JPH0743105B2 - Dryer for high-moisture solid combustible materials - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a dryer for high-moisture solid combustible materials, and more particularly to a dryer in which the dried solid materials and odorous gases dried in the dryer are transferred to an incinerator, and the exhaust gas generated during the incineration process of the dried solid materials and odorous gases in the incinerator is used as drying gas.

[Prior Art]

As is well known, various dryers are used to dry high-moisture solid combustible materials, such as bean curd refuse generated during tofu processing, sewage, human waste, and other sludge. In recent years, in response to demands for energy conservation and pollution-free treatment, dryers used in a closed-loop incineration system combined with an incinerator have been increasing.

That is, the dry solids and odorous gases dried in the dryer are transferred to an incinerator, where they are incinerated, and the exhaust gas generated during this process is introduced and used as a drying gas.

In the dry incineration system that combines the dryer and incinerator, the dried solids dried in the dryer are directly transferred to the incinerator and incinerated there, making it possible to provide a small and compact dry incineration system. Furthermore, the exhaust gas from the incinerator is returned directly to the dryer and used as drying gas, which also saves energy. In addition, the odorous gas is also incinerated, which has the advantage of eliminating odors.

Incidentally, one of the dryers conventionally used in the above-mentioned drying and incineration system is the dryer disclosed in Japanese Patent Laid-Open Publication No. 55-152310.

That is, the dryer is a dryer in which the dried solids and odorous gases dried in the dryer are transferred to the incinerator through a transfer pipe from an outlet formed at the top, and the exhaust gas generated in the incinerator during the incineration process of the dried solids and odorous gases is introduced from the bottom as drying gas. At the bottom where the drying gas is blown out, a porous dispersion plate is disposed to disperse the drying gas and introduce it into the dryer, and an inlet for the high-moisture solid combustible material to be dried is formed at the top.

Focusing on the drying process within the dryer, the high-moisture solid combustible materials placed into the dryer are dried while flowing to some extent by the drying gas blown out from the bottom of the dryer, and once dry, are transported by suction to the incinerator.

[Problem to be solved by the invention]

The above-mentioned conventional technology has the following drawbacks: the high-moisture solid combustibles fed into the dryer through the feeding port tend to accumulate in clumps on the porous dispersion plate at the bottom of the dryer, which clogs the drying gas outlet and makes it difficult to introduce the drying gas into the dryer.

In addition, if the high-moisture solid combustible material is in a lump state,
The small contact area per unit volume with the drying gas makes it difficult to improve drying efficiency. One solution to this problem is to use a conventional stirring rod or stirring blade to agitate the high-moisture solid combustibles located on the perforated dispersion plate. However, this merely agitates the high-moisture solid combustibles on the perforated dispersion plate, and its effectiveness is not particularly significant. Furthermore, when examining the dried solids after drying, although they are somewhat pulverized by the drying gas blown from the bottom, the particle size of the dried solids varies, with some large and some small agglomerates remaining at the bottom of the dryer. As a result, when the dried solids are suction-transported, large agglomerates remain at the bottom of the dryer, hindering smooth transport to the incinerator. Additionally, the particle size of the dried solids varies, and some large agglomerates may be included, making incineration in the incinerator time-consuming and difficult to improve.

Therefore, an object of the present invention is to prevent the blowing openings of the porous dispersion plate from being blocked by the loaded high-moisture solid combustibles, to ensure that the drying gas is well introduced into the dryer, and to increase the contact area per unit volume of the high-moisture solid combustibles with the drying gas,
To provide a technology for improving the drying efficiency, and in addition, for smoothly transferring the dried solid matter from the top of the dryer to an incinerator, and for aligning the transferred dried solid matter to small particle sizes, thereby improving the incineration efficiency in the incinerator.

[Means for solving the problem]

In order to achieve the above object, the present invention has the following technical means: That is, to explain this using the reference numerals in the accompanying drawings corresponding to the embodiments, the present invention is a dryer 1 in which dried solid matter and odorous gases dried in the dryer 1 are transferred from an outlet 3 formed at the top to an incinerator 23 via a transfer pipe 22, and exhaust gases generated in the incineration treatment of the dried solid matter and odorous gases in the incinerator 23 are introduced from the bottom as drying gas, the bottom of which is provided with a porous dispersion plate 7 having holes 8 formed therein for dispersing the drying gas and introducing it into the dryer 1, and the dryer 1 has an inlet 4 for introducing high-moisture solid combustible material to be dried formed at the top; The dryer 1 has a rotating shaft 5 disposed vertically in the center of the interior thereof, and the rotating shaft 5 has a plurality of fine solid particle passing holes 12 formed therethrough at a position below the inlet 4 for passing the dried solid particles thrown from below from the lower surface 11b to the upper surface 11a when the dried solid particles have a diameter smaller than R. Also, the upper and lower surfaces 11a and 11b each have a repelling pin for repelling the dried solid particles to the inner peripheral surface 17 of the dryer 1.
A plurality of driers 13 are arranged upright, and the outer peripheral end 16 and the drier 1
A baffle plate 11 is attached to the inner circumferential surface 17, and defines a drop gap P through which the high-moisture solid combustible material introduced from above falls downward.
A blowing blade 10 is disposed below the blowing blade 10 so that the dried solid matter can be blown upward by a swirling flow caused by rotation, and a screw 9 is disposed below the blowing blade 10 to transport the dried solid matter toward the upper blowing blade 10. Between the baffle plate 11 and the blowing blade 10,
The dry solids are blown upward by the swirling flow caused by the blowing blades 10, and then the blown upward hits the lower surface 11b of the baffle plate 11, and those that do not pass through the fine solid particle passage holes 12 are flicked onto the inner peripheral surface 17 of the dryer 1 by the flicking pins 13 on the lower surface 11b, and then the dry solids that fall along the inner peripheral surface 17 are blown downward again by the blowing blades 10, forming a swirling flow region 18 in which the dry solids flow.

[Effect]

The operation of the above-described configuration will now be described. First, high-moisture solid combustible material is fed into the dryer 1 through the feed port 4.
Then, the high-moisture solid combustibles fall onto the baffle plate 11. Since the upper surface 11a of the baffle plate 11 is provided with repelling pins 13, the high-moisture solid combustibles are repelled by the repelling pins 13 toward the inner peripheral surface 17 of the dryer 1 and collide with the inner peripheral surface 17.
The high-moisture solid combustible materials that collide with 17 fall downward along the inner peripheral surface 17 through the drop gap P. Then, even during the process of falling downward through the drop gap P, they come into contact with the drying gas introduced from the bottom of the dryer 1, where heat exchange occurs, and drying progresses. After this, they fall onto the screw 9 and are carried upward.

Next, the dry solids of the high-moisture solid combustibles that have dried to a certain extent are transferred onto the blowing blades 10, and are blown upward by the swirling flow of the blowing blades 10. Here, the dry solids are broken down into smaller pieces. The dry solids blown upward are then crushed by the lower surface of the baffle plate 11.
The particles collide with the repelling pins 13 of the nozzle 11b, and are repelled by the action of the repelling pins 13 toward the inner peripheral surface 17 of the dryer 1.
Here too, the dried solids are crushed and broken down, and the drying process continues.
Thereafter, the dried solid matter falls downward along the inner peripheral surface 17. Then, it is thrown upward again by the throwing blade 10, and as a result, the dried solid matter is caused to swirl and flow in the swirl flow region 18. Then, the particle size of the dried solid matter becomes small and the solid particles reach a desired dry state, and the solid particles pass through the fine solid particle passage holes 11b of the baffle plate 11.
The dried material passes through 2 and is transported upward by the flow of the drying gas to the outside of the dryer 1 through the outlet 3.

[Example]

Next, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. First, an example of a dryer 1 used in the present invention is shown in Figs. 1 to 12.

Reference numeral 1 denotes a cylindrical dryer, which has a gas supply port 2 at the bottom, a dry solid material discharge port 3 at the top, and an inlet 4 for the high-moisture solid combustible material to be dried slightly above the middle. That is, it is arranged vertically in the direction of gravity.
A rotating shaft 5 is disposed vertically in the center of the dryer 1 and is rotated by an electric motor 6. A porous dispersion plate 7 having a large number of holes 8 formed therein for dispersing the drying gas and introducing it into the dryer 1 is disposed horizontally at the bottom of the dryer 1 where the gas supply port 2 opens. A screw 9 is disposed above the plate so as to be rotated by the rotating shaft 5. In addition, a blowing blade 10 having a central tubular portion 10a for attaching to the rotating shaft 5 is disposed above the screw 9. The relationship between the screw 9 and the blowing blade 10 is such that the dried solid material transported upward by the screw 9 is placed on the upper surface 9a of the screw 9 and transported to the upper part, and then
It is designed so that the swirl flow generated by the blower blades 10 can splash the air upward.

Next, a baffle plate 11 is attached to the same rotating shaft 5 above the flying blade 10. The surface of the baffle plate 11 is formed with fine solid particle passage holes 12 of small diameter R penetrating vertically, and a repelling pin 13 is disposed upright on each of the upper and lower surfaces 11a, 11b. A falling gap P for the dried solid material is formed between the outer peripheral edge 16 of the baffle plate 11 and the inner peripheral surface 17 of the dryer 1, and a swirling flow region 18 for the dried solid material is defined between the baffle plate 11 and the flying blade 10.

In this embodiment, in addition to the one combination of the flying blade 10 and baffle plate 11, another combination of blade 10 and baffle plate 11 is formed in the stage above, and a swirling flow region 18 defined by them is formed. In this embodiment, another flying blade 10 is provided in the uppermost stage. Furthermore, the inlet 4 for dried solid material opens into the swirling flow region 18 of the second stage, and a cross-shaped crushing blade 14 having crushing pins 15 is attached to the part corresponding to the inlet 4. Of course, this crushing blade 14 is also rotated by the rotary shaft 5.

Next, the overall system diagram will be explained according to Figure 13.

Reference numeral 20 denotes a hopper for storing high-moisture solid combustible material, which is connected to the inlet 4 of the dryer 1 via a screw conveyor 21 at the bottom. The dry solid discharge outlet 3 of the dryer 1 is connected to the incinerator 23 via a transfer pipe 22. More specifically, the discharge outlet 3 and the swirl flow area 25 of the burner 24 of the incinerator 23 are connected to each other.
The solid-gas separator 26 is connected to the transfer pipe 22 at its upper part and has an ejector 27 at its lower part. The primary side of the ejector 27 is connected to a gas chamber 29 provided in a side wall 28 of the solid-gas separator 26, and the secondary side of the ejector 27 is connected to the swirl flow area 25 of the incinerator 23.

On the other hand, an exhaust pipe 31 is led out from the upper part of the separation space 30 of the funnel-shaped solid-gas separator 26, and the gas separated in the solid-gas separator 26 is discharged through a cyclone 32, an induced draft fan 33, and an exhaust pipe 34. A dust box 35 is connected to the lower part of the cyclone 32 as usual.

The hopper 20 for storing high-moisture solid combustibles, such as soybean refuse, has a supply port 35' and an air inlet 36 formed at its top, and an air pipe 39 having a blower 38 connects the introduction port 37 at the top to the inlet 40 of the solid-gas separator 26.

The exhaust gas outlet 41 of the incinerator 23 and the gas inlet 2 of the dryer 1 are connected by an exhaust gas return pipe 42 .
A secondary air introduction pipe 44 is drawn out from a branch point 43 downstream of the attachment position of the blower 38 of the air supply pipe 39, and is connected to the combustion chamber
The combustion chamber 53 is connected to a secondary air nozzle 45 provided facing the combustion chamber 53. A steam jacket 46 is provided around the combustion chamber 53, and a water softener 47, a water supply tank 48, and a water supply pipe 49 are connected to the steam jacket.
The steam generated at 46 is discharged from a steam outlet 50 and is used for processing products related to this plant. A waste oil tank 51 and a waste oil supply pipe 52 are connected to the burner 24.

The operation of the above configuration will now be described.

First, the high-moisture solid combustible material fed from the feed port 35 is fed into the hopper.
20. From here, it is carried to the inlet 4 of the dryer 1 by the screw conveyor 21. Then it is fed into the dryer 1 from the inlet 4. It is then crushed by the crushing pins 15 of the crushing blades 14. Then, as it falls downward due to gravity, it is bounced off by the second-stage jumping blades 10 in this example and flows. As it passes through, it comes into countercurrent contact with the gas from below and the drying progresses. Now, at this initial stage, the moisture content is still high, so rather than being carried to the discharge outlet 3 by the gas, it is first thrown onto the second baffle plate 11 at the lower stage.
The baffle plate 11 has a repelling pin 13 on its upper surface 11a, so the repelling pin
The particles are then repelled by the baffle plate 13 as shown by arrow B, collide with the inner peripheral surface 17 of the dryer 1, and fall downward along the inner peripheral surface 17 as shown by arrow C. This downward fall C is made possible by the passage gap P between the outer peripheral edge 16 of the baffle plate 11 and the inner peripheral surface 17. Of course, even during this process, the particles come into contact with the hot drying gas, heat exchange occurs, and drying progresses. After this, the particles fall onto the screw 9 and are carried upward. Because they are moved upward by the screw 9, clogging of the gas supply port 2 and the porous dispersion plate 7 is prevented.

Next, the dry solids of the high-moisture solid combustibles that have dried to a certain extent are transferred onto the blowing blade 10 as shown by arrow E, and are blown upward by the blowing blade 10 as shown by arrow F. Alternatively, the apparent specific gravity is reduced, and the dry solids are blown upward by the swirling flow generated by the blade 10.
Here, the particles are further broken down, i.e., their particle size becomes smaller.
The specific surface area of each solid increases, improving the efficiency of contact with the drying gas. Then, the solids collide with the repelling pins 13 on the lower surface 11b of the baffle plate 11, and are pushed against the inner peripheral surface 17 by the action of the repelling pins 13.
It is thrown to the side as shown by arrow G. It is also crushed here.
The particles are broken down into smaller particles, which improves the efficiency of contact with the drying gas. After this, the particles fall downward along the inner peripheral surface 17.

In other words, the dried solids were in the form of lumps. Alternatively, the dried solids with large particle sizes flowed into the swirling flow region 18 as shown by arrows C → D → E → F → G → C.
The solid particles are swirled and fluidized by the air, which breaks down the agglomerates and crushes and disperses them to smaller particle sizes. As a result, the specific surface area of each crushed and finely divided solid particle increases, improving the contact efficiency with the drying gas. This improves the heat exchange efficiency, increases the degree of drying, and results in uniform drying of each part of the dried solid. Now, the solid particles, which have been reduced in particle size and reached the desired dry state, are transported upward by the hot drying gas from the lower surface 11b of the baffle plate 11 through the fine solid particle passage holes 12.
In this embodiment, the particles are subjected to the same action in the second stage swirling flow region 18, where they are further broken down and dried. In this second stage swirling flow drying, the temperature of the hot air drying gas is slightly lowered and it contains moisture, so the efficiency of heat and moisture exchange is extremely high.

Then, it is thrown upward by the final flying blade 10,
The hot air drying gas is carried out of the exhaust port 3.

On the other hand, by driving the blower 38, air is introduced into the separation space 40 of the solid-gas separator 26 through the inlet 37 of the hopper 20 and the air pipe 39. That is, the odorous gas in the hopper 37 is also collected.

The dried solid matter is separated into solid and gaseous matter by the above-mentioned air supply, and the solid matter is broken down into small pieces. The gaseous matter is then exhausted from the exhaust pipe 31, the cyclone 32, and the exhaust stack 34. On the other hand, part of the supplied air is led to the ejector 27 through the air chamber 29, and the separated and broken down solid matter is sucked in by the action of the ejector 27, and is then sent directly to the incinerator 23.
The dried solids are then sent to the swirling flow section 25, where they are combusted by the burner 24. In this case, the dry solids are broken down into small pieces, so the combustion efficiency is good.
This is made possible by the air that has transported the dried solids. Of course, the secondary air introduced into the combustion chamber 53 via the secondary air supply pipe 44 branched downstream of the blower 38 is also effective.

Here, the dried solid matter is incinerated, and the exhaust gas is returned to the gas supply port 2 of the dryer 1 through the return pipe 42.
There it is left to dry.

As can be seen from the above example, according to this invention, after drying in the dryer 1, the dried solid material is transferred as is to the incinerator 23 and incinerated there. Therefore, a small and compact means for treating high-moisture solid combustibles can be provided, and since the exhaust gas from the incinerator 23 is returned as is to the dryer 1 and used as drying gas, energy is saved. In addition, since odorous gases are also incinerated, odors can of course be removed. Furthermore, by using the baffle plate 11, the blowing blades 10 and the screw 9 to cause a swirling flow of the high-moisture solid combustibles within the dryer 1, efficient drying can be achieved.

[Effects of the Invention]

As described above in detail, the present invention uses the ejection pins of the baffle plate to eject the dried solid matter that hits the upper and lower surfaces of the baffle plate onto the inner peripheral surface of the dryer, making it easy to break down the dried solid matter, and also allowing dried solid matter that has not yet reached the desired dry state and has a particle size larger than the diameter of the fine solid particle passage holes to be returned to the swirl flow system. Also, the drop gap allows the high-moisture solid combustible matter that has been ejected onto the inner peripheral surface of the dryer by the ejection pins to fall below the baffle plate. Furthermore, the fine solid particle passage holes of the baffle plate allow the crushed and broken down solid matter to fall below the baffle plate.
The solid particles that have reached the desired dry state can be passed through the upper surface of the baffle plate in a state of small particle size, making it easy to make the dry state and particle size of the solid particles uniform.

In addition, the flying blades installed below the baffle plate
The dry solid material can be carried upward by the swirling flow, which allows the dry solid material to be crushed and broken down into smaller pieces, and also allows the dry solid material to be swirled.The swirling flow also improves the contact efficiency between the dry solid material and the drying gas.

Furthermore, a screw provided below the blowing blade can receive and transport upward the dried solid matter that is bounced off the baffle plate and falls along the inner circumferential surface of the dryer,
This prevents the accumulation of dry solids on the porous dispersion plate, and also allows the dry solids carried upward to be smoothly transferred to the blowing blades, allowing the blowing blades to be used effectively.

The swirling flow region ensures a space for the dry solid material to swirl and flow, allowing the high-moisture solid combustible material to be smoothly dried to a desired dry state.

The high-moisture solid combustibles fed from the inlet of the dryer are dried while being swirled in the swirling flow area by the baffle plate, the blowing blades and the screw, so that the high-moisture solid combustibles do not pile up in a lump state on the porous dispersion plate at the bottom of the dryer, and the drying gas outlet is prevented from being blocked, so that the drying gas can be efficiently introduced into the dryer.
During the swirling flow, the particles are crushed and broken down into smaller particle sizes, which increases the contact area per unit volume between the solids to be dried and the drying gas, improving the drying efficiency.
After the dry solid material reaches the desired dry state, it passes through the fine solid particle passage holes of the baffle plate in a small particle state and is transported from the top of the dryer to the outside, thereby allowing the dry solid material to be smoothly transported to the incinerator. The small particle size dry solid material transported to the incinerator is solid particles with a small diameter and uniform particle size that have passed through the fine solid particle passage holes of the baffle plate,
Incineration is easy to carry out, which makes it easy to improve incineration efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings show an embodiment of the present invention, in which FIG. 1 is a front view including a longitudinal section of the essential part of a dryer, FIG. 2 is a model diagram for explaining swirl fluidization drying, FIG. 3 is a plan view of a porous dispersion plate, and FIG. 4 is a longitudinal front view of the porous dispersion plate taken along line X-X in FIG. 3.
FIG. 5 is a plan view of the screw, FIG. 6 is a side view of the screw, FIG. 7 is a plan view of the blowing blade, FIG. 8 is a side view of the blowing blade, FIG. 9 is a plan view of the baffle plate, FIG. 10 is a side view of the baffle plate, FIG. 11 is a plan view of the crushing blade, FIG. 12 is a side view of the crushing blade, and FIG. 13 is a system diagram of the drying and incineration device.

Continued from the front page (72) Inventor: Ikuro Shishido 3-2-16 Nishitaga, Taihaku-ku, Sendai, Miyagi Prefecture (72) Inventor: Toru Yoshida 3-8-8 Kongosawa, Taihaku-ku, Sendai, Miyagi Prefecture (72) Inventor: Hideo Seki 6-5 Honmachi, Aoba-ku, Sendai, Miyagi Prefecture (72) Inventor: Shinya Watanabe 3-14-28 Kaigamori, Aoba-ku, Sendai, Miyagi Prefecture (56) References: JP 64-67300 (JP, A) JP 55-152310 (JP, A) JP 40-22628 (JP, B1)

Claims (1)

[Claims] 1. The dry solids and odorous gases dried in the dryer 1 are discharged from the exhaust port 3 formed at the top into the transfer pipe 22.
a drying chamber 23 for transferring the dried solid matter and odorous gases to an incinerator 23 via a nozzle 11b, and introducing exhaust gas generated in the incineration of the dried solid matter and odorous gases in the incinerator 23 as drying gas from the lowest part of the dryer 1, the lowest part of the dryer from which the dried gas is blown out being provided with a porous dispersion plate 7 having holes 8 formed therein for dispersing the dried gas and introducing it into the dryer 1, and the dryer 1 being provided with an inlet 4 for feeding high-moisture solid combustible material to be dried at the top; the dryer 1 being provided with a rotating shaft 5 arranged vertically in the center of the interior, the rotating shaft 5 being provided with a plurality of fine solid particle passing holes 12 penetrating therethrough below the inlet 4 for allowing the dried solid matter blown from below to pass from the lower surface 11b to the upper surface 11a when the dried solid matter is smaller than its diameter R, and repelling pins being provided on each of the upper and lower surfaces 11a, 11b for repelling the dried solid matter to the inner peripheral surface 17 of the dryer 1
A plurality of driers 13 are arranged upright, and the outer peripheral end 16 and the drier 1
A baffle plate 11 is attached to the inner circumferential surface 17, and defines a drop gap P through which the high-moisture solid combustible material introduced from above falls downward.
A blowing blade 10 is disposed below the blowing blade 10 so that the dried solid matter can be blown upward by a swirling flow caused by rotation, and a screw 9 is disposed below the blowing blade 10 to transport the dried solid matter toward the upper blowing blade 10. Between the baffle plate 11 and the blowing blade 10,
The dry solids are blown upward by the swirling flow caused by the blowing blades (10), and then the blown upward hits the lower surface (11b) of the baffle plate (11), and those that do not pass through the fine solid particle passage holes (12) are flicked onto the inner peripheral surface (17) of the dryer (1) by the flicking pins (13) on the lower surface (11b), and then the dry solids that fall along the inner peripheral surface (17) are blown upward again by the blowing blades (10) and flow, forming a swirling flow region (18).