JPH11193987A - Rotary kiln - Google Patents

Abstract

PROBLEM TO BE SOLVED: To let heating gas flow with the same conditions in each inner tube, and to reduce amount of heat dissipation, in an indirect heating type and multiple tube type rotary kiln. SOLUTION: In an outer tube 12 which is arranged horizontally to be rotatably driven and which has a single pipe structure, a plurality of inner tubes 13 having a double pipe structure of an inner pipe 13a and an outer pipe 13b are stored and fixed. One end of each inner pipe 13a of the inner tube 13 is gathered to be located at the entrance 2 of the outer tube 12, and the other end of each inner pipe 13a is gathered to be located at the exit 3 of the outer tube 12. The opening between the inner pipe 13a and the outer pipe 13b of the inner tube 13 is made to be a heating channel 18. A heat insulating layer is formed by enclosing air in a space part 19 between the outer tube 12 and the inner tube 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to waste (for example,
The present invention relates to an indirectly heated rotary kiln in which municipal solid waste is subjected to pyrolysis gasification.

[0002]

2. Description of the Related Art In recent years, as a next-generation waste disposal method,
The waste is heated under an inert atmosphere and pyrolyzed. The generated pyrolysis gas and pyrolysis residue (carbon and ash) are burned at high temperature with a small amount of air in a combustion and melting furnace, Gasification to remove ash as molten slag
The melting method has been developed and demonstration operation has been performed in some parts.
In such a method, a rotary kiln is employed to thermally decompose the waste into gas, and the waste is indirectly heated and dried by heat from the outside to be thermally decomposed.

[0003] An indirectly heated rotary kiln used for pyrolysis gasification of waste is arranged sideways so as to be rotatable by being tilted downward by about 3 degrees, as schematically shown in FIG. A charging hopper 5 is provided via a duster 4 at an inlet 2 at one longitudinal end of an outer cylinder 1 having a double pipe structure, and a pyrolysis gas 6a is provided at an outlet 3 at the other longitudinal end of the outer cylinder 1. A separation chamber 7 is provided to separate the waste 6 from the pyrolysis residue 6b. In a state where the outer cylinder 1 is rotated at a low speed, the waste 6 charged into the charging hopper 5 is gradually fed into the outer cylinder 1 by the duster 4. The heating gas 9 is circulated from the outlet 3 toward the inlet 2 through the heating channel 8 formed in the double tube portion of the outer cylinder 1 while being supplied to the outer cylinder 1. The material 6 is heated, dried, thermally decomposed, and the generated pyrolysis gas 6
a is taken out from the upper part of the separation chamber 7 and sent directly to the downstream combustion / melting furnace, while the pyrolysis residue 6b containing metals is once taken out from the lower part of the separation chamber 7 to separate the metals. After that, it is sent to the combustion / melting process.

[0004] Reference numeral 10 denotes a rotary joint, and 11 denotes a seal plate.

[0005] However, in the case of the rotary kiln, since the heat transfer efficiency is low due to the indirect heating method, it is necessary to ensure a sufficient contact area with the waste 6, so that there is a problem that the outer cylinder 1 becomes long. is there. Further, since the outer cylinder 1 becomes longer, a larger installation area is required, and there is a problem that land use is greatly affected.

On the other hand, a multi-cylinder type rotary kiln used for treating dioxin-containing waste is known as a device capable of increasing the amount of treatment without making the outer cylinder 1 relatively long. That is, as shown schematically in FIG. 4, the multi-cylinder type rotary kiln accommodates and fixes a plurality of inner cylinders 13 in an outer cylinder 12 having a single tube structure that is rotatably arranged sideways and has a single tube structure. A space formed between the tube 13 and the outer tube 12 is used as a heating channel 8 to allow a heating gas to flow.

[0007]

However, in the case of a multi-cylinder rotary kiln of the indirect heating type as shown in FIG. 4, since the outer diameter of the outer cylinder 12 is large, a large amount of heat is dissipated. Is inevitably determined, and its area is large. Therefore, unless a structure such as a baffle plate is used, it is difficult to adjust the optimum flow velocity in accordance with the flow rate, and the heating gas can have uneven flow and uneven temperature. There is a problem that it is also difficult to heat evenly with a heating gas.

In view of the above, the present invention provides an indirect heating type multi-cylinder rotary kiln in which the optimum flow velocity can be adjusted according to the flow rate of the heating gas, and the heating gas under the same conditions flows through each inner cylinder. To be able to
It is intended to reduce the amount of heat radiation.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an inner tube and an outer tube which are rotatably driven and arranged laterally with one end in a longitudinal direction as an inlet and the other end as an outlet. By storing and fixing a plurality of inner cylinders having a double-pipe structure, and the gap between the inner pipe and the outer pipe of the inner cylinder,
A heating channel through which a heating gas flows is provided, and a space between the outer cylinder and the inner cylinder is formed as a heat insulating layer by air sealing.

In the inner tube, the gap between the outer tubes is used as a heating channel, so that by adjusting the size of the outer tubes, it is possible to adjust the flow velocity optimally according to the flow rate of the heating gas. In addition, a heating gas under the same conditions can be supplied to each inner cylinder, and the amount of heat radiation can be reduced because the heat insulation layer is provided between the inner and outer cylinders.

[0011] Further, instead of filling air into the space between the outer cylinder and the inner cylinder, a structure in which a heat insulating material is filled is provided, so that the heat insulating property is enhanced, and the amount of heat radiation is further reduced. Can be reduced.

[0012]

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

FIGS. 1 (a) and 1 (b) show an embodiment of the present invention, in which an outer cylinder having a single-tube structure in which one end in the longitudinal direction is an inlet 2 and the other end is an outlet 3 and a refractory material 14 is lined. 12
Is tilted downward by about 3 degrees and is disposed so as to be rotatable and driven, and a double pipe structure is formed in the outer cylinder 12 by an inner pipe 13a and an outer pipe 13b which are arranged concentrically with a required gap. A plurality (three in the figure) of inner tubes 13 serving as heating passages 18 for the heating gas 9 are accommodated between the inner tube 13a and the outer tube 13b, and both ends of the inner tube 13 in the longitudinal direction are accommodated. The space between the outer tube 12 and each inner tube 13 is partitioned by a partition plate 15, and the inner tubes 13a of each inner tube 13 are assembled at each end position to form a collecting tube portion 16, 17, one collecting pipe section 16 is located in the inlet 2 and the other collecting pipe section 17 is located in the outlet 3
And the heating gas 9 flows in from the outlet 3 side of the outer cylinder 12, so that the heating flow between the inner pipe 13 a and the outer pipe 13 b of the inner cylinder 13 is regulated by the partition plate 15. The passage 18 is made to flow, and furthermore, between the inner surface of the outer tube 12 and the outer surface of the outer tube 13b of the inner tube 13 and the inner tube 12
A heat insulating layer is formed in the space 19 formed between the air gaps by sealing air.

In FIG. 1, the same parts as those in FIG. 3 are denoted by the same reference numerals.

While the outer cylinder 12 and the inner cylinder 13 are integrally rotated at a low speed, the waste 6 is supplied by the duster 4 through the collecting pipe section 16 of the inlet 2 while the inner pipe of each inner cylinder 13 is When the heating gas 9 is caused to flow through the heating channel 18 formed between the outer tube 13a and the outer tube 13b,
Heating while being passed through the inner tube 13a of each inner tube 13,
Pyrolysis gas 6a generated by drying and pyrolysis
Is taken out from the upper part of the separation chamber 7 through the collecting pipe part 17 of the outlet 3, while the thermal decomposition residue 6 b is taken out from the lower part of the separation chamber 7.

In the above, the heating gas 9 for indirectly heating the waste 6 flows through the heating channel 18 formed between the inner tube 13a and the outer tube 13b constituting the inner tube 13. Because of this, the area outside the inner cylinder 13 is inevitably determined as shown in FIG. 4, and it is easier to adjust the flow rate according to the flow rate than when flowing through the heating channel 8 having a large area. In addition, the heating gas 9 under the same conditions (temperature, flow rate, flow rate) can flow through each inner cylinder 13, and each inner cylinder 13 can be uniformly heated. In addition, since a heat insulating layer is formed by air sealing in the space 19 outside the inner cylinder 13, the amount of heat radiation outside the outer cylinder 12 can be reduced, and efficient operation can be performed. Can be.

Next, FIG. 2 shows another embodiment of the present invention. In the same configuration as that shown in FIGS. Instead of filling the space 19 between the inner cylinders 13 with air, a heat insulating material 20 is filled.

As shown in FIG. 2, the heat insulation can be further enhanced, and the amount of heat radiation to the outside can be further reduced.

In the above-described embodiment, a case has been described in which three inner cylinders 13 having a double pipe structure are accommodated in the outer cylinder 12, but even if there are two, four or more inner cylinders are used. It goes without saying that various changes may be made without departing from the spirit of the present invention.

[0020]

As described above, according to the rotary kiln of the present invention, the following excellent effects are exhibited. (1) A plurality of inner cylinders having a double-pipe structure with an inner pipe and an outer pipe are housed and fixed in an outer cylinder that is rotatably driven so that one end in the longitudinal direction is an inlet and the other end is an outlet. The gap between the inner tube and the outer tube of the inner tube is used as a heating flow path for flowing a heating gas, and the space between the outer tube and the inner tube is insulated by air. Since it is configured as a layer, the heating gas can be flowed into the gap between the outer tubes in the inner tube, so that the optimal flow rate can be adjusted according to the flow rate, and The heating gas under the same conditions can be flowed, so that each inner cylinder can be heated evenly, and furthermore, the heat radiation to the outside can be suppressed by the heat insulating layer by filling the space between the inner and outer cylinders with air. As a result, operation efficiency can be improved. (2) Instead of filling air into the space between the outer cylinder and the inner cylinder, by using a structure filled with a heat insulating material, the heat insulating effect can be further enhanced. This is advantageous because the amount of heat radiation can be reduced.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a rotary kiln of the present invention, in which (A) is a schematic cut-away side view, and (B) is a view taken in the direction of arrows A in (A).

FIG. 2 shows another embodiment of the present invention.
It is sectional drawing corresponding to (b).

FIG. 3 is a schematic diagram illustrating an example of a rotary kiln.

FIG. 4 is a schematic longitudinal sectional view showing an example of a multi-cylinder rotary kiln.

[Explanation of symbols]

 2 Inlet 3 Outlet 9 Heating Gas 12 Outer Tube 13 Inner Tube 13a Inner Tube 13b Outer Tube 18 Heating Channel 19 Space 20 Heat Insulation

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Munetaka Hagiya 3-1-1-15 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries Co., Ltd.

Claims (2)

[Claims] A plurality of inner cylinders each having a double-pipe structure formed by an inner pipe and an outer pipe are housed in an outer cylinder which is rotatably driven and has one end in the longitudinal direction as an inlet and the other end as an outlet. And fix the gap between the inner tube and the outer tube of the inner tube,
A rotary kiln having a configuration in which a heating channel through which a gas for heating is circulated and a space between the outer cylinder and the inner cylinder is a heat insulating layer formed by air filling. 2. The rotary kiln according to claim 1, wherein the space between the outer tube and the inner tube is filled with a heat insulating material instead of filling air.