JP2007225239A - Combustion gas bleeding probe and combustion gas bleeding structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustion gas bleeding probe and an bleeding structure capable of easily removing coating sticking to a tip of the probe, fire-proof material, or the like, while maintaining high cooling performance. <P>SOLUTION: In the combustion gas bleeding probe 2 bleeding high temperature combustion gas while cooling it by low temperature gas, an inner face of a tip of the probe in a side contacting the high temperature combustion gas is formed such that its inner diameter gradually increases as it nears the tip. In the combustion gas bleeding structure 1 provided with the combustion gas bleeding probe 2 bleeding the high temperature combustion gas while cooling it by the low temperature gas, the fire-proof material 3 provided in a neighborhood of the tip of the probe 2 in a side contacting the high temperature combustion gas is formed such that its inner diameter gradually increases as it separates away from the tip. Since taper parts 2h, 3b are formed, the coating 6 can be loosened and easily removed from a front side (a furnace side) of the probe 2 by using a stream of water jetted by high pressure or the like. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a combustion gas extraction probe and a combustion gas extraction structure, and in particular, for extracting chlorine by extracting a part of combustion gas from a kiln exhaust gas passage from a kiln bottom of a cement kiln to a bottom cyclone. The present invention relates to a combustion gas extraction probe and a combustion gas extraction structure used in a cement kiln chlorine bypass facility or the like.

  In the past, attention has been paid to the fact that chlorine is a particular problem among chlorine, sulfur, alkali, etc. that cause problems such as clogging of preheaters in cement production facilities. Chlorine bypass equipment is used to bleed out the part to remove chlorine.

  As shown in FIG. 3, the chlorine bypass system 41 is protruded from a rising portion 43 that is a part of the kiln exhaust gas flow path from the bottom of the kiln 42 to the bottom cyclone, and sucks high-temperature combustion gas. And a bleed gas processing facility including a secondary mixing chamber 45, a cyclone 46, a heat exchanger 47, a bag filter 48, and the like disposed downstream of the probe 44.

  For example, as shown in FIG. 4, the probe 44 includes a cylindrical inner cylinder 44a through which high-temperature combustion gas flows in the direction of arrow A, a cylindrical outer cylinder 44b surrounding the inner cylinder 44a, and an inner cylinder 44a. From a plurality of (four in the figure) cooling air discharge holes 44c, cooling air passages 44e formed between the inner cylinder 44a and the outer cylinder 44b, and a cooling fan 49 (see FIG. 3). Cooling air inlet 44d for supplying the cooling air C to the cooling air passage 44e. In addition, in order to protect the front-end | tip part of the side which contacts the hot combustion gas of the probe 44, the refractory 50 is constructed.

  When part of the kiln exhaust gas of about 1000 ° C. generated in the cement kiln 42 (see FIG. 3) is extracted using the probe 44, the cooling air is supplied from the cooling fan 49 to the probe 44 through the cooling air inlet 44d. C is supplied, and the cooling air C is introduced into the inner cylinder 44a from the discharge hole 44c through the cooling air passage 44e and mixed with the combustion gas. As a result, the high-temperature combustion gas is rapidly cooled so that the outlet gas temperature T (see FIG. 3) of the probe 44 is about 450 ° C.

  Probes used in the above-mentioned chlorine bypass facilities require high chlorine recovery efficiency because the amount of chlorine brought into cement kilns has increased with the recent increase in the use of chlorine-containing recycling resources. Has been. Therefore, for example, in Patent Document 1, in a probe for extracting a high-temperature combustion gas while cooling it with a low-temperature gas, the high-temperature combustion gas is placed in a direction substantially perpendicular to the suction direction of the high-temperature combustion gas. A combustion gas extraction probe is disclosed in which a low-temperature gas is introduced and mixed and cooled so as to reach the center of the flow.

International Publication No. WO2005 / 050114 Pamphlet

  However, as the amount of recycled resources increases, the sulfur content in the combustion gas of the cement kiln also increases. Therefore, as shown in FIG. 4, the coaching 60 is more attached to the tip of the probe 44 provided in the chlorine bypass facility. The removal of the coaching 60 was one of the factors that hindered the stable operation of the cement kiln and the chlorine bypass facility.

  Therefore, the present invention has been made to solve the above-described problem, and maintains a high cooling performance, and can easily remove the coating that adheres to the probe tip and the like. And it aims at providing a combustion gas extraction structure.

  In order to achieve the above object, the present invention provides a combustion gas extraction probe for extracting a high-temperature combustion gas while cooling the high-temperature combustion gas with a low-temperature gas. It is characterized in that the inner diameter is gradually increased as it approaches the tip.

  According to the present invention, the inner surface of the tip portion of the probe that contacts the high-temperature combustion gas gradually increases in inner diameter as it approaches the tip portion, so that it grows in an arch shape at the tip portion and is difficult to remove. The coaching can be dropped to the front (furnace side) of the probe by jetting high-pressure water, and the coaching can be easily removed. In addition, according to the present invention, since only the shape of the tip of the probe is changed, the cooling performance of the probe is not deteriorated.

  The combustion gas extraction probe includes an inner cylinder through which the high-temperature combustion gas flows, an outer cylinder surrounding the inner cylinder, a discharge hole for the low-temperature gas formed in the inner cylinder, the inner cylinder, and the A cooling air passage formed between the outer cylinder and a cooling air inlet that supplies the low-temperature gas to the cooling air passage; It can be formed such that the inner diameter gradually increases as it approaches the part. Further, the tip of the combustion gas extraction probe can be configured to have a frustoconical internal space.

  Further, the combustion gas extraction probe can extract a part of the combustion gas from the kiln exhaust gas passage from the kiln bottom of the cement kiln to the bottom cyclone. As a result, stable operation of the cement kiln and the chlorine bypass facility can be ensured.

  Further, the present invention provides a combustion gas bleeder structure having a combustion gas bleeder probe for bleeding a high temperature combustion gas while being cooled by a low temperature gas, and is provided in the vicinity of the tip of the probe on the side in contact with the high temperature combustion gas. The refractory is formed so that the inner diameter gradually increases as the distance from the tip portion increases.

  According to the present invention, the refractory provided near the tip of the probe on the side in contact with the high-temperature combustion gas is formed so that the inner diameter gradually increases as the distance from the tip increases. Coaching, which has been difficult to remove, can be dropped to the furnace side by spraying high-pressure water or the like, and the coaching can be easily removed. Further, according to the present invention, it is not necessary to change the shape of the probe, so that the cooling performance of the probe is not deteriorated.

  The refractory can be configured to have a truncated cone-shaped space that opens from the tip of the combustion gas extraction probe.

  Moreover, it is preferable to apply | coat the refractory material which contains 10 mass% or more and 70 mass% or less of carbon to the surface of the said refractory which contacts the said high temperature combustion gas. By covering the surface of the refractory with such a refractory material, it is possible to reduce the work of removing the coating and the wear of the furnace material.

  Furthermore, with the combustion gas extraction structure, a part of the combustion gas can be sucked from the kiln exhaust gas passage from the bottom of the cement kiln to the bottom cyclone. As a result, stable operation of the cement kiln and the chlorine bypass facility can be ensured.

  As described above, according to the present invention, it is possible to provide a combustion gas extraction probe and a combustion gas extraction structure that maintain high cooling performance and that can easily remove the coating that adheres to the tip of the probe.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a first embodiment of a combustion gas extraction probe (hereinafter abbreviated as “probe”) and a combustion gas extraction structure (hereinafter abbreviated as “extraction structure”) according to the present invention. The structure 1 includes a probe 2 and a refractory 3 constructed at the tip of the probe 2 on the side in contact with the high-temperature combustion gas.

  The probe 2 includes a cylindrical inner cylinder 2a through which combustion gas flows in the direction of arrow B, a cylindrical outer cylinder 2b surrounding the inner cylinder 2a, and a plurality (four in the figure) drilled in the inner cylinder 2a. From a discharge hole 2c for cooling air as a low temperature gas, a cooling air passage 2g formed between the inner cylinder 2a and the outer cylinder 2b, and a cooling fan (not shown, corresponding to the cooling fan 49 in FIG. 4) A cooling air inlet 2d for supplying the cooling air C to the cooling air passage 2g.

  The inner cylinder 2a includes a combustion gas inlet 2e and an outlet 2f. The combustion gas inlet 2e is inserted into the rising part 4 of the cement kiln, and the combustion gas outlet 2f is connected to the extraction gas processing facility at the subsequent stage. At the distal end of the probe 2, the inner cylinder 2 a is formed to have a tapered shape having a larger diameter as it approaches the distal end, that is, to have an internal space 2 i having a truncated cone shape. It is a feature of the present invention that such a tapered portion 2h (internal space 2i) is provided.

  The outer cylinder 2b is formed in a cylindrical shape whose cross section is concentric with the inner cylinder 2a so as to surround the inner cylinder 2a. The outer cylinder 2b is provided with a cooling air inlet 2d for guiding the cooling air C from the cooling fan into the probe 2, and a space between the outer cylinder 2b and the inner cylinder 2a becomes a cooling air passage 2g, The cooling air passage 2g is closed at the tip of the probe 2.

  A plurality of discharge holes 2c are arranged at equal positions from the combustion gas inlet 2e of the inner cylinder 2a in the combustion gas flow direction (arrow B direction), that is, in the axial direction of the inner cylinder 2a. Cooling air C introduced in the gas flow direction is discharged.

  The refractory 3 is applied to protect the tip of the probe 2 on the side in contact with the combustion gas. The refractory 3 also has a tapered shape that increases in diameter as it moves away from the tip of the probe 2 (towards the center of the furnace) so as to be continuous with the tapered portion 2h of the probe 2, that is, a frustoconical internal space. 3a is formed. The refractory 3 is also characterized by the provision of such a tapered portion 3b.

  Moreover, it is preferable to apply a carbon-containing amorphous refractory material as a coating preventing adhesion material on the surface of the refractory 3. As the refractory material, for example, a carbon coating material C-49 (manufactured by NGK Adrec Co., Ltd.) having a composition as shown in Table 1 can be used.

This carbon coating material is, for example, a refractory material having a maximum use temperature of 1600 ° C., a maximum particle diameter of 0.2 mm, and a spray application required amount of about 4 kg / m ² , and is used to reduce adhesion of slag / coaching, In addition to reducing the work of removing the coaching, it is possible to prevent the oxidation of the carbon-containing casters and the like and reduce the wear of the furnace material. Therefore, in addition to the bleed structure according to the present invention, this refractory material can be used in various places such as preheaters and calcining furnaces for cement firing equipment for the purpose of reducing the work of removing the coating and reducing the wear of the furnace material. In addition, although the carbon content rate of the said carbon coating material is 49 mass%, the carbon containing amorphous refractory material whose carbon content rate is 10 mass% or more and 70 mass% or less can be used according to a use.

  When extracting a part of the kiln exhaust gas of about 1000 ° C. generated in the cement kiln using the probe 2, the probe 2 is illustrated in FIG. 4 from the cooling air inlet 2 d in the same manner as the probe 44 shown in FIG. Cooling air C is supplied from the cooling fan that does not, and the cooling air C is introduced into the inner cylinder 2a from the discharge hole 2c through the cooling air passage 2g and mixed with the combustion gas. As a result, the combustion gas is rapidly cooled so that the outlet gas temperature of the probe 2 is about 450 ° C.

  Here, as shown in FIG. 4, in the conventional probe 44, the coaching 60 competes with the inner surface of the inner cylinder 44a, and the coaching 60 does not fall off unless the arch-shaped portion is cut. Then, as shown in FIG. 1, since the tapered portions 2h and 3b are formed in the distal end portion of the inner cylinder 2a of the probe 2 and the refractory 3, respectively, the probe 2 is utilized by utilizing a water flow or the like jetted from the coaching 6 at a high pressure. It can be easily removed by dropping it forward (furnace side).

  Next, a second embodiment of the bleed structure according to the present invention will be described with reference to FIG.

  The bleed structure 11 includes a probe 12 and a refractory 13 constructed at the tip of the probe 12 on the side in contact with the high-temperature combustion gas.

  The probe 12 is configured in the same manner as the conventional probe 44 shown in FIG. 4, and the components 12a to 12e are the same as the components 44a to 44e of the probe 44 of FIG.

  The refractory 13 is applied to protect the tip of the probe 12 on the side in contact with the combustion gas. The refractory 13 is formed to have a tapered shape having a larger diameter as it moves away from the tip of the probe 12 (toward the center of the furnace), that is, has a truncated cone-shaped internal space 13a. The refractory 13 is also characterized by the provision of such a tapered portion 13b.

  In addition, it is preferable to apply a carbon-containing amorphous refractory material having a composition as shown in Table 1 as a coating adhesion preventing material on the surface of the refractory 13 as well.

  By using the bleed structure 11, as shown in FIG. 4, the coaching 60 competes with the inner surface of the conventional refractory 50, and the coaching 60 does not fall off unless the arch-shaped portion is cut. In the invention, as shown in FIG. 2, since the tapered portion 13b is formed in the refractory 13, it can be easily removed by dropping the coaching 16 to the furnace side using a water flow injected at a high pressure. . At this time, since a conventional probe can be used as it is, a probe having high cooling performance can be installed as it is.

  In addition to the cement bypass kiln chlorine bypass facility, the probe and the bleed structure having the above-described configuration can be used when extracting high-temperature combustion gas while cooling it with low-temperature gas in various combustion furnaces.

It is sectional drawing which shows 1st Embodiment of the probe concerning this invention, and an extraction structure. It is sectional drawing which shows 2nd Embodiment of the extraction structure concerning this invention. It is a flowchart of the chlorine bypass facility of a cement kiln. It is sectional drawing which shows an example of the conventional probe and an extraction structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Extraction structure 2 Probe 2a Inner cylinder 2b Outer cylinder 2c Discharge hole 2d Cooling air inlet part 2e Inlet part 2f Outlet part 2g Cooling air passage 2h Tapered part 2i Internal space 3 Refractory 3a Internal space 3b Taper part 4 Rising part 6 Coaching 11 Bleeding structure 12 Probe 12a Inner cylinder 12b Outer cylinder 12c Discharge hole 12d Cooling air inlet 12e Cooling air passage 13 Refractory 13a Internal space 13b Taper 16 Coaching

Claims (8)

In a combustion gas extraction probe that extracts a high-temperature combustion gas while cooling it with a low-temperature gas,
A combustion gas bleeder probe characterized in that an inner surface of a tip portion of the probe on a side in contact with the high-temperature combustion gas is formed so that an inner diameter gradually increases toward the tip portion.   An inner cylinder through which the high-temperature combustion gas flows, an outer cylinder surrounding the inner cylinder, a discharge hole for the low-temperature gas formed in the inner cylinder, and the inner cylinder and the outer cylinder are formed. A cooling air passage and a cooling air inlet that supplies the low-temperature gas to the cooling air passage, and the inner surface of the tip of the inner cylinder is formed so that the inner diameter gradually increases as it approaches the tip. The combustion gas bleeder probe according to claim 1, wherein   The combustion gas bleeder probe according to claim 1 or 2, wherein the tip has a frustoconical internal space.   4. The combustion gas bleeder according to claim 1, wherein the combustion gas bleeder probe bleeds a part of the combustion gas from a kiln exhaust gas passage from a kiln bottom of a cement kiln to a bottom cyclone. probe. In the combustion gas bleed structure with a combustion gas bleed probe that bleeds the hot combustion gas while cooling it with the low temperature gas,
A combustion gas bleed structure comprising a refractory provided in the vicinity of the tip of the probe in contact with the high-temperature combustion gas so that the inner diameter gradually increases as the probe moves away from the tip.   6. The combustion gas bleed structure according to claim 5, wherein the refractory has a frustoconical space that opens from the tip of the probe.   The combustion gas bleed structure according to claim 5 or 6, wherein a refractory material containing 10 mass% or more and 70 mass% or less of carbon is applied to a surface of the refractory that is in contact with the high-temperature combustion gas. .   The combustion gas bleeder according to claim 5, 6 or 7, wherein the combustion gas bleeder structure sucks a part of the combustion gas from a kiln exhaust gas passage from the kiln bottom of the cement kiln to the bottom cyclone. Construction.

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