JP2022087616A - Method of treating waste - Google Patents

Abstract

To efficiently treat waste sludge to make inorganic porous granules while reducing the treatment cost, by feeding waste sludge in a from of dehydrated cake, efficiently granulating the dehydrated cake, and efficiently drying the dehydrated cake being granulated.SOLUTION: There is provided a method of treating waste, comprising: a dehydration step of pressurizing waste sludge containing inorganic powder to produce dehydrated cake; a granulation drying step of producing dried granules by feeding the dehydrated cake obtained by the dehydration step into a rotary drum 1 and rotating the rotary drum 1 to agitate, heat, granulate and dry the dehydrated cake; and a calcination step of calcining the dried granules obtained by the granulation drying step to convert the inorganic powder into inorganic porous granules having open pores, by combusting/removing components combustible or removable by heat contained in the dried granules.SELECTED DRAWING: Figure 1

Description

The present invention relates to, for example, a method for treating waste that produces an inorganic porous powder or granular material from waste sludge discharged from a plating factory as a raw material.

The waste sludge generated in the plating factory is dehydrated by a filter press and discarded without being effectively used as a dehydrated cake. A method for effectively utilizing waste sludge as an inorganic porous powder or granular material has been developed. (See Patent Documents 1 and 2)

Patent Document 1 recycles and effectively utilizes three types of waste: pulp sludge, dust collected from a foundry, and clay generated from a silica sand factory or an aggregate production factory, and is an inorganic porous body. The method of In this method, a mixture consisting of 10 to 30% by mass of pulp sludge, 33 to 40% by mass of dust collected during regeneration and recovery of cast sand, and 40 to 50% by mass of clay is granulated and fired at a temperature of 700 to 1200 ° C. By doing so, an inorganic porous body having a bulk specific gravity of 0.8 g / cm ³ or less, a water absorption rate of 30% or more, a pH of 7 or less, and a compression strength of 0.5 kg or more is produced. In this method, a raw material and water are mixed and molded by an extrusion molding machine or the like, dried by a dryer, and then fired to produce an inorganic porous body.

In Patent Document 2, waste sludge containing silica and alumina discharged as sludge waste from a foundry is used as a main component, and a raw material having a strong heat loss of 20% or more by weight is used, and water and the raw material are mixed. Granules or lumps are obtained from the mixture, and the granules or lumps are heated to 900 ° C. or higher and fired to obtain an inorganic porous body. In this method, waste sludge containing silica and alumina is dried, then finely crushed, mixed with water and kneaded, granulated with a water content of 10 to 30% by weight, and dried in a granular state. After removing the water content, it is fired to produce an inorganic porous powder or granular material.

In the above treatment method, waste sludge is granulated, dried to reduce the water content, and then calcined to produce an inorganic porous powder or granular material. This method has a drawback that it takes a long time to dry and cannot be efficiently manufactured because it is dried and fired in a granulated state. Further, when manufactured by a method of pressing and granulating, the void ratio decreases, and a method of rolling and granulating on a rotating plate rotating in an inclined posture, for example, in bread granulation, a filter press or the like There is a drawback that it is not possible to efficiently granulate by supplying a dehydrated cake that has been pressurized and dehydrated.

Japanese Patent Application Laid-Open No. 2003-73181 Japanese Unexamined Patent Publication No. 10-81576

The present invention has been developed for the purpose of eliminating the above drawbacks. An object of the present invention is to supply a dehydrated cake in the form of a dehydrated cake for efficient granulation, and to efficiently dry the sludge while granulating, thereby efficiently converting waste sludge into inorganic porous powder or granules while reducing the treatment cost. The purpose is to provide a method for treating waste that can be treated.

Means for Solving Problems and Effects of Invention

A method for treating waste according to an aspect of the present invention includes a dehydration step of pressurizing waste sludge containing inorganic powder to form a dewatered cake, and a dewatered cake obtained in the dewatering step is supplied into a rotating drum to form a dewatered drum. The dehydrated cake is stirred, heated, and dried while granulating to obtain a dry granule, and the dried granule obtained in the granulation drying step is fired. The process includes a baking step of burning down the heat-burning components contained in the dried granule to make the inorganic powder into an inorganic porous powder or granular material having open cells.

In the above waste treatment method, a dehydrated cake is supplied to a rotating drum to efficiently granulate, and the granulated material is granulated while being dried with high efficiency to obtain a dry granulated material, and the dried granulated material is fired. This has the advantage that waste sludge can be efficiently and effectively used as an inorganic porous powder or granular material while reducing the treatment cost.

In the method for treating waste according to another aspect of the present invention, in the granulation and drying step, the dehydrated cake is continuously supplied to the inside of the rotating drum while rotating the rotating drum, and the dehydrated cake is dried while being granulated. To make a dried granule.

The above method has the advantage that the dehydrated cake that has been pressed for dehydration and agglomerated can be continuously supplied to a rotating rotating drum to be processed into a dried granulated body that has been granulated and dried extremely efficiently. be.

In the waste treatment method according to another aspect of the present invention, in the granulation drying step, the rotation axis of the rotating drum is arranged in a horizontal posture and rotated.

This method has a feature that the supplied dehydrated cake can be efficiently granulated and dried while being evenly stirred in a rotating drum rotating in a horizontal posture.

In the method for treating waste according to another aspect of the present invention, in the granulation drying step, a rotating drum having a large number of sorting openings for transmitting particles having a predetermined particle size or less is used for the rotating drum, and the rotating drum is rotated. The dried granules are sorted and discharged at the sorting opening of the rotary drum to obtain sorted dried powders having a predetermined particle size.

In the above waste treatment method, a dehydrated cake is supplied to a rotating drum to be efficiently granulated, dried with high efficiency, and the particle size is also selected to select and dry powder particles having a predetermined particle size. By firing the sorted and dried powders and granules, the waste sludge can be efficiently made into inorganic porous powders and granules while further reducing the treatment cost.

As a method for treating waste according to another aspect of the present invention, a granulation cylinder having a layer structure in which an inner cylinder is arranged inside an outer cylinder having a perforated plate having a sorting opening as a cylinder is used for a rotating drum. Then, for the inner cylinder, a granulation cylinder having a passage gap through which the dried granules larger than the sorting opening are passed is used.

With the above method, while preventing clogging of the sorting opening of the outer cylinder, the dehydrated cake can be granulated and dried inside the rotating drum and efficiently discharged as sorted and dried powders sorted to a specific particle size. There are features.

In the waste treatment method according to another aspect of the present invention, the passage gap of the inner cylinder provided in the rotating drum is used as a slit.

In the above method, the dehydrated cake supplied to the rotating drum is passed through the slit of the inner cylinder to be dispersed, and the dispersed dehydrated cake is rolled on the inner surface of the perforated plate of the outer cylinder to efficiently granulate. It has the advantage that it can be dried to form a dried granule, and the dried granulated product can be discharged from the sorting opening of the perforated plate and efficiently processed into a sorted dry powder granule.

In the waste treatment method according to another aspect of the present invention, plated sludge is used for waste sludge.

The above method has a feature that the plated sludge, which is troublesome and costly to dispose of, can be effectively used as an inorganic porous powder or granular material containing a large amount of metal components.

In the method for treating waste according to another aspect of the present invention, the rotating shaft of the rotating drum is formed into a cylindrical shape, and the dehydrated cake is supplied into the rotating drum from the cylindrical rotating shaft.

The above method has a feature that the dehydrated cake can be efficiently and smoothly supplied into the rotating drum and dehydrated while being granulated with high efficiency by the rotating drum to be processed into a dry granulated product.

In the waste treatment method according to another aspect of the present invention, the dried granulated material is calcined at a temperature of 300 ° C. or higher in the calcining step.

In the waste treatment method according to another aspect of the present invention, the dried granulated material is calcined at a temperature of 1200 ° C. or lower in the calcining step.

It is a schematic process diagram which shows the waste treatment method which concerns on one Example of this invention. It is a vertical vertical sectional view which shows an example of the granulation drying apparatus used in the granulation drying process. It is a vertical cross-sectional view of the granulation drying apparatus shown in FIG. It is an exploded perspective view of the rotary drum of the granulation drying apparatus shown in FIG. It is an exploded perspective view which shows another example of a rotating drum. It is sectional drawing which shows the other example of the supply mechanism of a granulation drying apparatus. It is sectional drawing which shows the other example of the supply mechanism of a granulation drying apparatus.

Hereinafter, the present invention will be described in detail with reference to the drawings. In the following description, terms indicating a specific direction or position (for example, "upper", "lower", and other terms including those terms) are used as necessary, but the use of these terms is used. The purpose is to facilitate understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. Further, the parts having the same reference numerals appearing in a plurality of drawings indicate the same or equivalent parts or members.
Further, the embodiments shown below show specific examples of the technical idea of the present invention, and do not limit the present invention to the following. In addition, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are not intended to limit the scope of the present invention to the specific description, but are exemplified. It was intended. Further, the contents described in one embodiment and the embodiment can be applied to other embodiments and the embodiments. In addition, the size and positional relationship of the members shown in the drawings may be exaggerated in order to clarify the explanation.

In the waste treatment method of the present invention, as waste sludge, for example, only plating sludge discharged from a plating factory is used, and an inorganic porous powder or granule is used without adding other components such as other waste sludge. However, the present invention does not specify waste sludge as plated sludge, and all other waste sludge that is dehydrated, granulated, and fired to become inorganic porous powder granules can be used. However, in the waste treatment method of the present invention, since the inorganic material is combined into a porous state to form an inorganic porous powder or granular material, the waste sludge is specified to contain the inorganic material. As the waste sludge containing an inorganic material, not only the waste sludge of a single factory but also a plurality of types of waste sludge having different components discharged from a plurality of different factories can be used. For waste sludge discharged from a single factory that does not contain inorganic materials, inorganic powder is added or waste sludge containing inorganic components is mixed and used as a raw material. Further, in the above treatment method, waste sludge containing fiber components such as paper sludge is used as a raw material to efficiently granulate with the fiber components, and the fibers are used as organic fibers in the firing step. By burning off, it can be made into a porous inorganic porous powder or granule with open cells. Further, sludge discharged from a pharmaceutical factory can be added to control the components of the inorganic porous powder or granular material.

[Embodiment 1]
As shown in the schematic process diagram of FIG. 1, the waste treatment method includes a dehydration step in which waste sludge is pressurized to form a dehydrated cake, and granulation in which the dehydrated cake is dried while being granulated to form a dry granule. In the drying step and the baking step of baking the dried granules into inorganic porous powders and granules, the waste sludge is made into porous inorganic porous powders and granules.

[Dehydration process]
In the dehydration step, all methods and devices for pressurizing and dehydrating waste sludge containing a large amount of water can be used, but a filter press is preferably suitable. The filter press can efficiently dehydrate waste sludge with extremely high water content into a dehydrated cake. The plating sludge discharged from the plating factory can be dehydrated with a filter press to efficiently make a dehydrated cake. Waste sludge, which is a mixture of plated sludge and paper sludge, can be efficiently dehydrated with a filter press and processed into a dehydrated cake. Further, paper sludge and sludge discharged from a pharmaceutical factory can be mixed to make waste sludge as a raw material. However, the device for dewatering waste sludge in the dewatering process is not specified in the filter press, for example, the waste sludge is injected into a cylinder whose tip is blocked by a porous plate, and the piston pressurizes and dehydrates. A device for making a dehydrated cake can also be used. In the dehydration step, waste sludge containing 70% by weight to 90% by weight of water is pressurized to obtain a dehydrated cake having a water content of 50% by weight or less.

[Granulation drying process]
In the granulation and drying step, the dehydrated cake obtained in the dehydration step is supplied into a rotary drum, the rotary drum is rotated, the dehydrated cake is agitated, heated, and dried while being granulated. And.
The above treatment method is a unique method of granulating and drying a dehydrated cake that has been pressurized and dehydrated while granulating and drying it in a granulation and drying step to obtain a dry granulated body. Therefore, this granulation and drying method is used. The granulation drying equipment used in the process will be described in detail below.

(Granulation drying device 100)
2 to 4 show a granulation drying device 100 using a dehydrated cake as a drying granule. FIG. 2 is a vertical vertical cross-sectional view of the granulation drying device 100 as viewed from the side, FIG. 3 is a vertical cross-sectional view of the granulation drying device 100 shown in FIG. 2, and FIG. 4 is a rotary drum 1 of the granulation drying device 100. The exploded perspective view of is shown. The granulation drying device 100 shown in these figures supplies a dehydrated cake to the inside of a cylindrical rotary drum 1, dries the supplied dehydrated cake while granulating with the rotary drum 1, and rotates as a dry granulator. Discharge from drum 1.

Further, the granulation drying device 100 shown in the figure uses, as the rotary drum 1, a rotary drum 1 having a large number of sorting openings 17 that allow particles having a predetermined particle size or less to pass through, and a dehydrated cake is supplied. The rotating drum 1 is rotated to stir the dehydrated cake and dried while granulating to obtain a dry granulated material, and the particle size of the dried granulated material is sorted by the sorting opening 17 of the rotating rotating drum. It has a structure in which it is discharged from the rotary drum 1 as a sorted dry powder or granular material having a predetermined particle size.

In the above-mentioned granulation drying apparatus 100, in the granulation drying step, the dehydrated cake to be supplied is dried while being granulated to obtain a dry granulation body, and the dried granulation body is selected to be smaller than a specific particle size. Then, it is discharged as sorted dry powder granules. The sorted and dried powder or granular material discharged from the sorting opening 17 of the granulation drying device 100 is a grain that has been sorted to a diameter smaller than that of the sorting opening 17. As described above, in the granulation and drying step, the treatment method of sorting the dried granules to a particle size smaller than the sorting opening 17 to obtain the sorted and dried powder or granules is a predetermined particle size in the firing step which is the next step. Since the sorted and dried powders and granules selected below are calcined, there is an advantage that waste sludge can be efficiently converted into inorganic porous powders and granules while reducing the treatment cost. However, in the processing method of the present invention, in the granulation and drying step, the dried granules do not necessarily have to be sorted and dried powders having a particle size smaller than that of the sorting opening 17, and the dried granules do not necessarily have to be the sorted and dried powders inside the rotary drum 1. It can also be taken out from the rotary drum 1 as a dried granulated material that has been granulated and dried, and fired in the next step.

The above-mentioned granulation drying device 100 supplies a dehydrated cake to the outer case 7 having a closed structure, the rotary drum 1 arranged inside the outer case 7, the motor 3 for rotating the rotary drum 1, and the rotary drum 1. It is provided with a supply mechanism 50 for heating and a heating blower mechanism 4 for heating and drying the dehydrated cake in the rotary drum 1.

(Rotating drum 1)
In the rotary drum 1, both ends of the granulation cylinder 11 are closed with end plates 12, and the inside of the granulation cylinder 11 is used as a drying chamber 2 to dry the dehydrated cake. The rotary drum 1 has a rotary shaft 6 fixed to the center of the end plate 12. The rotating shaft 6 is arranged in a horizontal posture in the outer case 7 via the bearing 31. The rotary shaft 6 is rotated by the motor 3 to rotate the rotary drum 1. In order to heat and dry the dehydrated cake in the rotating drum 1, heated air is forcibly blown into the rotating drum 1. The heated air can flow into the drying chamber 2 of the rotating drum 1 from the outside of the outer case 7 to dry the dehydrated cake, and can be forcibly blown from the rotating shaft 6 to the drying chamber 2 to dry the dehydrated cake.

The rotary drum 1 has, for example, an outer diameter of 40 cm to 1 m and an axial total length of 40 cm to 1 m. The optimum value can be set in consideration of the water content, the particle size, and the like required for the sorted and dried powder. The granulation cylinder 11 in the figure has a two-layer structure including an outer cylinder 11A and an inner cylinder 11B, and a gap is provided between the outer cylinder 11A and the inner cylinder 11B. The inner cylinder 11B is provided with a passage gap 16 through which a dry granulated body having a larger grain size than the sorting opening 17 of the perforated plate 13 is passed. The rotary drum 1 of FIGS. 3 and 4 has a structure in which the dehydrated cake is dispersed in the inner cylinder 11B and can smoothly pass through the passage gap 16 of the slit by using the passage gap 16 of the inner cylinder 11B as a slit extending in the axial direction. In the inner cylinder 11B of FIG. 3, a plurality of rods 15 are arranged in a cylinder shape in a posture extending in the axial direction and parallel to each other, and a slit passing gap 16 is provided between the rods 15. A cylindrical pipe is suitable for the rod 15. In the inner cylinder 11B, the supplied dehydrated cake collides with the surface of each rod moving in a circular orbit, is dispersed, and passes through the passage gap 16 of the slit. The dehydrated cake that collides with the rod 15 and is dispersed is passed through the passing gap 16 and supplied to the inside of the outer cylinder 11A. The passage gap 16 of the slit is wider than the inner diameter of the sorting opening 17 so that the dispersed dehydrated cake can pass smoothly, and is set to, for example, 5 mm to 20 mm.

In the outer cylinder 11A, a plurality of cylinders 13A and 13B made of a perforated plate 13 are coaxially arranged with a gap provided. Since the outer cylinder 11A rotates and rolls the dehydrated cake on the inner surface to granulate into a dry granulated body, it is preferably a cylinder, but it may be an elliptical cylinder or a polygon similar to a cylinder as an octagon or more. You can also do it. The perforated plate 13 of the tubular body 13A located on the outermost circumference of the rotary drum 1 has a through hole 13a as a sorting opening 17. The ideal shape of the sorting opening 17 is circular, but it is also possible to discharge the sorted dried powder granules granulated into a spherical shape as a polygon. The tubular body 13B located inside the tubular body 13A located on the outermost circumference is made of a perforated plate 13 having a through hole 13b larger than the sorting opening 17. Since the rotary drum 1 has a perforated plate 13 having a through hole 13b larger than the sorting opening 17 arranged inside, there is a feature that clogging of the sorting opening 17 can be prevented and sorted and dried powder particles can be efficiently discharged. .. Further, the rotary drum 1 in which the cylinders 13A and 13B of the perforated plate 13 are arranged in a multi-layer structure rolls the dehydrated cake on the inner surface of the perforated plate 13 of each layer to granulate, so that the sorted and dried powder granules are more spherical. There is also a feature that it can be granulated and discharged in a state close to. Since the outer cylinder 11A composed of the multi-layered cylinders 13A and 13B rolls the dehydrated cake on the inner surface of the cylinders 13A and 13B of each layer to granulate the dried granules, the inner diameter of the through hole 13b penetrates. It is wider than the inner diameter of the hole 13a, for example, 1.5 times or more, preferably 2 times or more the inner diameter of the through hole 13a. The rotary drum 1 described above is composed of an outer cylinder 11A and an inner cylinder 11B, and further, the outer cylinder 11A is composed of a plurality of cylinders 13A and 13B. It may be composed of a tubular perforated plate, or may be configured as a single cylinder provided with a sorting opening without having a two-layer structure of an outer cylinder and an inner cylinder.

The perforated plate 13 of the granulation cylinder 11 is suitable for punching metal provided with innumerable through holes 13a and 13b. In the punching metal of the outermost perforated plate 13, the maximum particle size of the sorted dried powder or granular material is specified by the through holes 13a and 13b. In the granulation drying device 100 using plated sludge as waste sludge, the inner diameter of the through hole 13a serving as the sorting opening 17 can be set to, for example, 2 mm to 4 mm, but the inner diameter of the sorting opening 17 is the sorted dry powder or granular material. Since the particle size is specified, the optimum value is set in consideration of the use of the inorganic porous powder or granular material produced by firing the sorted and dried powder or granular material. For example, the inner diameter of the sorting opening 17 is preferably 1 mm or more. It can be 2 mm or more, and further, for example, smaller than 10 mm, preferably smaller than 8 mm.

In the above rotary drum 1, the outermost cylindrical body 13A is a perforated plate 13, and the through hole 13a of the perforated plate 13 is used as a sorting opening 17, and the dry granulated body granulated in the rotary drum 1 is rotated. The structure is such that sorting is performed through the sorting opening 17 of the rotary drum 1 and discharged as sorted dry powder particles having a predetermined particle size. However, the rotary drum does not necessarily have to have a sorting opening with the outermost cylinder as a perforated plate, but as a cylinder without a sorting opening on the outermost circumference, it is granulated and dried inside the rotating rotating drum. It is also possible to discharge the granules.

In the rotary drum 1 shown in FIG. 5, the outermost cylindrical body 14A is a cylindrical metal plate 14 having no through hole, and the dried granulated bodies granulated on the inner surface of the tubular body 14A are sorted by particle size and passed through. It has a structure in which it is temporarily stored inside the cylinder 14A without causing it to be stored. In the rotary drum 1 shown in the figure, the outer cylinder 11A of the granulation cylinder 11 is composed of a cylinder 14A made of a metal plate 14 and a cylinder 13B made of a perforated plate 13 arranged inside the cylinder 14A. ing. This rotary drum 1 is a dry granulation body granulated to a predetermined particle size without sorting and discharging the dry granulation body to be granulated internally by the outermost tubular body 14A to a predetermined particle size. Is stored inside the outermost cylinder 14A. In the granulation cylinder 11 shown in the figure, a cylinder 13B made of a perforated plate 13 having a through hole 13b is arranged inside the outermost cylinder 14A, and a plurality of rods 15 are formed into a cylinder inside the cylinder 13B. An inner cylinder 11B is provided. The granulated cylinder 11 having this structure allows the dehydrated cake supplied to the inside of the inner cylinder 11B to pass through the slit-shaped passing gap 16 while granulating and drying inside the inner cylinder 11B, and to the outside of the inner cylinder 11B. The dried granulated body, which is granulated and dried on the inner surface of the arranged tubular body 13B of the perforated plate 13 and granulated to a particle size smaller than that of the through hole 13b, is passed through the tubular body 13B, and further, the outermost cylinder. Granulate, dry and store inside the body 14A.

The rotary drum 1 having the above structure discharges the dried granulated body stored inside the outermost tubular body 14A from the rotary drum 1. The rotary drum 1 shown in FIG. 5 is provided with an opening / closing opening 20 in the outer cylinder 11A in order to discharge the dried granulated material internally granulated to the outside, and the opening / closing 20 is opened by the opening / closing lid 21. It has a structure that opens and closes. The rotary drum 1 shown in FIG. 5 is provided with an opening 20 not only in the outermost cylinder 14A but also in the inner cylinder 11B composed of the cylinder 13B arranged inside the cylinder 13B and the plurality of rods 15. The opening / closing lid 21 includes a first opening / closing lid 21X that opens / closes the opening 20 of the outermost cylinder 14A, a second opening / closing lid 21Y that opens / closes the opening 20 of the inner cylinder 13A, and an inner cylinder 11B. It is provided with a third opening / closing lid 21Z that opens / closes the opening 20. In this rotary drum 1, the outermost cylinder 14A is partially opened in a state where the first opening / closing lid 21X is removed, and in this state, the rotary drum 1 is inverted and the opening 20 is in a downward posture. By doing so, the dried granules temporarily stored inside the cylinder 14A fall and are discharged. Further, in the rotary drum 1, with the second opening / closing lid 21Y and the third opening / closing lid 21Z removed, all the openings 20 of the outer cylinder 11A and the inner cylinder 11B are opened, and the inside of the drying chamber 2 is cleaned. Or maintained.

The rotary drum 1 described above is composed of an outer cylinder 11A and an inner cylinder 11B, and further, the outer cylinder 11A is composed of a plurality of cylinders 14A and 13B. It may be composed of a tubular metal plate, or may be configured as a single cylinder without a sorting opening without having a two-layer structure of an outer cylinder and an inner cylinder.

The rotary drum 1 has a rotary shaft 6 fixed to end plates 12 at both ends. The rotating shaft 6 penetrates the end plate 12 and is arranged in the drying chamber 2. Since the rotary drum 1 rotates about the rotary shaft 6, the rotary shaft 6 can be arranged on the central axis of the cylinder to rotate the cylindrical rotary drum 1 in a well-balanced manner. The rotary drum 1 is rotated by a motor 3 via a rotary shaft 6. Both ends of the rotating shaft 6 rotatably penetrate the end faces of the outer case 7. The rotating shaft 6 is connected to the outer case 7 in a horizontal posture via a bearing 31. Further, the rotary shaft 6 has a sprocket 32 fixed to an end projecting to the outside of the outer case 7, and is rotated by a motor 3 via the sprocket 32 and the chain 33.

(Heating ventilation mechanism 4)
The heating air blowing mechanism 4 forcibly blows heated air into the drying chamber 2 in the rotating drum 1 to dry the supplied dehydrated cake. The heated ventilation mechanism 4 in the figure includes a heated air source 40 for forcibly blowing heated air, and a ventilation duct 41 for supplying the heated air supplied from the heated air source 40 into the drying chamber 2. The heated air source 40 shown in FIG. 2 includes a blower 40A for supplying pressurized air and a heater 40B for heating the air supplied from the blower 40A. The heated air source 40 adjusts the air volume of the heated air to be forcibly blown by the rotation speed of the blower 40A, and adjusts the temperature of the heated air to be forcibly blown by the calorific value of the heater 40B. However, as a heated air source, a burner that burns oil or other fuel can be used instead of the heater.

The ventilation duct 41 is piped from the outside to the inside of the outer case 7, and supplies the heated air supplied from the heated air source 40 to the drying chamber 2 of the rotary drum 1. The ventilation duct 41 in the figure branches the heated air of the heated air source 40 into the first duct 41A and the second duct 41B, and blows air into the drying chamber 2.

The first duct 41A blows heated air to the rotating shaft 6 of the rotating drum 1. The rotary shaft 6 shown in FIG. 2 supplies heated air from the left end and supplies dehydrated cake from the right end in the figure. The heating region 6A to which the heated air is supplied and the dehydrated cake region 6B to which the dehydrated cake is supplied are partitioned by the partition wall 18. The heating region 6A has a plurality of through holes 6a around which the heated air is discharged into the drying chamber 2, and the dehydrated cake region 6B is provided with a drop opening 9 for discharging the dehydrated cake into the drying chamber 2. The rotary shaft 6 has a left end connected to the ventilation duct 41 via a coupler 19 that is rotatable and does not leak air, and the right end is connected to the supply mechanism 50. The granulation drying device 100 that blows heated air to the drying chamber 2 via the rotating shaft 6 can efficiently dry the dehydrated cake by blowing heated air to the center of the drying chamber 2. However, the dryer does not necessarily have to supply the heated air from the rotating shaft 6 to the drying chamber 2, and the dehydrated cake can be dried by the heated air blown from another region to the drying chamber 2.

The second duct 41B passes through the end plate 12 of the rotary drum 1 and blows heated air into the drying chamber 2. In the second duct 41B, the upward duct 41b is connected to the tip of the horizontal duct 41a arranged inside the exterior case 7, and the tip opening of the upward duct 41b approaches the facing surface of the end plate 12. And are arranged. As shown in the cross-sectional views of FIGS. 2 and 3, the second duct 41B forcibly blows air to the outside of the plurality of ventilation openings 12a provided in the end plate 12, and the heated air is dried from the ventilation openings 12a in the drying chamber 2. Blow inside. Further, the second duct 41B shown in FIG. 2 is forcibly blown to a hollow rod 15 which is arranged in an annular shape inside the rotary drum 1 and whose both ends are fixed to the end plate 12. Since the hollow rod 15 has both ends opened and fixed to the end plate 12, the heated air supplied from the right end opening in FIG. 2 passes through the inside and is discharged to the left end to be heated by the heated air. To. The hollow rod 15 heated by the heated air heats the dehydrated cake supplied from the rotating shaft 6 and passes it outward through the passing gap 16 of the adjacent hollow rod 15.

The heated air supplied to the outer case 7 from the first duct 41A and the second duct 41B is discharged from the exhaust port 43 provided in the outer case 7. The exterior case 7 of FIG. 2 is provided with an exhaust port 43 by connecting exhaust pipes 42 on both sides of the upper portion. The exhaust stack 42 is connected to the exhaust port 43 at the tip with an adjusting lid 44 whose opening area can be adjusted. The adjusting lid 44 is connected to a flange 42A provided at the tip of the exhaust stack 42 via a shaft 45 so as to be rotatable in a horizontal plane. The adjusting lid 44 moves from a position where the exhaust port 43 at the tip of the exhaust stack 42 is completely closed to a position where the exhaust port 43 is opened, and controls the amount of air discharged from the outer case 7. The adjusting lid 44 is adjusted to an opening degree for most efficiently drying the dehydrated cake supplied to the drying chamber 2.

(Supply mechanism 50)
The supply mechanism 50 includes a transport pipe 51 for passing the dehydrated cake inward and supplying it into the drying chamber 2, and a forced transport mechanism 52 for axially transporting the dehydrated cake supplied to the supply side of the transport pipe 51. ing. Further, the supply mechanism 50 shown in the figure includes a hopper 60 to which the dehydrated cake is supplied on the supply side of the transport pipe 51.

(Transport pipe 51)
The granulation drying device 100 uses the rotating shaft 6 of the rotating drum 1 as a hollow pipe in combination with the transport pipe 51 of the supply mechanism 50. The transport pipe 51 used in combination with the rotating shaft 6 has a cylindrical shape and is a metal pipe having a strength that allows it to rotate while supporting the rotating drum 1 in a horizontal posture. Further, the transport pipe 51 has an inner diameter that allows the dehydrated cake supplied from the hopper 60 provided on the supply side to pass through the inside and be transported to the inside of the rotary drum 1. The inner diameter of the transport pipe 51 varies depending on the size of the rotary drum 1, the type of dehydrated cake, and the processing amount of the granulation drying device 10, but is, for example, 3 cm to 20 cm, preferably 4 cm to 15 cm. The transport pipe 51 that supplies the dewatered cake of the plated sludge to the rotary drum 1 has, for example, an inner diameter of about 5 cm.

Further, the hollow rotary shaft 6 used in combination with the transport pipe 51 shown in FIG. 2 is provided with a drop opening 9 that opens in the drying chamber 2. The transport pipe 51 shown in the figure is provided with a drop opening 9 for supplying the dehydrated cake in the central portion of the rotary drum 1. The rotating shaft 6 which is the transport pipe 51 opens a plurality of drop openings 9 along the circumferential direction. The transport pipe 51 is provided with, for example, two or four drop openings 9 separated in the circumferential direction, and the dehydrated cake can be dispersed and dropped while rotating. Further, the transport pipe 51 of the rotating shaft 6 can be provided with a plurality of drop openings 9 along the axial direction. Since the transport pipe 51 having this structure can supply the dehydrated cake into the drying chamber 2 through the drop opening 9 by separating the dehydrated cake in the axial direction of the rotating shaft 6, the dehydrated cake is dispersed and supplied into the drying chamber 2 and dried efficiently. There are features that can be done. The drop opening 9 provided apart in the axial direction opens the drop opening 9 opened on the front end side and the rear end side in a state of being displaced in the circumferential direction, and makes the dehydrated cake more efficient. It can be well dispersed and supplied to the drying chamber 2. However, in FIG. 2, in order to make it easier to understand the shape in which the plurality of drop openings 9 are provided apart in the axial direction, the drop openings 9 on the front end side and the rear end side are opened without being displaced in the circumferential direction. There is.

(Forced transport mechanism 52)
The transport pipe 51 of the rotary shaft 6 is connected to a forced transport mechanism 52 that supplies the dehydrated cake into the drying chamber 2 of the rotary drum 1. The forced transfer mechanism 52 includes a spiral transfer member 53 that is vertically extended and arranged inside the transfer pipe 51, and a rotation mechanism 54 that rotates the spiral transfer member 53. The forced transfer mechanism 52 for transferring the dehydrated cake by the spiral transfer member 53 sets the spiral transfer member 53 and the transfer pipe 52, which is the rotation shaft 6, in opposite directions of rotation, and increases the relative rotation speeds of the dehydrated cake. Can be transferred efficiently. The forced transfer mechanism 52 for transferring the dehydrated cake by the spiral transfer member 53 can transfer the dehydrated cake without necessarily rotating the spiral transfer member 53 by the rotation mechanism 54. This is because the dehydrated cake can be transferred by rotating the rotating shaft 6 of the transport pipe 51 without rotating the spiral transport member 53.

In the forced transfer mechanism 52 of FIG. 2, the spiral transfer member 53 is a screw conveyor 55. The screw conveyor 55 has spiral fins 55B fixed around the central shaft 55A. As the spiral transport member 53, as shown in FIG. 6, a spiral coil 56 formed by spirally winding a metal wire can also be used. The spiral transport member 53 rotates the rear end of the spiral coil 56 with a rotation mechanism 54 to transfer the dehydrated cake. The spiral transfer member 53 can efficiently transfer the dehydrated cake by using the spiral coil 56 as a thick metal wire having a diameter of, for example, 1 cm. Further, the dehydrated cake can be smoothly transferred by using the spiral coil 56 as a coil spring that elastically deforms. This is because the dehydrated cake can be smoothly transferred while the coil spring is elastically deformed in the transferred state of the dehydrated cake.

The forced transfer mechanism 52 of FIG. 7 includes a piston 57 that pushes out the dehydrated cake supplied to the transfer pipe 51, and an actuator 59 that is connected to the piston 57 via a connecting rod 58 and reciprocates the piston 57 in the axial direction. ing. The forced transfer mechanism 52 forcibly conveys the dehydrated cake supplied to the supply side of the transfer pipe 51 in the axial direction by the piston 57. The forced transfer mechanism 52 retracts the piston 57 to the rear of the hopper 60 by the actuator 59, supplies the dehydrated cake falling from the hopper 60 to the receiving portion 60A on the supply side of the transfer pipe 51, and in this state, pushes the piston 57. The dehydrated cake is pumped forward and dropped from the drop opening 9 into the drying chamber 2. The forced transfer mechanism 52 has a simple structure and has a feature that the dehydrated cake can be reliably supplied to the drying chamber 2.

(Hopper 60)
In the supply mechanism 50 of FIG. 2, the hopper 60 is connected to the supply side of the transfer pipe 51. The hopper 60 temporarily stores the dehydrated cake and supplies it to the transport pipe 51. Since the supply mechanism 50 connecting the hopper 60 to the transport pipe 51 can supply the supplied dehydrated cake to the transport pipe 51 while temporarily storing the supplied dehydrated cake in the hopper 60, the dehydrated cake is intermittently supplied to the hopper 60. , The dehydrated cake can be supplied to the drying chamber 2 with a preferable transfer amount.

Further, the supply mechanism 50 of FIG. 2 includes a stirring mechanism 61 that stirs the dehydrated cake supplied to the hopper 60 and supplies it to the transport pipe 51. The stirring mechanism 61 includes a stirring blade 62 for the dehydrated cake and a rotating mechanism 64 for rotating the stirring blade 62. Since the supply mechanism 50 agitates the dehydrated cake supplied to the hopper 60 and supplies the dehydrated cake to the transport pipe 51, the dehydrated cake is supplied to the transport pipe 51 without being clogged, and the forced transport mechanism 52 smoothly smoothes the drying chamber. Can be supplied to 2. The hopper 60 is connected to the transport pipe 51 by opening the upper side and forming a downward squeeze shape toward the lower side. The stirring mechanism 61 includes a plurality of + stirring blades 62 provided on the rotating shaft 63 and a rotating mechanism 64 for rotating the rotating shaft 63 to which the stirring blades 62 are fixed by a motor 64A or the like.

Further, in the exterior case 7 shown in FIGS. 2 and 3, a rotary feeder 8 for discharging the sorted and dried powder particles falling from the rotary drum 1 to the outside of the case is arranged below the rotary drum 1. The rotary feeder 8 includes a rotary cylinder 81 used in combination with the second duct 41B, and a casing 80 having a U-shaped cross section in which the rotary cylinder 81 is arranged inside. The rotary cylinder 81 radially fixes a plurality of fins 82 at regular intervals. In the rotary cylinder 81 shown in the cross-sectional view of FIG. 3, six fins 82 are radially fixed. In the rotary feeder 8, the rotating rotary cylinder 81 moves the fins 82 along the inner surface of the casing 80, and the sorting dry powder of the drop chamber 83 formed inside the rotary cylinder 81, the fins 82, and the casing 80. The particles are discharged to the outside of the outer case 7. The casing 80 is provided with a discharge port 84 at the lower end, and the sorted and dried powder particles are discharged to the outside from the drop chamber 83 communicating with the discharge port 84. In the granulation drying device 100 of FIG. 2, a rotary cylinder 81 is connected to a motor 3 that rotates a rotary drum 1 via a chain 36 and a sprocket 37. The granulation drying device 100 can rotate the rotary drum 1 and the rotary cylinder 81 of the rotary feeder 8 with one motor 3. Since the rotary cylinder 81 used in combination with the second duct 41B blows heated air while rotating, it is connected to the heated air source 40 via a coupler 19 that is rotatable and does not leak heated air.

The above-mentioned granulation drying apparatus 100 dries the dehydrated cake supplied as follows while granulating to obtain a dry granulation body, and the granulated dry granulation body is selected and selected dry powder granules. Discharge as.
(1) The rotary drum 1 is rotated so that the heated air is blown into the rotary drum 1 from the heated ventilation mechanism 4. In this state, the dehydrated cake is supplied to the hopper 60, and the dehydrated cake is stirred by the stirring mechanism 61 of the hopper 60 and supplied into the rotary drum 1 via the transport pipe 51.
The dehydrated cake supplied to the transport pipe 51 is pressure-fed to the rotary shaft 6 which is the transport pipe 51 by the screw conveyor 55 of the forced transport mechanism 52, the spiral coil 56, or the piston 57, and dried from the drop opening 9 of the transport pipe 51. It falls into the chamber 2. Since the rotating drum 1 is rotating in this state, the dehydrated cake is dropped into the drying chamber 2 of the rotating rotating drum 1.
(2) The rotating rotating drum 1 rolls the supplied dehydrated cake on the inner surface of the outer cylinder 11A to granulate and dry it with heated air. The dried granules dried while being granulated pass through the sorting opening 17 and are discharged from the rotary drum 1 as sorted dry powder granules. The sorted and dried powder particles discharged from the rotary drum 1 fall and are supplied to the rotary feeder 8.
(3) The rotary feeder 8 guides the sorted and dried powder particles falling from the rotary drum 1 to the discharge port 84 in the drop chamber 83, and discharges the sorted and dried powder particles from the discharge port 84 to the outside of the outer case 7.

[Baking process]
The dried granules discharged from the granulation drying apparatus 100 are calcined in a firing furnace to obtain an inorganic porous powder granules having open cells. The calcining furnace calcins the dried granules at, for example, 800 ° C., and burns out components such as water and organic substances contained in the dried granules to obtain an inorganic porous powder or granules. As such a firing furnace, for example, a firing furnace for firing in a batch system can be used. The firing temperature of the dried granules can be set to a temperature at which organic substances are burnt down, water is vaporized and evaporated to form porous voids, and the dried granules can be firmly bonded. Therefore, for example, 400 ° C. or higher. The temperature is preferably 600 ° C. or higher, more preferably 800 ° C. or higher. If the calcination temperature is too high, a part of the dried granules melts, the porosity decreases, and the calcination cost increases. Therefore, the temperature is preferably 1200 ° C. or lower, more preferably 1000 ° C. or lower. Instead of the firing furnace for batch firing, the dry granulation can be continuously fired in a tunnel furnace or a rotary kiln where the dry granulation is continuously transferred by a conveyor and fired.

Using the above equipment, plated sludge is used for waste sludge, and this plated sludge is dehydrated with a filter press to make a dehydrated cake, and the dehydrated cake is dried while being granulated with the above-mentioned granulation drying device. The inorganic porous powder or granular material obtained by treating the dried granules having a particle size of 3 mm or less and firing the dried granules at 800 ° C. for 2 hours in an electric furnace for batch firing is excellent in water absorption. It has properties and water retention. When this inorganic porous powder or granular material is immersed in water, microorganisms propagate in a few days, so that it can be used for water treatment by microorganisms. Further, as a porous inorganic particle, it can be effectively used for various other uses, for example, a soil conditioner that is sprayed on soil to supply water and fertilizer over time.

Furthermore, since the above waste treatment method can generate inorganic porous powders and granules from other waste sludge as a raw material, various waste sludge can be effectively used as a raw material without specifying the waste sludge as plating sludge. It can be an inorganic porous powder or granular material that can be produced.

100 ... Granulation drying device 1 ... Rotating drum 2 ... Drying chamber 3 ... Motor 4 ... Heating blower mechanism 6 ... Rotating shaft 6A ... Heating area 6a ... Through hole 6B ... Material area to be dried 7 ... Exterior case 8 ... Rotary feeder 9 ... Drop opening 11 ... Granulation cylinder 11A ... Outer cylinder 11B ... Inner cylinder 12 ... End plate 12a ... Blower opening 13 ... Perforated plate 13A, 13B ... Cylinder 13a, 13b ... Through hole 14 ... Metal plate 14A ... Cylinder 15 ... Rod 16 ... Passing gap 17 ... Sorting opening 18 ... Partition 19 ... Coupler 20 ... Opening 21 ... Opening / closing lid 21X ... First opening / closing lid 21Y ... Second opening / closing lid 21Z ... Third opening / closing lid 31 ... Bearing 32 ... Sprocket 33 ... Chain 36 ... Chain 37 ... Sprocket 40 ... Heating air source 40A ... Blower 40B ... Heater 41 ... Blower duct 41A ... First duct 41B ... Second duct 41a ... Horizontal duct 41b ... Upward duct 42 ... Exhaust pipe 42A ... Flange 43 ... Exhaust port 44 ... Adjusting lid 45 ... Shaft 50 ... Supply mechanism 51 ... Supply pipe 52 ... Forced transport mechanism 53 ... Spiral transport member 54 ... Rotation mechanism 55 ... Screw conveyor 55A ... Central shaft 55B ... Fin 56 ... Spiral coil 57 ... Piston 58 ... Conrod 59 ... Actuator 60 ... Hopper 60A ... Receiving part 61 ... Stirring mechanism 62 ... Stirring blade 63 ... Rotating shaft 64 ... Rotating mechanism 64A ... Motor 80 ... Casing 81 ... Rotating cylinder 82 ... Fin 83 ... Falling chamber 84 …Vent

Claims (10)

A dewatering process that pressurizes waste sludge containing inorganic powder to make a dewatered cake,
The dehydrated cake obtained in the dehydration step is supplied into a rotating drum, and the dehydrated cake is supplied.
A granulation drying step of rotating the rotating drum, stirring the dehydrated cake, heating the cake, and drying the dehydrated cake while granulating to obtain a dry granule.
The dried granules obtained in the granulation drying step are fired to obtain
A firing step of burning off the heat-burning components contained in the dried granules to turn the inorganic powder into an inorganic porous powder granules having open cells.
Waste disposal methods including. The waste disposal method according to claim 1.
In the granulation drying step
While rotating the rotating drum, the dehydrated cake is continuously supplied to the inside of the rotating drum.
A method for treating waste, which is obtained by drying the dehydrated cake while granulating it to obtain the dried granulated body. The waste disposal method according to claim 1 or 2.
In the granulation drying step
A method for treating waste that rotates by arranging the rotation axis of the rotating drum in a horizontal posture. The waste disposal method according to any one of claims 1 to 3.
In the granulation drying step
For the rotary drum, a rotary drum having a large number of sorting openings that allow particles having a predetermined particle size or less to pass through is used.
A method for treating waste in which the dried granules are sorted and discharged at the sorting opening of the rotating rotating drum to obtain sorted dry powders having a predetermined particle size. The waste disposal method according to claim 4.
On the rotating drum
Using a granulated cylinder having a layer structure in which the inner cylinder is arranged inside the outer cylinder having the perforated plate having the sorting opening in the shape of a cylinder,
In the inner cylinder
A method for treating waste using a granulation cylinder having a passage gap through which a dry granulation body larger than the sorting opening is passed. The waste disposal method according to claim 5.
A method for treating waste in which a passage gap of the inner cylinder provided in the rotary drum is used as a slit. The waste disposal method according to any one of claims 1 to 6.
A method for treating waste using plated sludge for the waste sludge. The waste disposal method according to any one of claims 1 to 7.
The rotating shaft of the rotating drum is cylindrical.
A method for treating waste in which the dehydrated cake is supplied into the rotating drum from the cylindrical rotating shaft. The waste disposal method according to any one of claims 1 to 8.
In the firing step,
A method for treating waste by firing the dried granules at a temperature of 300 ° C. or higher. The waste disposal method according to claim 9.
In the firing step,
A method for treating waste by firing the dried granules at a temperature of 1200 ° C. or lower.

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