JP2008149256A - Sludge flocculation tank and sludge concentration apparatus equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sludge flocculation tank capable of rationalizing a circulating flow and a revolving flow to stably form good sludge flocs and easily detaching a baffle set to simply perform replacement, cleaning, etc. <P>SOLUTION: In the sludge flocculation tank 1 equipped with a tank body 2 and a stirrer 4 constituted by attaching stirring blades 6 and 7 to a rotary shaft 5 provided along the axial center of the tank body 2 and constituted so as to flocculate sludge by stirring the mixture of sludge and a flocculant supplied to the tank body 2 by the stirrer 4 to form flocculated sludge, the baffle set 10 constituted by attaching a baffle plate 9 to a spindle 8 is attached in such a manner as to be detachable along the inner wall of the tank body 2 and rotatable around the spindle 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sludge agglomeration tank that forms a sludge floc by agitating a mixture of sludge and a flocculant supplied to a tank body with a stirrer, and a sludge concentrator equipped with the same.

  In order to discard or incinerate various types of sludge, the sludge is dehydrated with a dehydrator. However, it is difficult to efficiently dehydrate sludge only with the processing capacity of the dehydrator. For this reason, prior to the dewatering treatment by the sludge dehydrator, the sludge is concentrated by the sludge concentrating device.

  The sludge concentrator includes a sludge agglomeration tank and a sludge concentrator that concentrates the sludge by filtering the moisture contained in the agglomerated sludge supplied from the sludge agglomeration tank and discharging it as a separation liquid. . Here, the prior art example of a sludge aggregation tank is shown in FIG.

  FIG. 5 is a longitudinal sectional view of a conventional sludge agglomeration tank. A sludge agglomeration tank 101 shown in FIG. 5 includes, for example, a cylindrical tank body 102 having an upper surface opened and a stirrer 104 provided inside the tank body 102. The stirrer 104 includes a motor 103 as a driving source, a rotary shaft 105 provided in the vertical direction along the axial center of the tank body 102, and two upper and lower stirring blades attached to the rotary shaft 105. 106 and 107.

  In this sludge aggregation tank 101, sludge (raw mud) is supplied from the raw mud supply pipe 121 to the lower part of the tank body 102. For example, a polymer is added to the sludge flowing through the raw mud supply pipe 121 as a flocculant, The sludge to which this polymer is added is stirred by the stirrer 104 in the tank body 102, and the sludge is floculated into solid components contained in the sludge, and this aggregated sludge is connected to the upper part of the tank body 102. The aggregated sludge introduction pipe 122 is supplied to a sludge concentrator (not shown) and concentrated.

  By the way, when the stirring blades 106 and 107 of the stirrer 104 rotate in the illustrated arrow direction in the sludge aggregation tank 101, a swirl flow and a circulating flow are generated in the tank body 102 as the sludge flow. Here, the swirl flow is a flow that rotates in the horizontal direction as the rotary blades 106 and 107 rotate, and the circulating flow rotates the sludge discharged toward the inner wall of the tank body 102 by the rotary blades 106 and 107. This is a flow that recirculates toward the center without the blades 106 and 107. These swirl flow and circulation flow are generated around the upper and lower stirring blades 106 and 107, respectively, but FIG. 5 shows the swirl flow and circulation flow separately for convenience.

  Thus, in the reaction between the sludge and the polymer in the sludge agglomeration tank 101, appropriate mixing and stirring is required, and for this purpose, the polymer needs to be diffused by an appropriate circulation flow. In addition, the growth of sludge flocs requires collision and contact between the sludge flocs, the sludge flocs and the stirring blades 106 and 107, and the sludge flocs and the inner wall of the tank body 102. For this purpose, an appropriate swirl flow is required. Become. Therefore, the balance between the circulation flow and the swirl flow is an important factor for the reaction between the sludge and the polymer and the growth of the sludge floc.

  By the way, since the mixture of sludge and polymer has viscosity, the stirring blades 106 and 107 need a certain length and area. However, if the area of the stirring blades 106 and 107 is increased in this way, The mixture of sludge and polymer rotates in synchronism with the rotation of the stirring blades 106 and 107, resulting in a dead space where the mixing action does not work in the center, and the mixing and stirring of the sludge and the polymer is insufficient. The problem that a sludge floc is not formed occurs.

  Therefore, as shown in FIGS. 6 and 7, vertical rib-shaped baffle plates 109 are attached to a plurality of circumferential positions (four in the illustrated example) on the inner wall of the tank body 102, and sludge and polymer are separated by these baffle plates 109. It is practiced to prevent co-rotation of the mixture. 6 is a longitudinal sectional view of a conventional sludge agglomeration tank, and FIG. 7 is a sectional view taken along line BB in FIG.

Also, as shown in the longitudinal sectional view of FIG. 8, a plurality of plate-like baffle plates 109 'extending horizontally toward the center are attached to the upper and lower sides of the stirring blades 106, 107 on the inner wall of the tank body 101, and these There has also been proposed a method in which the flow of the mixture near the inner wall is guided toward the center by the baffle plate 109 'to promote the generation of a circulating flow and prevent the mixture from co-rotating (Patent Document 1).
reference).
Japanese Patent No. 3460842

  By the way, in the sludge aggregation tank 101 shown in FIG.6 and FIG.7, cancellation | release of the co-rotation phenomenon of a mixture is limited to the vicinity of the inner wall of the tank main body 102, and there exists a problem that the effect of co-rotation prevention is inadequate.

  Further, according to the sludge agglomeration tank 101 shown in FIG. 8, it is possible to relatively effectively prevent the co-rotation phenomenon, but the mounting angle of the baffle plate 109 ′ cannot be adjusted. Depending on the type and nature, the balance between the swirling flow and the circulating flow cannot always be maintained properly, and it may be difficult to form a good sludge floc.

  Furthermore, in the conventional sludge agglomeration tank 101 shown in FIGS. 6 to 8, the baffle plates 109 and 109 ′ are fixed. Therefore, when troubles such as entanglement of the baffle plates 109 and 109 ′ occur. However, there is a problem that entangled impurities cannot be easily removed, and cleaning of the tank body 102 is not easy.

  The present invention has been made in view of the above problems, and the object of the process is to optimize the circulation flow and the swirl flow to stably form a good sludge floc and to easily remove the baffle set. An object of the present invention is to provide a sludge agglomeration tank that can be easily replaced, cleaned, and the like, and a sludge concentrator equipped with the same.

  In order to achieve the above object, the invention described in claim 1 is provided with a tank body and a stirrer in which a stirring blade is attached to a rotating shaft provided along the axis center of the tank body, and is supplied to the tank body. In a sludge flocculation tank in which sludge is flocated by agitating a mixture of sludge and flocculant to be agglomerated sludge by agitating the mixture, a baffle set having a baffle plate attached to a support shaft is provided on the inner wall of the tank body And is attached so as to be rotatable about the support shaft.

  Invention of Claim 2 filters the water | moisture content contained in the sludge coagulation tank of Claim 1, and the coagulation sludge supplied from this sludge coagulation tank in the invention of Claim 1, and discharges it as a separated liquid. The sludge concentrator is configured to include a sludge concentrator that concentrates the sludge.

  According to the invention described in claim 1, since the baffle set is detachably attached along the inner wall of the tank body and is rotatable about the support shaft, the sludge properties, the type and amount of flocculant, and the sludge aggregation The baffle set can be rotated around the support shaft according to the conditions, etc., and the baffle mounting angle can be adjusted without stopping the operation, and the circulation flow and swirl flow are optimized to stabilize a good sludge floc. Can be formed. In addition, if troubles such as entanglement of contaminants on the baffle plate occur, the baffle set can be easily removed to remove the contaminants, and the inside of the tank body can be easily cleaned. It can be easily replaced with a baffle set having baffle plates of different shapes.

  According to invention of Claim 2, the favorable sludge floc formed with the sludge aggregation tank of Claim 1 can be efficiently concentrated with a sludge concentration apparatus.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a longitudinal sectional view showing a basic configuration of a sludge concentrating apparatus according to the present invention. The sludge concentrating apparatus shown in the figure includes a sludge aggregating tank 1 and a sludge concentrator 11 according to the present invention, and a flocculant is added. The sludge thus formed is agglomerated in a sludge agglomeration tank 1 to be flocked, and this flocified agglomerated sludge is concentrated by a sludge concentrator 11.

  The sludge agglomeration tank 1 includes a cylindrical tank body 2 having an open upper surface and a stirrer 4 that is rotated by a motor 3. A raw mud supply pipe 21 is connected to the lower part of the tank body 2. ing. Further, from the upper part of the tank body 2, the aggregated sludge introduction pipe 22 is led out horizontally toward the sludge concentrator 11. In addition, the detail of a structure of the sludge aggregation tank 1 is mentioned later.

  The concentrator 11 has a cylindrical filter tube 13 disposed in a vertical direction inside a cylindrical tank-shaped outer tube 12 having a sealed structure, and a spiral screw 14 is rotatably accommodated in the filter tube 13. Configured.

  Here, the peripheral surface of the portion of the filtration cylinder 13 facing the outer cylinder 12 constitutes a filtration surface 13a made of a punching plate, a wedge wire or the like, and a concentrated sludge discharge pipe 15 is formed from the lower part of the filtration cylinder 13. Is led out horizontally, and a concentrated sludge pump 16 is provided in the middle.

  Separately, the separated liquid take-out pipes 17 and 18 are led out from the upper and lower sides of the outer cylinder 12, and these separated liquid take-out pipes 17 and 18 stand up perpendicularly to the inverted U-shaped separated liquid discharge pipe 19. It is connected to the upward flow pipe 19a. Here, the separation liquid discharge pipe 19 includes a horizontal pipe 19b extending horizontally from the upper end of the upward flow pipe 19a and a downward flow pipe 19c extending vertically downward from the end of the horizontal pipe 19b.

  The spiral screw 14 is configured by spirally winding a screw blade 14b around a rotating shaft 14a, and a motor 20 as a drive source is connected to the rotating shaft 14a. The outer diameter of the spiral screw 14 is set to be slightly smaller than the inner diameter of the filtration surface 13a of the filter cylinder 13, and there is a small gap between the outer peripheral edge of the spiral screw 14 and the filtration surface 13a of the filter cylinder 13. Is formed.

  Next, the detail of the structure of the said sludge aggregation tank 1 is demonstrated based on FIGS. 2 is a longitudinal sectional view of the sludge aggregation tank according to the present invention, FIG. 3 is a sectional view taken along the line AA of FIG. 2, and FIG. 4 is a side view of the baffle set.

  As shown in FIGS. 2 and 3, the sludge aggregation tank 1 according to the present invention includes a cylindrical tank-shaped tank body 2 and a stirrer 4 that is rotationally driven by a motor 3. Two agitating blades 6 and 7 are vertically attached to a rotating shaft 5 arranged vertically in the central portion of the motor 2, and the motor 3 as a drive source is directly connected to the upper end of the rotating shaft 5. Yes.

  Thus, in the sludge flocculation tank 1 according to the present embodiment, the baffle set 110 is detachably attached to the inner wall of the tank body 2 so as to be detachable and rotatable along the inner wall. ing. Here, as shown in FIG. 4, each baffle set 10 is configured by welding three baffle plates 9 in the vertical direction of a vertical round bar-like support shaft 8 extending in the vertical direction. In the state where 10 is set in the tank body 2 as shown in FIG. 2, the baffle plates 9 attached to the respective support shafts 8 are respectively positioned above and below the stirring blades 6 and 7 of the stirrer 4. It is attached to the position.

  As shown in FIG. 3, each baffle plate 9 is a member that is curved in a planar arc shape extending horizontally toward the center of the tank body 2, and is operated by rotating the support shaft 8 by operating the upper portion thereof. Each baffle plate 9 rotates around the support shaft 8 together with the support shaft 8, and its mounting angle is adjusted within the range of Δθ shown in the figure. The baffle plate 9 may be a flat plate, but a curved plate as in the present embodiment is more effective.

  Thus, each baffle set 10 is assembled from above along the inner wall of the tank body 2 so that the support shaft 8 is in the vertical direction, and the lower end portion of the support shaft 8 is rotated by the bottom surface of the tank body 2. Supported as possible.

  Next, the operation of the sludge concentration apparatus shown in FIG. 1 will be described.

  In the sludge concentrating apparatus according to the present invention, sludge (raw mud) is supplied from the raw mud supply pipe 21 to the sludge agglomeration tank 1, and a polymer is added as a flocculant to the sludge flowing through the raw mud supply pipe 21, The sludge to which the polymer has been added is agitated by the agitator 4 in the sludge agglomeration tank 1, and the solid component contained in the sludge is flocked to become agglomerated sludge.

  Here, in the sludge agglomeration tank 1, the action of the baffle plate 9 of the baffle set 10 prevents co-rotation in synchronism with the stirring blades 6 and 7 of the mixture of sludge and polymer. Since the baffle set 10 is attached to the inner wall of the tank body 2 so as to be rotatable about the support shaft 8, the baffle set 10 depends on the properties of sludge, the type and amount of polymer added, the state of sludge aggregation, etc. Can be rotated around the support shaft 8 to adjust the mounting angle of the baffle plate 9 within the range of the angle Δθ shown in FIG. 3 without stopping the operation. For this reason, the circulating flow and the swirling flow of the mixture generated by the rotation of the stirring blades 6 and 7 of the stirrer 4 can be optimized, and a good sludge floc can be stably formed. In practice, the strength of the swirling flow can be adjusted by changing the rotational speed of the stirring blades 6 and 7 of the stirrer 4, and the circulation flow can be adjusted by changing the mounting angle of the baffle plate 9 of the baffle set 10. The strength can be adjusted.

  Thus, as a result of being able to stably form a good sludge floc as described above, the polymer addition rate is reduced, the sludge agglomeration tank 1 is reduced in size and size, and the types of usable polymers are increased. An effect can also be obtained.

  In addition, since the baffle set 10 is detachably attached to the tank body 2, the baffle set 10 can be easily removed from the tank body 2 in the case where troubles such as entanglement of the baffle plate 9 occur. The inside of the tank main body 2 can be easily cleaned by removing the contaminants, and can be easily replaced with another baffle set having a baffle plate having a different shape as necessary.

  Furthermore, since the sludge flocculation tank 1 according to the present embodiment can perform the above function only by adding the baffle set 10 to the tank body 2 without performing special processing on the existing tank body 2, The above effects can be obtained without significant cost increase.

By the way, as shown in FIG. 1, the sludge liquid level h ₂ in the filter cylinder 13 is set lower than the sludge liquid level h ₁ in the sludge agglomeration tank 1 (h ₂ <h ₁ ). Due to the differential pressure based on the difference between the positions h ₁ and h ₂ (head difference) Δh ₁₂ (= h ₁ −h ₂ ), the coagulated sludge in the sludge coagulation tank 1 passes through the coagulated sludge introduction pipe 22 and the sludge concentrator 11 It is introduced into the filter cylinder 13 from above.

Thus, in the sludge concentrator 11, the spiral screw 14 is rotationally driven in the filter cylinder 13 by the motor 20, and the aggregated sludge introduced into the filter cylinder 13 is rotated by the rotating spiral screw 14. And the water contained therein passes through the filtration surface 13a of the filtration cylinder 13 and is stored in the outer cylinder 12 as a separation liquid. Here, since the water level h ₃ of the separation liquid in the separation liquid discharge pipe 19 is set lower than the liquid level h ₂ in the filter cylinder 13 (h ₃ <h ₂ ), both of h ₂ and h ₃ With the differential pressure based on the difference (head difference) Δh ₂₃ (= h ₂ −h ₃ ) as the filtration pressure, the water separated from the aggregated sludge passes through the filtration surface 13a of the filtration cylinder 13 and enters the separation liquid in the outer cylinder 12. As housed. Further, in this case, since the outer cylinder 12 is disposed below the water level h _{3 of the} separation liquid, the separation liquid accommodated in the outer cylinder 12 is filled in the outer cylinder 12 and is contained in the separation liquid. The filtration surface 13a of the filtration cylinder 13 will be buried.

  Then, the separation liquid stored in the outer cylinder 12 flows into the separation liquid discharge pipe 19 from the separation liquid take-out pipes 17 and 18 connected to the upper and lower sides of the outer cylinder 12, and the upward flow pipe of the separation liquid discharge pipe 19. 19a flows upward, overflows in the horizontal pipe 19b, flows downward in the downward flow pipe 19c, and is discharged to the outside. Further, the coagulated sludge conveyed downward in the filter cylinder 13 by the rotation of the spiral screw 14 is concentrated by separating water in the middle thereof to become concentrated sludge, and this concentrated sludge is converted by the concentrated sludge pump 16. It is discharged to the outside through the concentrated sludge discharge pipe 15 and is subjected to a dehydration process by a dehydrator (not shown).

  Thus, according to the sludge concentrating apparatus according to the present embodiment, a good sludge floc formed by the sludge aggregating tank 1 can be efficiently concentrated by the sludge concentrator 11.

It is a longitudinal section showing the basic composition of the sludge concentration device concerning the present invention. It is a longitudinal cross-sectional view of the sludge aggregation tank which concerns on this invention. It is the sectional view on the AA line of FIG. It is a side view of the baffle set of the sludge aggregation tank concerning the present invention. It is a longitudinal cross-sectional view of the sludge aggregation tank which concerns on the prior art example 1. FIG. It is a longitudinal cross-sectional view of the sludge aggregation tank which concerns on the prior art example 2. It is the BB sectional view taken on the line of FIG. It is a longitudinal cross-sectional view of the sludge aggregation tank which concerns on the prior art example 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sludge aggregation tank 2 Tank main body 3 Motor 4 Stirrer 5 Rotating shaft 6,7 Stirring blade 8 Support shaft 9 Baffle plate 10 Baffle set 11 Concentrator 12 Outer tube 13 Filter tube 13a Filtration surface 14 Spiral screw 14a Rotating shaft 14b Screw blade 15 Concentrated sludge discharge pipe 16 Concentrated sludge pump 17, 18 Separation liquid discharge pipe 19 Separation liquid discharge pipe 19a Upflow pipe 19b Horizontal pipe 19c Downflow pipe 20 Motor 21 Raw mud supply pipe 22 Aggregated sludge introduction pipe

Claims (2)

A tank main body, and a stirrer comprising a stirring blade attached to a rotating shaft provided along the axis center of the tank main body, and a mixture of sludge and flocculant supplied to the tank main body are stirred by the stirrer. In the sludge agglomeration tank which flocates sludge to make it agglomerated sludge,
A sludge agglomeration tank characterized in that a baffle set having a baffle plate attached to a support shaft is detachably attached along the inner wall of the tank body and is rotatable about the support shaft.   The sludge agglomeration tank according to claim 1 and a sludge concentrator for concentrating sludge by filtering the moisture contained in the agglomerated sludge supplied from the sludge agglomeration tank and discharging it as a separated liquid. Characterized sludge concentrator.

Images