the bearing. The driving energy increases. For this reason, a special bearing having high wear resistance is required as a bearing in order to have a structure that can sufficiently withstand this, and the production cost is increased.
[0009]
The present invention suppresses an increase in frictional resistance by supporting a movable dewatering plate with a bearing in a dehydrating plate supporting structure including a sludge treatment mechanism having a movable dewatering plate, noting the problems of the above-described conventional device, An object of the present invention is to provide a dehydrating plate supporting structure capable of reducing driving energy.
[0010]
[Means for Solving the Problems]
As a means for solving the above-mentioned problems, the present invention provides a sludge treatment mechanism that naturally dehydrates the water of sludge supplied from one end by gravity, or dewaters under pressure and discharges it from the other end, with the plate surface oriented vertically. A plurality of flat plates are constituted by a dehydration plate group arranged at predetermined intervals in parallel with each other, and a movable shaft that rotatably supports the movable dehydration plate group among the dehydration plate groups is a central shaft and a hollow shaft inserted into the outer periphery thereof. , And a movable dewatering plate group is rotatably mounted on the hollow shaft, and the dewatering plate supporting structure for the sludge treatment apparatus is configured so that the center shaft is connected to and supported at the eccentric position of the crankshaft.
[0011]
According to the dewatering plate support structure of the present invention having the above-described structure, the movable dewatering plate is operated smoothly and efficiently, and sludge treatment is effectively performed. The target sludge treatment apparatus includes a sludge thickening apparatus and a sludge dewatering apparatus, and both types of apparatuses have a movable dewatering plate. The movable dewatering plate is rotatably mounted on a movable shaft eccentrically connected to the crankshaft, and the crankshaft is rotated by a drive unit to make the movable shaft circularly move, thereby raising, moving forward, descending, and retreating the movable dewatering plate. Are performed, and a concentration or dehydration treatment is performed.
[0012]
During the concentration or dehydration treatment, sludge is placed on the dehydration plate, and the load acts on the dehydration plate. However, since the movable shaft is formed as a double shaft consisting of a middle shaft and a hollow shaft fitted to the outside, the load is increased by fixing the middle shaft to the crankshaft and rotatably supporting the dewatering plate with the hollow shaft. It can be distributed as a distributed load in the direction. Therefore, when the crankshaft is rotated, the movable shaft moves circularly, and each of the upward, forward, downward, and backward movements of the movable dewatering plate can be efficiently performed with small friction. In the conventional support structure in which the movable shaft is supported on the crankshaft by the bearing, the above configuration prevents the occurrence of the rubbing motion during the circular motion of the movable shaft in the bearing. As a matter of course, the driving energy can be reduced by eliminating the rubbing motion.
[0013]
Embodiment
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an essential part of a sludge concentrating apparatus provided with a dewatering plate support structure of an embodiment, FIG. 2 is a front view of the same apparatus as viewed from an arrow II-II in FIG. 1, and FIG. . As shown in the figure, the sludge concentrator comprises a fixed dewatering plate group 2 in which a plurality of flat plates whose plate surfaces are oriented vertically are arranged between two inner plates 1 and 1 and a movable dewatering plate group 3. And a driving unit B for driving the movable dehydrating plate group 3 via the crankshaft 13.
[0014]
Each dehydration plate of the fixed dehydration plate group 2 and the movable dehydration plate group 3 has a plurality of elongated flat plates whose plate surfaces are vertically oriented at predetermined intervals, and the fixed dehydration plate 2 and the movable dehydration plate 3 are alternately arranged. Adjacent flat plates are arranged at predetermined intervals. The fixed dewatering plate group 2 and the fixed dewatering plate 2 and the movable dehydration plate group 3 and the movable dewatering plate 3 are denoted by the same reference numerals because they have the same group of members and one plate. Hereinafter, the single dewatering plates 2 and 3 will be described as representatives unless otherwise specified.
[0015]
Fixed dewatering plate 2, none of the movable dewatering plate 3 rising piece 2 _H, 3 _H is provided at its one end, this one end as a supply position S of the sludge, is formed so as sludge does not flow out to the rear. The fixed dewatering plate 2 is fixed to the inner plates 1 and 1 by fixed shafts 2x penetrating both ends and rising pieces, and the movable dewatering plate 3 is a movable shaft inserted through support pieces 3a and 3a extending downward near both ends. It is supported by 3x, 3x, and is driven by making the movable shafts 3x, 3x circularly move on the crankshaft 13 as described later. In addition, 1x is a connection shaft that connects the inner plates 1 and 1.
[0016]
When the upper surfaces of the movable dehydrator plates 3 and the upper surfaces of the fixed dehydrator plates 2 are stopped, the upper surfaces of the dehydrator plates 2 and 3 in both groups form a substantially planar shape. It is provided so as to form an upward inclination at a predetermined angle toward the discharge section T in front of the other end. Further, on the upper surface of the movable dewatering plate 3, a large number of saw-tooth-shaped tooth pieces (projections) are continuously provided as sludge feed elements 4 for promoting feed to sludge. 5 is a spacer.
[0017]
As shown in FIG. 2, the enrichment mechanism A is supported on outer plates 10 and 10 via a crankshaft (eccentric shaft) 13. As can be seen from the plan view of FIG. 3, the crankshafts 13 are provided on the left and right sides near the front and rear ends in the longitudinal direction of the apparatus (total of four places). The bearing unit 11 is connected to a rotating shaft 11x supported by the bearing unit 11. Sprockets 12a and 12b are provided on the rotating shaft 11x, and the sprockets 12a are provided near both ends of a power shaft 15x connected to an output shaft of an electric motor 15 which is an actuator of the driving unit B. A chain 14a is wound around the shaft 15a, and the crankshaft 13 is rotated. A chain 14b is wound around the sprocket 12b between the front and rear sprockets 12b, 12b and is driven synchronously.
[0018]
As shown in FIG. 5, the movable dehydrating plate 3 is rotatably attached to the movable shaft 3x, and both ends of the movable shaft 3x are connected to and fixed to the crankshaft 13. The crankshaft 13 is supported by a bearing unit (member) 11 attached to a pair of left and right outer plates 10 and 10, and the movable shaft is a double shaft composed of a central shaft 3xa and a hollow shaft 3xb rotatably inserted around its outer periphery. The central shaft 3xa is eccentrically fixed to the crankshaft 13, and the movable dewatering plate 3 is rotatably mounted on the hollow shaft 3xb. The eccentric crankshaft is rotated by the power of the motor 15 to move the multi-axis movable shaft 3x in a circular motion, whereby the movable dewatering plate 3 is formed so as to be able to move upward, forward, downward and backward. I have.
[0019]
The sludge concentrating apparatus of this embodiment having the above-described configuration is used for condensing sludge for the convenience of transporting sludge such as human waste generated in agricultural settlements and the like, and for increasing the efficiency of subsequent processing operations. . In order to effectively concentrate the sludge fed into this apparatus, a flocculant is previously charged into a storage tank to form flocculated sludge, and this flocculated sludge is fed from a supply position S of the apparatus. When the coagulated sludge is introduced, the water is concentrated to a predetermined moisture content on the inclined surface formed by the fixed dewatering plate 2 and the movable dewatering plate 3 and is discharged to the discharge part T at the front end.
[0020]
As is well known, the concentration of sludge is for greatly reducing the volume of sludge. Even if the water content is reduced by only a few percent, the volume is reduced to a fraction. This is because, for example, when sludge having a water content of 98% is concentrated to 96%, the relationship between the volume V of the sludge having the water ratio P and the volume V 'of the sludge having the water ratio P ′ is V ′ = V · (1−P). / (1−P ′), V ′ = V · (1−0.98) / (1−0.96) = V · 0.02 / 0.04 = 1 / 2V. It is easily understood from the fact that the volume is / 2. The apparatus in the illustrated example is developed with the objective of concentrating the sludge having a water content of 98.5 to 98% to a water content of 3 to 5% and achieving a function of reducing the volume to 1/2 to 1/3. It was done.
[0021]
Now, sludge is supplied to the supply position S of the concentrator at the timing shown in FIG. 6A (a). The sludge may be charged at any timing from the diagram (a) of FIG. 6A to the diagram (h) of FIG. 6B described later, but for convenience, the description will be made on the assumption that the sludge is charged in the state of the diagram (a). I do. (B) In the figure, the movable dewatering plate 3 further sinks down to approximately half the height of the fixed dewatering plate 2 and the movable dewatering plate 3 is lowered to the lowermost position. FIGS. 7A and 7B show cross-sectional states of the relationship between the fixed dewatering plate 2 and the movable dewatering plate 3 in FIG. 6B (h) and FIG. 6A (a).
[0022]
When the overlap between the fixed dewatering plate 2 and the movable dewatering plate 3 changes from the state shown in FIG. 6A to the state shown in FIG. 6B, a predetermined gap is previously provided between the fixed dewatering plate 2 and the movable dewatering plate 3. 5, the water contained in the sludge falls downward from the gap by natural fall due to gravity, but the overlap of both dewatering plates is slightly lower than the upper surface of the fixed dewatering plate 2 in FIG. (B), the height of the dewatering plate 2 changes to about half of the height, so that the resistance due to the gap when the desorbed liquid passes from the fixed dewatering plate 2 to below the movable dewatering plate 3 gradually decreases, While the desorbed liquid changes from the state shown in FIG. 6A to the state shown in FIG. 6B, most of the liquid that can be desorbed drops and is desorbed (see also FIG. 7).
[0023]
In the state of the intermediate position in FIG. 6C (c), the movable dewatering plate 3 rises from the lowermost position and rises slightly below the upper surface of the fixed dewatering plate 2 and overlaps. It increases in the direction opposite to the direction in which the liquid is dropped, the resistance of the gap to the liquid to be removed increases, and the liquid to be released can only fall very slightly.
[0024]
In FIG. 6D, the movable dewatering plate 3 further rises from the state shown in FIG. 6C by circular motion and is located at the rearmost position, and the upper surface of the movable dewatering plate 3 is slightly higher than the upper surface of the fixed dewatering plate 2. To rise. Therefore, the sludge is supported on the upper surfaces of both dewatering plates 3. At the intermediate position in FIG. 6E (e), the upper surface of the movable dewatering plate 3 rises above the upper surface of the fixed dewatering plate 2, as opposed to the intermediate position in FIG. 6A and FIG. The overlap is approximately half of the height of the movable dewatering plate 3. Therefore, the sludge supported on the fixed dewatering plate 2 is transferred onto the movable dewatering plate 3 and lifted.
[0025]
In FIG. 6F, the movable dewatering plate 3 comes out above the upper surface of the fixed dewatering plate 2 to be at the uppermost position, and the sludge is lifted to the uppermost position and moved forward from the position shown in FIG. 6D. (G) At the intermediate position in the figure, the height position of the movable dewatering plate 3 is lower than in the figure (f), but the sludge is moved further forward than in the figure (f). (H) Although the movable dewatering plate 3 has an upper surface near the same level as the fixed dewatering plate 2 at the foremost position in the figure, the sludge is sent to the frontmost position and the sludge is transferred to the fixed dewatering plate 2. 6A (d) to 6B (h), dehydration is performed during rotation of the movable dehydrating plate 3 due to a change in resistance to liquid leaving the gap.
[0026]
(H) After the sludge is sent to the foremost position in the state shown in the figure, the movable dewatering plate 3 is lowered again and the state changes to the intermediate position in the figure (a). When the movable dewatering plate 3 is brought to the frontmost position, the sludge can be discharged to the front discharge section T once the water is released from the water and the sludge is sent forward from the charging position. The sludge is discharged in the cycle, but if the sludge cannot be discharged in one cycle, the above cycle is repeated a plurality of times, two or three times, to send the sludge forward and discharge. Become. In the discharge cycle, the upper surfaces of the fixed dewatering plate 2 and the movable dewatering plate 3 are inclined upward and forward so that the sludge stays on the dewatering plate for a certain period of time and is forced forward by the sludge feed element. I send it to
[0027]
When the above operation cycle is repeated to condense sludge, sludge is thrown into the fixed dewatering plate 2 and the movable dewatering plate 3, and this sludge load acts on both dewatering plates 2 and 3. The load acting on the dehydrating plate 3 acts in a distributed manner in the length direction of the movable shaft 3x. The movable shaft 3x includes a center shaft 3xa and a hollow shaft 3xb. The center shaft 3xa is fixed to the crankshaft 13, and the movable dewatering plate 3 is rotatably supported by the hollow shaft 3xb. Therefore, the distributed load acting on the movable shaft 3x is supported by the central shaft 3xa and the hollow shaft 3xb, and even if the central shaft 3xa makes a circular motion by rotating the crankshaft 13, the frictional force between the movable shaft 3x and the hollow shaft 3xb decreases. , The movable shaft 3x rotates smoothly, and therefore the driving energy also decreases.
[0028]
On the other hand, in the conventional configuration in which the movable shaft 3x does not employ a multi-shaft configuration as described above, the movable shaft 3x is rotatably supported on the crankshaft 13 so that it is naturally supported by bearings. The self-aligning action of the bearing causes the movable shaft to make a rubbing motion within the bearing, resulting in increased friction and increased drive energy. However, in this embodiment, a double-shaft configuration is employed, so that the sliding motion is eliminated, the friction is not increased, and the driving energy is reduced. Further, the use of the hollow shaft increases the rigidity of the movable shaft and further improves the durability.
[0029]
In the above-described embodiment, the sludge feed element 4 has been described as an example including saw-tooth-shaped tooth pieces. However, the present invention is not limited to this, and any other shape may be used as long as sludge can be fed effectively. The fixed shaft 2x is provided so as to be adjustable in position so that the inclination of the upper surface of the fixed dewatering plate 2 can be finely adjusted. Note that no pressurizing member is provided above the fixed dewatering plate 2 and the movable dewatering plate 3.
[0030]
Further, in the illustrated example, the movable dehydrating plate 3 is moved upward, forward, downward, and backward by the crankshaft 13 and the motor 15. However, as a mechanism for performing each of the above operations, for example, a lifting cylinder, A configuration may be adopted in which a cylinder that moves in the horizontal direction is attached to the movable dehydrating plate 3 via a link mechanism, and any cylinder capable of performing the above operations may be used.
[0031]
Further, in the above embodiment, the example of the sludge concentrating device is shown, but the dehydrating plate supporting structure having the movable dehydrating plate can be applied to the dehydrating device disclosed in Japanese Patent Application Laid-Open No. 6-155090. This dewatering device is a device in which a pressurizing section is provided to the above-mentioned sludge concentrating device, and two dewatering plate groups are both movable dewatering plates, and is a device for separating and removing most of the water contained in the sludge. If the movable dehydrating plate of this dehydrating device is also supported by the movable shaft of the above embodiment, the operation of the dehydrating device becomes smooth and the driving energy can be reduced.
[0032]
【The invention's effect】
As described in detail above, the dewatering plate support structure of the present invention supports the movable dewatering plate of the sludge treatment mechanism rotatably on the movable shaft, the movable shaft is formed from a center shaft and a hollow shaft, and the center shaft is a crankshaft. And the movable dewatering plate is rotatably mounted on the hollow shaft, so that even if a sludge load acts on the movable dewatering plate, the load can be distributed in the axial direction. The rotation is supported by the small friction between the hollow shafts, so that the effect is obtained that the operation is smooth and the driving energy is reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the inside of a main part of a sludge concentrating apparatus according to an embodiment; FIG. 2 is a front view as viewed from an arrow II-II in FIG. 1; FIG. 3 is a plan view of the same apparatus; FIG. FIG. 5 is an enlarged cross-sectional view taken along line VV in FIG. 4 (a detailed cross-sectional view of the movable shaft and the crankshaft).
FIG. 6A is an explanatory view of a thickening action by a sludge thickening mechanism. FIG. 6B is an explanatory view of a thickening action by a sludge thickening mechanism. FIG. 7 is an explanatory view of an enlarged cross section of the thickening action. FIG. 8 is an arrow VIII-VIII in FIG. Bottom view as seen from above [Explanation of symbols]
1 inner board 2 fixed dewatering board (group)
3 movable dehydration board (group)
4 Sludge feed element 5 Spacer 10 Outer plate 13 Crank shaft 15 Motor S Supply position T Discharge section

Claims (3)

A sludge treatment mechanism that naturally dehydrates the water of the sludge supplied from one end by gravity, or dewaters under pressure and discharges from the other end, has a plurality of flat plates whose plate surfaces are vertically arranged at predetermined intervals in parallel with each other. A movable shaft for rotatably supporting the movable dehydrating plate group of the dehydrating plate group is formed as a double shaft composed of a central shaft and a hollow shaft inserted around its outer periphery. A dewatering plate support structure for a sludge treatment device in which a plate group is rotatably mounted and a center shaft is connected and supported at an eccentric position of a crankshaft. The dewatering device for a sludge treatment apparatus according to claim 1, wherein the movable dewatering plate group is connected to a driving unit via a crankshaft so as to perform ascent, forward, descend, and retreat movements. Board support structure. The sludge treatment apparatus according to claim 1, wherein the sludge treatment mechanism includes a plurality of groups of movable dewatering plates and a pressing unit, and a movable shaft of each movable dehydration plate is formed as a double shaft. Dehydration plate support structure.

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