JP6598355B2 - Sludge drying treatment method and sludge drying treatment apparatus - Google Patents

Description

  The present invention relates to a method for drying sludge discharged from a sewage treatment plant or the like, and a sludge drying treatment apparatus.

  Sludge containing organic matter discharged from sewage treatment plants, human waste treatment plants, wastewater treatment facilities, food factories, etc. is dried and then incinerated to become incinerated ash, which is discarded in landfills. In order to burn sludge without using auxiliary fuel, it is desirable to reduce the moisture content of sludge to about 70% by mass. Moreover, when discarding dried sludge directly, it is desired to reduce the water content to 40% by mass or less in order to reduce the volume.

  In order to dry the sludge, various drying methods are known. Basically, hot air drying in which the sludge is stirred and brought into contact with hot air to evaporate water contained in the sludge is the mainstream. However, since sludge is highly sticky, it tends to adhere to the inner wall of the dryer and the stirring blade, and the stirring blade becomes heavier and insufficiently stirred, resulting in poor drying, and the stirring blade does not move. The problem of becoming impossible was easy to occur. For this reason, the stickiness is reduced by mixing the sludge with other things, and the adhesion of the sludge to the inner wall and the stirring blade of the dryer has been reduced.

  For example, in Patent Document 1 below, a dryer having a plurality of stirring paddles arranged radially with respect to a rotating shaft in a horizontally installed cylindrical casing, and the sludge being stirred by the stirring paddle in the casing. There is disclosed a drying method in which hot air is blown and heated directly, or steam is supplied to a jacket provided in a casing and indirectly heated. By mixing solid sludge containing carbon in organic sludge and having a particle size of several millimeters or less, the solid fine particles become the core of cracks in the lump of organic sludge. It is described that the adhesion of organic sludge to the inside of the dryer can be reduced. And patent document 1 mentions woody biomass, such as a wood chip, and coal as a solid fine granule.

  On the other hand, in the following Patent Document 2, the object to be treated is not limited to activated sludge, but to the object to be dried, slaked lime powder, dried sludge, solid residue discharged from the pyrolysis furnace, etc. A thermal decomposition treatment system is disclosed in which a particulate solid is mixed and dried, and is then led to a thermal decomposition furnace for thermal decomposition.

  Further, Patent Document 3 below discloses a sludge solidification treatment device that adds quick lime as a dehydrating agent to sludge, supplies carbon dioxide gas and air, and heats and drys by reaction heat between quick lime and carbon dioxide gas. Has been.

Japanese Patent No. 5086875 JP 2001-121125 A Japanese Patent No. 2987136

  However, in the drying method described in the above-mentioned patent document, the sludge is heated by convection heat transfer using hot air, conduction heat transfer from the jacket, or reaction heat between quick lime and carbon dioxide, and the odor component is volatilized from the sludge. In order to do so, there is a problem that the exhaust gas must be exhausted through a deodorizing facility, which increases the cost of deodorizing.

  Accordingly, an object of the present invention is to provide a sludge drying treatment method and a sludge drying treatment apparatus capable of efficiently drying sludge while suppressing volatilization of sludge odor components.

  In order to achieve the above object, the sludge drying treatment method of the present invention is a sludge kneaded product obtained by previously kneading sludge and powder particles that reduce the adhesiveness of the sludge, while repeatedly pulverizing and applying impact by dropping. It is characterized by drying at normal temperature by contacting with normal temperature air.

  According to the present invention, the sludge kneaded material previously kneaded with sludge and the granular material that reduces the stickiness of the sludge is pulverized by a drop impact, and the specific surface area is increased. it can. Moreover, by drying sludge with room temperature air, the heating cost can be reduced and the odor component contained in the exhausted air can be reduced, so the cost required for deodorization can be reduced.

  In the sludge drying treatment method of the present invention, the granular material is preferably one or a mixture of two or more selected from the group of incinerated ash and dried sludge. According to this, the stickiness of the sludge is lowered and it becomes easy to be pulverized by a drop impact.

  In the sludge drying treatment method of the present invention, it is preferable that the moisture content of the sludge before drying is 70 to 85 mass%, and the moisture content of the granular material is 10 mass% or less. According to this, by kneading a granular material using a general sludge as a processing target, the stickiness of the sludge can be reduced, and it can be easily pulverized by a drop impact.

  In the sludge drying treatment method of the present invention, it is preferable that the amount of the granular material kneaded in the sludge is 10 to 60 parts by volume with respect to 100 parts by volume of the sludge. According to this, the stickiness of sludge can be reduced and it can be made easy to grind by a drop impact.

  In the sludge drying treatment method of the present invention, the temperature of the sludge kneaded material that is dried at room temperature is preferably 0 to 40 ° C. According to this, since the odor component which volatilizes from sludge decreases, the cost required for deodorization can be reduced.

  The sludge drying treatment apparatus of the present invention scrapes up the kneading part, the cylindrical main body, and the sludge kneaded material, which are kneaded with sludge and powder particles that reduce the stickiness of the sludge. In order to repeatedly drop the sludge kneaded product, a rotary drying unit having a plurality of scooping plates disposed on the inner peripheral surface of the cylindrical main body in order to drop and crush on the bottom of the cylindrical main body, A rotary drive unit that rotates the rotary drying unit, and an air supply unit that supplies room temperature air to the rotary drying unit.

  According to the sludge drying treatment apparatus of the present invention, the sludge kneaded product of the sludge and the granular material kneaded in the kneading unit is scraped up by the scraping plate disposed on the inner peripheral surface of the rotary drying unit, and then the cylinder It can be dropped and crushed on the bottom of the main body and brought into contact with room temperature air. The sludge kneaded material is pulverized by a drop impact, increases its specific surface area, and can be efficiently dried at room temperature. In addition, drying the sludge with room temperature air can reduce the heating cost and the odor component contained in the exhausted air can be reduced, so that the cost required for deodorization can also be reduced.

  In the sludge drying treatment apparatus of the present invention, the scraping plate is a plurality of plates protruding from the inner peripheral surface of the rotary drying unit at predetermined intervals in the circumferential direction and extending along the axial direction. It is preferable that it consists of a shape-like protrusion. According to this, the sludge kneaded material is scraped up to a high position in the rotation direction and dropped onto the bottom of the cylindrical main body, whereby the impact due to the drop can be effectively applied and pulverized efficiently.

  In the sludge drying treatment apparatus according to the present invention, the rotary drying section is transported on the inner peripheral surface thereof at predetermined intervals along the axial direction and extending in an annular, arcuate or spiral shape along the circumferential direction. The conveying protrusion has a saw-tooth cross-sectional shape along the axial direction, and the slant kneaded product has a surface inclined on the surface opposite to the conveying direction. It is preferable that it is looser than the inclination. According to this, the sludge kneaded material that has been scraped is dropped on the saw blade-shaped transfer projections on the inner peripheral surface of the rotary drying unit, and is efficiently pulverized. Further, the conveyance protrusions fall along the inclination of the surface on the conveyance direction side because the inclination of the surface on the conveyance direction side of the sludge kneaded material is gentler than the inclination of the surface opposite to the conveyance direction. The sludge kneaded product can be advanced in the conveying direction. Thus, since the sludge kneaded material slowly moves in the cylindrical main body, it is possible to increase the residence time and increase the drying efficiency.

  According to the present invention, the previously kneaded sludge kneaded material is pulverized by a drop impact and the specific surface area is increased, so that it can be efficiently dried even at room temperature. In addition, drying the sludge with room temperature air can reduce the heating cost and the odor component contained in the exhausted air can be reduced, so that the cost required for deodorization can also be reduced.

It is a schematic explanatory drawing showing one Embodiment of the sludge drying processing apparatus which concerns on this invention. It is a fragmentary perspective view which shows the shape of the scraping board and conveyance protrusion of the inner periphery of the rotary drying part of the sludge drying processing apparatus. It is drawing explaining the grinding | pulverization process of the sludge kneaded material in a rotary-type drying part. It is drawing showing other embodiment of the scraping board which concerns on this invention. It is explanatory drawing of the crushability test method of sludge kneaded material. It is a graph which shows the result of having investigated drying efficiency before crushing of sludge kneaded material, and after crushing.

  Hereinafter, the sludge drying treatment apparatus and sludge drying treatment method of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic diagram of a sludge drying treatment apparatus 100. The sludge drying treatment apparatus 100 includes an input unit 1 for introducing sludge and powder, a kneading unit 2 for kneading the sludge and the powder, and a rotary drying unit 3 for drying the sludge kneaded material at room temperature. The transfer unit 4 for transferring the sludge kneaded material from the kneading unit 2 to the rotary drying unit 3, the air supply unit 5 for supplying the drying air to the rotary drying unit 3, and the rotary drying unit 3 A drive unit 6 for rotating the air, an exhaust duct 7 for exhausting air from the rotary drying unit 3, a dust collecting unit 8 connected to the exhaust duct 7, and a dust collecting unit 8 as necessary A deodorizing unit 9 that is connected to the rotary drying unit, and a drying sludge collecting unit 10 that collects the dried sludge, and a transfer unit 11 that is connected to the dried sludge collecting unit 10 and transfers the dried sludge to a storage yard or a truck exit. .

  The charging unit 1 is disposed above the kneading unit 2, and is a charging port including a hopper having a conical or quadrangular pyramid-shaped funnel shape whose diameter is reduced toward the kneading unit 2. And is supplied to the kneading section 2. Here, the hopper for feeding the sludge and the hopper for feeding the powder may be one common hopper, but in a more preferred form, the sludge hopper and the powder hopper are independent, An inlet opening / closing mechanism is provided at the lower part of the hopper, so that the supply amount can be limited and the blending amount can be adjusted. By separating the sludge and the granular material inlet, variation in the blending amount and clogging of the inlet can be suppressed.

  The kneading part 2 is a batch type or continuous type kneading machine for kneading sludge and granular materials, and is preferably a kneading machine that can uniformly knead even a highly viscous fluid and has low power consumption. However, the shape and arrangement of the kneading blades are not particularly limited, and a known kneading machine may be used. Further, the transfer unit 4 for transferring the sludge kneaded material from the kneading unit 2 to the rotary drying unit 3 is not particularly limited as long as even a highly viscous sludge kneaded material can be transferred. For example, a mono pump or a screw conveyor is used. Can do. Alternatively, when a kneader that performs both kneading and transfer, such as a biaxial kneading extruder, is employed, the transfer unit 4 can be omitted and the kneading unit 2 can be directly connected to the rotary drying unit 3.

  The air supply unit 5 that supplies the drying air to the rotary drying unit 3 is not particularly limited, and for example, a centrifugal blower, an axial flow blower, or a positive displacement blower can be used. In the present invention, as will be described later, the drying air is room temperature air and does not require equipment for heating the air.

  The rotary drying unit 3 includes a horizontally disposed cylindrical main body 3a (FIG. 1 shows a cross section cut along a plane including the cylindrical axis of the cylindrical main body 3a), and an inner periphery of the cylindrical main body 3a. A scraping plate 3b disposed on the surface and a conveying projection 3c are provided, and can be continuously rotated with the central axis of the cylindrical main body 3a as a rotation axis. The structure of the drive unit 6 that rotates the cylindrical main body 3a is not particularly limited. For example, the cylindrical main body 3a is rotatably supported by a plurality of support wheels 6a and is provided on the outer periphery of the cylindrical main body 3a. The cylindrical main body 3a can be rotated by engaging the drive gear 6b with the waistline gear 3d and driving the drive gear 6b with the motor 6c.

  The transfer part 4 is connected to one end part of the cylindrical main body 3a, and a sludge kneaded material can be supplied. The sludge is pulverized in the cylindrical main body 3a, slowly moves toward the other end of the cylindrical main body 3a while being dried in contact with the dry air, and is discharged via the dried sludge recovery unit 10. The

  On the other hand, the drying air is supplied from the air supply unit 5, passes through the cylindrical main body 3 a, and is exhausted from the exhaust duct 7. The direction of flowing the drying air may be a co-flow that flows in the same direction as the moving direction of the sludge kneaded material as shown in FIG. There may be.

  FIG. 2 shows a partial perspective view of the shape of the scraping plate 3b and the conveying projection 3c formed on the inner periphery of the cylindrical main body 3a. FIG. 3 is a cross-sectional view taken along a plane perpendicular to the axial direction of the rotary drying unit 3. The scraping plate 3b is a plurality of plate-like projections provided on the inner peripheral surface of the cylindrical main body 3a so as to protrude along the axial direction at predetermined intervals in the circumferential direction. With the rotation of 3a, the sludge kneaded material M is (a) scraped up to a high position of the cylindrical main body 3a, (b) dropped onto the bottom of the cylindrical main body 3a, and (c) the sludge kneaded material M is pulverized. , Can be performed repeatedly.

  In the above, the sludge kneaded material M that has been scraped has a larger impact force and is finely pulverized when dropped onto the hard inner wall of the cylindrical main body 3a than to drop it onto the soft sludge kneaded material. Can do. For this reason, the amount h of the scraping plate 3b is increased or the number n of the scraping plates 3b is increased to increase the amount and frequency of the sludge kneaded material M so that the sludge sludge kneaded material M does not accumulate. Then, the sludge kneaded material M can be efficiently pulverized. In other words, the amount of protrusion h and the number n are designed so that the sludge kneaded material M that has fallen is scraped up before the falling sludge kneaded material M is dropped and does not remain on the bottom of the cylindrical body 3a. Good. Then, when the number n is increased and the sludge kneaded material M is divided and scraped up and dropped as a small lump and pulverized, the specific surface area is larger, the contact area with air is increased, and the drying efficiency is improved.

  The scraping plate 3b may be a flat projection as shown in FIG. 3, but for example, as shown in FIG. 4 (a), a curved projection 3b1 or shown in FIG. 4 (b). If the surface where the sludge kneaded material M is swept up is a recess, such as the protrusion 3b2 whose tip is bent to form a dike, the sludge kneaded material M will be rolled up even if the scooping plate is tilted. It becomes difficult and the sludge kneaded material M can be scraped up to a high position. By dropping the sludge kneaded material M from a high position, the drop impact can be increased and the sludge kneaded material M can be pulverized more finely. The length of the scraping plates 3b, 3b1, 3b2 is not particularly limited, and may be a plate that is long in the axial direction from one end to the other end of the cylindrical main body 3a, but is divided into a plurality of portions in the axial direction. The adjacent plates may be arranged in steps.

  Further, the rotary drying unit 3 is provided on the inner peripheral surface of the cylindrical main body 3a at a predetermined interval along the axial direction, and a conveyance protrusion 3c that extends in an annular, arcuate or spiral shape along the circumferential direction. Can be provided. For example, as shown in FIGS. 1 and 2, the cross-sectional shape along the axial direction of the transport protrusion 3 c is a saw blade, and the inclination of the surface 3 ca on the transport direction side of the sludge kneaded material is the transport direction. A protrusion that is looser than the inclination of the opposite surface 3cb can be adopted, and the inclination angle of the surface 3ca on the conveyance direction side with respect to the tangent to the inner peripheral surface of the cylindrical main body 3a is preferably 45 to 60 °. To do. The lump of sludge kneaded material falls from a high place and collides with the corners of the conveying projections 3c, and is crushed by the corners of the projections. The pulverized sludge kneaded product can proceed along a gentle slope on the transport direction side, but is immediately interrupted by the steep slope on the surface opposite to the transport direction, so it will gradually move in the transport direction, The residence time of the sludge kneaded material in the rotary drying unit 3 can be increased, and the sludge kneaded product can be dried until it has been brought into contact with the drying air for a long time and has a low water content.

  In another embodiment of the present invention, in addition to the scraping plate 3b for scraping up the sludge and the transport protrusion 3c for transporting the sludge kneaded material, for example, a cone, a pyramid, etc. Can be provided with an acute-angle-shaped splitting projection (not shown). In still another embodiment of the present invention, it is possible to employ a method of transporting the cylindrical main body 3a by tilting it toward the discharge side with a gentle slope without using the transport protrusion 3c. When such a conveying method is adopted, a configuration in which the scraping plate and the splitting projection are combined or a configuration having only the scraping plate may be used.

  The dried sludge dried in contact with the drying air in the rotary drying unit 3 is spontaneously dropped from the other end of the rotary drying unit 3 to the dried sludge recovery unit 10 and recovered, and is transferred to a transfer unit such as a bell conveyor. 11 is carried out.

  On the other hand, since the air discharged from the rotary drying unit 3 entrains the dust of the dried sludge, it passes through the dust collecting unit 8 to remove the dust, and deodorizes by passing through the deodorizing unit 9 as necessary. Can do. The dust collection part 8 is not specifically limited, For example, a cyclone, a bag filter, and an electric dust collector can be used. The deodorizing unit 9 is not particularly limited, and for example, an adsorption tower filled with activated carbon, a scrubber for spraying water, or the like can be used.

  Next, the sludge drying treatment method of the present invention performed using the above sludge drying treatment apparatus will be described.

  The sludge to be treated in the present invention is not particularly limited, but representative examples include sludge containing organic matter discharged from a sewage treatment plant, human waste treatment plant, wastewater treatment facility, food factory, and the like. The present invention is suitable for drying sludge having a moisture content of 70 to 85% by mass among these sludges.

  Such sludge containing organic matter has high adhesiveness, and as described above, it is difficult to perform a drying treatment as it is. Therefore, in the sludge drying treatment of the present invention, in the kneading section 2 of the sludge drying treatment apparatus 100, after adding powder to the sludge and kneading to obtain a sludge kneaded product with reduced adhesiveness, the rotary type In the dryer 3, the drying treatment is performed by contacting with the drying air.

  It is preferable that the granular material added to sludge is 1 type chosen from the group of incinerated ash and dry sludge, or a mixture of 2 or more types. Of these, incinerated ash and dried sludge are landfill waste that is disposed of as industrial waste, and sludge drying by actively reusing such industrial waste as an additive to reduce the stickiness of sludge. Costs for processing can be saved, and the environmental load can be reduced.

  Incinerated ash and dried sludge may contain gravel with a particle size (maximum diameter) of several millimeters to several centimeters, but the granular material in the present invention contains such gravel. It may be. However, the content of 5% by mass or more in the granular material is preferably a particle size (maximum diameter) of 3 mm or less, and more preferably a particle size of 1 mm or less.

  The moisture content of the granular material is preferably 10% by mass or less, and more preferably 5% by mass or less. When the moisture content of the powder exceeds 10% by mass, the moisture content of the sludge kneaded product when kneaded into sludge increases, and the effect of reducing the tackiness tends to be weakened.

  The sludge kneaded product obtained by kneading sludge and powder is preferably adjusted so that the moisture content before the drying treatment is 70 to 60% by mass, and adjusted to be 65 to 60% by mass. More preferred. Thereby, when an impact is applied, it can be made easy to collapse.

  The amount of the granular material kneaded in the sludge is preferably 10 to 60 parts by volume and more preferably 25 to 50 parts by volume with respect to 100 parts by volume of the sludge. If the added amount of the granular material is less than 10 parts by volume, the adhesiveness of the sludge kneaded product is not sufficiently lowered, and it becomes difficult to be pulverized in the rotary drying unit 3 and it is difficult to increase the drying efficiency. On the contrary, if the amount of added granular material is more than 60 parts by volume, there is an upper limit to the amount of sludge kneaded material that can be processed in the rotary drying unit 3 per unit time. The amount is reduced and the economy is deteriorated.

  As described above, the method of supplying the sludge kneaded material previously kneaded in the kneading unit 2 to the rotary drying unit 3 by the transfer unit 4 adopting the transfer method that can be easily transferred even with high viscosity, It is the most efficient. Even if the sludge and the granular material are directly supplied to the rotary drying unit 3 without mixing the sludge and the granular material, the sludge and the granular material are not mixed uniformly, and the drying efficiency is not good.

  In the rotary drying unit 3 of the present invention, the sludge kneaded material is scraped up toward the upper part of the cylindrical main body 3a by the scraping plate 3b along with the rotation of the cylindrical main body 3a, and the scraping plate 3b exceeds the repose angle. When tilted, it rolls up from the scraping plate 3b and falls to the bottom of the cylindrical main body 3a, and collides with sludge kneaded material, preferably the hard inner peripheral surface of the cylindrical main body 3a, more preferably a projection that gives a crushing effect, and finely collides. While being crushed and the specific surface area is increased, the inside of the sludge kneaded mass becomes a new surface and comes into contact with air, so that the drying efficiency is improved.

  If the supply amount of the sludge kneaded material is too large, the sludge kneaded material may remain in the bottom of the cylindrical main body 3a without being able to scoop up the sludge. In such a state, the sludge kneaded material overlaps and falls on the sludge kneaded material, which is not preferable because the collision effect is weakened. In addition, when the ability to convey the sludge kneaded material toward the discharge port is low, the sludge kneaded material that could not be scraped up is always left in the vicinity of the upstream side of the cylindrical main body 3a close to the supply port of the sludge kneaded material, and the crushing efficiency It is easy to get into a bad situation. For this reason, when the sludge kneaded material is positively conveyed by the conveying protrusions 3c so as not to stay, the above-mentioned stayed material disappears, and the drying efficiency can be improved. Therefore, it can be said that the above-described asymmetric saw blade-shaped transfer protrusion 3c has a structure excellent in drying ability, which also contributes to increasing drying efficiency.

  Another feature of the sludge drying treatment method of the present invention is that the sludge kneaded product is contacted with room temperature air and dried at room temperature. Here, normal temperature means the temperature of air that can be used in the working environment, and is preferably 0 to 40 ° C., more preferably 0 to 20 ° C. By drying the sludge kneaded material at room temperature and drying it at room temperature, the energy cost required for heating can be saved, and the deodorizing cost required for deodorizing the exhaust air is reduced because there are few odor components volatilized from the sludge kneaded material. can do. For example, when the deodorization part 9 is an adsorption tower, the usage-amount of activated carbon can be saved. Further, if the odor is low, a method of releasing the air as it is without providing the deodorizing unit 9 is also conceivable. And if it is supply of normal temperature air, since it is not necessary to provide a heating means in the air supply part 5, a heating cost can be reduced.

  In the present invention, the reason why the sludge can be dried at room temperature, as described above, is to reduce the adhesiveness by kneading the dried granular material into the sludge, by dropping it after scraping up in the dryer, This is because the sludge kneaded product is finely pulverized to increase the contact surface with air and increase the drying efficiency.

  In the present invention, the moisture content of the sludge kneaded product after drying is preferably 65 to 55% by mass, and more preferably 60 to 55% by mass. With such a moisture content, landfill processing can be performed as it is in addition to incineration.

  In the following examples, an example will be described in which sewage sludge having a water content of about 70% is mixed with incinerated ash having a particle size of 5 to 10 μm to reduce tackiness and increase crushability.

[Preparation method of sludge kneaded material]
Example 1
100 parts by volume of sewage sludge (water content 73 mass%) and 50 parts by volume of incinerated ash were put into a water tank and kneaded with a stirrer to obtain the sludge kneaded material of Example 1.

(Example 2)
100 parts by volume of sewage sludge (water content 73 mass%) and 25 parts by volume of incinerated ash were kneaded by the method described in Example 1 to obtain a sludge kneaded product of Example 2.

(Example 3)
100 parts by volume of sewage sludge (water content 73 mass%) and 10 parts by volume of incinerated ash were kneaded by the method described in Example 1 to obtain a sludge kneaded product of Comparative Example 1.

(Comparative Example 1)
The sewage sludge (water content 73 mass%) was kneaded without adding incineration ash to obtain a sludge kneaded product of Comparative Example 1.

<Test Example 1>
[Adhesion test method]
A SUS plate having a size of 30 cm in length and 30 cm in width was loaded with 100 g of the sludge kneaded material prepared as described above, and after the surface was flattened, the plate was tilted to examine the tackiness of the sludge kneaded material. .
X: Sludge kneaded material falls when the plate is tilted 75 degrees.
Δ: Sludge kneaded material falls when the plate is tilted 60 degrees.
○: Sludge kneaded material falls when the plate is tilted 45 degrees.

[Crushability test method]
As shown in FIG. 5, 100 g of sludge kneaded material M was made into a ball-like lump, dropped onto a protrusion P from a height of 30 cm, and friability was examined according to the following evaluation criteria.
X: The sludge kneaded material M only pierces the protrusion P and is not crushed.
(Triangle | delta): The sludge kneaded material M pierces the protrusion P, and a part collapses a little.
○: The sludge kneaded material M pierces the protrusions P, and a part of the sludge kneaded material collapses.
(Double-circle): Sludge kneaded material M cracks along the front-end | tip of the protrusion P. FIG.

[Test results]
Table 1 shows the results of testing the tackiness and friability of the above four types of sludge kneaded materials. In Example 1 in which 50 parts by volume of incinerated ash was added to sludge, the stickiness of the sludge kneaded product was reduced to the extent that it easily dropped if the plate was tilted 45 degrees. When it collided with an object, it was easily crushed. In Example 2 in which 25 parts by volume of incinerated ash was added to the sludge, the stickiness of the sludge kneaded material was reduced to the extent that it easily dropped if the plate was tilted 45 degrees. When it collided with an object, it was crushed as expected. In Example 3 in which 10 parts by volume of incinerated ash was added to the sludge, the sludge kneaded product falls when the plate is tilted 60 degrees when the plate is tilted 60 degrees. But only a part of the sludge was crushed. In Comparative Example 1 in which the incinerated ash was not added to the sludge, the sludge kneaded material did not fall even if the plate was tilted 75 degrees, and the sludge kneaded balls were not crushed even when colliding with the protrusions. Adhered to stick.

<Test Example 2>
The room temperature drying efficiency of the sludge kneaded material prepared in Example 1 before and after crushing was compared by measuring the change in moisture content over time.

  As shown in FIG. 6, the water content decreases more rapidly after crushing than before crushing. Therefore, the sludge kneaded material can be dried more quickly.

1: Input unit 2: Kneading unit 3: Rotary drying unit 3a: Cylindrical body 3b: Scooping plate 3b1: Modification 1 of the scooping plate
3b2: Modification 2 of the scraping plate
3c: Conveying protrusion 3d: Girth gear 4: Transfer unit 5: Air supply unit 6: Drive unit 6a: Support wheel 6b: Drive gear 6c: Motor 7: Exhaust duct 8: Dust collector 9: Deodorizing unit 10: Dry sludge Collection unit 11: Transfer unit 100: Sludge drying apparatus M: Sludge kneaded material

Claims (7)

While sludge kneaded with a sludge having a moisture content of 70 to 85% by mass and incinerated ash in advance and having a moisture content of 60 to 70% by mass , repeatedly impacted by dropping and pulverizing, A method of drying sludge characterized by drying at normal temperature by contacting with normal temperature air. Method for drying treatment of the sludge according to claim 1, wherein the water content of the ash is not more than 10 wt%. The method for drying treatment of sludge according to claim 1 or 2, wherein the sludge kneaded product is dried at room temperature so that the water content is 65 to 55 mass%. The method for drying treatment of sludge according to any one of claims 1 to 3, wherein the amount of the incinerated ash to be kneaded into the sludge is 10 to 60 parts by volume of the incinerated ash with respect to 100 parts by volume of the sludge.   The temperature of the said sludge kneaded material dried at the said normal temperature is 0-40 degreeC, The drying processing method of the sludge as described in any one of Claims 1-4. A kneading part for kneading sludge and sludge to reduce the adhesiveness of the sludge to obtain a sludge kneaded product,
Rotary drying having a cylindrical main body, and a plurality of scraping plates arranged on the inner peripheral surface of the cylindrical main body to scrape the sludge kneaded material and drop it to the bottom of the cylindrical main body for crushing And
In order to repeatedly drop the sludge kneaded product, a rotary drive unit that rotates the rotary drying unit;
An air supply unit for supplying room temperature air to the rotary drying unit;
Equipped with a,
The rotary drying unit has conveyance protrusions extending on the inner peripheral surface thereof at predetermined intervals along the axial direction and in an annular shape, an arc shape, or a spiral shape along the circumferential direction, The conveying protrusion has a cross-sectional shape along the axial direction that is saw-toothed, and the slant kneaded product has a surface inclined on the side in the conveying direction that is gentler than the surface on the opposite side to the conveying direction. A sludge drying treatment device.   7. The scraper plate is composed of a plurality of plate-like protrusions protruding from the inner peripheral surface of the rotary drying unit at predetermined intervals in the circumferential direction and extending along the axial direction. The sludge drying treatment apparatus described in 1.