JP6209370B2 - Sludge aggregation apparatus and method, and sludge treatment apparatus - Google Patents

Description

  The present invention is, for example, a sludge agglomeration apparatus and method suitable for aggregating sludge in a dehydration process for reducing the volume of sludge discharged from a wastewater treatment facility or a water purification treatment facility, and the sludge agglomeration. The present invention relates to a sludge treatment apparatus configured using the apparatus.

  While it is required to reduce the amount of waste and reduce the environmental load, dewatering technology to reduce the volume of sludge discharged from wastewater treatment facilities and water purification facilities is extremely important and more efficient. Sludge dewatering technology is desired.

  The sludge dehydration treatment is generally composed of a coagulation step of coagulating sludge using a coagulant and a dehydration step of dehydrating the coagulated sludge using a dehydrator. The success or failure of sludge dehydration depends largely on how effectively it can be agglomerated by a flocculant.

  Among the methods of aggregating sludge using a flocculant, there is known a method of aggregating sludge by using a polymer flocculant and an agitation process with two stages of different rotation speeds when agitating sludge. (For example, Patent Documents 1 to 4).

  Moreover, the injection amount of the flocculant necessary for the coagulation of sludge can be reduced as compared with the prior arts shown in Patent Documents 1 to 4, and the water content of the dehydrated cake obtained after dehydration is reduced to further reduce the amount of waste. As a sludge aggregation apparatus that can be reduced, there is a sludge aggregation method (apparatus) shown in Patent Document 5. In Patent Document 5, a first polymer flocculant solution is poured into sludge, and the sludge and the first polymer flocculant solution are mixed by high-speed stirring at 1000 rpm or more to adjust mixed sludge. A second step of injecting a solution of the second polymer flocculant into the mixed sludge and mixing the mixed sludge and the second polymer flocculant solution to form a floc floc by stirring at 10 to 500 rpm; And an agitation method (apparatus) for sludge having a stirring step.

  According to the sludge flocculation method (apparatus) shown in Patent Document 5, since the high-speed stirring at 1000 rpm or more is performed in the first stirring step, the first polymer flocculant can be uniformly dispersed in the sludge. One polymer flocculant can be distributed to the details of the sludge. Then, by uniformly dispersing the first polymer flocculant in the sludge, useless polymer flocculant can be reduced, and the injection amount of the polymer flocculant can be reduced. Moreover, since the flocculent sludge becomes dense by spreading the polymer flocculant to the details of the sludge, the water content of the dewatered cake after the dewatering treatment can be reduced.

Japanese Patent Laid-Open No. 57-130599 JP-A-62-277200 JP-A-11-57800 JP 2006-263514 A International Publication No. 2012-108312

  However, in the sludge flocculation method (apparatus) shown in Patent Document 5, since it is necessary to stir the polymer flocculant at high speed, the driving power of the stirrer for high speed stirring is large, and the power consumption cannot be reduced. was there.

  In addition, even when it is not always necessary to stir sludge at high speed (for example, when the amount of sludge to be treated is small), power stir is incurred.

  Further, when the stirrer for high-speed stirring is broken, the first stirring step does not function at all, so that the dewatering function of the sludge treatment apparatus is greatly impaired.

  The present invention has been made in view of the above-described points, and an object of the present invention is to provide a sludge agglomeration apparatus and method, and a sludge treatment apparatus capable of achieving effective agglomeration without waste and at the same time saving energy. Is to provide.

The sludge aggregating apparatus according to the present invention includes a first aggregating apparatus that agitates and aggregates mixed sludge in which a solution of a first polymer flocculant is injected into sludge, and mixed sludge that is mixed and agitated by the first aggregating apparatus. A second flocculating device that stirs the mixed sludge injected with the second polymer flocculant solution at a lower speed than the stirring speed of the first flocculating device to form a flocculated floc to obtain the flocculated sludge. And the first aggregating device includes a powered stirrer that stirs the mixed sludge, and a non-powered stirrer that preliminarily stirs the mixed sludge installed on the upstream side of the powered stirrer and stirred by the powered stirrer. The non-powered stirring mechanism is configured to change the flow direction of the mixed sludge using the power of the mixed sludge flow, while the powered stirrer Installed in the first stirring unit A structure for driving rotation of the stirring blade which is the driving source, the rotational speed, the sludge first polymer flocculant by stirring even more strongly pre stirred mixed sludge in the unpowered stirring mechanism The stirring speed in the second aggregating apparatus is set to a stirring speed that causes the formed dense agglomerated sludge to agglomerate to form a large agglomerated floc. It is characterized by being set.
Since the non-powered stirring mechanism is installed in addition to the powered stirrer as described above, the stirring effect of the mixed sludge is increased, and accordingly, the driving power of the powered stirrer can be reduced and energy saving can be achieved. Further, when the driving power of the powered agitator is the same, the stirring effect of the mixed sludge is increased, and the first polymer flocculant can be more uniformly dispersed in the sludge. The molecular flocculant can be spread to more sludge details.
In addition, when it is not always necessary to stir sludge at high speed (for example, when the amount of sludge to be treated is small), the drive of the powered stirrer of the first aggregating device is stopped and stirring is performed only by the non-powered stirring mechanism. It is also possible to perform agglomeration. That is, it is possible to perform an efficient operation according to the amount of sludge to be treated, and energy saving can be achieved also from this point.
Further, even when the stirrer for high-speed stirring is broken, stirring by the non-powered stirring mechanism can be performed, so that the operation of the first aggregating device can be continued although the efficiency is lowered.

Moreover , it is preferable that the rotational speed of the stirring blade of the powered stirrer is a predetermined rotational speed of 850 rpm or more.

Further, the non-powered agitation mechanism of the sludge aggregating apparatus is installed with a plurality of fluid mixing plates circumferentially attached to the pipe inner wall on the upstream side of the powered agitator, and before being agitated by the powered agitator. It is preferable to pre-stir the mixed sludge.
Agitation of mixed sludge by a non-powered agitation mechanism generally has a smaller mixing force by agitation than agitation by a powered agitator. Therefore, as in the present invention, the mixed sludge can be stirred more effectively by first preliminarily stirring the mixed sludge with a non-powered stirring mechanism and further stirring with a powered stirrer.

Moreover, it is preferable to install the inorganic flocculant addition apparatus which adds an inorganic flocculant to sludge in the upstream of the said 1st flocculence apparatus. Alternatively, on the downstream side of the second flocculating device, a concentrating device that concentrates the flocculated sludge obtained by the second flocculating device to obtain concentrated sludge, and an inorganic flocculant added to add the inorganic flocculant to the concentrated sludge obtained by the concentrating device It is preferable to install the device.
In addition to agglomerating sludge by two-stage stirring with different rotation speeds using a polymer flocculant, the water content of the dehydrated cake can be further reduced by adding an inorganic flocculant before or after addition, The chromaticity of the dehydrated filtrate can be reduced.

Next, the sludge agglomeration method according to the present invention includes a first agglomeration step in which the mixed sludge in which the solution of the first polymer flocculant is injected into the sludge is agglomerated and mixed by the first agglomeration step. A second coagulation step in which the mixed sludge obtained by injecting a solution of the second polymer flocculant into the sludge is agglomerated by stirring at a lower speed than the agitation speed of the first coagulation step to form a coagulation floc to obtain coagulation sludge; has a first aggregating step, mixing prior to the mixing sludge is agitated with a step of stirring using the power, the Oite the power on the upstream side of the step of agitating using the power Pre-stir sludge without power, and the pre-stir step is a step of stirring by changing the flow direction of the mixed sludge using the force of the flow of the mixed sludge, Meanwhile step of agitating using the power, the driving of the stirring blade A process for stirring are rotationally driven by the source, the rotational speed, aggregation sludge the first polymer flocculant was spread to the detail of the sludge by stirring even more strongly the preliminary stirred mixed sludge On the other hand, the stirring in the second flocculation step is set to a stirring speed at which the formed flocculated sludge is flocculated to form a large flocculated floc. Yes.

Here, it is preferable that the rotation speed of the stirring blade in the step of stirring using the power of the first aggregation step is a predetermined rotation speed of 850 rpm or more.

  The step of stirring without power is preferably used as preliminary stirring on the upstream side of the step of stirring with the power.

  Moreover, it is preferable to provide the process of adding an inorganic flocculant to sludge in the upstream of the said 1st aggregation process. Alternatively, a step of obtaining the concentrated sludge by concentrating the coagulated sludge obtained in the second coagulation step and a step of adding an inorganic coagulant to the concentrated sludge obtained in the step are provided downstream of the second coagulation step. It is preferable.

  The sludge treatment apparatus according to the present invention includes a sludge storage tank for storing sludge from a water treatment system, the sludge aggregating apparatus, and a sludge dewatering machine for dewatering the agglomerated sludge sent from the sludge aggregating apparatus. It is characterized by having.

  According to the present invention, effective aggregation without waste can be performed, and at the same time, energy saving can be achieved.

It is the whole sludge processing apparatus 1-1 schematic. 3 is a schematic cross-sectional view of a main part of a first aggregating device 40. FIG. It is the whole sludge processing apparatus 1-2 schematic. It is the whole sludge processing apparatus 1-3 schematic. It is a principal part schematic sectional drawing of the 1st aggregation apparatus 40-4. It is a figure which shows the 1st aggregation apparatus 40-5, Fig.6 (a) is principal part schematic sectional drawing, FIG.6 (b) is an AA cross-sectional arrow view of Fig.6 (a). It is a principal part schematic sectional drawing of the 1st aggregation apparatus 40-6. It is a principal part schematic sectional drawing of the 1st aggregation apparatus 40-7. It is a principal part schematic sectional drawing of the 1st aggregation apparatus 40-8. It is a side view of the 1st aggregation apparatus 40-9. It is a side view of the 1st aggregation apparatus 40-10.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 is an overall schematic diagram of a sludge treatment apparatus (sludge coagulation dehydration apparatus) 1-1 according to the first embodiment of the present invention. As shown in the figure, the sludge treatment apparatus 1-1 includes a sludge storage tank 10 for storing sludge from a water treatment system, a sludge aggregation apparatus 30 for aggregating sludge sent from the sludge storage tank 10, and a sludge. A sludge dehydrator 100 that dehydrates the coagulated sludge sent from the coagulation apparatus 30 is provided.

  The sludge agglomeration device 30 also includes a first agglomeration device 40 that introduces sludge transferred from the sludge storage tank 10 and a first polymer aggregating agent solution that is injected into the sludge introduced into the first agglomeration device 40. 1 chemical injection means 70, a second aggregating device 80 for introducing the mixed sludge mixed and stirred by the first aggregating device 40 (the mixed sludge and the first polymer flocculant), and the second aggregating device 80. And a second chemical injection means 90 for injecting a solution of the second polymer flocculant into the sludge.

  The sludge storage tank 10 stores sludge from the water treatment system. The sludge to be stored (the object to be treated) may be either organic sludge or airless sludge.

  Examples of the organic sludge include organic sludge generated in sewage treatment, human waste treatment, and various industrial wastewater treatment. More specifically, first sedimentation basin sludge, surplus sludge, anaerobic digested sludge, aerobic digested sludge, septic tank sludge, digested detachment liquid and the like can be mentioned. The organic sludge may contain an inorganic substance.

  Examples of the inorganic sludge include inorganic sludge generated in water purification treatment, construction wastewater treatment, and various industrial wastewater treatment. Here, the sludge generated in the water purification treatment is sludge discharged from a settling pond, a waste mud pond, a concentration tank, or the like in the water purification treatment facility. The inorganic sludge may contain organic matter.

  As mentioned above, in this sludge treatment apparatus 1-1, although both organic sludge and inorganic sludge can be made into a to-be-processed object, from a viewpoint that the effect of this invention can be enjoyed more, organic sludge. Among them, non-dehydrated anaerobic digested sludge is particularly preferable.

  The sludge stored in the sludge storage tank 10 is transferred to the first aggregating device 40 by the transfer pump 20.

  FIG. 2 is a schematic cross-sectional view of a main part of the first aggregating device 40. As shown in the figure, the first aggregating device 40 is configured by installing a non-powered stirring mechanism 60 on the upstream side of the powered stirrer 50.

  The powered stirrer 50 is a blade-type stirrer in this example, and is connected to the first stirring unit 51 having a substantially T-shaped pipe shape, a stirring blade 53 installed in the first stirring unit 51, and the stirring blade 53. A shaft 55 drawn out of the first stirring unit 51 and a motor (drive source) 57 for rotating the shaft 55 are provided. Then, by driving the motor 57 and rotating the stirring blade 53, the sludge introduced into the first stirring portion 51 from the upstream side of the first stirring portion 51 is stirred, and the stirred sludge is discharged downstream. The rotation speed of the stirring blade 53 is set to a predetermined rotation speed of 850 rpm or more in this example.

  The non-powered stirring mechanism 60 is configured by alternately installing a right stirring blade 63 twisted in the right direction and a left stirring blade 65 twisted in the left direction in a tubular housing 61. This is a mechanism for stirring the sludge without power by changing the flow direction of the sludge by the stirring blades 63 and 65 using the force of the flow of the mixed sludge flowing in the housing 61. This non-powered stirring mechanism 60 is preferably a non-blocking structure for sludge that has little trapping of residue and the like and has no flanges or pins. The shape and structure of the stirring blades 63 and 65 can be variously changed.

  Returning to FIG. 1, the first chemical injection means 70 is connected to the first polymer flocculant dissolution tank 71 and the first polymer flocculant dissolution tank 71 from the first polymer flocculant dissolution tank 71 to the upstream pipe of the non-powered stirring mechanism 60. And a first polymer flocculant pump 73 for transferring one polymer flocculant.

  As the first polymer flocculant, any of an anionic polymer flocculant, a nonionic polymer flocculant, a cationic polymer flocculant, and an amphoteric polymer flocculant can be used. When treating organic sludge, it is particularly preferable to use a cationic polymer flocculant or an amphoteric polymer flocculant.

  Examples of the anionic polymer flocculant include sodium polyacrylate, a copolymer of sodium acrylate and acrylamide, polysodium methacrylate, a copolymer of sodium methacrylate and acrylamide, and the like.

  Examples of nonionic polymer flocculants include polyacrylamide and polyethylene oxide.

  Examples of cationic polymer flocculants include acrylate polymer flocculants (also referred to as “DAA polymer flocculants”), methacrylate polymer flocculants (also referred to as “DAM polymer flocculants”), and amide groups. , Nitrile groups, amine hydrochlorides, formamide groups, and the like, and polyvinylamidines (also referred to as “amidine polymer flocculants”), polyacrylamide Mannich modified products, and the like. Examples of the DAA polymer flocculant include a polymer of a quaternized product of dimethylaminoethyl acrylate, a copolymer of a quaternized product of dimethylaminoethyl acrylate and acrylamide, and the like. Examples of the DAM polymer flocculant include a polymer of a quaternized product of dimethylaminoethyl methacrylate and a copolymer of a quaternized product of dimethylaminoethyl methacrylate and acrylamide.

  Examples of amphoteric polymer flocculants include, for example, dimethylaminomethyl acrylate quaternized products of acrylamide and acrylic acid, dimethylaminomethyl methacrylate quaternized products of acrylamide and acrylic acid, and the like. Can do.

  However, the above is an example of the first polymer flocculant and is not limited thereto.

  The molecular weight of the first polymer flocculant is preferably 4.5 million or more. A more preferable molecular weight is 5 million or more. The molecular weight here is an average molecular weight determined by a viscosity method. When the polymer flocculant is dispersed in sludge by high-speed stirring, the molecular chain of the polymer flocculant may be broken by high-speed stirring. Therefore, if the molecular weight of the polymer flocculant is too low, the polymer flocculant aggregates. Power is weakened. For this reason, by using a polymer flocculant having a molecular weight of 4.5 million or more, even if the molecular chain is broken by high-speed stirring, it is possible to maintain a certain degree of cohesive force of the polymer flocculant.

  From the same viewpoint as the molecular weight, the viscosity of the first polymer flocculant is preferably 150 mPa · s or more, particularly 175 mPa · s or more, and more preferably 200 mPa · s or more. The viscosity at this time is a value measured by dissolving the polymer flocculant in pure water at 2 g / L and using a B-type viscometer at a rotation speed of 25 ° C. and 60 rpm.

  When the molecular weight of the first polymer flocculant is 4.5 million or more, the injection amount of the first polymer flocculant is the total injection amount of the first polymer flocculant and the second polymer flocculant described below. It is preferable to adjust and add so that it may become 45-95 mass% of this, It is preferable to adjust and add so that it may occupy 50-95 mass% especially, and 55-90 mass% especially among them.

  If the ratio of the injection amount of the first polymer flocculant is too high, the injection amount of the second polymer flocculant becomes too small, and the flocculent flocs may not grow. As a result, the filterability deteriorates in the concentration process and the dehydration process. On the other hand, when the ratio of the injection amount of the first polymer flocculant is too low, the ratio of the polymer flocculant uniformly dispersed in the sludge by high-speed stirring is reduced in the first flocculation apparatus 40 (powered stirrer 50). For this reason, the effect of high-speed stirring is reduced. For this reason, by controlling the injection amount of the first polymer flocculant to 45 to 95% by mass of the total injection amount, it is possible to uniformly disperse the polymer flocculant in the sludge and to grow the floc floc.

  Examples of the solvent in the first polymer flocculant solution include pure water, tap water, industrial water, ground water, treated water for various wastewater treatment, seawater, and the like. From the viewpoint of exerting it, pure water is preferable. This also applies to the second polymer flocculant solution described below. On the other hand, from the viewpoint of economy, tap water, industrial water, ground water, and treated water for various wastewater treatment are preferable. This also applies to the second polymer flocculant solution.

  The concentration of the polymer flocculant in the first polymer flocculant solution may be 1 to 3 g / L, but is preferably 3 g / L or more, more preferably 5 g / L or more, and still more preferably. It is 10 g / L or more. In the coagulation of sludge with a polymer flocculant, the polymer flocculant solution is generally prepared at 1 to 3 g / L, and usually a polymer flocculant solution of 3 g / L or more is used. Absent. The reason for this is that when the polymer flocculant concentration is 3 g / L or more, the polymer flocculant solution becomes highly viscous. Therefore, at the rotational speed of the stirrer used in the conventional flocculation tank (about 10 to 500 rpm), This is because it is difficult to uniformly disperse the polymer flocculant in the sludge. On the other hand, in the high-speed stirring in the first flocculating device 40 (powered stirrer 50), the polymer flocculant can be uniformly dispersed in the sludge even when a high concentration solution of 3 g / L or more is used. As a result, there is an advantage that the amount of dissolved water of the polymer flocculant can be reduced. Another advantage of using a high-concentration polymer flocculant solution is that the polymer flocculant concentration in the sludge containing the polymer flocculant can be increased, so the amount of polymer flocculant injected can be reduced. The water content of the dehydrated cake after the dehydration treatment can be reduced. For example, when 200 mL of a 2 g / L polymer flocculant solution is injected into 1 L of sludge (0.4 g as a polymer flocculant), the concentration of the polymer flocculant in the sludge is 333 mg / L. On the other hand, when 40 mL of 10 g / L of polymer flocculant is injected into 1 L of sludge (0.4 g of polymer flocculant is injected), the concentration of the polymer flocculant in the sludge is 385 mg / L. Thus, even when the same 0.4 g of polymer flocculant is added, a solution of 10 g / L of polymer flocculant is used rather than using a solution of 2 g / L of polymer flocculant. However, the concentration of the polymer flocculant in the sludge can be increased, the amount of the polymer flocculant injected can be reduced, and the water content of the dehydrated cake after the dehydration treatment can be reduced.

  The second aggregating apparatus 80 includes a tank-shaped second stirring unit 81, a stirring blade 83 installed in the second stirring unit 81, and a shaft 85 connected to the stirring blade 83 and drawn out of the second stirring unit 81. And a motor (drive source) 87 that rotationally drives the shaft 85. Then, by driving the motor 87 and rotating the stirring blade 83, the sludge introduced into the second stirring unit 81 from the upstream side is stirred, and the stirred sludge is discharged downstream. The rotational speed of the stirring blade 83 may be a general rotational speed in the conventional sludge aggregating apparatus, that is, 10 to 500 rpm. The reason is that in the second flocculating device 80, the second polymer flocculant needs to be brought into gentle contact with the mixed sludge prepared in the first flocculating device 40 to grow the flocculated floc. From this point of view, the rotation speed at the time of stirring in the second aggregating apparatus 80 may be 10 to 500 rpm, more preferably 20 rpm or more or 400 rpm or less, and particularly preferably 30 rpm or more or 300 rpm or less. In addition, the rotation speed at the time of stirring in the second aggregating apparatus 80 is adjusted at 10 to 500 rpm according to the kind of sludge, the property of sludge, the molecular weight of the polymer flocculant, the dissolution concentration of the polymer flocculant, and the like. Is preferred.

  The second chemical injection means 90 includes a second polymer flocculant dissolving tank 91 and a second polymer flocculant dissolving tank 91 into the second stirring unit 81 of the second aggregating apparatus 80. And a second polymer flocculant pump 93 for transferring the flocculant.

  As the second polymer flocculant, the same polymer as the first polymer flocculant can be used. In this case, the second polymer flocculant may be the same type of polymer flocculant as the first polymer flocculant, or may be a different type of polymer flocculant. From the viewpoint that the first and second polymer flocculant dissolution tanks 71 and 91 can be shared, the second polymer flocculant uses the same type of polymer flocculant as the first polymer flocculant. preferable. The polymer flocculant concentration in the second polymer flocculant solution may be 1 to 3 g / L, but is preferably 3 g / L or more, more preferably 5 g / L or more, and even more preferably 10 g. / L or more.

  As the sludge dehydrator 100, a screw press dehydrator is used, but various other dehydrators conventionally known can also be used. For example, a belt press dehydrator, a centrifugal dehydrator, a vacuum dehydrator, a filter press dehydrator, a multiple disk dehydrator, or the like may be used.

  Next, the operation of the sludge treatment apparatus 1-1 will be described. First, the sludge stored in the sludge storage tank 10 is transferred to the first aggregating device 40 by the transfer pump 20. At the same time, the first polymer flocculant pump 73 supplies a solution of the first polymer flocculant from the first polymer flocculant dissolution tank 71 into the upstream pipe of the non-powered stirring mechanism 60, and the sludge Injected into.

  Then, the mixed sludge into which the first polymer flocculant is injected is introduced into the non-powered stirring mechanism 60, and the flow direction of the sludge is changed a plurality of times by the stirring blades 63 and 65, thereby Is stirred.

  The mixed sludge stirred by the non-powered stirring mechanism 60 is introduced into the powered stirrer 50 and further mixed and stirred by the high-speed rotation of the stirring blade 53 of the powered stirrer 50 at 850 rpm or higher. By this high-speed stirring, the first polymer flocculant can be uniformly dispersed in the sludge, and the first polymer flocculant can be distributed to the details of the sludge.

  According to the first aggregating device 40 (first aggregating step), in addition to the powered stirrer 50 (the step of stirring using power), the non-powered stirring mechanism 60 (the step of stirring without power) is installed. The stirring effect of the mixed sludge is further increased, and accordingly, the driving power of the powered stirrer 50 can be reduced and energy saving can be achieved. Specifically, in this example, in order to obtain the same mixed state, stirring is performed with only the powered stirrer 50 (no powerless stirring mechanism 60 is installed) and with the first aggregating device 40. When compared with the case where it was performed, in the first aggregating apparatus 40, the rotational speed of the stirring blade 53 of the powered stirrer 50 could be reduced by about 15%, and the driving power thereof could be reduced by about 15%. In other words, according to the first aggregating device 40, the stirring effect that required a rotational speed of 1000 rpm when stirring was performed only with the powered stirrer 50 could be achieved at a rotational speed of 850 rpm. Of course, if the drive power of the powered stirrer 50 of the first flocculating device 40 is kept at 1000 rpm, it goes without saying that the stirring effect of the mixed sludge is further increased. In this case, the moisture content of the dehydrated cake described below is 850 rpm. As compared with the case of the number of rotations, it can be further reduced by about 1-2%.

  In particular, according to the first agglomeration device 40, the powered agitator 50 agitates the mixed sludge by the agitating blade 53 (rotational flow), and the non-powered agitation mechanism 60 utilizes the flow force of the mixed sludge to flow the mixed sludge. It is the structure (vortex flow) which stirs by changing a direction, and the stirring state (rotation flow and vortex flow) of the mixed sludge by both differs greatly. Therefore, the mixed state of the mixed sludge can be made a more complicated flow, and the stirring effect of the mixed sludge can be further increased.

  By the way, the mixing sludge by the non-powered stirring mechanism 60 generally has a smaller mixing force by stirring than the stirring by the powered stirrer 50. In view of this, in the first aggregating apparatus 40, first, the mixed sludge is preliminarily stirred by the non-powered stirring mechanism 60, and then the stirring is further performed by the powered stirrer 50, thereby more effectively mixing the sludge. To be stirred.

  As described above, according to the first aggregating apparatus 40, the first polymer flocculant can be uniformly dispersed in the sludge by the preliminary agitation, the high-speed agitation, and the complicated agitation by different agitation methods. Since the polymer flocculant can be distributed to the details of the sludge, neutralization of the surface charge of the sludge and agglomeration by the adsorption or crosslinking action of the polymer can be performed simultaneously.

  As described above, the rotational speed of the powered agitator 50 is preferably a high speed of 850 rpm or more, but a more preferable rotational speed is 1000 rpm or more, a further preferable rotational speed is 2000 rpm or more, and an even more preferable rotational speed is 3000 rpm or more. It is. This rotational speed is preferably adjusted at 850 rpm or higher according to the type of sludge, the sludge properties, the molecular weight of the polymer flocculant, the dissolution concentration of the polymer flocculant, and the like. When the rotational speed is increased, the stirring time may be shortened, so there is no particular upper limit on the rotational speed, but at present, it has been confirmed experimentally effective up to 15000 rpm.

  The stirring time in the powered stirrer 50, that is, the time for mixing and stirring the first polymer flocculant solution and sludge is preferably 20 seconds or less, particularly preferably 1 second to 20 seconds, and more preferably 1 second to 15 seconds. Seconds, even more preferably 1 to 10 seconds. If the stirring time by high-speed stirring is too long, the molecular chain of the polymer flocculant is broken to such an extent that the cohesive force of the polymer flocculant is weakened. Therefore, by controlling the stirring time to 20 seconds or less, the polymer flocculant is evenly dispersed in the sludge without weakening the cohesive force of the polymer flocculant, and the polymer flocculant is spread to the details of the sludge. be able to.

  As described above, according to the first flocculating device 40, the polymer flocculant can be uniformly dispersed in the sludge, so that the useless polymer flocculant can be reduced and the injection amount of the polymer flocculant can be reduced. it can. Moreover, since the flocculent sludge becomes dense by spreading the polymer flocculant to the details of the sludge, the water content of the dewatered cake after the dewatering treatment can be reduced. The solution of the polymer flocculant is a high-viscosity liquid, and the polymer flocculant can be uniformly dispersed in the sludge at the rotational speed of a stirrer (about 10 to 500 rpm) used in a general flocculation tank. It was difficult and the polymer flocculant could not be distributed to the details of the sludge. For this reason, the injection amount of the polymer flocculant was increased and the moisture content of the dehydrated cake was deteriorated. On the other hand, in the first flocculating device 40, the polymer flocculant can be uniformly dispersed in the sludge by the preliminary stirring by the non-powered stirring mechanism 60 and the high speed stirring by the powered stirrer 50. Can be spread to the details of the sludge. For this reason, the injection amount of the polymer flocculant can be reduced, and the water content of the dehydrated cake can be reduced.

  In addition, since a high-concentration polymer flocculant can be used by high-speed stirring, the amount of the polymer flocculant used can be reduced, and the equipment can be reduced in size and energy can be saved. Furthermore, when the dehydrated filtrate is returned to the water treatment system, the amount of returned water can be reduced, so that energy saving and space saving of the entire water treatment system can be achieved.

  Next, in FIG. 1, the mixed sludge that has passed through the first aggregating device 40 is introduced into the second stirring unit 81 of the second aggregating device 80. At the same time, the second polymer flocculant is injected from the second polymer flocculant dissolution tank 91 into the second stirring unit 81 by the second polymer flocculant pump 93. In the second aggregating apparatus 80, the stirring blade 83 is rotated at a stirring speed (10 to 500 rpm, hereinafter also referred to as “normal stirring”) lower than the stirring speed in the first aggregating apparatus 40, and the mixed sludge and the second The polymer flocculant solution is mixed and stirred to form a floc floc to obtain agglomerated sludge (second aggregating step).

  Since the polymer flocculant is uniformly dispersed in the sludge details in the first aggregating device 40, the neutralization of the surface charge of the sludge and the aggregation due to the adsorption or crosslinking action of the polymer can be performed simultaneously. In the agglomeration apparatus 80, a large coagulation floc can be formed by relatively slowly stirring and mixing the polymer flocculant with the mixed sludge obtained in the first aggregation apparatus 40, and the aggregation sludge having good filterability. Can be formed.

  The stirring time in the second stirring unit 81, that is, the time for mixing and stirring the second polymer flocculant solution and the mixed sludge is preferably 1 minute to 20 minutes. The reason is that in the second flocculating device 80, the polymer flocculant needs to be brought into gentle contact with the mixed sludge prepared in the first flocculating device 40 to grow the flocculated floc. From this point of view, the stirring time in the second aggregating apparatus 80 is preferably 1 to 20 minutes, more preferably 2 minutes or more and 15 minutes or less, and more preferably 3 minutes or more and 10 minutes or less. preferable.

  Next, the coagulated sludge obtained by forming coagulation flocs with the second coagulation apparatus 80 is transferred to the sludge dewatering machine 100, where it is solid-liquid separated to obtain a dehydrated cake as a solid, and dehydrated as a liquid. Obtain the filtrate.

  According to this sludge treatment apparatus 1-1, since the moisture content of a dewatering cake can be reduced, the amount of waste can be reduced.

  By the way, when it is not always necessary to stir sludge at high speed (for example, when the amount of sludge to be treated is small), the driving of the powered stirrer 50 of the first aggregating device 40 is stopped, and only the non-powered stirring mechanism 60 is used. Aggregation can also be carried out by stirring. That is, it is possible to perform an efficient operation according to the amount of sludge to be treated, and energy saving can be achieved also from this point.

  Furthermore, even when the powered stirrer 50 breaks down, stirring by the non-powered stirring mechanism 60 can be performed, so that the operation of the first aggregating device 40 can be continued although the efficiency is lowered.

  In the case where the first polymer flocculant and the second polymer flocculant are the same polymer flocculant, the first polymer flocculant dissolution tank 71 and the second polymer flocculant dissolution tank 91 are provided. One polymer flocculant dissolution tank may be used in combination.

[Second Embodiment]
FIG. 3 is an overall schematic diagram of a sludge treatment apparatus (sludge coagulation / dehydration apparatus) 1-2 according to the second embodiment of the present invention. In the sludge treatment apparatus 1-2 shown in the figure, the same or equivalent parts as those in the sludge treatment apparatus 1-1 shown in FIGS. 1 and 2 are denoted by the same reference numerals (provided with the suffix “-2”). Items other than those described below are the same as those in the embodiment shown in FIGS.

  In the sludge treatment apparatus 1-2 shown in the figure, the difference from the sludge treatment apparatus 1-1 is the configuration of the sludge agglomeration apparatus 30-2. In the upstream, the inorganic flocculant addition device 110-2 for introducing the sludge from the sludge storage tank 10-2, and the third chemical injection means 120-2 for supplying the inorganic flocculant to the inorganic flocculant addition device 110-2, It is only the point which installed.

  The inorganic flocculant addition device 110-2 is connected to the tank-shaped inorganic flocculant stirring unit 111-2, the stirring blade 113-2 installed in the inorganic flocculant stirring unit 111-2, and the stirring blade 113-2. And a shaft 115-2 drawn out of the inorganic flocculant agitation unit 111-2 and a motor (drive source) 117-2 for rotationally driving the shaft 115-2. And by driving the motor 117-2 and rotating the stirring blade 113-2, the sludge introduced into the inorganic flocculant stirring unit 111-2 from the upstream side is stirred, and the stirred sludge is discharged downstream. . The rotational speed of the stirring blade 113-2 may be a general rotational speed in the conventional sludge aggregation apparatus, that is, 10 to 500 rpm. In addition, it is preferable to adjust the rotational speed at the time of stirring in the inorganic flocculant addition apparatus 110-2 in 10-500 rpm according to the kind of sludge, the property of sludge, etc. Moreover, what is necessary is just to set stirring time suitably.

  The third chemical injection means 120-2 includes an inorganic flocculant storage tank 121-2 and an inorganic flocculant pump 123-2 that transfers the inorganic flocculant from the inorganic flocculant storage tank 121-2 to the inorganic flocculant stirring unit 111-2. It is equipped with.

  Examples of the inorganic flocculant to be added include ferric chloride, aluminum sulfate, aluminum chloride, polyaluminum chloride, and polyferric sulfate.

  The inorganic flocculant is preferably added after diluting with diluting water from the viewpoint of reducing the viscosity and facilitating dispersion in the sludge, and increasing the volume and facilitating uniform dispersion by dilution. From the above viewpoint, the dilution factor of the inorganic flocculant is preferably 2 to 5 times. A more preferable dilution ratio is 3 to 4 times. As the diluting liquid, pure water, tap water, industrial water, ground water, treated water for various wastewater treatment, seawater, etc. can be used, but from the economical viewpoint, industrial water, groundwater, treated water for various wastewater treatment are preferable. .

  If the inorganic flocculant is added in an amount of 1.0% by mass (converted to Fe) or more with respect to TS of the sludge, the dehydration effect can be enhanced. It is a waste of agent. Therefore, from this point of view, it is preferable to add the inorganic flocculant in an amount of 1.0 to 10% by mass (converted to Fe) with respect to the sludge. It is even more preferable to add at a ratio of 0% by mass (Fe conversion) or less, of which 2% by mass (Fe conversion) or more or 6.0% by mass (Fe conversion) or less.

  As described above, if the inorganic flocculant addition device 110-2 and the third chemical injection unit 120-2 are installed, the sludge sent from the sludge storage tank 10 is supplied to the inorganic flocculant stirring unit 111-2. At the same time, the inorganic flocculant is added from the third chemical injection means 120-2 by the inorganic flocculant pump 123-2, stirred by the stirring blade 113-2 and mixed with the sludge, and then the first flocculant 40-2, and the same agglomeration and dehydration treatment as in the case of the sludge treatment apparatus 1-1 is performed.

  Thus, in addition to aggregating sludge by the two-stage stirring process with different rotation speeds using the first and second aggregating devices 40-2 and 80-2, the inorganic aggregating agent adding device 110-2 is installed. Thus, by adding the inorganic flocculant in advance, not only can the moisture content of the dehydrated cake be reduced, but also the chromaticity of the dehydrated filtrate can be reduced.

  In the sludge aggregating apparatus 30-2, the sludge and the inorganic aggregating agent in the inorganic aggregating agent agitating unit 111-2 are agitated and mixed using the agitating blade 113-2, but the agitation is not performed, and the sludge agglomerating apparatus 30-2 is merely inorganic in the sludge. It is good also as a structure which only adds a flocculant. In this case, the inorganic flocculant addition apparatus 110-2 may be omitted, and the inorganic flocculant may be directly injected from the third chemical injection means 120-2 into the upstream pipe of the first flocculence apparatus 40-2.

[Third Embodiment]
FIG. 4 is an overall schematic diagram of a sludge treatment apparatus (sludge coagulation dehydration apparatus) 1-3 according to the third embodiment of the present invention. In the sludge treatment apparatus 1-3 shown in the figure, the same or corresponding parts as those in the sludge treatment apparatus 1-1 shown in FIGS. 1 and 2 are denoted by the same reference numerals (provided with the suffix “-3”). Items other than those described below are the same as those in the embodiment shown in FIGS.

  In the sludge treatment apparatus 1-3 shown in the figure, the difference from the sludge treatment apparatus 1-1 is only the configuration of the sludge agglomeration apparatus 30-3. Specifically, the second agglomeration apparatus 80-3. The concentration device 130-3 that concentrates the coagulated sludge obtained by the second coagulation device 80-3 to obtain the concentrated sludge, and the inorganic coagulant added to the concentrated sludge obtained by the concentration device 130-3 It is only the point which installed the flocculant addition apparatus 140-3.

  As the concentrator 130-3, for example, using a centrifugal concentrator, a screw concentrator, an elliptical plate concentrator, a sieve, or the like, it is possible to employ a device that concentrates condensed sludge without applying pressure, Further, for example, a method of condensing the coagulated sludge while applying pressure using a belt press concentrator, a filter press concentrator, or the like may be employed. From the viewpoint of further reducing the amount of water and further enhancing the effect of adding the inorganic flocculant, it is more preferable to employ an apparatus that concentrates while applying pressure.

  In the present concentration device 130-3, it is preferable to concentrate so that the TS of the concentrated sludge is 50 to 150 g / L, and in particular, the TS of the concentrated sludge is 80 g / L or more or 140 g / L or less. Even more preferred. “TS” means an evaporation residue, and in this case, the concentration of a substance remaining when sludge is evaporated to dryness at 105 to 110 ° C. When the TS of the concentrated sludge is lower than 50 g / L, it becomes easy to disperse the inorganic flocculant in the next step, but the inorganic flocculant flowing out to the concentrated filtrate side increases, making it impossible to effectively use the inorganic flocculant. The amount of agent added increases. For this reason, it is preferable to concentrate so that TS of concentrated sludge may be 50 g / L or more. In general, in order to concentrate the coagulated sludge to a TS of 80 g / L or more, in the method of concentration by gravity concentration, that is, the self-weight of the coagulated sludge, the concentration pressure is insufficient. On the other hand, when the TS of the concentrated sludge is higher than 150 g / L, the concentrated sludge becomes close to solid, and the inorganic flocculant cannot be dispersed inside the concentrated sludge, and the effect of the inorganic flocculant cannot be sufficiently exhibited. The amount of inorganic flocculant added increases. From such a viewpoint, as described above, it is preferable to concentrate so that the TS of the concentrated sludge is 50 to 150 g / L.

  When condensing the agglomerated sludge while applying pressure, the pressure applied to the agglomerated sludge may be appropriately adjusted so that the TS of the agglomerated sludge falls within the above range. As a standard for the pressure applied to the coagulated sludge, it is preferable to apply a pressure of 0.5 to 50 kPa to the coagulated sludge, and in particular, a pressure of 1 kPa to 40 kPa, particularly 3 kPa or more or 30 kPa or less is applied to the coagulated sludge. Even more preferred.

  The shape of the concentrated sludge formed by the present concentration device 130-3 is not particularly limited. For example, considering the dispersibility of the inorganic flocculant, it is preferable to use a flat plate shape.

  The inorganic flocculant addition apparatus 140-3 is an apparatus for adding an inorganic flocculant to the concentrated sludge from the concentration apparatus 130-3.

  In this sludge treatment apparatus 1-3, the dewatering effect can be further enhanced by adding an inorganic flocculant to the concentrated sludge obtained by the concentration apparatus 130-3.

  Examples of the inorganic flocculant used include ferric chloride, aluminum sulfate, aluminum chloride, polyaluminum chloride, and polyferric sulfate.

  Inorganic flocculants should be added to the concentrated sludge after dilution with dilution water from the viewpoint of reducing the viscosity and making it easy to impregnate and disperse in the concentrated sludge and increasing the volume by diluting to facilitate uniform dispersion. Is preferred. From the above viewpoint, when the TS of the concentrated sludge is 100 to 150 g / L, the dilution factor of the inorganic flocculant is preferably 2 to 5 times. A more preferable dilution ratio is 3 to 4 times. As dilution water, pure water, tap water, industrial water, groundwater, treated water for various wastewater treatment, seawater, etc. can be used, but from the viewpoint of economy, industrial water, groundwater, treated water for various wastewater treatment are preferred. .

  If the inorganic flocculant is added in an amount of 1.0% by mass (Fe conversion) or more with respect to TS of the organic sludge, the dehydration effect can be enhanced. It is a waste of inorganic flocculants. Therefore, from such a viewpoint, it is preferable to add the inorganic flocculant in an amount of 1.0 to 10% by mass (converted to Fe) with respect to the organic sludge. It is even more preferable to add at a ratio of 8.0% by mass (Fe conversion) or less, of which 2% by mass (Fe conversion) or more or 6.0% by mass (Fe conversion) or less.

  After the inorganic flocculant and post-addition step, before the dehydration step, if necessary, pressurize or gently mix the concentrated sludge to which the inorganic flocculant has been added. You may make it disperse | distribute inside. However, it is not always necessary to introduce an inorganic flocculant dispersion step.

  An inorganic flocculant storage tank 141-3 is connected to the inorganic flocculant addition apparatus 140-3 via an inorganic flocculant pump 143-3.

  And the coagulation sludge containing the aggregation floc discharged | emitted from the 2nd aggregation apparatus 80-3 is introduce | transduced into the concentration apparatus 130-3. In the concentrating device 130-3, the coagulated sludge is concentrated to become concentrated sludge, which is supplied to the inorganic coagulant adding device 140-3. The inorganic coagulant is added to the concentrated sludge and transferred to the sludge dehydrator 100. Then, solid-liquid separation is performed in the sludge dehydrator 100 to obtain a dehydrated cake as a solid and a dehydrated filtrate as a liquid.

[Other various first aggregating devices]
In addition to the first aggregating device 40 (40-2, 40-3), first aggregating devices having various structures are conceivable. 6, 8, Ri FIG der showing a first agglomerator 40-5,7,8 according to another embodiment of FIG. 9 is the invention respectively, 5, 7, 10, 11 respectively It is a figure which shows the 1st aggregation apparatus 40-4,6,9,10 concerning a reference example. Each will be described below. In the first aggregating apparatuses 40-4, 5, 6, 7, 8, 9, and 10 shown in the drawings, the same or corresponding parts as those in the first aggregating apparatus 40 shown in FIGS. However, subscripts “−4, 5, 6, 7, 8, 9, 10” are attached to each). Items other than those described below are the same as those in the embodiment shown in FIGS.

  FIG. 5 is a schematic cross-sectional view of a main part of the first aggregating device 40-4. The first aggregating apparatus 40-4 shown in FIG. 2 is different from the first aggregating apparatus 40 shown in FIG. 2 in that a non-powered agitation mechanism 60-4 is installed on the downstream side of the powered agitator 50-4. It is. Since the structure of the powered stirrer 50-4 itself and the structure of the non-powered stirring mechanism 60-4 itself are the same as those shown in FIG. 2, detailed description thereof will be omitted.

  In the case of the first flocculating device 40-4, the mixed sludge into which the first polymer flocculant has been injected is first introduced into the powered stirrer 50-4, and at high speed due to the high-speed rotation of the stirring blade 53-4. After being mixed, the mixture is introduced into the non-powered stirring mechanism 60-4, and the flow direction of sludge is changed in various directions by the stirring blades 63-4 and 65-4, thereby being stirred without power. .

  Also in the case of the first aggregating device 40-4, since the non-powered stirring mechanism 60-4 is installed in addition to the powered stirrer 50-4, the stirring effect of the mixed sludge becomes larger. -4 driving power can be reduced, and energy saving can be achieved.

  Also in the case of the first aggregating device 40-4, the powered agitator 50-4 stirs the mixed sludge by the agitating blade 53-4 (rotational flow), and the non-powered stirring mechanism 60-4 uses the power of the mixed sludge flow. This is a configuration in which the mixing sludge is stirred by changing the flow direction of the mixed sludge (vortex flow), and the mixed sludge stirring state (rotational flow and vortex flow) is greatly different. Therefore, the mixed state of the mixed sludge can be made a more complicated flow, and the stirring effect of the mixed sludge can be further increased.

  As described above, according to the first flocculating device 40-4, the polymer flocculant can be uniformly dispersed in the sludge by high-speed stirring and complicated stirring by different stirring methods. Therefore, the neutralization of the surface charge of the sludge and the aggregation due to the adsorption or crosslinking action of the polymer can be performed simultaneously.

  In addition, you may install the non-powered stirring mechanism 60 (60-4) in both the upstream and downstream of the power agitator 50 (50-4). If comprised in this way, the stirring effect will increase further and reduction of the power of the power agitator 50 (50-4) can be achieved.

  6A and 6B are diagrams illustrating the first aggregating device 40-5, in which FIG. 6A is a schematic cross-sectional view of a main part, and FIG. 6B is a cross-sectional view taken along the line AA in FIG. In the first aggregating apparatus 40-5 shown in the same figure, a substantially T-shaped pipe-shaped first stirring unit 51-5, a stirring blade 53-5 installed in the first stirring unit 51-5, and a stirring blade 53 -5 and a shaft 55-5 that is drawn out of the first stirrer 51-5 and a motor (drive source) 57-5 that rotationally drives the shaft 55-5. Further, a non-powered stirring mechanism 60-5 is configured by installing a plate-like fluid mixing plate 59-5 in the upstream pipe constituting the first stirring unit 51-5.

  That is, the first aggregating device 40-5 has a structure in which a non-powered stirring mechanism 60-5 is integrally incorporated in a powered stirrer 50-5 (a main body housing of the first stirring unit 51-5). This saves space and increases efficiency.

  The non-powered agitation mechanism 60-5 has four flat fluid mixing plates 59-5 arranged at equal intervals on the upstream inner wall of the pipe constituting the first agitation unit 51-5. It consists of Each fluid mixing plate 59-5 has a substantially isosceles triangular shape. The shape of the fluid mixing plate 59-5 may be any shape or number other than a substantially isosceles triangle shape, but since the fluid used is sludge, it has a shape without sludge or pin that is used for sludge and has little catch on the residue. Preferably, the structure can be variously changed.

  If the first flocculating device 40-5 is configured in this way, the mixed sludge introduced into the first flocculating device 40-5 is first stirred without power by the flow being disturbed by the non-powered stirring mechanism 60-5. After mixing, high-speed stirring is performed by the high-speed rotation of 850 rpm or more of the stirring blade 53-5 of the powered stirrer 50-5, and further mixing is performed.

  Also in the first aggregating apparatus 40-5, since the non-powered stirring mechanism 60-5 is installed in addition to the powered stirrer 50-5, the stirring effect of the mixed sludge becomes larger, and the powered stirrer 50- 5 can be reduced in power consumption. Also in this example, since the stirring of the mixed sludge by the non-powered stirring mechanism 60-5 becomes the high-speed stirring preliminary stirring by the powered stirrer 50-5, the mixed sludge can be stirred more effectively. Moreover, since the non-powered stirring mechanism 60-5 is installed in the upstream (upstream side) of the powered stirrer 50-5, the returning phenomenon of the mixed sludge to the upstream side by the stirring blade 53-5 can be prevented.

  In this example, one row of the fluid mixing plates 59-5 is provided, but a plurality of rows may be provided at intervals in the fluid flow direction. Further, the number of fluid mixing plates 59-5 installed in a circumferential shape is not limited to four as described above, and may be one or more, and the shape of the fluid mixing plate 59-5 may be variously changed. It is possible and does not necessarily have to be flat.

  FIG. 7 is a schematic cross-sectional view of a main part of the first aggregating device 40-6. In the first aggregating device 40-6 shown in the figure, the difference from the first aggregating device 40-5 shown in FIG. It is only the point installed in the downstream of the power agitator 50-6. That is, the non-powered stirring mechanism 60-6 is configured by installing the plate-like fluid mixing plate 59-6 in the downstream pipe constituting the first stirring unit 51-6.

  In this case, the mixed sludge is first introduced into the powered agitator 50-6 and mixed at high speed by the high speed rotation of the agitating blade 53-6, and then introduced into the non-powered agitation mechanism 60-6. By changing the flow direction of the sludge by the fluid mixing plate 59-6, stirring is performed without power. Effective mixing can be realized by mixing and stirring the two.

  FIG. 8 is a schematic cross-sectional view of a main part of the first aggregating device 40-7. The first aggregating device 40-7 shown in the figure is different from the first aggregating device 40-5 shown in FIG. 6 in that a non-powered agitation mechanism 60-7 constituted by a fluid mixing plate 59-7 is provided. It is the point which connected and installed in the upstream of the 1st stirring part 51-7 as a different body from the piping which comprises the 1st stirring part 51-7 of the power agitator 50-7.

  That is, in the case of the first aggregating device 40-7, a single fluid-free stirring mechanism 60-7 is configured by installing a flat fluid mixing plate 59-7 inside the pipe-shaped main body 67-7. doing. A flange is provided at both ends of the main body 67-7, one end of which is connected to a flange provided at the upstream end of the first stirring unit 51-7, and the other end is connected to the non-powered stirring mechanism 60-7. Connected to the upstream pipe and flange.

  The integral structure of the first agitating part 51-5 and the fluid mixing plate 59-5 having a substantially T-shaped pipe shape shown in FIG. 6 is not easy in producing a casting. On the other hand, if the non-powered stirring mechanism 60-7 forming the fluid mixing plate 59-7 is manufactured separately from the first stirring unit 51-7 as in the first aggregating device 40-7 shown in FIG. Both the stirring unit 51-7 and the non-powered stirring mechanism 60-7 can be easily manufactured, which is preferable. In other words, the first aggregating device 40-7 can be easily configured simply by connecting the non-powered stirring mechanism 60-7 to the powered stirrer 50-7 produced as a standard device.

  Further, since the powered stirrer 50-7 and the non-powered stirring mechanism 60-7 are configured separately, for example, when the fluid mixing plate 59-7 is deteriorated and needs to be replaced, or more effective. When it is desired to update to a non-powered stirring mechanism having a structure, it is only necessary to replace the portion of the non-powered stirring mechanism 60-7, so that the replacement workability is improved and the maintenance cost can be reduced.

  Further, in order to increase the effect of non-powered stirring, even when a plurality of fluid mixing plates 59-7 are installed in the flow direction, a plurality of the single power-free stirring mechanisms 60-7 are connected in series. Since it is only necessary to connect, the structure can be easily changed as necessary.

  In the first aggregating apparatus 40-7 shown in FIG. 8, the non-powered stirring mechanism 60-7 is installed on the upstream side of the powered stirrer 50-7, but the powerless stirring on the downstream side of the powered stirrer 50-7. The mechanism 60-7 may be installed as in the case of the first aggregating device 40-6 shown in FIG. Further, a non-powered stirring mechanism 60-7 may be installed on the upstream side and the downstream side of the powered stirrer 50-7.

  FIG. 9 is a schematic sectional view of a main part of the first aggregating apparatus 40-8. The first aggregating apparatus 40-8 shown in the figure is different from the first aggregating apparatus 40-7 shown in FIG. 8 in the structure of a single non-powered stirring mechanism 60-8.

  In other words, in the case of the first aggregating apparatus 40-8, the pipe-shaped main body 67-8 is flangeless and is not provided with flanges at both ends thereof. In the case of this example, for example, a bolt nut not shown between the flange provided at the upstream end of the first stirring unit 51-8 and the flange of the pipe end connected to the upstream side of the non-powered stirring mechanism 60-8. It is the structure which clamps the non-powered stirring mechanism 60-8 by connecting by. Even if comprised in this way, the effect similar to the case of the 1st aggregation apparatus 40-7 shown in the said FIG. 8 will be produced.

  Also in the case of the first aggregating device 40-8, a non-powered stirring mechanism 60-8 may be installed on the downstream side or upstream side and downstream side of the powered stirrer 50-8.

  FIG. 10 is a side view of the first aggregating device 40-9. As shown in the figure, the first aggregating device 40-9 bends the pipe-shaped first stirring unit 51-9 of the powered stirrer 50-9 into an L shape, and thereby this first stirring unit 51 -9 itself is a non-powered stirring mechanism 60-9.

  That is, the first stirring unit 51-9 is bent in an L shape so that the sludge flow is disturbed in the bent portion. In other words, this non-powered stirring mechanism 60-9 is obtained by adding a powerless stirring function to the casing structure itself of the first stirring unit 51-9.

  The sludge flow direction may be the upward direction (upward flow) as indicated by the solid line arrow in FIG. 10 or the downward direction (downward flow) as indicated by the dotted line arrow. Is desirable. That is, for example, in the first stirring unit 51 shown in FIG. 2, gas tends to accumulate near the root portion of the stirring blade 53 on the shaft 55, and there is a risk of causing cavitation and the like when the stirring blade 53 is rotated at a high speed. If the upward flow is configured, the fluid flow enters the portion where the gas reservoir is likely to be generated, and the gas is easily taken away, so that the gas reservoir is not easily generated.

  If the non-powered stirring mechanism 60-9 is configured as described above, the flow direction of the mixed sludge is changed depending on the piping shape itself, and thereby the stirring effect can be obtained without complicating the internal structure.

  The powerless stirring mechanism 60-9 includes the powerless stirring mechanisms 60 and 60-4 shown in FIGS. 2 and 5, and the powerless stirring mechanism 60-5 shown in FIGS. 6, 7, 8, and 9. , 60-6, 60-7, 60-8 may be installed in combination.

  FIG. 11 is a side view of the first aggregating apparatus 40-10. The first aggregating apparatus 40-10 is different from the first aggregating apparatus 40-9 shown in FIG. 10 in that a vertical side portion of the L-shaped first agitating part 51-10 of the powered agitator 50-10 is used. The length dimension is formed long, and the number of the stirring blades 53-10 accommodated therein is two.

  If the stirring blades 53-10 are multistage, the mixed fluid can be stirred and mixed more effectively. The rotating shafts of the stirring blades 53-9 and 10 shown in FIGS. 10 and 11 are installed in parallel with the flow of the fluid, so that the stirring blade 53-10 is not flat but can be easily screwed. It can be done.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. Note that any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are exhibited.

1-1 Sludge treatment equipment (sludge coagulation dehydration equipment)
DESCRIPTION OF SYMBOLS 10 Sludge storage tank 20 Transfer pump 30 Sludge aggregation apparatus 40 1st aggregation apparatus 50 Powered stirrer 51 1st stirring part 53 Stirring blade 55 Shaft 57 Motor (drive source)
Reference Signs List 60 Non-powered stirring mechanism 61 Housing 63 Right stirring blade 65 Left stirring blade 70 First chemical injection means 71 First polymer flocculant dissolution tank 73 First polymer flocculant pump 80 Second flocculant 81 Second stirrer 83 Agitation blade 85 Shaft 87 Motor (drive source)
90 Second chemical injection means 91 Second polymer flocculant dissolution tank 93 Second polymer flocculant pump 100 Sludge dewatering machine 1-2 Sludge treatment device (sludge flocculant dewatering device)
1-3 Sludge treatment equipment (sludge coagulation dehydration equipment)

Claims (10)

A first aggregating device for aggregating the mixed sludge obtained by injecting a solution of the first polymer flocculant into the sludge;
Aggregated flocs are formed by aggregating mixed sludge obtained by injecting a solution of the second polymer flocculant into the mixed sludge mixed and stirred by the first aggregating device at a lower speed than the agitation rate of the first aggregating device. And a second aggregating device for obtaining agglomerated sludge,
The first aggregating apparatus includes a powered stirrer that stirs the mixed sludge, and a non-powered stirring mechanism that is installed upstream of the powered stirrer and pre-stirs the mixed sludge before being stirred by the powered stirrer. And the non-powered stirring mechanism is configured to change the flow direction of the mixed sludge using the force of the mixed sludge flow, while the powered stirrer is the first The stirring blade installed in the stirring unit is driven to rotate by a drive source, and the rotational speed of the first polymer is obtained by further strongly stirring the mixed sludge preliminarily stirred in the non-powered stirring mechanism. It is set to a rotational speed that allows the flocculant to reach the details of the sludge to make the flocculent sludge dense,
On the other hand, the agitation in the second aggregating apparatus is set to a stirring speed at which the formed dense agglomerated sludge is agglomerated to form a large agglomerated floc. The sludge aggregation apparatus according to claim 1,
The sludge agglomeration apparatus characterized in that the rotating speed of the stirring blade of the powered stirrer is a predetermined rotating speed of 850 rpm or more. The sludge aggregation apparatus according to claim 1 or 2,
The non-powered stirring mechanism is installed by attaching a plurality of fluid mixing plates circumferentially to the inner wall of the upstream pipe of the powered stirrer, and premixes the mixed sludge before being stirred by the powered stirrer A sludge agglomeration apparatus characterized by: The sludge aggregation apparatus according to claim 1, 2 or 3,
The sludge agglomeration apparatus characterized in that an inorganic flocculant addition apparatus for adding an inorganic flocculant to the sludge is installed upstream of the first agglomeration apparatus. The sludge aggregation apparatus according to claim 1, 2 or 3,
On the downstream side of the second flocculating device, a concentrating device for concentrating the flocculated sludge obtained by the second flocculating device to obtain concentrated sludge, and an inorganic flocculant adding device for adding an inorganic flocculant to the concentrated sludge obtained by the concentrating device And a sludge agglomeration apparatus characterized by the installation of A first flocculation step of stirring and flocculating the mixed sludge in which the solution of the first polymer flocculant is injected into the sludge;
Aggregating flocs are formed by aggregating the mixed sludge obtained by injecting the solution of the second polymer flocculant into the mixed sludge mixed and agitated in the first agglomeration step at a lower speed than the agitation speed of the first agglomeration step. A second agglomeration step to obtain agglomerated sludge,
The first aggregating step includes the steps of stirring using the power of the mixed sludge, a mixed sludge before being stirred using a Oite the power on the upstream side of the step of agitating using the power to non-powered And pre-stirring ,
The pre-stirring step is a step of stirring by changing the flow direction of the mixed sludge using the force of the mixed sludge flow, while the step of stirring using the power is a step of driving the stirring blade with a driving source. The rotational speed of the first agglomerating agent is spread to the sludge details by stirring the pre-stirred mixed sludge even more strongly. It is set to a precise rotation speed,
On the other hand, the agitation in the second agglomeration step is set at an agitation speed at which the formed dense agglomerated sludge is agglomerated to form large agglomerated flocs. The sludge aggregation method according to claim 6,
The sludge agglomeration method, wherein the rotation speed of the stirring blade in the agitation step using the power of the first agglomeration step is a predetermined rotation speed of 850 rpm or more. It is the sludge aggregation method according to claim 6 or 7 ,
A sludge agglomeration method comprising a step of adding an inorganic aggregating agent to sludge upstream of the first agglomeration step. It is the sludge aggregation method according to claim 6 or 7 ,
On the downstream side of the second flocculation step, a step of obtaining the concentrated sludge by concentrating the flocculated sludge obtained in the second flocculation step and a step of adding an inorganic flocculant to the concentrated sludge obtained in the step were provided. A method for coagulating sludge. A sludge storage tank for storing sludge from the water treatment system;
The sludge aggregating apparatus according to claim 1, wherein sludge sent from the sludge storage tank is agglomerated.
A sludge dewatering machine for dewatering the agglomerated sludge sent from the sludge aggregating device;
A sludge treatment apparatus characterized by comprising:

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