阅读说明：本技术 有机性污泥的处理设备及处理方法 (Treatment equipment and treatment method for organic sludge ) 是由 倭常郎 于 2020-01-23 设计创作，主要内容包括：本发明的有机性污泥的处理设备及处理方法,其具备浓缩机构(2),该浓缩机构(2)对添加凝聚剂B而凝聚的有机性污泥(C)进行浓缩,其中,从浓缩温水供给机构向浓缩机构(2)供给比50℃高且低于100℃的温度范围的浓缩温水(F),并与有机性污泥(C)混合。(The organic sludge treatment facility and treatment method of the present invention comprises a concentration means (2) for concentrating organic sludge (C) coagulated by adding a coagulant (B), wherein concentrated warm water (F) having a temperature range higher than 50 ℃ and lower than 100 ℃ is supplied from a concentrated warm water supply means to the concentration means (2) and mixed with the organic sludge (C).)

1. An apparatus for treating organic sludge, comprising a thickening means for thickening organic sludge coagulated by adding a coagulant, wherein concentrated warm water in a temperature range higher than 50 ℃ and lower than 100 ℃ is supplied from a concentrated warm water supply means, and the concentrated warm water is mixed with the organic sludge in the thickening means.

2. The facility for treating organic sludge according to claim 1, wherein the temperature of the concentrated warm water is in a range of 60 ℃ to 90 ℃.

3. The facility for treating organic sludge according to claim 1 or 2, wherein the organic sludge is concentrated by the concentration means to a sludge concentration of 5 wt% or more.

4. The facility for treating organic sludge according to any one of claims 1 to 3, wherein the concentration mechanism is a vertical filtration concentrator comprising:

a thickening tank having a central axis extending in a longitudinal direction, the main body being a thickening filter screen to which the organic sludge is supplied, and the outer periphery of the thickening filter screen being a filtrate chamber; and

a transport mechanism for transporting the organic sludge by attaching a screw to a rotary shaft along the central axis of the thickening tank and rotating the rotary shaft and the screw by a rotation drive mechanism,

the rotating shaft of the conveying mechanism is hollow and cylindrical, and 2 or more through holes are formed in a cylindrical wall portion of the rotating shaft, and the concentrated warm water is supplied to the hollow portion in the rotating shaft and is discharged from the through holes, thereby being supplied to and mixed with the organic sludge.

5. The apparatus for treating organic sludge according to any one of claims 1 to 3, wherein the concentration mechanism is a screw concentrator including:

a casing having a central axis extending in a transverse direction, a main body part being a thickening filter screen to which the organic sludge is supplied, and a filtrate chamber on an outer periphery of the thickening filter screen; and

a conveying mechanism in which a screw is attached to a rotating shaft along the central axis of the casing, and the rotating shaft and the screw are rotated by a rotation driving mechanism to convey the organic sludge,

the concentrated hot water is supplied from the concentrated hot water supply means and mixed with the organic sludge.

6. The facility for treating organic sludge according to any one of claims 1 to 3, wherein the concentration mechanism is a belt concentrator including an endless concentration-filtration filter cloth capable of traveling while being wound around 2 or more rollers, the concentration-filtration section in which the concentration-filtration filter cloth travels in a horizontal direction supplies organic sludge to a sludge supply section on the opposite side of the traveling direction of the concentration-filtration filter cloth, and the organic sludge is filtered and concentrated by the concentration-filtration filter cloth,

the concentrated hot water is supplied from the concentrated hot water supply mechanism and mixed with the organic sludge at a position closer to the traveling direction side of the concentrated filter cloth than the sludge supply unit in the concentrated filter unit.

7. A method for treating organic sludge, wherein organic sludge coagulated by adding a coagulant is concentrated by a concentration means, wherein concentrated warm water at a temperature higher than 50 ℃ and lower than 100 ℃ is supplied from a concentrated warm water supply means to the concentration means and mixed with the organic sludge.

8. The method for treating organic sludge according to claim 7, wherein the temperature of the concentrated warm water is in a range of 60 ℃ to 90 ℃.

9. The method of treating organic sludge according to claim 7 or 8, wherein the organic sludge is concentrated by the concentration means to a sludge concentration of 5 wt% or more.

[ technical field ] A method for producing a semiconductor device

The present invention relates to an organic sludge treatment facility including a concentration mechanism for concentrating organic sludge, and to a method for treating organic sludge in which organic sludge is concentrated by the concentration mechanism, wherein organic sludge concentration is performed by adding a flocculant to sewage sludge or the like generated from a sewage treatment plant and condensing the sludge.

This application claims priority based on japanese application No. 2019-013444, filed in japan on 29/1/2019, the contents of which are incorporated herein by reference.

[ background of the invention ]

For example, patent document 1 discloses an organic sludge treatment facility including: a thickening mechanism connected to the treated sludge supply path for thickening the supplied treated sludge; a dewatering mechanism that dewaters the concentrated sludge concentrated by the concentrating mechanism; a concentrated sludge supply path connecting the concentration mechanism and the dehydration mechanism; and a dewatering and drainage tank for storing dewatering and drainage water obtained by dewatering the concentrated sludge by the dewatering mechanism. A dewatering and drainage circulation supply path is connected to the dewatering and drainage tank, and the dewatering and drainage circulation supply path can supply the electrolyte and supply the dewatering and drainage stored in the dewatering and drainage tank to the concentrated sludge supply path to circulate the dewatering and drainage to the dewatering mechanism.

Further, patent document 1 discloses that a washing water supply mechanism is connected to the thickening mechanism, and washing water is supplied from the washing water supply mechanism to the treated sludge being thickened by the thickening mechanism; the supply amount of the cleaning water supplied from the cleaning water supply mechanism to the thickening mechanism is equal to or smaller in volume with respect to the supply amount of the treated sludge supplied to the thickening mechanism. It is also disclosed that warm water of about 50 ℃ is preferably used as the washing water.

[ Prior art documents ]

[ patent document ]

Patent document 1: japanese patent laid-open publication No. 2017-170346

[ summary of the invention ]

[ problem to be solved by the invention ]

The reason why warm water is preferably used as the washing water is that the organic sludge to which the flocculant is added is heated by the warm water in the thickening means, and the proteins in the organic sludge are thermally denatured, and the retained water is separated, whereby the organic sludge can be discharged as drainage water together with the washing water. Therefore, the dewatering efficiency of the dewatering mechanism can be further improved.

However, in the treatment facility and the treatment method disclosed in patent document 1, the temperature of the washing water is preferably about 50 ℃, and even if such washing water is supplied to the organic sludge at 25 ℃ in an equal amount to the maximum washing water supply amount with respect to the sludge supply amount as described above, the organic sludge can be heated only to about 38 ℃. Therefore, the dewatering efficiency of the dewatering mechanism may not be reliably improved.

The present invention has been made under such a background, and an object thereof is to provide an apparatus and a method for treating organic sludge, which can achieve a sufficiently low water content by heating the organic sludge in a concentration mechanism.

[ MEANS FOR SOLVING PROBLEMS ] to solve the problems

The organic sludge treatment facility of the present invention includes a concentration means for concentrating organic sludge coagulated by adding a coagulant, and supplies concentrated warm water having a temperature range higher than 50 ℃ and lower than 100 ℃ from a concentrated warm water supply means, the concentrated warm water being mixed with the organic sludge in the concentration means.

The method for treating organic sludge according to the present invention is a method for treating organic sludge in which organic sludge coagulated by adding a coagulant is concentrated by a concentration means, and concentrated warm water at a temperature higher than 50 ℃ and lower than 100 ℃ is supplied from a concentrated warm water supply means to the concentration means, and the concentrated warm water is mixed with the organic sludge in the concentration means.

In the apparatus and method for treating organic sludge configured as described above, concentrated warm water at a temperature higher than 50 ℃ and lower than 100 ℃ is supplied from the concentrated warm water supply means to the concentration means for concentrating organic sludge, and the concentrated warm water is mixed with the organic sludge in the concentration means. Therefore, the organic sludge can be concentrated to a sufficiently high concentration in the concentration means, and when the dewatering means is provided at the subsequent stage, the dewatering efficiency can be improved.

The inventors of the present invention have made various studies and found the following: in particular, when the organic sludge is mixed raw sludge, the water content of the organic sludge can be reduced by about 1% for every 10 ℃ rise in the sludge temperature as described later. Therefore, the higher the sludge temperature, that is, the higher the temperature of the concentrated warm water, the more likely the water content of the concentrated organic sludge is to be reduced. Further, the viscosity of the organic sludge is reduced by heating the organic sludge, and therefore, the efficiency of dewatering the concentrated organic sludge is also improved.

Further, since the aggregation inhibitor contained in the liquid of the organic sludge can be replaced in the concentrated warm water by mixing the concentrated warm water with the organic sludge in the concentrating means, the flocculant such as ferric Polysulfate (PFS) added to the concentrated organic sludge can be prevented from being consumed by the aggregation inhibitor, the flocculant can be efficiently reacted with the solid content of the concentrated organic sludge, and the amount of the flocculant to be added can be reduced.

When the temperature of the concentrated warm water is 50 ℃ or lower, the above-mentioned effects of the reduction in the viscosity of the organic sludge and the separation of water cannot be sufficiently obtained. In addition, when the temperature of the concentrated warm water exceeds 100 ℃, the treatment becomes difficult. As described above, the higher the temperature of the concentrated hot water, the more the reduction in the viscosity of the organic sludge and the separation of water due to thermal denaturation of proteins are promoted, but for example, when the hot water used in the treatment facility is used as the concentrated hot water, a temperature range of 60 ℃ to 90 ℃ is realistic and preferable.

In addition, when the organic sludge after the concentration is dewatered as described above, the organic sludge is preferably concentrated by the concentration means to a sludge concentration of 5 wt% or more, more preferably, for example, to a sludge concentration in the range of 8 wt% to 10 wt%, in order to further improve the dewatering efficiency. Further, when the organic sludge concentrated in the same manner is dewatered, it is preferable to add a flocculant to the organic sludge concentrated by the concentration means.

Here, as the concentration mechanism, a vertical filtration concentrator may be used, the vertical filtration concentrator including:

a thickening tank having a central axis extending in a longitudinal direction, the main body being a thickening filter and supplying the organic sludge to the inside, and the outer periphery of the thickening filter being a filtrate chamber; and

and a conveying mechanism for conveying the organic sludge by attaching a screw to a rotary shaft along the central axis of the thickening tank and rotating the rotary shaft and the screw by a rotation driving mechanism.

In the case of using such a vertical filtration thickener, the concentrated warm water can be supplied and mixed into the organic sludge by forming the rotating shaft of the transport mechanism in a hollow cylindrical shape, forming 2 or more through holes in the cylindrical wall portion of the rotating shaft, and supplying the concentrated warm water into the hollow portion in the rotating shaft and discharging the concentrated warm water from the through holes.

As the concentration mechanism, a screw concentrator including:

a casing having a central axis extending in a transverse direction, a main body part being a concentration filter screen and supplying the organic sludge to the inside, and a filtrate chamber around the concentration filter screen; and

and a conveying mechanism for conveying the organic sludge by attaching a screw to a rotary shaft along the central axis of the casing and rotating the rotary shaft and the screw by a rotation driving mechanism.

When such a screw thickener is used as the thickening means, the thickened hot water is supplied from the thickened hot water supply means, and the screw is rotated by the rotation drive means to be mixed with the organic sludge.

As the concentration means, a belt concentrator may be used, which includes an annular concentration filtration cloth wound around 2 or more rollers and capable of traveling, and which filters and concentrates the organic sludge supplied to a sludge supply unit on the opposite side of the traveling direction of the concentration filtration cloth among concentration filtration units in which the concentration filtration cloth travels in the horizontal direction, by the concentration filtration cloth.

In the case of using such a belt thickener, the concentrated warm water is supplied from the concentrated warm water supply means to a position on the traveling direction side of the concentrated filter cloth in the concentrated filter unit with respect to the sludge supply unit, whereby the concentrated warm water can be mixed with the organic sludge on the concentrated filter cloth traveling in the horizontal sludge filter unit. In addition to these vertical filtration thickeners, belt thickeners, and screw thickeners, other thickeners such as a cylinder thickener and a honeycomb thickener may be used as long as they do not break the organic sludge, other than a centrifugal thickener which breaks the flocculated organic sludge.

[ Effect of the invention ]

As described above, according to the present invention, the organic sludge is heated by supplying and mixing the concentrated warm water to the organic sludge in the concentrating means, and the protein in the organic sludge can be thermally denatured reliably to separate water, so that the organic sludge can be concentrated to a high concentration with a sufficiently low water content.

[ description of the drawings ]

FIG. 1 is a schematic view showing an apparatus for treating organic sludge according to embodiment 1 of the present invention.

Fig. 2 is a detailed view of the embodiment shown in fig. 1.

Fig. 3 is a view showing an example 1 of the relationship between the temperature of the concentrated hot water and the water content of the organic sludge (concentrated sludge) in the embodiment shown in fig. 1 and 2.

FIG. 4 is a graph showing the relationship between the temperature and the water content of the organic sludge (concentrated sludge) heated with concentrated hot water in example 1 shown in FIG. 3.

Fig. 5 is a view showing an example 2 of the relationship between the temperature of the concentrated hot water and the water content of the organic sludge (concentrated sludge) in the embodiment shown in fig. 1 and 2.

FIG. 6 is a graph showing the relationship between the temperature and the water content of the organic sludge (concentrated sludge) heated with concentrated hot water in example 2 shown in FIG. 5.

Fig. 7 is a diagram showing example 3 of the relationship between the temperature of the concentrated hot water and the water content of the organic sludge (concentrated sludge) in the embodiment shown in fig. 1 and 2.

FIG. 8 is a graph showing the relationship between the temperature and the water content of the organic sludge (concentrated sludge) heated with the concentrated hot water of example 3 shown in FIG. 7.

Fig. 9 is a view showing a1 st modification example of the concentration mechanism and the dehydration mechanism of the 1 st embodiment shown in fig. 1 and 2.

Fig. 10 is a view showing a2 nd modification example of the concentration mechanism and the dehydration mechanism of the 1 st embodiment shown in fig. 1 and 2.

FIG. 11 is a schematic view showing an apparatus for treating organic sludge according to embodiment 2 of the present invention.

[ detailed description ] embodiments

Fig. 1 and 2 show a1 st embodiment of the organic sludge treatment facility according to the present invention, and the following describes the 1 st embodiment of the organic sludge treatment facility, and also describes a method for treating the organic sludge according to the present invention. The organic sludge treatment facility of the present embodiment includes:

a coagulation mechanism 1 for coagulating an organic sludge a such as sewage sludge, for example, mixed raw sludge generated and supplied from a sewage treatment plant, by adding a polymer flocculant B to the organic sludge a;

a thickening mechanism 2 for thickening the sludge C having the solid content agglomerated to some extent by the agglomerating mechanism 1;

a dewatering mechanism 3 for dewatering the concentrated sludge D concentrated by the concentration mechanism 2; and

and a concentrated sludge supply path 4 connecting the concentration means 2 and the dewatering means 3.

As shown in fig. 2, the coagulation mechanism 1 includes a bottomed cylindrical coagulation tank 1A, and the coagulation tank 1A holds an organic sludge a and a polymer flocculant B supplied from the bottom and has a central axis extending in the vertical direction. The coagulation tank 1A is provided with a stirring mechanism 1B, and the stirring mechanism 1B is configured such that a stirring blade 1B is attached to a rotating shaft 1A along the central axis of the coagulation tank 1A, and the rotating shaft 1A and the stirring blade 1B are rotated by a rotation driving mechanism 1c such as a motor provided in the upper part of the coagulation tank 1A, whereby the organic sludge a and the polymer flocculant B are stirred and mixed. The coagulated sludge C coagulated by stirring and mixing with the polymer coagulant B by the stirring mechanism 1B is drawn out from the upper part of the coagulation tank 1A and supplied to the concentration mechanism 2.

The thickening mechanism 2 in the present embodiment is a vertical filtration thickener, and includes a bottomed cylindrical thickening tank 2A, the thickening tank 2A holding the flocculated sludge C supplied from the flocculation mechanism 1, and having a central axis extending in the vertical direction similarly to the thickening tank 1A, and the flocculated sludge C being supplied from the upper part of the thickening tank 2A into the thickening tank 2A. The main body of the concentration tank 2A is a concentration filter screen 2A formed of a wedge wire, a punching wire, or the like, and the outer periphery of the concentration filter screen 2A is a filtrate chamber 2 b.

The thickening tank 2A is provided with a conveying mechanism 2B, a screw 2d is attached to a rotating shaft 2C along the central axis of the thickening tank 2A, and the rotating shaft 2C and the screw 2d are rotated by a rotary driving mechanism 2e such as a motor provided at the upper portion of the thickening tank 2A to convey the flocculated sludge C. The flocculated sludge C supplied from the upper part of the thickening tank 2A is concentrated by separating water by the thickening strainer 2A while being conveyed downward by the conveying mechanism 2B, is thickened to a sludge concentration of 5 wt% or more, preferably to a sludge concentration range of 8 wt% to 10 wt%, is extracted from the bottom of the thickening tank 2A, and is supplied to the thickened sludge supply line 4 as thickened sludge D.

The bottoms of the thickener tank 2A and the coagulation tank 1A are formed in a truncated cone shape whose diameter decreases downward. The water separated from the flocculated sludge C by the thickening strainer 2a is stored in the filtrate chamber 2b and treated as the drain water E.

Concentrated hot water F having a temperature in the range of higher than 50 ℃ and lower than 100 ℃, preferably in the range of 60 ℃ to 90 ℃ is supplied by a pump 2C from a concentrated hot water supply means not shown, and is mixed with the flocculated sludge C supplied from the flocculation means 1 in the concentration means 2.

Here, the rotary shaft 2c of the transport mechanism 2B of the concentration mechanism 2 is hollow and cylindrical, and a plurality of (2 or more) through holes are formed in the cylindrical wall portion of the rotary shaft 2 c. The concentrated hot water F is supplied from the lower end of the rotating shaft 2C to the hollow portion inside the rotating shaft 2C, is discharged from the through hole, and is supplied to and mixed with the flocculated sludge C supplied from the flocculation mechanism 1 and stored in the concentration tank 2A. Thus, in the present embodiment, in the concentration mechanism 2, the flocculated sludge C is heated to thermally denature the protein, the retained water is separated and discharged as the drain water E together with the concentrated warm water F, and the concentrated sludge D is concentrated to the above-described concentration.

As the concentrated hot water F and the later-described dehydrated hot water H, the exhaust gas treatment tower drain of the sludge incineration facility provided in the organic sludge treatment facility, the scrubber drain of the sludge drying facility, or the hot water generated by the digestion gas generator can be used. In addition, water supply heated by a boiler, sand filtration, or the like may be used.

In the concentrated sludge supply path 4 to which the concentrated sludge D concentrated in this manner is supplied, a pump 4A that sends out the concentrated sludge D to the dewatering mechanism 3 is provided, and a mixing mechanism 4B such as a high-speed mixer is provided between the pump 4A and the dewatering mechanism 3. In the mixing means 4B, an inorganic flocculant such as ferric Polysulfate (PFS) or a flocculant G such as a polymer flocculant is supplied by a pump 4C, and added to and mixed with the concentrated sludge D.

In the present embodiment, in the dewatering mechanism 3 to which the concentrated sludge D added and mixed with the flocculant G is supplied, the strainer 3B for filtering the concentrated sludge D is disposed in the casing 3A, and the concentrated sludge D is supplied to the 1 st space 3A1 among 2 or more spaces in the casing 3A partitioned by the strainer 3B.

Here, the dewatering mechanism 3 in the present embodiment is a vertical screw press, and includes:

an inner screen 3A, which is the screen 3B of the 2 nd screen 3B, is disposed in the housing 3A in a cylindrical or conical shape centered on an axis extending in the longitudinal direction and coaxial with the housing 3A;

an outer screen 3b which is cylindrical or conical and coaxial with the inner screen 3A, and which is disposed inside the housing 3A at an interval outside the inner screen 3A; and

and a spiral belt 3d which is spirally twisted around the axis, is accommodated between the inner strainer 3a and the outer strainer 3b, and is relatively rotated with respect to the inner strainer 3a and the outer strainer 3b around the axis by a rotation driving mechanism 3c such as a motor.

In the present embodiment, the space between the inner screen 3A and the outer screen 3b is defined as the 1 st space 3A1 to which the concentrated sludge D is supplied, and the space inside the inner screen 3A and the space inside the housing 3A outside the outer screen 3b are defined as the 2 nd space 3A 2. In the present embodiment, the dehydrating hot water H having a temperature in the range of 50 ℃ to less than 100 ℃, preferably 60 ℃ to 90 ℃ is supplied to the 2 nd space 3a2 by the pump 3P, not shown, by the dehydrating hot water supply means. Note that, these inner filter mesh 3a and outer filter mesh 3b are also formed of wedge wires, punched metal, or the like.

The casing 3A is a bottomed cylindrical shape centered on the axis, and the concentrated sludge D is supplied from the bottom of the casing 3A to the 1 st space 3A1 through a supply pipe 3f connected to a connection plate 3e in the form of a circular ring plate connecting the bottoms of the inner strainer 3A and the outer strainer 3b, and is separated from water by the inner strainer 3A and the outer strainer 3b while being conveyed upward by the relative rotation of the screw belt 3D.

Further, an annular plate-shaped substrate 3C is provided at an upper portion in the housing 3A, and the outer screen 3b is attached and fixed to an inner peripheral portion of the substrate 3C. Further, a lid 3D is provided at an upper opening of the case 3A above the substrate 3C, the inner screen 3A is fixed to the lid 3D, and the rotation driving mechanism 3C is disposed on the lid 3D, and the spiral belt 3D is rotated by a cylindrical spiral support body covering an upper portion of the inner screen 3A.

In the present embodiment, the inner screen 3a and the outer screen 3b are fixed to the housing, and the screw belt 3d is rotationally driven by the rotational drive mechanism 3c, but the screw belt 3d may be fixed in reverse to rotate the inner screen 3a and the outer screen 3b, or the screw belt 3d and the inner screen 3a and the outer screen 3b may be rotated in reverse directions to each other.

Further, the space in the upper portion of the housing 3A between the substrate 3C and the lid 3D serves as a discharge chamber 3E, and the annular upper opening portion of the 1 st space 3A1 in the discharge chamber 3E serves as a discharge port 3F, and a pressing ring 3G having a truncated conical outer peripheral surface centered on the axis is provided in the discharge port 3F, the pressing ring 3G facing upward toward the outer peripheral side. The concentrated sludge D is conveyed upward in the 1 st space 3a1 by the spiral belt 3D, and simultaneously, water is separated and dewatered from the concentrated sludge D, and the obtained dewatered sludge I flows out to the discharge chamber 3E from the discharge port 3F while being pressed by the press ring 3G and is discharged.

In the present embodiment, the hot dehydrated water H is also supplied from the bottom of the casing 3A to the 2 nd space 3A2 in the casing 3A. The dehydrated warm water H supplied to the 2 nd space 3a2 in this way heats the concentrated sludge D in the 1 st space 3a1 in the same manner as the concentration mechanism 2, so that the proteins of the concentrated sludge D are thermally denatured to separate the retained water, and the dehydrated warm water H is filtered by the inner strainer 3a and the outer strainer 3b, and is discharged as the drain water J from the drain pipe 3H which is branched from the 2 nd space 3a2 together with the dehydrated warm water H cooled by heating the concentrated sludge D.

In the organic sludge treatment facility and the treatment method having the above-described configuration, the thickening means 2 is provided in a stage preceding the dewatering means 3, the thickening means 2 thickens the aggregated sludge C aggregated by adding the polymer flocculant B to the organic sludge a in the aggregating means 1, and the dewatering means 3 dewaters the thickened sludge D concentrated by the thickening means 2.

Then, concentrated warm water F having a temperature higher than 50 ℃ and lower than 100 ℃ is supplied from a concentrated warm water supply means to the concentration means 2, and is mixed with the flocculated sludge C. Therefore, in the thickening mechanism 2 at the front stage of the dewatering mechanism 3, the thickened sludge D can be heated to thermally denature the protein, and the water retained in the thickened sludge D can be separated, so that the dewatering efficiency of the dewatering mechanism 3 at the rear stage can be improved.

Here, FIGS. 3, 5 and 7 are views showing the relationship between the temperature of the concentrated hot water F and the water content of the concentrated sludge D in examples 1 to 3, in which the three types of organic sludge A having a sludge concentration of 2 wt% are treated at a ratio of 10m according to embodiment 1³[ solution ] aggregated sludge C which is supplied to the aggregation means 1 and aggregated, and the temperature of the concentrated warm water F is 3.3m by using the water in the concentration means 2³The temperature of the concentrated warm water F when the concentrated warm water F is heated and concentrated; fig. 4, 6, and 8 are graphs showing the relationship between the temperature and the water content of the concentrated sludge D heated by the concentrated warm water F in examples 1 to 3.

The organic sludge a of example 1 is mixed raw sludge, the organic sludge a of example 2 is mixed raw sludge rich in excess, and the organic sludge a of example 3 is digested sludge. In these examples 1 to 3, the concentrated hot water F was heated to be supplied with water by a boiler, 11 wt% of ferric Polysulfate (PFS) was added in example 1, and 5 wt% of ferric Polysulfate (PFS) was added in example 2.

As is clear from fig. 3 to 8, when the temperature of the concentrated hot water F supplied to the concentration mechanism 2 and mixed with the flocculated sludge C exceeds 50 ℃, the ratio of the water content of the concentrated sludge D to be lower relative to the ratio of the temperature of the concentrated hot water F to be higher starts to be higher, and the water content tends to be lower as the temperature of the concentrated hot water F is higher. Therefore, according to the organic sludge treatment facility and the organic sludge treatment method configured as described above, the water content of the concentrated sludge D can be reduced as described above, and the dewatering efficiency in the dewatering mechanism 3 at the subsequent stage of the concentrating mechanism 2 can be improved. In fig. 5, the hot water temperature of 80 ℃ is plotted at 2 points because the concentrated hot water F of 80 ℃ is repeatedly supplied 2 times.

Further, since the condensed hot water F and the condensed sludge C are mixed in the concentration means 2 in this manner, the aggregation inhibitor contained in the liquid of the condensed sludge C can be replaced with the condensed hot water F, and therefore, the flocculant G such as ferric polysulfate added to the condensed sludge D in the condensed sludge supply path 4 can be prevented from being consumed by the aggregation inhibitor, and the flocculant G can be efficiently reacted with the solid content of the condensed sludge D.

Further, by heating the flocculated sludge C with the concentrated hot water F, the reactivity of the flocculant G with the concentrated sludge D can be improved, and the amount of the flocculant G added can be reduced. Further, by heating the concentrated sludge D in this manner, the viscosity of the concentrated sludge D is reduced, and therefore the dewatering efficiency when dewatering the concentrated sludge D by the dewatering mechanism 3 can be further improved.

When the temperature of the concentrated hot water F is 50 ℃ or lower, the water content of the concentrated sludge D cannot be effectively reduced as shown in fig. 3 to 8. Further, if the temperature of the concentrated hot water F is 100 ℃ or higher, the workability of the concentrated hot water F is impaired. Further, the higher the temperature of the concentrated hot water F, the more the separation of water and the reduction in viscosity due to the thermal denaturation of the protein in the concentrated sludge D can be promoted, but as described above, when the hot water used in the facility for treating organic sludge is used as the dehydrated hot water H, a temperature range of 60 ℃ to 90 ℃ is realistic.

In order to further improve the dewatering efficiency of the dewatering means 3 at the subsequent stage of the thickening means 2 as described above, the sludge concentration of the thickened sludge D thickened by the thickening means 2 is preferably thickened to 5 wt% or more, and more preferably to a range of 8 wt% to 10 wt% of the sludge concentration.

In the organic sludge treatment facility and treatment method according to the present embodiment, the concentrated sludge D is supplied to the 1 st space 3A1 of the 2 or more spaces partitioned by the filter screen 3B disposed in the casing 3A and filtering the concentrated sludge D in the dewatering mechanism 3, and the dewatering warm water H having a temperature higher than 50 ℃ and lower than 100 ℃ is supplied from the dewatering warm water supply mechanism to the 2 nd space 3A 2. Then, by heating the concentrated sludge D supplied to the 1 st space 3a1 with the dehydrated warm water H supplied to the 2 nd space 3a2 in this manner, the viscosity of the concentrated sludge D is also lowered, and the water retained in the concentrated sludge D is separated by thermal denaturation of proteins.

The water separated from the concentrated sludge D is filtered by the filter screen 3B and flows into the 2 nd space 3a2, and is discharged together with the cooled dehydrated warm water H, so that the water content of the dehydrated sludge I discharged from the discharge port 3F to the discharge chamber 3E can be further reduced. Further, as described above, since the viscosity of the concentrated sludge D is decreased and the filtration resistance is decreased, the moisture separated from the concentrated sludge D can be easily discharged to the 2 nd space 3a 2. Therefore, according to the present embodiment, the dehydrated sludge I can be reduced in water content and the water separated from the concentrated sludge D can be effectively discharged.

Here, if the temperature of the dehydrated warm water H is 50 ℃ or lower, the above-described effects of the viscosity reduction and the moisture separation of the concentrated sludge D cannot be sufficiently obtained. In addition, when the temperature of the dehydrated warm water H is higher than 100 ℃, the operation is difficult as in the case of the concentrated warm water F. It should be noted that the higher the temperature of the dehydrated warm water H, the more the viscosity reduction of the concentrated sludge D and the water separation due to the thermal denaturation of the protein can be promoted, but in the case where the warm water used in the facility for treating the organic sludge is used as the dehydrated warm water H as described above, the temperature range of 60 ℃ to 90 ℃ is realistic as in the case of the concentrated warm water F.

In the processing facility of the present embodiment, a vertical screw press having:

an inner filter mesh 3A which is cylindrical or conical with an axis extending in the longitudinal direction as the center and is provided in the housing 3A;

an outer screen 3b which is cylindrical or conical and coaxial with the inner screen 3A, and which is provided inside the housing 3A at an interval outside the inner screen 3A; and

and a spiral band 3d that is spirally twisted around the axis, is accommodated between the inner strainer 3a and the outer strainer 3b, and rotates relative to the inner strainer 3a and the outer strainer 3b around the axis.

The space between the inner screen 3a and the outer screen 3B as the screen 3B is the 1 st space 3a1 to which the concentrated sludge D is supplied, and the space inside the inner screen 3a and the space outside the outer screen 3B are the 2 nd space 3a2 to which the dehydrated warm water H is supplied.

In the vertical screw press having such a configuration, the concentrated sludge D supplied to the 1 st space 3a1 between the inner screen 3a and the outer screen 3b is dewatered by the inner screen 3a and the outer screen 3b while being transported in the axial direction by the relative rotation of the screw belt 3D, and therefore, a large filtration area can be secured, and more effective filtration can be realized. In addition, since the concentrated sludge D supplied to the 1 st space 3a1 can be heated by the dehydrated warm water H supplied to the 2 nd space 3a2 inside and outside the 1 st space 3a1, the separation of moisture caused by thermal denaturation of proteins can also be more effectively promoted. It is preferable that 80% or more of the filtration surface of the inner filter web 3a and the outer filter web 3b is in direct contact with the hot water H for dehydration all the time. Thus, in the dewatering process of the concentrated sludge D, the concentrated sludge D supplied to the 1 st space 3a1 through the strainer can be sufficiently heated, and the separation of water by the thermal denaturation of protein can be more effectively promoted. Further, since the filter surface is always in direct contact with the dehydrated warm water H, the filter surface does not come into contact with the atmosphere, and therefore clogging due to drying of the filter surface can be prevented.

In the present embodiment, the vertical screw press having the two screens 3B of the inner screen 3a and the outer screen 3B is used as the dewatering mechanism 3, but a vertical screw press having a cylindrical or conical screen centered on an axis extending in the longitudinal direction and provided with a screw twisted around the axis and rotating around the axis, or a horizontal screw press or a belt press described below may be used. Alternatively, a rotary press or a multiple plate type screw press may be used.

Next, fig. 9 shows a1 st modification of the concentration mechanism 2 and the dehydration mechanism 3 of the 1 st embodiment shown in fig. 1 and 2, and the same parts as those of the 1 st embodiment shown in fig. 1 and 2 are given the same reference numerals. In this first modification, the concentration mechanism 2 is a screw type concentrator.

That is, the concentration mechanism 2 in the 1 st modification includes:

a cylindrical housing 11, a main body portion of the housing 11 serving as a thickening screen 11a, the flocculated sludge C being supplied to the inside of the housing 11, and an outer periphery of the thickening screen 11a serving as a filtrate chamber 11b, the housing 11 having a central axis extending in a transverse direction; and

a conveying mechanism 12, the conveying mechanism 12 having a screw 12b mounted on a rotary shaft 12a along the above-mentioned central axis of the housing 11, and conveying the coagulated sludge C by rotation of the rotary shaft 12a and the screw 12b driven by a rotary drive mechanism (not shown).

Then, on the side of the conveying direction in which the aggregated sludge C is conveyed by the conveying mechanism 12, the concentrated hot water F is supplied from a concentrated hot water supply mechanism not shown, and is mixed with the aggregated sludge C by the rotation of the screw 12b, as in embodiment 1. In the thickening mechanism 2 of modification 1, the flocculated sludge C is filtered by the thickening strainer 11a while being conveyed by the rotation of the screw 12b of the conveying mechanism 12, and is thickened to a sludge concentration of about 6 wt%, for example. The concentrated sludge D thus concentrated is pumped out by the pump 4A and supplied to the dewatering mechanism 3, but the lumps of the concentrated sludge D are easily disintegrated by heating, and therefore a small amount of the polymer flocculant G may be added in addition to the inorganic flocculant G.

In addition, in the modification 1, a horizontal screw press is also used as the dewatering mechanism 3. That is, the dewatering mechanism 3 in modification 1 also includes a cylindrical housing 13 and a conveying mechanism 14, the main body of the housing 13 is a dewatering screen 13a, the concentrated sludge D is supplied into the housing 13, the periphery of the dewatering screen 13a is a filtrate chamber 13b, the housing 13 has a central axis extending in the lateral direction, the conveying mechanism 14 is provided with a screw 14b attached to a rotating shaft 14a along the central axis of the housing 13, and the rotating shaft 14a and the screw 14b are rotated by a not-shown rotation driving mechanism to convey the concentrated sludge D.

Here, the screw 14b of the conveying mechanism 14 of the dewatering mechanism 3 is formed such that the pitch decreases in the conveying direction of the concentrated sludge D, and the concentrated sludge D is compressed and dewatered while being conveyed by the screw 14 b. In the modification 1, the hot water H for dehydration may be supplied to and mixed with the dehydration mechanism 3.

Next, fig. 10 shows a2 nd modification of the concentration mechanism 2 and the dehydration mechanism 3 of the 1 st embodiment shown in fig. 1 and 2, and the same reference numerals are given to the same parts as those of the 1 st embodiment shown in fig. 1 and 2. In this modification 1, the concentration mechanism 2 is a belt concentrator.

That is, the concentration mechanism 2 in the 2 nd modification includes an annular concentration filtration cloth 22 wound around 2 or more rollers 21 and capable of traveling, and the condensed sludge C is filtered and concentrated by the concentration filtration cloth 22 based on gravity, and the condensed sludge C is supplied to a sludge supply portion 22A on the opposite side of the traveling direction R of the concentration filtration cloth 22 in the concentration filtration portion 22A in which the concentration filtration cloth 22 travels in the horizontal direction.

In the 2 nd modification example, concentrated hot water F is supplied from a concentrated hot water supply mechanism not shown to the position on the traveling direction R side of the concentrated filter cloth 22 with respect to the sludge supply portion 22A in the concentrated filter portion 22A, and is mixed with the flocculated sludge C having a sludge concentration of about 6 wt%, for example. The inorganic flocculant G may be supplied to the concentrated sludge D at a position closer to the traveling direction R of the concentration filtration cloth 22 than the position at which the concentrated hot water F is supplied. Further, a screw 23 for reacting the inorganic coagulant G with the concentrated sludge D may be provided.

In addition, in the 2 nd modification, the dewatering mechanism 3 is also a belt press. That is, in the dewatering mechanism 3, the dewatering filter cloth 31 is wound around 2 or more rollers 32 and can travel, and the compression filter cloth 33 is wound around the 2 or more rollers 32 and can travel so as to sandwich the concentrated sludge D between the dewatering filter cloth 31, and the concentrated sludge D is compressed and dewatered between the dewatering filter cloth 31 and the compression filter cloth 33.

In the modification 2, the dewatering filter cloth 31 of the dewatering mechanism 3 and the concentration filter cloth 22 of the concentration mechanism 2 are formed continuously and annularly, and the dewatering filter cloth 31 after dewatering the concentrated sludge D is returned to the concentration mechanism 2 as the concentration filter cloth 22. In the modification 2, the dewatering hot water H may be supplied and mixed to the concentrated sludge D supplied to the dewatering mechanism 3.

In addition to the screw thickener and the belt thickener according to modifications 1 and 2, a cylinder thickener or a honeycomb thickener, for example, may be used as long as the thickener does not destroy the flocculated sludge C other than the centrifugal thickener which destroys the flocculated sludge C. Further, the concentration mechanism 2 and the dehydration mechanism 3 of embodiment 1, modification 1, and modification 2 may be used in combination as appropriate.

In addition, although the dewatering warm water H supplied to the dewatering mechanism 3 is discharged as the drain water J in the above embodiment 1, the dewatering warm water discharged from the dewatering mechanism 3 may be recycled by circulating and supplying the water to the concentration mechanism 2 as the circulating and concentrated warm water K as in the embodiment 2 of the present invention shown as a schematic diagram in fig. 11. In fig. 11, the same components as those in fig. 1 are denoted by the same reference numerals.

In the case of embodiment 2, since the separation liquid discharged from the dewatering means 3 is also contained in the dewatering warm water as the circulating concentrated warm water K discharged from the dewatering means 3, according to embodiment 2, the insoluble solid content (SS) in the separation liquid can be captured by the concentration means 2, and the SS recovery rate can be improved. In addition, since the residual polymer in the separated liquid can be effectively utilized, the performance of the dewatering mechanism 3 can be improved, and the temperature of the concentrated sludge D can be further increased, thereby further improving the dewatering efficiency.

[ INDUSTRIAL APPLICABILITY ]

By applying the above-described apparatus and method for treating organic sludge to this field, it is possible to provide an apparatus and method for treating organic sludge, which can heat the organic sludge in the concentration means to sufficiently reduce the water content.

[ description of symbols ]

1 agglomeration mechanism

2 concentration mechanism

2A concentration tank

2a, 11a concentration filter screen

2b, 11b filtrate Chamber

2B and 12 conveying mechanism

2c, 12a axis of rotation

2d, 12b screw

3 dewatering mechanism

4 concentrated sludge supply path

11 casing

21 roller

22 concentration filtration cloth

A organic sludge

B Polymer coagulant

C coagulated sludge

D concentrating the sludge

E. J drainage

F concentrated warm water

G coagulant

H-dehydrated warm water

I dewatered sludge

K circulation concentrated warm water