JPH102668A - Drying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set a proper residence time and to increase drying efficiency by providing a drying tower to effect drying of an object to be dried by dry air while the object is upward moved, and a storage tank to temporarily store the object discharged from the drying tower and effect the circulation feed thereof to a feed conveyor, and partially discharge as a product, and setting proper residence time, and drying efficiency. SOLUTION: An object to be dried fed to a drying tower 3 is dried by dry air while the object is upward moved by a screw conveyor 9. Since drying air takes a route across a transfer passage for a dried object through a vertical portion and a horizontal partition 11 several times, drying efficiency is remarkably improved. An object to be processed discharged from a drying tower 3 to a storage tank 19 is temporarily stored therein and partially discharged as a product to the outside of a system by a product conveyor 23. The rest is fed in a circulating manner to a feed conveyor 1 by a scraper conveyor 22 and re-dried in a drying tower 3 together with a new object to be dried. Thus, a proper residence time for an object to be dried is set.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a drying device,
Particularly, the present invention relates to a drying apparatus for drying crushed combustible waste when converting combustible waste such as waste plastic, household waste, waste paper, etc. into solid fuel.

[0002]

2. Description of the Related Art Conventionally, as a drying apparatus of this type, a peripheral surface of a horizontal cylindrical rotary drum having an infinite number of ventilation holes on a peripheral surface, a hot air supply duct at a lower part, and an exhaust duct at an upper part. An air supply pipe provided with a number of vent holes on the peripheral surface is arranged at the axis of the rotating drum or the one covered with the provided housing, and a number of partition walls are radially provided between the rotating drum and the air supply pipe. It is known that a large number of small chambers are formed by mounting (see JP-A-63-49690). The drying device throws the object to be dried into the rotating drum or each small chamber from one end of the rotating drum which is appropriately inclined, dries the object to be dried by hot air while stirring the object to be dried by rotation of the rotating drum, and outputs the product from the other end. It is to be discharged as.

[0003]

However, in the conventional drying apparatus, the drying time (residence time) of the object to be dried can be adjusted to some extent by the degree of opening and closing of the outlet, but it is difficult to set an appropriate residence time. There is a defect.
Further, since the hot air contacts only once across the moving direction of the object to be dried, there is a problem that the heat transfer efficiency (drying efficiency) is reduced. Therefore, the present invention can set an appropriate residence time,
It is another object of the present invention to provide a drying apparatus capable of significantly improving the drying efficiency.

[0004]

In order to solve the above-mentioned problems, a drying apparatus according to the present invention comprises a supply conveyor for transporting a material to be dried cut out from a hopper, and a drying device supplied from the supply conveyor. A drying tower that dries by a drying air that is aerated in the same direction while being transported to the drying tower, a drying air supply unit that supplies the drying air to the drying tower, and temporarily stores the material to be dried discharged from the drying tower. And a storage tank that circulates and supplies a part of the supply to the supply conveyor. It is preferable that the cutout amount of the hopper is provided so as to be adjustable according to the amount of the material to be dried in the storage tank. The drying tower is a cylindrical vertical cylinder having an inlet at the lower end and an outlet at the upper end of the material to be dried and the drying air, and is coaxially arranged in the cylinder, and has a cylindrical shape having a smaller diameter as appropriate. And a screw conveyor having a cylindrical casing provided with countless ventilation holes, and a vertical partition for axially dividing the space between the cylindrical body and the casing into two,
It is preferable to include a horizontal partition which alternately divides the cylindrical body and the casing which are divided into two by the vertical partition into multiple stages in the radial direction. The drying air supply means is preferably provided so that the temperature and the supply amount of the drying air can be adjusted according to the temperature of the drying air at the inlet of the drying tower and the pressure of the drying air at the outlet. Further, it is preferable that the product delivery amount of the storage tank is provided so as to be adjustable in accordance with the storage amount of the material to be dried in the storage tank and the moisture content of the material to be dried at the product outlet.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are schematic configuration diagrams showing a combustible waste drying facility as an example of an embodiment of a drying apparatus according to the present invention, and are an enlarged sectional view taken along line II-II in FIG. In the figure, 1 is the required size (for example, 40 mm or less)
A supply conveyor for horizontally transporting combustible waste (dry matter), which is crushed into a hopper (not shown) and whose cut-out amount is adjustable by an air lock damper 2,
The material to be dried conveyed by the supply conveyor 1 is a drying tower 3
Supplied to The drying tower 3 is to dry the object to be dried by the drying air that is passed in the same direction while vertically transporting the object to be dried, and the inlets 4 and 5 for the object to be dried and the drying air are provided at the lower end,
A vertical cylindrical body 7 having an outlet 6 at an upper end thereof;
A screw conveyor 9 having a cylindrical casing 8 disposed coaxially over substantially the entire length thereof in the cylindrical body 7 and having a cylindrical shape having a diameter smaller than that of the cylindrical body 7 and provided with countless ventilation holes; A vertical partition 10 (see FIG. 2) for dividing the space between the body 7 and the casing 8 into two in the axial direction, and a horizontal partition for alternately dividing the space between the cylindrical body 7 and the casing 8 into two by the vertical partition 10 in the radial direction. It is composed of a partition 11 and a heat insulating material 12 (see FIG. 2) that covers the outer periphery of the cylindrical body 7. The drying air inlet 5 of the drying tower 3 is configured to supply the drying air from the drying air supply means 13. The drying air supply means 13 includes a hot air generating device 14 that sucks outside air and heats the air to a required temperature, and a drying air inlet 5 that combines hot air from the hot air generating device 14 and drying air from a drying air circulation path described later. And a hot air fan 15 for supplying air to the
3 receives a signal from a thermometer 16 for detecting the temperature of the inlet 5 of the drying air and a signal from a pressure gauge 17 for detecting the pressure of the drying air at the outlet 6 of the drying tower 3, and receives the heating temperature of the hot air generator 14. And a dry air controller 18 for adjusting the supply amount of the hot air fan 15.

At the outlet 6 of the drying tower 3, the material to be dried discharged from the drying tower 3 is temporarily stored, circulated and supplied to the supply conveyor 1, and a part of the material is dried as a product (dried material). An outgoing storage tank 19 is connected via a duct 20. The storage tank 19 includes a tank 21 having the duct 20 connected to an upper end thereof, a scraper conveyor 22 for circulating the material to be dried stored in the tank 21 to the supply conveyor 1, and a part of the material to be dried. Conveyor as a product. The tank 21 is provided with level switches 24 and 25 for detecting a high level and a low level of the amount of the material to be dried stored in the tank 21. A moisture meter 26 for detection is provided, and signals from the level switches 24 and 25 are input to a damper controller 27 that controls the cut-out amount of the air lock damper 2, and the signals from the level switch 25 and the moisture meter 26 are provided. The signal is configured to be input to a product conveyor controller 28 that controls the payout amount of the product conveyor 23. On the other hand, the drying air introduced into the storage tank 19 flows from the upper end of the tank 21 together with the dust into the cyclone 2.
After being separated from dust in the cyclone 29, the dust is sucked by the circulation fan 30, a part of the dust is released to the atmosphere through the deodorizing device 31, and the remaining part is passed through the drying air circulation path 32 and the drying air supply means 13 hot air fans 15 are circulated and supplied. The dust discharged from the cyclone 29 is combined with the dust discharged from the product conveyor 23 to form a product.

In the flammable waste drying facility having the above-described configuration, the material to be dried supplied from the hopper to the drying tower 3 via the air lock damper 2 and the supply conveyor 1 is moved vertically upward by the screw conveyor 9. The drying is performed by the drying air supplied from the drying air supply means 13 and flowing in the same direction. In drying the object to be dried, the ventilation of the drying air is restricted by the vertical partition 10 and the horizontal partition 11, and zigzag-shaped across the transfer path of the object to be dried several times as shown by a white arrow A in FIG. Therefore, the drying efficiency is significantly improved. Further, the temperature of the drying air inlet 5 is detected by the thermometer 16, the pressure of the drying air at the outlet 6 of the drying tower 3 is detected by the pressure gauge 17, and the drying air controller 18 supplies the drying air from the drying air supply means 13. The temperature and pressure of the drying air are controlled to a temperature suitable for the properties of the material to be dried and a supply amount irrespective of the state in the drying tower 3. The object to be treated discharged from the drying tower 3 together with the drying air into the storage tank 19 is temporarily stored therein, a part of which is discharged as a product by the product conveyor 23 outside the system, and the remainder is scraper. It is circulated and supplied to the supply conveyor 1 by the conveyor 22, and is dried again in the drying tower 3 together with a new material to be dried supplied from the hopper. During the temporary storage of the material to be dried in the storage tank 19, when the storage amount of the material to be dried is detected to be low level by the level switch 25, the product conveyor 23 controls the product conveyor 23 to control the product by the product conveyor 23. While the dispensing starts, the moisture meter 26
Is controlled by the product conveyor controller 28 so that the product conveyor 23 discharges the product (the number of revolutions of the product conveyor) so that the moisture content of the product becomes a predetermined value (predetermined dry state). In addition, when the material to be dried is difficult to dry, the product delivery amount is smaller than the supply amount of the material to be dried, so the storage level of the material to be dried in the tank increases, but the storage level is high. And level switch 2
4, the control of the damper controller 27 stops the cutout of the material to be dried from the air lock damper 2 and discharges the product while circulating. If the storage level is low, the level switch is used. When the detection is performed by the damper controller 25, the cutout of the object to be dried from the air lock damper 2 is restarted under the control of the damper controller 27. Note that the drying state of the object to be dried can also be adjusted by reducing the amount of the object to be dried cut out from the air lock damper 2. Therefore,
The drying time (residence time) can be greatly changed according to the properties of the material to be dried. On the other hand, the drying air introduced into the storage tank 19 is supplied to the cyclone 2 together with dust from above.
After being supplied to 9 and separated from the dust, it is sucked by the circulation fan 30 and a part is radiated to the atmosphere through the deodorizing device 31 while the remainder is circulated to the dry air supply means 13 through the dry air circulation path 32. Supplied. Therefore, the exhaust gas is reused, and the energy saving effect can be greatly improved. The dust separated by the cyclone 29 is combined with the dust discharged from the product conveyor 23 to become a product.

[0008]

As described above, according to the drying apparatus of the present invention, the material to be dried is circulated and supplied to the drying tower through the storage tank, and the moving path of the drying air in the drying tower is the same as that of the material to be dried. Since it is along the transfer path, it is possible to set an appropriate residence time of the material to be dried, and it is possible to remarkably improve the drying efficiency. A vertical cylindrical body for the drying tower, a screw conveyor having a casing provided with an infinite number of ventilation holes, a vertical partition for axially dividing the cylindrical body and the casing into two parts;
Since the drying tower becomes vertical and the drying air moves a plurality of times through the transfer path of the material to be dried, by forming the horizontal partition in which the divided cylinder and the casing are alternately divided into multiple stages in the radial direction, the drying tower becomes vertical. In addition, the installation space can be reduced, and the heat transfer capacity coefficient can be significantly increased.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a combustible waste drying facility which is an example of an embodiment of a drying apparatus according to the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Supply conveyor 2 Air lock damper 3 Drying tower 4 Inlet 5 Inlet 6 Outlet 7 Cylindrical body 8 Casing 9 Screw conveyor 10 Vertical partition 11 Horizontal partition 12 Heat insulator 13 Dry air supply means 14 Hot air generator 15 Hot air fan 16 Thermometer 17 Pressure Total 18 Dry air controller 19 Storage tank 20 Duct 21 Tank 22 Scraper conveyor 23 Product conveyor 24 Level switch 25 Level switch 26 Moisture meter 27 Damper controller 28 Product conveyor controller

Claims (5)

[Claims] 1. A supply conveyor for transporting a material to be dried cut out from a hopper, and a drying tower for drying the material to be dried supplied from the supply conveyor vertically by a drying air passed in the same direction while vertically moving the material to be dried. A drying air supply means for supplying drying air to the drying tower, and a storage tank for temporarily storing the material to be dried discharged from the drying tower, circulating and supplying the same to the supply conveyor, and discharging a part of the drying product. A drying device comprising: 2. The drying apparatus according to claim 1, wherein the cut-out amount of the hopper is provided so as to be adjustable according to the amount of the material to be dried in the storage tank. 3. The drying tower according to claim 1, wherein the drying tower is provided coaxially with a cylindrical vertical cylinder having an inlet at the lower end and an outlet at the upper end of the drying object and the drying air. A screw conveyor having a cylindrical casing having an appropriately small cylindrical shape and provided with an infinite number of ventilation holes, a vertical partition for dividing the space between the cylindrical body and the casing into two in the axial direction, and a cylinder divided into two by the vertical partition The drying device according to claim 1, further comprising a horizontal partition in which the body and the casing are alternately divided into multiple stages in the radial direction. 4. The method according to claim 1, wherein the drying air supply means is provided such that the temperature and the supply amount of the drying air can be adjusted according to the temperature of the drying air at the inlet of the drying tower and the pressure of the drying air at the outlet thereof. The drying device according to claim 1, 2, or 3, wherein 5. The product dispensing amount of the storage tank is provided so as to be adjustable in accordance with the storage amount of the material to be dried in the storage tank and the moisture content of the material to be dried at the product outlet. Item 5. A drying device according to Item 1, 2, 3, or 4.