JPH023911B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a rotary dryer with a steam pipe and an aeration type that is most suitable for drying coal, powdered chemical products, and the like.

[Prior art]

Conventionally, a rotary dryer with a steam pipe used for drying coal and other materials to be dried has a rotary dryer with a steam pipe that penetrates into the rotating drum 1, as shown in the side sectional view in FIG. 4 and the front sectional view in FIG. Steam S or hot water is sent from a steam inlet 3 to a large number of steam pipes 2 via a pressure rotary joint 9, and this is used as a heat source to the inlet 4 of the material to be dried.
The heat is transferred from the air to the material to be dried M supplied by a feeder 5 installed around the rotating shaft of the drum 1, and the moisture evaporated there is transferred to air introduced from a carrier gas inlet 6 installed around the feeder 5. The carrier gas G is exhausted from the system through the carrier gas outlet 7.

The dried material M dried in the above manner is taken out from the dry product outlet 8, and the steam S as the heating medium is circulated through the steam pipe 2 and then discharged to the drain outlet 1 via the pressure rotary joint 9. It is becoming more and more common.

Further, this drum 1 is moved around the tire 1 by a roller 11 rotated by a drive device (not shown).
2 in the direction of arrow R.

However, in the above-mentioned conventional rotary dryer, the carrier gas G only flows over the upper surface of the material to be dried M, and the evaporation surface area of the material to be dried M is small, and the humidity of the carrier gas G increases from the inlet to the outlet. This has the disadvantage of slow evaporation, and there is also the problem of corrosion of the steam pipe 2 due to moisture.

On the other hand, a louver is provided in the cylindrical rotating body to feed hot gas from below, and the hot gas is passed through the layer of the wet material to be dried supplied in the rotating body to fluidize and dry the material to be dried. A rotary flow type dryer has been proposed in Japanese Patent Application Laid-open No. 156179/1983. This dryer has a louver arranged along the inner circumferential surface of a rotating body, and a heat transfer tube for supplying a heat medium such as steam inside the annular louver.

However, in this device, by providing a louver along the inner circumferential surface of the rotating body, a duct is placed on the inner circumferential wall of the rotating body, so this duct occupies a considerable volume inside the rotating body. become. Therefore, there is a problem in that the processing space is reduced, and a large number of heat transfer tubes cannot be inserted, and as a result, the processing amount cannot be increased.

In particular, in the case of a louver, since the hot gas ejected from the hot gas outlet is the main heat source for drying, a large amount of hot gas is required, resulting in an increase in operating costs.

In addition, since the hot gas injection port has a large slit-like opening, it is difficult to adjust the hot gas supply position and amount, and it also depends on the properties and processing amount of the wet material to be dried. There is a problem in that the spouts need to be individually designed.

Since the louver is disposed on the inner circumferential wall surface, it cannot actively stir the material to be dried, which is also disadvantageous in terms of shortening the drying time.

[Purpose of the invention]

The present invention is a rotary dryer with a steam pipe combined with ventilation, which is capable of making the carrier gas supply path as compact as possible, which is a problem with the conventional rotary dryer, and making effective and wide use of the space inside the drum. The purpose is to provide

Another object of the present invention is to provide a rotary dryer with a steam pipe that can also be used for ventilation, which can increase the drying speed by passing a carrier gas through the layer of the material to be dried while imparting a sufficient stirring action to the material to be dried.

Another object of the present invention is to provide a rotary dryer with a steam pipe that is simple in structure, compact, and inexpensive to operate.

[Structure of the invention]

In order to achieve the above object, the present invention includes a plurality of carrier gas introduction pipes that are floated above the inner peripheral surface along the longitudinal direction of the rotating drum; A steam pipe combined with ventilation, comprising a plurality of steam pipes arranged in a multilayer annular shape on the circumferential side, and configured to supply carrier gas into the layer of material to be dried from a gas outlet provided in the carrier gas introduction pipe. It is a rotary dryer.

[Function] A carrier gas introduction pipe is arranged in a ring shape along the inner peripheral surface in the longitudinal direction of the rotating drum, floating above the inner peripheral face, and a steam pipe is further arranged in a ring shape on the inner peripheral side of this pipe line. Therefore, a sufficient stirring action can be given to the material to be dried, and the carrier gas can be supplied through the layer of the material to be dried, so that the drying speed can be increased.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view of a rotary dryer with steam pipes in Embodiment 1 of the present invention, and FIG. 2 is a front sectional view of FIG. 1. The rotary dryer with a steam pipe according to the first embodiment has almost the same structure as the conventional example shown in FIG. 4, and the same parts are designated by the same numbers.

That is, it is a rotary dryer with steam pipes in which the drum 1 rotates in the direction of arrow R, using steam S or hot water passing through a large number of steam pipes 2 penetrating a rotating drum 1 as a heat source, and the drying material M The flow of , the flow of steam S, etc. are the same as in the conventional example shown in FIG. 4, so a description thereof will be omitted.

Therefore, in the present invention, as shown in FIG. 1, a large number of gas introduction pipes 13 are installed in the outermost portion of the drum 1 in an annular manner at positions slightly floating above the inner peripheral wall of the drum 1, and When the gas introduction pipes 13 reach the position below the material M to be dried, that is, the drying air introduction part shown at A in FIG. 2, the carrier gas G, which is drying air, flows through these gas introduction pipes. 13 to be introduced into the carrier gas inlet 6
is provided.

In order to introduce the carrier gas G into the material M to be dried from the gas introduction pipe 13, the gas introduction pipe 13 is provided with holes 1 as shown in FIG.
A large number of 4A are provided in the longitudinal direction. By directing the holes 14A toward the center of the drum 1, the carrier gas G can be effectively supplied to the layer of the material to be dried M to fluidize and dry it.

Further, although the carrier gas inlet 6 is provided on the side of the dried product outlet 8, it may be provided on the side of the dried product inlet 4.

In the rotary dryer with a steam pipe of the present invention having the above-described configuration, the drying material M is dried mainly by heat transfer from the steam pipe 2, and the carrier gas G is further supplied to the drying material M. Since the steam is introduced from the bottom so that it can be used in conjunction with ventilation drying, the surface area of the steam is increased and the drying efficiency is increased.

In addition, a rotary dryer with a steam pipe is characterized by the fact that it uses only a small amount of carrier gas G, which is drying air.The present invention makes use of this feature while increasing the drying speed. The machine can also be made more compact.

〔Effect of the invention〕

As described above, the rotary dryer with steam pipes for combined ventilation according to the present invention has a plurality of carrier gas inlet pipes that are floated above the inner circumferential surface of the rotating drum along the longitudinal inner circumferential surface of the rotating drum. A plurality of steam pipes are provided in a multilayer ring shape on the inner peripheral side of the carrier gas introduction pipe, and the carrier gas is supplied into the layer of the material to be dried from the gas outlet provided in the carrier gas introduction pipe. It is configured to have the following effects.

(1) Since the large number of carrier gas introduction pipes 13 and the steam pipes 2 installed inside them are arranged in an annular shape along the inner peripheral surface of the drum 1, the material to be dried M is heated by heat transfer from the steam pipes 2. While drying, a carrier gas G is introduced from the lower layer of the material to be dried M,
Since the material to be dried M can be passed through the layer to be fluidized and also used for ventilation drying, the evaporation area becomes larger and the drying efficiency increases.

(2) The large number of carrier gas introduction pipes 13 arranged in an annular manner inside the drum 1 are arranged in a state slightly floating above the inner circumferential surface of the drum 1, so that the material to be dried M does not pass through the carrier gas introduction. The carrier gas G can be moved around the pipe 13, thus stirring the material to be dried and supplying the carrier gas G into the dispersed material to be dried, thereby achieving fluidization and drying effects of the material to be dried. I can help.

(3) Since the carrier gas introduction pipe 13 is arranged annularly inside the drum 1 as described above, there is an advantage that the dryer can be made much more compact than the conventional rotary dryer with a steam pipe.

(4) In addition, it is possible to reach a low level of product dryness of the material to be dried M, and the humidity on the surface of the steam pipe 2 can be kept below the dew point, so the problem of corrosion caused by moisture in the steam pipe 2 is also improved. , the use of high-grade corrosion-resistant materials is also eliminated.

Furthermore, the structure of the conduit 13 for introducing the carrier gas G is simpler than that of a conventional device equipped with a louver that sends hot gas from below, and moreover, this carrier gas G can be effectively supplied into the material M to be dried. Since the amount of carrier gas introduced can be small, the operating cost is also low.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a rotary dryer with a steam pipe according to Embodiment 1 of the present invention, FIG. 2 is a front sectional view of FIG. 1, and FIG. 3 is an enlarged sectional view of the gas introduction pipe shown in FIG. 2. It is a diagram. FIG. 4 is a side sectional view of a conventional rotary dryer with steam pipes, and FIG. 5 is a front sectional view of FIG. 4. DESCRIPTION OF SYMBOLS 1... Drum, 2... Steam pipe, 6... Carrier gas inlet, 11... Roller, 13... Gas introduction pipe, G... Carrier gas, M... Material to be dried,
S...Steam.

[Claims]

1. In a drying device that dries a plywood veneer while conveying it, there are branch paths branching from the conveyance path at any number of locations in the conveyance path formed by the device, and a branch path that branches from the conveyance path to the branch path by the operation of an operating mechanism. A passage switching device is installed to switch the passage of plywood veneer,
Furthermore, a reference length confirmation device is installed to confirm the length of the veneer veneer in the direction perpendicular to the fibers before drying shrinkage starts, and the veneer veneer thus confirmed arrives at the appropriate position above each path switching device in the conveying direction. A length check detector is installed to measure the length in the same direction each time, and the value confirmed by the standard length confirmation device for each veneer veneer being transported is compared with the value measured by the length check detector. A control device is provided for controlling the veneer veneer to branch into a branching path by activating an operating mechanism of a path switching device located at a lower position closest to the length check detector when there is a predetermined difference. Features: Drying equipment for veneer veneer.