JPH0720548Y2 - Drying equipment for solid particles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a drying device which evaporates and dries the surface moisture of solid particulate matter such as coal or limestone or slag that has been accumulated in the field and contains moisture such as rainwater. In particular, the present invention relates to a solid granular drying device capable of blowing hot hot air at a higher flow rate than an air dispersion plate to fluidize and dry an object to be dried, and increase the drying speed to reduce the size of the drying device itself. Is.

[Prior Art] Conventionally, as a device capable of increasing the drying speed by ejecting high-temperature hot air at a high flow rate from an air dispersion plate to fluidize and dry the material to be dried, for example, Japanese Patent Laid-Open No. 55-146305. There is a coal dryer as shown in the publication.

This conventional coal dryer will be described with reference to FIG.
FIG. 5 shows a coal fuel supply system for a fluidized bed combustor. Reference numeral 7 is a coal bottle, 8 is a screw feeder, 9 is a coal dryer similar to the present invention, and 10 is dried coal. A crusher that crushes to a size suitable for burning in the combustion section of a fluidized bed combustor, 11 is a rotary space blocker, 12 is a crusher
10 is an air carrier for sending coal fed from the rotary space circuit breaker 11 to the combustion section of the fluidized bed combustor as fuel, 12a is a carrier air dispersion plate, and 12b is a carrier air supply pipe. , 12c are coal conveying pipes to the combustion section, and 12d are air ejection pipes whose ends are opened in the conveying direction of the coal conveying pipes 12c for ejecting auxiliary air for conveyance.

The coal dryer 9 in the coal supply system for such a fluidized bed combustor has a drying chamber 9c in the upper part and an air having a hot air supply port in the lower part via an air dispersion plate 9b provided under the container 9a. A chamber 9d is formed, and a rotary shaft is
A large number of bars 9g are mounted around the rotary plate 9f at substantially equal intervals between the rotary plates 9f provided at predetermined intervals in the axial direction of 9e and are mounted rotatably by the rotary shaft 9e. The hot air blown from the air chamber 9d by the dispersion plate 9b fluidizes the coal sent from the screw feeder 8 into the drying chamber 9c, and at the same time the bar 9g that rotates rotates the coal to dry it while stirring and discharging it. To the next coarse crusher 10. In addition, 9k in the figure is an outlet for the dry exhaust gas.

[Problems to be Solved by the Invention] In the coal dryer 9 as described above, the material to be dried supplied to the inside of the drying chamber 9c by the hot air blown from the air chamber 9d through the air dispersion plate 9b into the drying chamber 9c. It has the advantage that it can fluidize the coal and that the fluidized coal is agitated by the bar 9g provided around the rotating plate 9f to maximize the degree of contact between the material to be dried and the hot air. On the other hand, on the other hand, there is a factor of poor drying efficiency as follows.

That is, in the coal dryer 9 shown in FIG. 5, the coal to be dried enters the rotary stirring bar 9g portion above the air dispersion plate 9b in the drying chamber 9c and is fluidized and stirred by the bar 9g. However, in the drying process in such a state, the distance from the time when the material to be dried enters the rotary stirring section consisting of the rotary plate 9f, the bar 9g, and the rotary shaft 9e until it is discharged is short. The structure is such that the residence time of the material to be dried cannot be taken sufficiently. That is, the direction of supply and discharge of the material to be dried to the stirring section is the same as the stirring direction (the rotating direction of the bar 9g), and the position 9h at which the material to be dried is introduced into the rotating stirring section and the rotating stirring section Since the distance to the discharging position 9i is short and the material to be dried is easily discharged from the stirring section quickly, it is difficult to secure a sufficient residence time in the drying section of the material to be dried, especially if the material to be dried contains moisture. In the case of a lump containing a lot of particles and sticking to each other in an adhesive state, it is discharged from the discharge section without being dried sufficiently, and it is crushed by the next coarse crusher 10 and reduced to flow. Since it will be sent to the bed combustion unit, not only the combustion efficiency is deteriorated, but also the crushing efficiency in the crusher 10 is reduced, and the adhesion of fine particles in the crusher 10 and the coal to the fluidized bed combustion unit. Adhesion inside the transfer pipe 12c and flow There is a problem that the fuel supply to the combustion portion not performed smoothly.

Further, since the stirring member in the stirring unit is composed of a bar 9g, as described above, a large amount of water adheres to each other and particles adhere to each other, and moreover, it is dried such that it contains sticky particles. There is also a drawback that it is difficult to sufficiently dry the product because it is difficult to impart sufficient force to loosen the lumps of particles that are stuck to each other with 9 g of the bar and the improvement of the drying efficiency due to fluidization is not exhibited.

The present invention has been made in view of the above-mentioned drawbacks, and even when the material to be dried is a lump with a high content of water in which the particles are stuck to each other, it is possible to secure the required retention time in the drying chamber. It is possible to dry the clumps by thoroughly scraping them and contacting them with hot air due to fluidization, to improve the drying speed as much as possible, improve the drying efficiency, and make the device compact. An object of the present invention is to provide a drying device for various solid particles.

[Means for Solving the Problems] In order to achieve the above object, the present invention is directed to a drying device in which the inside is divided into an upper drying chamber and a lower air chamber by an air distribution plate, and a large number of air distribution plates are provided in the drying device. Slit-shaped openings are provided side by side, and the paddle shaft is rotatably and at a variable speed by being laid horizontally in the drying chamber in the drying chamber, and the paddle shaft is covered with a space in the axial direction of the paddle shaft. A plurality of paddles for agitating dry matter are attached, and the paddles are attached to the paddle shaft by shifting the attachment angles in the axial direction of the paddles adjacent to each other in the axial direction of the paddle, and the paddle itself is attached to the paddle shaft. The object to be dried is tilted with respect to the axis of the shaft so as to give an agitating force in the axial direction, and the tilt angle is adjustable, and the paddle shaft of the drying chamber is covered on one end side and the other end side, respectively. With the dry matter supply port An exhaust port is provided, high-temperature hot air is introduced into the air chamber, and the hot air is jetted into the drying chamber at high speed through the slit-shaped openings of the air dispersion plate to fluidize the material to be dried. Is.

[Operation] When the material to be dried is supplied into the drying chamber from the supply port of the material to be dried on one end side of the paddle shaft of the drying chamber, the material to be dried is jetted from the air chamber into the drying chamber through the air dispersion plate. For example, about 600
Fluidized by hot air at a high temperature of ℃, the paddle is rotated by the rotation of the paddle shaft to scrape up the material to be dried, the particles are well stirred, and the material to be dried is tilted with respect to the paddle shaft. By the action of the attached paddle, it is dried while being moved in the axial direction of the paddle. At this time, even if the material to be dried contains a lump in which the particles are stuck to each other, it is loosened by the tapping action of the paddle and the contact rate between the hot air and the loosened particles is improved and fluidization is smoothed. The drying is performed smoothly, and the required residence time is secured by moving the material to be dried in the paddle axial direction.
The lumps as described above are crushed and the crushing force of the lumps is sufficiently exerted to sufficiently dry the material to be dried. The above drying operation is performed by high-temperature hot air (for example, 600 ° C) being blown at high speed through the slit-shaped openings to fluidize the material to be dried, so the temperature difference with the material to be dried is large. Is very large, and the drying heat source is at a high temperature, so the amount of hot air required for drying may be small, and the contact with hot air due to the fluidization of the particles scraped by the paddle is extremely good Goods are dried well. Further, as described above, the amount of heat transfer is large, so that the device is made compact. Furthermore, since the paddle rotation speed and the mounting angle of the paddle when viewed in the axial direction are changeable, the type of the material to be dried and the amount of attached water,
Depending on the characteristics such as the degree of sticking of particles to each other and the degree of agglomeration, the moving speed and residence time of the material to be dried, or
The striking force or the scraping force of the paddle can be adjusted to obtain the desired dryness.

[Embodiment] The present invention will be described in detail below with reference to an embodiment shown in the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of a solid granular material drying apparatus according to the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a sectional view of FIG. It is a top view. In this example, the case where the material to be dried is coal will be described.

As shown in FIG. 1, the drying apparatus main body 1 is provided with an air dispersion plate 2 at a substantially central portion in the height direction, and a drying chamber 3 is provided at an upper portion thereof.
And an air chamber 4 at the bottom. Bottom plate 30 of drying chamber 3
As shown in FIG. 2, the cross section is formed in a gutter shape having a partially semicircular cross section, and the air dispersion plate 2 is formed in the central arc portion. The bottom plate 30 also defines the upper end of the air chamber. The air dispersion plate 2 is shown by D in FIG. 2 in the direction along the arc.
As shown in FIG. 1, a plurality of slit-shaped openings 20 elongated in the range are arranged side by side at regular intervals in the longitudinal direction of the paddle shaft 5. The opening 20 is shown by a line in FIG.

A refractory material 43 such as castable is lined on the inner wall surface of the air chamber 4 including the back surface of the bottom plate 30 and is protected against high temperature hot air of about 600 ° C. This refractory material 43
Is also applied to the air dispersion plate 2, and a part of the opening 20 is formed of a refractory material 43.

In the drying chamber 3, paddle shafts 5 are rotatably provided by bearings 50 mounted on both outer side walls of the drying chamber 3 via brackets, and the paddle shafts 5 are axially rotatable. Paddles 51 (six in this embodiment) are attached at substantially equal intervals, and each paddle 51 has its arm 51a penetrated by the paddle shaft 5, and the paddle shaft 5 is sandwiched between the screw parts of the arm 51a. It is detachably attached to the paddle shaft 5 by screwing and tightening nuts 51b from both sides. paddle
51 is formed in a flat plate shape so as to scrape up the material to be dried by its rotation, and its tip end portion is bent in the rotation direction of the paddle so as to ensure the scraping up of coal. The tip of the paddle 51 is set at a position close to the bottom plate 30. The paddles 51 are attached such that the mounting angles of the paddles 51 adjacent to each other in the axial direction of the paddle are different from each other when viewed in the axial direction, and in the present embodiment, the paddles 51 adjacent to each other in the axial direction are mounted in the circumferential direction. Are mounted with the phases sequentially shifted by 120 degrees (see FIG. 2). More paddle
As shown in FIG. 4, 51 is attached to the paddle shaft 5 while being inclined with respect to the axis of the paddle shaft 5, and is set to about 10 degrees in this embodiment. The direction of inclination of the paddle 51 is a method in which the lime as the material to be dried is moved in the paddle axis direction by the rotation of the paddle 51 around the paddle axis 5.
The four paddles 51 on the coal supply side are mounted in such a manner that they are inclined with respect to the axis of the paddle shaft 5 and face the mounting openings 32a on the side wall of the coal discharge pipe 32, which will be described later on the coal discharge side. Two of them are installed in parallel with the axis of the paddle shaft 5.

Further, if the tilt angle of the paddle 51 with respect to the axis of the paddle shaft 5 is adjusted by loosening the nut 51b and rotating the arm 51a of the paddle, the moving speed of the coal in the axial direction can be adjusted, and the drying chamber 3 can be adjusted. The residence time of the coal inside is adjusted, and the degree of dryness can be adjusted by the moisture content of the coal.

On the other hand, one end of the paddle shaft 5 on the upper wall of the drying chamber 3 is provided with a coal supply port 31 facing the lower paddle shaft 5, and the side wall of the drying chamber 3 on the other end of the paddle shaft 5 is dried. As shown in FIG. 2, a lower end portion 32b of a mounting opening 32a of the discharging pipe 32 to the side wall of the drying chamber 3 is provided with a starting end of the partial semicircular bottom plate 30. It is formed so as to almost coincide with the part.

Further, a hot air supply port 41 is provided on the wall of the air chamber 4 on the side where the coal supply port 31 is located, and drying of coal is completed on the upper wall of the drying chamber 3 on the side where the coal discharge pipe 32 is located. A hot air outlet 42 is provided.

Reference numeral 52 denotes a chain wheel for rotationally driving the paddle shaft 5, which is provided at an output shaft end of a driving electric motor (not shown) and is rotationally driven by tensioning the chain between the chain wheel and the chain wheel. By setting this drive motor as a variable speed motor, the rotation speed of the paddle 51 can be adjusted to adjust the moving speed of the coal and the impact force (scraping force) on the coal, making it easy to adjust the dryness of the coal. To be done.

The operation will be described based on the case where the drying apparatus having such a configuration is incorporated in the coal supply system shown in FIG.

Contains a large amount of surface water stored in the coal bottle 7 (for example,
10%), coal containing coal in which particles are stuck to each other into a small lump or a large lump is supplied from the coal supply port 31 of the dryer main body 1 to the inside of the drying chamber 3 by the screw feeder 8 to form an air dispersion plate. 2 and the hot air is supplied from the lower hot air supply port 41 to the air chamber 4
When the paddle shaft 5 is rotated by rotating a paddle shaft 5 by driving a drive current machine (not shown), the coal having a small particle size is generated. Approximately 60 high-speed injection from the slit 20 of the air dispersion plate 2
While being fluidized by the hot air at a high temperature of 0 ° C. and being moved to the exhaust pipe 32 side, the surface moisture is instantaneously and efficiently evaporated due to the contact between the surface moisture and the hot air at a high temperature. In this case, since the hot air has a high temperature, the amount of hot air required for drying may be small. Further, the temperature difference between hot air and the coal to be dried is large, so the amount of heat transferred to the coal is large and the drying device can be made compact. Further, coal having a relatively small particle size in which particles are stuck to each other and coal having a large particle size (for example, 50 mm or less) in which particles are stuck to each other are attached to the rotary shaft 5. While being crushed by being flattened by the flat plate-shaped paddle 51, the lumps are loosened and moved to the coal discharge tube 32 side in the paddle axial direction, and in the state where the lumps are loosened and contact with the particles is promoted Is efficiently dried by. Since the lower end 32b of the opening 32a of the side wall portion of the discharge chamber 32 of the discharge tube 32 is high in the drying chamber 3, the paddle 51 when coal is stored in at least a substantially semicircular trough-shaped bottom plate 30. Since the particles are stirred by, the stirring efficiency is good and the contact between the hot air and the particles is good.

In this way, while the coal is being dried in the drying chamber 3, the lumpy coal is gradually moved in the axial direction while being scraped by the paddle 51 and dried by the hot air in the fluidized bed. Adjacent paddles 51 mounted out of phase during axial movement to
However, since the coal that is scraped by the front paddle 51 and sent to the adjacent paddle 51 side on the downstream side is tapped after a while, the scraping force is effectively applied, and the predetermined amount is obtained by the axial movement. The drying time can be secured and a predetermined dryness (for example, 1% or less) can be obtained. On the other hand, the hot air obtained by drying the coal is discharged from the discharge port 42 of the upper wall of the air chamber 3 on the side of the tip discharge cylinder 32, and this discharge gas is sent to the carrier air supply pipe 12b of the air carrier 12 in FIG. Thus, the system is made compact by eliminating the need for a dust collector in the coal supply system, which is used as air for transportation.

The degree of dryness is adjusted by adjusting the tilt angle of the paddle 51 as viewed in the axial direction or the number of rotations of the paddle 51, and by adjusting the amount of hot air blown out from the air dispersion plate 2 (jetting speed) and the hot air temperature. Further, by appropriately combining these factors, the drying speed can be increased, the drying efficiency can be improved, and the heat transfer amount by the hot air at high temperature can be large, so that the device can be compactly assembled.

The coal that has dried to the discharge side in the drying chamber 3 has two paddles mounted parallel to the paddle axis located on the discharge side.
It is scraped up to the upper opening 32a by 51 and is sent from the opening 32a through the discharge tube 32 to the coal crusher 10 in FIG. 5, where it is crushed to a required particle size of, for example, 6 mm or less, and the lower air The air is transferred from the circuit breaker 11 to the air carrier 12, from which it is transferred to the combustion section of a fluidized bed combustor such as a fluidized bed boiler by a coal carrier pipe 12c for combustion.
In this way, at the stage where the coal is transferred from the crusher 10 to the fluidized bed combustor, since the coal has a predetermined dryness by the coal dryer 1, it adheres to the inside of the crusher 10 and the transfer device thereafter. The coal is smoothly conveyed without being clogged or clogged, and the operation of the fluidized bed combustion device is continuously and smoothly performed.

As a safety device for preventing the ignition of coal, a temperature detector is provided at the hot air outlet 42 of the drying device 1 to detect the hot air exhaust temperature, and the hot air exhaust temperature is kept constant, for example, 100 ° C. As described above, the temperature of the hot air supplied to the air chamber 4 may be controlled. In this case, the hot air temperature can be controlled by adjusting the fuel amount and the bypass air amount of a burner (not shown) of the hot air stove.

Further, a water spray device is installed in the drying chamber 3 of the drying device 1 so that when the hot air discharge temperature exceeds a certain temperature of, for example, 150 ° C., water is spray-sprayed into the drying chamber 3 to prevent ignition. It may be configured to.

Further, by providing the paddle 51 on the paddle shaft 5 in a detachable manner, it is possible to easily deal with the case where the paddle 51 is replaced by wear or when a paddle having a different shape is applied.

In addition, although the case where the material to be dried is coal has been described in the present embodiment, the solid granular material drying apparatus of the present invention is also suitably used for drying limestone or slag that is piled up and contains rainwater and the like.

[Effects of the Invention] As is clear from the above description, the present invention has the structure as described in the scope of claims for utility model registration, and therefore, even if the material to be dried contains a mass of particles sticking to each other. The impact force of the paddle surely loosens this, and the loosened particles instantaneously and efficiently evaporate the surface moisture due to the fluid contact with the high-temperature hot air blown out from the slit at high speed. Also, since the material to be dried is dried while being moved in the axial direction, a desired residence time can be secured and the above-mentioned lumps can be sufficiently loosened during this time, and fluidization is performed well, It is possible to obtain a sufficient dryness.

Since the drying source is high-temperature hot air, the amount of hot air required for drying can be small, and the temperature difference with the material to be dried is large, so that the drying device can be made compact.

Furthermore, since the paddle mounting angle with respect to the paddle axis and the rotation speed of the paddle shaft can be changed, the optimum residence time (drying speed) is set according to the properties of the material to be dried (water content, size of lump, amount, etc.). Can be set to obtain a desired degree of dryness, and as described above, the amount of hot air produced by using high-temperature hot air is small and the amount of heat transfer is large, so that the drying device can be compactly assembled.

Therefore, if this dryer is used, for example, by incorporating it into the fuel supply line of a fluidized bed combustor, a sufficient degree of dryness can be obtained, so that there is no sticking or clogging in the fuel supply line, and smooth and continuous operation is possible. Can supply fuel such as coal to
It enables stable operation of the fluidized bed combustion device.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 4 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a drying device, and FIG. 2 is a line II-II in FIG. FIG. 3 is a plan view of FIG. 1, and FIG.
FIG. 4 is a view taken along the line IV-IV in the figure and is a view for explaining a paddle mounting procedure, and FIG. 5 is a view showing a coal supply system to a fluidized bed combustion apparatus incorporating a conventional drying apparatus 9. 1 ... Drying device main body, 2 ... Air dispersion plate, 3 ... Drying chamber, 4 ... Air chamber, 5 ... Paddle shaft, 31 ... Coal supply port, 32 ... Coal discharge tube, 41 ... Hot air Supply port, 42 ... hot air exhaust port, 51 ... paddle, 51a ... paddle arm.

Claims (1)

[Scope of utility model registration request] 1. A drying device, the interior of which is divided into an upper drying chamber and a lower air chamber by an air dispersion plate, wherein a large number of slit-shaped openings are provided side by side in the air dispersion plate, and drying is performed in the drying chamber. Put the paddle shaft horizontally in the room,
In addition, it is provided at a variable speed, and a plurality of paddles for stirring the material to be dried are mounted on this paddle shaft at intervals in the axial direction of the paddle shaft. This paddle is mounted in the paddle shaft direction as seen in the axial direction. The angles are offset from each other and attached to the paddle shaft, and the paddle itself can be tilted to give a stirring force in the axial direction to the object to be dried with respect to the paddle shaft axis. In this condition, the paddle shaft of the drying chamber is provided with a supply port and a discharge port for the material to be dried at one end side and the other end side, respectively. An apparatus for drying solid particulate matter, characterized in that the hot air is jetted into the drying chamber at a high speed through the slit-shaped opening to fluidize the material to be dried.