JPH076738B2 - Dryer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The drying apparatus of the present invention classifies wet powder after wet pulverization, such as wet raw material, slurry raw material, and mud raw material, at the same time as drying and crushing. It is a device, and is particularly suitable for drying, crushing, and classifying wet powder particles having a wide particle size distribution.

[Prior Art] Conventionally, a spray dryer, a fluidized bed dryer, a rotary dryer and the like have been used to dry a wet raw material.
The spray dryer is suitable for drying slurry-like fine particles, but the product after drying is granulated and is not suitable for obtaining powder. Further, the fluidized bed dryer is suitable for a granular material in view of its principle, but is not suitable for a powdery material. The rotary dryer is suitable for drying raw materials in the form of granules having a large particle size to a lump.

[Problems to be Solved by the Invention] In the drying of the conventional machine described above, when a dry powder is to be obtained, crushing and classification after drying are required, and an extra step is added, resulting in equipment cost and operating economy. Is inferior.

[Means for Solving the Problems] Therefore, in the drying device of the present invention, the particle diameter is widened, and the wet raw material containing a large amount of powder is simultaneously dried and classified. It is installed in the vertical direction, has a multi-stage conical shape that expands downward, has a swivel pan that is rotated by a drive device, surrounds the swirl plate coaxially with the swivel plate, and has an upward direction. A ring-shaped casing extending toward the inlet, an inlet for injecting hot drying gas into the inside from the outer peripheral annular space of the swirl plate and the gap between the swirl plates at each stage, and after drying immediately below the intake port A dryer for discharging the coarse powder, a feed port for the wet raw material in the casing, and a suction discharge port for the dry fine powder component in the upper part of the casing, wherein the classification is performed in the lower part of the suction discharge port. A machine and in front It has a structure which is journalled plurality of rollers gap between the turning dish adjacent the lowermost turning dish supports only freely lowermost pivot plates change to the rod side of the hydraulic cylinder.

[Operation] In the drying device of the present invention, the wet raw material supplied to the center of the top of the rotating multi-stage swirling dish moves toward the outer peripheral side in a spiral manner while falling due to centrifugal force,
It exchanges heat with the hot gas introduced from the gap between the swirl pans of each stage and reaches the outer periphery of the swirl plate of the lowest stage while being gradually dried. Here, the hot gas rising at a high speed is blown up from the hot gas inlet provided in the outer peripheral annular space and drops again onto the swirl plate, and the above-described operation is repeated, and the drying gradually progresses. Of the raw material after drying, the fine powder component passes through the classifier installed at the upper part of the drying device and leaves the device through the discharge port.
It is collected by a dust collector or the like.

On the other hand, in order to discharge the coarse particles that cannot pass through the classifier that has finished drying from the drying device, the lowermost swivel pan is temporarily lowered by operating the hydraulic cylinder to enlarge the gap, and the total amount of hot gas is reduced. , The amount of air passing through all the voids is large, the amount of air passing through the hot gas intake of the outer peripheral annular space of the swirl dish is small, and the flow rate of the hot gas intake is weakened by changing the distribution ratio of both. The dry raw material is dropped onto the screw conveyor and discharged outside the device by the screw conveyor. After the dropping is almost completed, the lowermost swivel dish is raised again and a new infiltrating material is charged, and the original drying operation is continued.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall vertical sectional view showing an embodiment of a drying apparatus of the present invention, FIG. 2 is a partially enlarged sectional view, and FIG. 3 is an explanatory view of a flow state of raw materials in the drying apparatus. The arrow in FIG. 1 indicates the gas flow, the thin arrow in FIG. 3 indicates the gas flow, and the thick arrow indicates the movement of coarse particles.

In the figure, 1 is a casing, 2 is a reduction motor, 3 is an output shaft, 4 is a coupling, 5 is a rotary shaft of a swivel plate, 6 is a swivel plate, and 6a, 6b, 6c, 6d and 6e are formed in multiple stages. . 7 is a rail for rotating the lowermost swivel plate 6e, 8 is a roller, 9 is a hydraulic cylinder for raising and lowering the roller, 10 is a blade ring for supplying hot gas, 11 is a feed port for wet raw material, and 12 is a classifier. A rotary separator used, 13 is a suction / discharge port for dry fine powder, 14 is a hot gas supply port, and 15 is a screw conveyor.

At the center of the lower part of the cylindrical casing 1, the reduction motor 2
Multi-stage swivel plate 6 that is fitted to a vertical rotary shaft 5 that is connected to the output shaft 3 of
(6a, 6b, 6c, 6d, 6e) are arranged so as to be folded. An annular hot-gas supply blade ring 10 is fixedly installed on the outer periphery of the lowermost swirling plate 6e, and a screw conveyor 15 for discharging dry coarse particles is connected and arranged below the blade ring 10. On the other hand, the hot gas introduced into the apparatus through the hot gas supply port 14 provided at the lower part of the casing 1 branches inside, one is the blade ring 10 upwards, and the other is the swivel plate of each stage. Flows upward through the gaps 6 _X , 6 _X , 6 _X , 6 _Y. A raw material supply port 11 is provided in the middle part of the casing 1 so that the wet raw material can be sprayed to the uppermost swivel plate 6a.
As shown in the drawing, for example, the screw conveyor 15 may be used for horizontal supply, or the screw conveyor 15 may be inclined and dropped by gravity.

At the center of the upper part of the casing 1, a rotary separator 12 as a classifier is supported by bearings 12a, 12a so as to rotate in the same direction as the swivel plate 6 around a vertical axis, and is driven by a variable electric motor 12c.

At the upper part of the rotary separator 12, a suction discharge port 13 for sucking and discharging the dry fine powder that has passed through the rotary separator 12 is provided.
And is connected to a dust collector and a suction fan (not shown).

The operation of the drying apparatus of the present invention configured as above will be described. When the wet raw material is charged into the swirl tray 6 through the supply port 11 while the suction fan, the rotary separator 12, the reduction motor 2, and the screw conveyor 15 are driven, the raw material falls downward spirally by the swirl tray 6. During this time, heat is exchanged with the hot gas from the gaps 6 _X , 6 _X , 6 _X , and 6 _Y in each stage, and the hot gas comes into contact with the high-speed hot gas upward from the blade ring 10 and is inverted and blown upward. In this state, as shown in FIG. 3, as the drying progresses, the raw material starts to fluidize independently of each particle size, and the particles of large particle size (coarse particles) are blown up by the blade ring 10. , The levitation energy is lost in the middle of the apparatus without reaching the rotary separator 12, and it drops onto the swivel plate 6 again, and thereafter, the same circulation is repeated.
On the other hand, the fine powder that has been dried and separated from particles having a large particle size is conveyed to the rotary separator 12, where the blades of the rotary separator 12 are rotating at a rotation speed that defines a predetermined classification point.
Toward 12d, the fine powder passes through and is discharged to the outside of the device through the suction discharge port 13. Particles (called medium particles) that come into contact with the separator blades 12d and are splashed and cannot pass through are
It falls again on the swivel plate 6 and the above-mentioned circulation is repeated. Due to the impact of dropping on the swirl plate 6 during this circulation, the fine powder adhering to the coarse particles is separated, that is, crushed.

As described above, in order to discharge medium particles and coarse particles having a particle size equal to or larger than the classification point accumulated in the apparatus after a certain time has passed (this is referred to as drying time), the lowermost swirling plate 6e a plurality of hydraulic cylinders 9 is lowered by simultaneous operation, to expand the gap 6 _Y (gap 6 _X, 6 _X, 6 _X is unchanged). Then, the total amount of hot gas that enters from the hot gas supply port 14 does not change, and the amount of gas that flows in from the gap 6 _Y increases, so the amount of hot gas that enters from the blade ring 10 decreases and the inflow area of the blade ring 10 does not change. The flow velocity of gas entering from the blade ring 10 is reduced, and the coarse particles are overcome by gravity due to the blowing-up force and fall, toward the screw conveyor 15. After the dry particles on the upper part of the blade ring 10 are discharged in this manner, the lowermost swirling pan 6e is again raised to the original state, and then the wet raw material is charged. For the drying time and the dropping time, the drying time is selected according to the degree of water content of the wet raw material, and for example, the drying time is 3 minutes to 5 minutes.
Set the minutes and fall time to 10 to 20 seconds.

In this embodiment, the drying after the end of Chutsubu, the coarse discharge adopted measures which lowers the lowermost pivot plates 6e enlarged gap 6 _Y, lowering the flow rate by reducing the air volume of the blades ring 10 However, in addition to this, it is also possible to lower the lowermost swivel pan 6e to increase the passage area of the blade ring 10 to reduce the blade ring passage flow velocity and to drop the blade ring 10.

As described above, in the present invention, the raw material is crushed by the collision of the inner surface of the casing by the rotation of the swirl plate and the impact of the re-drop to the swirl plate after being blown up, and the material is dried in the fluidized state by the hot gas. Therefore, efficient drying of the particles alone can be realized.

In addition, since the swirling plate and the classifier have the same swirling direction, a stable solid-gas two-phase vortex is formed inside the device, and the primary classification is performed on the way to the swirling plate and the classifier (in other words, If so, coarse particles will return to the swirl plate without reaching the classifier), and the classifier efficiency will be good.

Furthermore, in order to facilitate the fluidized state, increasing the blade ring amount of air passing through the passage flow rate increases the lowermost pivot plates 6e to increase, it is also possible to reduce the gap 6 _Y.

[Effect of the Invention] In the drying device of the present invention, the slurry-like wet particle mixture after wet pulverization can be dried and crushed simultaneously, and fine powder and coarse powder can be obtained in different systems.

Further, as for the classification point, the rotation speed of the classifier can be freely selected by a remote command from the outside.

Further, since fluidization drying is carried out by an air flow for drying, the drying efficiency is high and the drying volume may be small, so that economical efficiency such as equipment cost is excellent.

Further, since coarse particles can be re-ground after removing fine powder, in this case, the capacity of the subsequent pulverizer can be reduced and over-pulverization of fine powder can be prevented.

[Brief description of drawings]

FIG. 1 is an overall vertical sectional view showing an embodiment of a drying apparatus of the present invention, FIG. 2 is a partially enlarged sectional view, and FIG. 3 is a flow state explanatory view of raw materials. 1 ... Casing, 2 ... Reduction motor, 5 ... Rotating shaft,
6 ...... turning dish, 6e ... the bottom turning dish, 6 _X ... gap (constant),
6 _Y : Gap (variable), 8 ... Roller, 9 ... Hydraulic cylinder, 10 ... Blade ring, 11 ... Wet material supply port,
12 …… Classifier (rotary separator), 13 …… Suction and discharge port, 14 …… Hot gas supply port, 15 …… Screw conveyor.

Claims (1)

[Claims] 1. A swivel plate having a rotating shaft installed in a vertical direction and having a multi-stage conical shape whose diameter expands downward, and a swivel plate which is rotated by a drive device, and the swivel plate is coaxial with the swivel plate. A ring-shaped casing surrounding the plate and extending upward, and an inlet for injecting hot gas for drying into the inside from a space between the outer peripheral annular space of the swirl plate and the swirl plates of each stage. A drying device comprising a screw conveyor for discharging coarse powder after drying just below the inlet, a supply port for wet raw material in the casing, and a suction discharge port for dry fine powder in the upper part of the casing. , A classifier is provided under the suction / exhaust port, and a plurality of rollers, which support only the lowermost swivel pan and can freely change the gap between the lowermost swivel pan and the adjacent swirl pan, are connected to the rod of the hydraulic cylinder. Drying characterized by bearing on the side Apparatus.