JP2005127667A - Rotary kiln - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary kiln having improved combustion efficiency by effectively supplying combustion air thereto. <P>SOLUTION: The rotary kiln comprises a front face part 3 having a plurality of combustion air supply ports and a rotary shell part 1a following it. Each of the combustion air supply ports 7 of the front face part 3 is opposed to a position where a charged combustion object W is moved with the rotation of the shell part 1a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rotary kiln furnace, and more particularly, to a rotary kiln furnace including a front surface portion having a combustion air supply port and a rotating body portion following the front surface portion.

  The rotary kiln type incinerator is a rotary cylindrical furnace in which the rotary kiln that constitutes the main combustion section is provided with a steel plate outer shell lined on the outer periphery. It has an excellent advantage that it can be incinerated stably for various combustibles with different properties, such as high-grade garbage and low-melting-point substances that impede fluidization of the fluidized bed. It has a wide range of uses because it can withstand

  Combustion air is supplied to the rotary kiln type incinerator from the front side of the rotary kiln, which is the side to supply the combustibles. The air supply port is usually divided into two stages, upper and lower, arranged horizontally. Has been placed. Among them, the nozzle arranged on the upper stage side is directed slightly downward so as to supply air toward the surface of the input combusted material (for example, Patent Documents 1 to 3).

However, the rotary kiln is designed to burn the combustible while rotating and transfer it to the rear, so that the internal combustible is lifted in the direction of rotation and transported with a slight inclination. Despite the fact that the flame generated from the object rises along the furnace wall in the direction of rotation, the above-mentioned conventional technology supplies combustion air without considering such a phenomenon in the furnace at all. Air does not contribute enough to combustion, and combustion efficiency is never high. In other words, among the supplied air, there is a considerable amount of air that does not contribute to the combustion of the combusted material, so it is necessary to supply more air than necessary, and the air supply equipment required for it, Exhaust gas treatment facilities with large capacities had to be installed, leading to a rise in equipment costs.
JP-A-5-223228. JP 2001-241850 A. JP-A-50-63775.

  Therefore, the problem to be solved by the present invention is that the supply of combustion air is made effective without using a large air supply facility, exhaust gas treatment facility, etc., and a rotary kiln furnace with high combustion efficiency is provided. It is to provide.

  The above object can be achieved by the invention described in the claims. That is, the characteristic configuration of the incinerator according to the present invention is provided with a front surface portion having a plurality of combustion air supply ports and a rotating body portion following the front surface portion, and the combustion air provided on the front surface portion. The supply port is provided so as to oppose the moving position of the combusted material that has been thrown in as the body portion rotates.

  According to this configuration, even if the charged combustion object is lifted in the rotation direction from the bottom part of the body part by the rotation of the body part, the combustion air supply port faces the position where the combustion object has moved. Is provided, the combustion air can be efficiently supplied to the combustion surface of the combusted material, the contact time between the combusted material and the combustion air can be extended, and the combustion efficiency is increased. be able to. In addition, by improving the combustion efficiency, the amount of air to be supplied can be reduced, and the amount of exhaust gas generated can be reduced accordingly, and the equipment cost related to the air supply system and the exhaust gas system can be reduced.

  As a result, it is possible to effectively supply the combustion air without using a large air supply facility, exhaust gas treatment facility, etc., and to provide a rotary kiln furnace with high combustion efficiency.

  The combustion air supply ports are arranged in two upper and lower stages, each of which has a plurality. The upper combustion air supply ports are inclined downward by 20 to 70 ° with respect to the horizontal direction, and the lower combustion air supply ports. It is preferable that the supply ports are arranged so that the arrangement becomes higher in the direction of rotation of the body portion in the range of 15 to 60 ° with respect to the horizontal direction.

  According to this configuration, the combustion air supply port at the upper stage can supply combustion air toward the combustion object located below, and the inside of the furnace rotates as the rotation from the lower combustion air supply port rotates. Combustion air can be supplied toward the moving position of the combusted object moving in the direction, and the supply of combustion air can be made more efficient.

  A plurality of the upper combustion air supply ports are juxtaposed substantially horizontally, and sequentially from the side closer to the combusted material so as to face the moving position of the combusted material as the barrel rotates. The lower combustion air supply port is inclined in a substantially horizontal direction within a range of 0 to 70 ° with respect to the trunk central axis, and the lower combustion air supply port is directed to the trunk central axis toward the moving position of the combusted object. On the other hand, it is preferable to incline from 0 to 70 ° sequentially from the side close to the combustible.

  According to this configuration, with the rotation of the furnace, the combustion air can be supplied more efficiently toward the movement position of the combusted material that moves in the rotation direction in the furnace, and the supply of the combustion air is reduced. It can be made even more efficient.

  A secondary combustion furnace may be connected to the downstream side. According to this configuration, ashing can be further promoted by promoting complete combustion of the combustible.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic overall cross-sectional structure of a rotary kiln-type incinerator according to the present embodiment, (a) shows a left side structure viewed from the front side, and (b) shows a front cross-sectional structure. This incinerator is composed of a rotary kiln furnace 1 inclined somewhat toward the downstream side and a secondary combustion furnace 2 connected to the downstream side thereof.

  The rotary kiln furnace 1 is provided with a combustible material input port 4 and a burner port 5 on the front surface portion 3 on the upstream side (left side of FIG. 1B), and also supplies combustion air into the furnace through an air duct 6 from a forced blower 10. It has an air supply port 7 for supply, and further, its body 1a is provided with an electric motor and is slowly rotated by a rotary drive device 8 disposed in the lower part, while burning the combustible material while stirring and downstream. To the side.

  The air supply port 7 is configured by being divided into an upper air supply port 7a and a lower air supply port 7b. Among these, the upper air supply port 7a is located above the combusted material input port 4 and the burner port 5, and as shown in FIG. 1 (a), it is arranged in three locations (7a1 to 7a3) in parallel in a substantially horizontal direction. The lower air supply port 7b is positioned below the combusted material input port 4 and the burner port 5, and is gradually increased upward from the bottom toward the rotation direction R of the rotary kiln. In such a manner, four locations (7b1 to 7b4) are provided so as to be inclined and arranged.

  The inclination angle θ1 of the lower air supply port 7b can be selected in a range of about 15 to 60 ° depending on the diameter of the rotary kiln furnace 1, the type, properties, and input amount of the combustible W. However, the four lower air supply ports 7b1 to 7b4 do not necessarily have to be inclined in a straight line as shown in FIG. 1 (a), so that they follow the inner peripheral surface of the body 1a of the rotary kiln furnace. May be arranged in an arc. This is because the unburned gas is effective against the fact that the combustible W is lifted so as to incline about 60 ° at the maximum in the rotation direction R as shown by the broken line in FIG. This is for the purpose of reducing the amount of air that does not contribute to combustion as much as possible, while effectively agitating the combustion air toward the combustible W.

  Further, as shown in FIG. 3, the lower air supply ports 7b1 to 7b4 provided at the four locations sequentially form the trunk central axis toward the lower air supply ports 7b4 to 7b1 located on the side closer to the combustible W. Inclined at a different angle in the range of θ3 = 0 to 70 ° in a substantially horizontal direction with respect to L. As a result, combustion air is more effectively blown toward the object to be burned W, and the amount of air that does not contribute to combustion can be further reduced.

  As shown in FIG. 1 (b), the three upper air supply ports 7a1 to 7a3 supply the air inclined at θ2 = about 20 to 70 ° downward with respect to the horizontal direction in the front surface portion 3. 3 and the upper stage located on the side closer to the combusted object W in the same manner as the lower air supply port 7b shown in FIG. 3 so as to oppose the moving position of the combusted object W accompanying the rotation of the body 1a. The air supply ports 7a3 to 7a1 are sequentially inclined at different angles in a range of θ3 = 0 to 70 ° in a substantially horizontal direction with respect to the central axis L. Also in this case, as shown in FIG. 2, the combustible W in the furnace is lifted from the bottom in the rotational direction R of the body 1a, and the combustion air is effectively supplied to the combustible W. This is for spraying.

  By doing in this way, the combustion air is evenly supplied to the surface of the combusted object W, and the flame generated from the combusted object W also moves along the inner peripheral surface of the body 1a of the rotary kiln furnace along the rotation direction. It is formed to a sufficient length. However, the numbers of the upper air supply ports 7a and the lower air supply ports 7b described above are not limited to the numbers shown in FIG. 1, but the diameter and length of the rotary kiln furnace 1 and the combustion to be introduced. It can be appropriately changed depending on the type, properties, input amount, etc. of the object W.

  Further, on the outlet side of the rotary kiln furnace 1, unburned gas generated from the combusted material in the rotary kiln furnace 1 is burned in the secondary combustion furnace 2. Further, the exhaust gas is discharged from the downstream side of the secondary combustion furnace 2, detoxified through an exhaust gas treatment facility (not shown), and released to the atmosphere.

As shown in FIG. 1, the same number of rotary kiln furnaces (examples) having two upper and lower air supply ports 7 of three upper air supply ports 7a and four lower air supply ports 7b are provided in the same number of places. A rotary kiln furnace (comparative example) that has two upper and lower air supply ports, and in which both the upper air supply port and the lower air supply port are not inclined as shown in FIG. In addition to supplying combustion air, about 1000 kg of waste plastic was put into the furnace, and the amount of air (ratio) required for combustion at the outlet of the rotary kiln and the combustion contribution rate contributing to combustion were measured. The results are shown in Table 1. As the rotary kiln, a rotary kiln having a rotation speed of 0.15 rpm, an inner diameter of 3 m, and a length of 5 m was used, and the combustion contribution rate was measured by measuring residual O _{2 at} a plurality of points and measuring unburned gas.

表１より、本実施例の場合、燃焼に寄与し得る空気が、比較例の場合に比べて約１４％高く、燃焼に必要な空気が、比較例に比べ空気比にして約３０％低減できることが分かる。

From Table 1, in this example, the air that can contribute to combustion is about 14% higher than that in the comparative example, and the air required for combustion can be reduced by about 30% in comparison with the comparative example. I understand.

[Another embodiment]
(1) In the above embodiment, a furnace in which a secondary combustion furnace is connected to a rotary kiln furnace has been illustrated. However, a stoker furnace such as a post-combustion stoker furnace may be connected as a secondary combustion furnace, or a rotary kiln furnace and a stoker Combustibles can be burned in each of the furnaces, and it can also be applied to furnaces of the type in which the combustion residue from the rotary kiln furnace is ashed simultaneously with the combustion residue from the stoker furnace. The present invention can be applied to a rotary kiln furnace alone without connecting the two.
(2) A jacket for allowing cooling air to flow may be provided on the outer periphery of the body portion of the rotary kiln furnace 1.

  The present invention can be applied to an incinerator for incinerating municipal waste, garbage, waste plastic, oil mud, sludge and various solid-liquid mixed wastes, as well as a cement kiln and a rotary kiln furnace for various other purposes.

Schematic half sectional configuration diagram of an incinerator using a rotary kiln furnace according to the present invention AA arrow view of FIG. BB arrow view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Body 2 Secondary combustion furnace 3 Front part 7 Combustion air supply port 7a Upper air supply port 7b Lower air supply port L Center axis W Combustion

Claims (4)

In a rotary kiln furnace provided with a front part having a plurality of combustion air supply ports and a rotating body part following this, a combustion air supply port provided in the front part is accompanied by rotation of the body part, A rotary kiln furnace is provided so as to face the moving position of the combusted material that has been charged. The combustion air supply ports are arranged in two upper and lower stages, each of which has a plurality. The upper combustion air supply ports are inclined downward by 20 to 70 ° with respect to the horizontal direction, and the lower combustion air supply ports. The rotary kiln furnace according to claim 1, wherein the supply ports are arranged so that the arrangement of the supply ports becomes higher in the direction of rotation of the body portion in a range of 15 to 60 ° with respect to the horizontal direction. A plurality of the upper combustion air supply ports are juxtaposed substantially horizontally, and sequentially from the side closer to the combusted material so as to face the moving position of the combusted material as the barrel rotates. The lower combustion air supply port is inclined in a substantially horizontal direction within a range of 0 to 70 ° with respect to the trunk central axis, and the lower combustion air supply port is directed to the trunk central axis toward the moving position of the combusted object. The rotary kiln furnace according to claim 2, wherein the rotary kiln is inclined by 0 to 70 ° sequentially from the side close to the combustible. The rotary kiln furnace according to any one of claims 1 to 3, wherein a secondary combustion furnace is connected to the downstream side.

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