JP3722596B2 - Drum type hot air dryer - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a drum-type hot air dryer suitable for drying combustible wastes.
[0002]
[Prior art]
Conventionally, a drum-type hot air dryer is used to dry the combustible waste in the pre-process of incineration, melting, or solidification. This drum-type hot-air dryer is used to inject combustible waste, which is an object to be dried, from one end of a rotating drum that is installed horizontally or slightly inclined, and blows hot air into the rotating drum while the inner circumference of the rotating drum is The object to be dried is moved by a feed blade projecting on the surface and a stirring blade provided on the stirring shaft, and is taken out from the outlet at the other end in a dried state.
[0003]
Such a drum type hot air dryer has no problem when it is operated in a normal state. However, if for some reason the waste treatment facility including the drum-type hot-air dryer is in an emergency stop, the rotation of the rotating drum will naturally stop, and the combustibility that has progressed to dry near the discharge port of the rotating drum Waste remains deposited. Although the facility shuts down at the same time as the hot air supply stops, the O ₂ concentration in the rotating drum rises due to leaked air, etc., and the rotating drum immediately after the stop is hot, so the combustible material accumulated inside There is a risk that the radioactive waste is gradually heated and spontaneously ignites in the rotating drum.
[0004]
If there is a fire due to such an ignition, it is necessary for the worker to rush to extinguish the fire quickly. Moreover, once a fire has occurred, it takes time to confirm the extinction, and it takes a long time for the entire facility to return to the normal operation state again.
[0005]
[Problems to be solved by the invention]
The present invention has been made in order to solve the above-described conventional problems and to provide a drum-type hot air dryer excellent in safety that does not cause a fire even when the facility is stopped.
[0006]
[Means for Solving the Problems]
The drum-type hot air dryer of the present invention, which has been made to solve the above-mentioned problems, puts an object to be dried from one end of a rotary drum having a feed blade on its inner peripheral surface, and discharges the other end while drying with hot air. In the drum-type hot air dryer to be taken out from the outlet, a spiral blade opposite to the feed blade is provided on the inner peripheral surface near the discharge port of the rotating drum, and the rotating drum is operated during normal operation when the facility is stopped. Is characterized in that it is rotated in the opposite direction. In addition, it is preferable to provide a nozzle for spraying water for humidification in a portion near the discharge port in the rotating drum when the equipment is in an emergency stop.
[0007]
The drum-type hot air dryer of the present invention rotates the rotating drum in the opposite direction to that during normal operation when the facility is stopped. By the spiral blade, the flammable waste which has been dried and is close to the discharge port of the rotating drum can be quickly sent out to the discharge port. For this reason, there is no possibility of spontaneous ignition in the rotating drum as in the prior art. Further, if the water for humidification is sprayed on the portion near the discharge port in the rotating drum at the time of emergency stop of the equipment, the occurrence of fire can be prevented more reliably.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described.
In FIG. 1, reference numeral 1 denotes a horizontal cylindrical rotating drum, and both ends thereof are rotatably supported by support rollers 2 and 2. A drum sprocket 3 is provided on the outer periphery of the rotating drum 1 and is rotated in a fixed direction by a drum rotating motor 4 via a chain 5. The rotating drum 1 may be installed with a slight inclination.
[0009]
One end of the rotating drum 1 is provided with an inlet 6 for a drying object, and an outlet 7 for a drying object is provided at the other end. A single blade-shaped feed blade 8 as shown in FIG. 2 is provided on the inner peripheral surface of the rotating drum 1, and the rotating object 1 is rotated and agitated by a dry object charged into the rotating drum 1 from the charging port 6. It is gradually transferred toward the discharge port 7 by the stirring blade 12 attached to the shaft 11. Although omitted in FIG. 1, a plurality of feed blades 8 are provided at a constant pitch in the circumference and the axial direction of the rotary drum 1.
[0010]
A hot air blowing nozzle 9 is provided on the end surface of the rotating drum 1 near the inlet 6, and hot air of about 200 to 600 ° C. is blown into the rotating drum 1. A stirring shaft 11 that is rotated by a motor 10 passes through a position that is slightly laterally offset from the center of the rotating drum 1. A plurality of stirring blades 12 are attached to the stirring shaft 11. For this reason, the object to be dried receives hot air from the hot air blowing nozzle 9 while being stirred by the stirring blade 12 and is gradually dried by the action of the stirring blade 12 attached to the feed blade 8 and the stirring shaft 11 while being dried. It will be transported towards.
[0011]
The above configuration is the same as that of a conventional drum-type hot air dryer. In the present invention, a spiral blade 13 opposite to the feed blade 8 is provided on the inner peripheral surface of the rotary drum 1 near the discharge port 7. is there. The spiral blade 13 is a continuous blade as shown in FIG. In the illustrated example, the spiral blade 13 is provided for about 1.5 rotations from the end on the discharge port 7 side, but normally only about 1.0 to 2.0 rotations may be provided. If the spiral blade 13 is too short or too low, the installed effect is small. On the other hand, if the spiral blade 13 is too long or too high, the transfer of the object to be dried in a normal operation state is hindered.
[0012]
The drum rotating motor 4 rotates the rotating drum 1 at a low speed in a certain direction in a normal operation state. However, at the time of emergency stop of the equipment, the rotary drum 1 is rotated in the opposite direction to that during normal operation. As a result, the combustible waste which has been dried and is near the discharge port 7 of the rotary drum 1 is quickly sent out to the discharge port 7 by the spiral blade 13. For this reason, there is no possibility of spontaneous ignition in the rotary drum 1 as in the prior art. At the same time, if the water for humidification is sprayed from the nozzle 14 provided on the end surface near the discharge port of the rotating drum 1, spontaneous ignition in the rotating drum 1 can be prevented more reliably.
[0013]
Since the spiral blade 13 is opposite to the feed blade 8, the spiral blade 13 acts to push back the dry object transferred by the feed blade 8 and the stirring blade 12 in the normal operation state. However, since the dried objects that are transferred one after another go over the spiral blade 13 toward the discharge port 7, the spiral blade 13 is a secondary that keeps the discharge charge of the dried object almost constant in the normal operation state. It also has a typical function.
[0014]
【The invention's effect】
As described above, the drum-type hot air dryer of the present invention is provided with spiral blades in a direction opposite to the feed blades on the inner peripheral surface near the discharge port of the rotary drum, and rotates when the equipment is in an emergency stop. The drum is rotated in the opposite direction to that during normal operation. For this reason, at the time of an emergency stop of an equipment, the combustible waste which dried in the part near the discharge port of a rotating drum can be quickly sent out to a discharge port. Therefore, there is no possibility that the combustible waste accumulated in the rotating drum will spontaneously ignite as in the prior art. In addition, although the combustible waste deposited in the part where the spiral blade in the rotating drum is not provided remains in the rotating drum as it is, since the degree of drying is low and it contains moisture, there is no risk of spontaneous ignition.
[Brief description of the drawings]
FIG. 1 is a sectional view of a drum type hot air dryer according to the present invention.
FIG. 2 is a cross-sectional view taken along the line AA of FIG.
3 is a cross-sectional view taken along the line BB in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rotating drum, 2 Support roller, 3 Drum sprocket, 4 Drum rotation motor, 5 Chain, 6 Drying object input port, 7 Drying object discharge port, 8 Feeding blade, 9 Hot air blowing nozzle, 10 Motor, 11 stirring shaft, 12 stirring blades, 13 spiral blades, 14 nozzles

Claims (2)

In a drum-type hot air dryer in which an object to be dried is introduced from one end of a rotating drum provided with a feed blade on the inner peripheral surface, and is taken out from the outlet at the other end while being dried by hot air, A drum-type hot air dryer characterized in that a spiral blade is provided on the peripheral surface in a direction opposite to that of the feed blade, and the rotating drum is rotated in the direction opposite to that during normal operation when the facility is stopped. The drum-type hot air dryer according to claim 1, wherein a nozzle for spraying water for humidification is provided in a portion near the discharge port in the rotary drum when the facility is stopped.

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