JPH05248767A - Lining structure for rotary kiln - Google Patents

Abstract

PURPOSE:To prolong the life of lining bricks by a method wherein a lining material boundary between the sintering zone and the refractory coating mounting demounting zone of a rotary kiln forms zebra structure wherein magnesite- chrome bricks and spinel bricks are laminated in a stripe-form manner. CONSTITUTION:For example, lining in the vicinity of a material boundary line 1 between a sintering zone 2 and a refractory coating mounting demounting zone 3 of a cement rotary kiln forms zebra structure wherein lining is effected such that magnesite-chrome bricks 12 and spinel bricks 13 are alternately partitioned in a stripe-form manner in the axial direction of the kiln at the ring unit of the inner wall of the kiln. This constitution compensates each defect with the advantage of other quality. As a result, a partial damage in the vicinity of the material boundary line 1 of kiln lining is suppressed, the difference in a step of a refractory coating adhesion thickness between the two lining bricks 12 and 13 is relaxed to effect ideal coating adhesion, and wear and the damage of the bricks 12 and 13 are reduced through the smooth flow of a raw material. This structure provides an increased life for the lining bricks 12 and 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary kiln lining structure, and more particularly to a brick construction structure of a rotary kiln firing zone and a coating / removal zone.

[0002]

2. Description of the Related Art A typical rotary kiln cement rotary kiln has a firing zone mainly lined with mag-chromic bricks, and a coaching attachment / detachment zone (hereinafter referred to as a detachment zone) Say) is mainly lined with magnesia spinel brick.

The refractory linings used for the firing zone and the detachable zone have brick characteristics (coating adhesion, spalling resistance, corrosion resistance, abrasion resistance, embrittlement resistance, and alkali resistance) so that they can be used in accordance with their respective usage conditions. In consideration of the above, bricks of the above-mentioned quality are lined.

[0004]

Conventionally, in the operation of a cement rotary kiln, the positions of the firing zone and the attachment / detachment zone are not constant due to the operating conditions such as the fluctuation of the cement raw material components, the fluctuation of the supply amount, and the shape of the combustion frame. It is known that the fluctuations are repeated. Moreover, the positions of the firing zone and the detachable zone are changed by switching the cement firing type. As mentioned above, the firing zone and the detachment zone of the cement rotary kiln are divided according to the brick conditions according to the firing conditions, and there is a limit to how the lining refractory bricks can respond to changes in the furnace conditions due to operating conditions, etc. The durability near the brick lining boundary tends to decrease.

That is, the mug used in the firing zone
Chromic bricks are excellent in heat resistance and coating adhesion, but when placed under the conditions of the detaching zone of the coating, the brick is greatly damaged by spalling due to heat change, and the detaching zone is also large. The spinel bricks used in the above have excellent spalling resistance, but when they are placed under the conditions of firing zone, they are exposed to higher temperatures than under the conditions of detaching zone and their coating is better than that of mag and black bricks. Since the material does not adhere easily, the coating layer becomes insufficient, and as a result, the temperature becomes too high (heat resistance problem), it easily reacts with the lime component in the cement component and melts away, and the thermal conductivity is about the same as that of mag bricks. Since it is 1.3 times higher, the skin temperature rises (about 350
(° to 400 ° C.), the expansion difference between the iron shell and the brick causes slippage at the joint surface between them, which causes fatigue of the iron skin, and the large amount of heat dissipated is not preferable from the viewpoint of energy saving.

[0006]

The present inventors have developed the present invention as a result of various examinations and experiments in order to solve the above-mentioned various defects of the conventional system, and the technical constitution of the present invention. Is characterized by having a zebra structure in which two or more types of refractory bricks are laminated in a stripe pattern at the boundary of the lining material between the firing zone and the coating / removal zone in the lining of the rotary kiln. The disadvantages of each are compensated by the advantages of other qualities, and as a result, partial damage near the material boundary of the rotary kiln lining is suppressed and the difference in the coating thickness between the two lining bricks is mitigated and ideal coating adhesion is achieved. The rotary kiln lining structure reduces the abrasion damage of bricks due to the smooth flow of raw materials, maintains a good furnace condition, and thus extends the life of lining bricks. Is shall. If there is a step in the coating thickness, the raw material stays and local wear occurs.

In the present invention, the zebra structure means a ring unit lined with a rotary kiln, which is arranged in a circumferential direction, in the axial direction of the rotary kiln, or in a stripe pattern obliquely to the axis of the rotary kiln, or gradually reduced in the axial direction of the kiln. This is an array and will be specifically described with reference to the accompanying drawings. These drawings are development views showing the arrangement positions of the refractory bricks on the lining of the rotary kiln, and an example of the cement rotary kiln will be described.

FIG. 1 shows an example in which the zebra structure of the present invention is arranged in stripes in the circumferential direction on a ring-by-ring basis. Reference numeral 1 is a material boundary line between the firing zone 2 and the coating / decoupling zone 3, and the lining near the border line 1 is a ring unit on the inner wall of the kiln in which mag-black bricks 12 and spinel bricks 13 are alternately partitioned in stripes. This is an example of lining.

As the refractory brick 12 of the firing zone 2, it is common to use direct bond mag black bricks or mag dolomite bricks due to thermal load, corrosion resistance to external components, stability of coating, and the like. As the refractory brick 13 of the coating / removal zone 3, it is general to use a magnesia spinel brick having resistance to spalling caused by repeated coating / removal due to temperature change. In the example of FIG. 1, the bricks 12 and 13 are alternately arranged and lined (1: 1), but these combinations can be changed depending on the conditions of use of the kiln. Further, in the illustrated example, the mag-black brick 12 and the spinel brick 13 are equally placed on the left and right around the material boundary line 1.
It has a striped zebra structure with, but if necessary, 5
The range of zebra structures can be expanded to 20 rings or more.

FIG. 2 shows another example of the present invention, which is an example in which a mag-black brick 12 and a spinel brick 13 are arranged in a zebra structure in the front and rear of the material boundary line 1 in the kiln axis direction and lined.
The range of this zebra structure can be arbitrarily determined according to the usage conditions of the kiln.

FIG. 3 shows a modification of the zebra structure in which the mutual arrangement of the mag black bricks 12 and the spinel bricks 13 is gradually decreased in the kiln axis direction before and after the material boundary line 1, but for the purpose of the present invention. This is an example of the best lining. As the gradual reduction method, mag / black bricks: spinel bricks are arranged and lined from the firing zone 2 to the coating / decoupling zone 3 in a ratio of, for example, 5: 1 → 1: 5. Therefore, the ratio of the spinel bricks 13 increases toward the coaching attachment / detachment zone 3.

FIG. 4 shows an example of a checkered structure (oblique zebra structure), and the reference numerals indicate the same members as the above-mentioned example.

FIG. 5 is a vertical cross-sectional view of the rotary kiln in the structure of FIG. 1 showing the state where the material is coated around the rotary kiln, and the coating layer 4 is attached to the inner surface of the spinel brick 13 to ensure stable operation. As a result, the abrasion damage of each brick is suppressed, and the life of the lining brick can be extended.

In this case, the adhesion of the coating in the zebra structure naturally adheres preferentially to the mag-black brick, but the coating layer gradually grows and develops from that portion, which promotes the adhesion of the coating on the spinel surface and further the bricks. The integration of coaching on the surface progresses.

Although the cement rotary kiln has been described in detail above, it is obvious to those skilled in the art that the present invention can be applied to the rotary kiln for other purposes.

[0016]

【The invention's effect】

(1) According to the present invention, it is possible to suppress damage to the lining bricks near the material boundary line due to fluctuations in operation, and it is possible to freely select and combine fired zone refractory bricks and coaching removable zone refractory bricks as needed.

(2) That is, by adopting a striped zebra structure: 1) It becomes possible to cope with changes in the operating conditions of the rotary kiln, and the life of the lining brick near the boundary can be extended.

2) The ideal raw material flow due to the adhered coating will not only reduce the abrasion and damage of the refractory brick, but also contribute to the increase of the amount of cement raw material burned out.

[Brief description of drawings]

FIG. 1 is a development view in which the zebra structure of the present invention is arranged in the circumferential direction.

FIG. 2 is a development view showing another example of the present invention.

FIG. 3 is a development view showing another example of the present invention.

FIG. 4 is a development view of a checkerboard pattern according to the present invention.

FIG. 5 is a vertical cross-sectional view showing an attached state of a coating.

[Explanation of symbols]

 1 Material boundary line 2 Firing zone 3 Coating attachment / detachment zone 4 Coating layer 5 Iron skin 12 Mag-black brick 13 Spinel brick

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 7, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

The refractory linings used for the firing zone and the detachable zone have brick characteristics (coating adhesion, spalling resistance, corrosion resistance, abrasion resistance, embrittlement resistance, and alkali resistance) so that they can be used in accordance with their respective usage conditions. ) Etc., the bricks of the above-mentioned quality are lined.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction content]

Above is the firing zone of the cement rotary kiln
I explained the detachable band in detail, but it is applicable to other parts as well.
Can also be in a rotary kiln for other purposes to which the present invention is applicable is where obvious to those skilled in the art. ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 10, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

[Title of Invention] Lining structure of rotary kiln

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary kiln lining structure, and more particularly to a brick construction structure of a rotary kiln firing zone and a coating / removal zone.

[0002]

2. Description of the Related Art A typical rotary kiln cement rotary kiln has a firing zone mainly lined with mag-chromic bricks, and a coaching attachment / detachment zone (hereinafter referred to as a detachment zone) Say) is mainly lined with spinel brick.

The refractory linings used for the firing zone and the detachable zone have brick characteristics (coating adhesion, spalling resistance, corrosion resistance, abrasion resistance, embrittlement resistance, and alkali resistance) so that they can be used in accordance with their respective usage conditions. In consideration of the above, bricks of the above-mentioned quality are lined.

[0004]

Conventionally, in the operation of a cement rotary kiln, the positions of the firing zone and the attachment / detachment zone are not constant due to the operating conditions such as the fluctuation of the cement raw material components, the fluctuation of the supply amount, and the shape of the combustion frame. It is known that the fluctuations are repeated. Moreover, the positions of the firing zone and the detachable zone are changed by switching the cement firing type. As mentioned above, the firing zone and the detachment zone of the cement rotary kiln are divided according to the brick conditions according to the firing conditions, and there is a limit to how the lining refractory bricks can respond to changes in the furnace conditions due to operating conditions, etc. The durability near the brick lining boundary tends to decrease.

That is, the mug used in the firing zone
Chromic bricks are excellent in heat resistance and coating adhesion, but when placed under the conditions of the detaching zone of the coating, the brick is greatly damaged by spalling due to heat change, and the detaching zone is also large. The spinel bricks used in the above have excellent spalling resistance, but when exposed to the conditions of the firing zone, they are exposed to higher temperatures than under the conditions of the detachment zone and the coating is superior to that of mag-chromic bricks. The coating layer is inadequate because it is hard to adhere to it, and as a result, the temperature becomes too high (heat resistance problem), it easily reacts with the lime component in the cement component and is melted, and the thermal conductivity of mag-chromic bricks is high. It is about 1.3 times higher than the above, so the skin temperature rises (about 3
(50 ° to 400 ° C.), the expansion difference between the iron shell and the brick causes slippage at the joint surface of the iron shell and the brick, which causes fatigue of the iron shell and the large amount of heat dissipated is not preferable in terms of energy saving.

[0006] Various attempts have been proposed in order to improve the drawback that the durability of these different kinds of bricks near the lining boundary tends to deteriorate.

[0007] For example, a cement rotary kiln furnace wall refractory structure constructed by combining and constructing a domite refractory and a spinel refractory in an alternating arrangement pattern (actually developed 62-2).
9092), but C in dolomite refractory
It is mentioned that aO and Al ₂ O ₃ in the spinel refractory easily react to form a low melting point liquid phase.

Therefore, the joint damage between the dolomite refractory material and the spinel refractory material in contact with each other is large, the wear rate is large, and the durability is poor.

[0009]

The present inventors have developed the present invention as a result of various examinations and experiments in order to solve the above-mentioned various defects of the conventional system, and the technical constitution of the present invention. Has a zebra structure in which the refractory bricks of mag-chromic bricks and spinel bricks are pasted together in a striped pattern at the boundary of the lining material between the firing zone and the coating / decoupling zone of the rotary kiln lining. By adopting such a configuration, each disadvantage is compensated by the advantages of other qualities, and as a result, partial damage near the material boundary of the rotary kiln lining is suppressed and the difference in coating thickness between the two bricks is mitigated. A rotary that can achieve ideal coaching adhesion, reduce brick abrasion damage due to smooth material flow, and maintain good furnace conditions, thus extending the life of lining bricks. There is provided a Lung lining structure. If there is a step difference in the coating thickness, the raw material stays and local wear occurs.

In the present invention, the zebra structure refers to an arrangement in which the inner lining of the rotary kiln is arranged in stripes in the axial direction of the rotary kiln or an arrangement in which the lining is gradually reduced in the axial direction of the kiln, which will be specifically described below with reference to the accompanying drawings. .. These drawings are development views showing the arrangement positions of the refractory bricks on the lining of the rotary kiln, and an example of the cement rotary kiln will be described.

FIG. 1 shows an example in which the zebra structure of the present invention is arranged in a ring unit of the lining in the circumferential direction, and FIG. 2 shows an example in which the zebra structure lining of the present invention is arranged in the axial direction of the kiln in a striped manner. Reference numeral 1 is a material boundary line between the firing zone 2 and the coating / decoupling attachment / detachment zone 3. The lining near the boundary line 1 is a ring unit of the inner wall of the kiln in FIG. 1, and a mag-chromic brick in the axial direction of the kiln in FIG. In this example, 12 and spinel brick 13 are alternately lined up in stripes and lined.

The mag-black brick used in the zebra structure of the present invention has a chemical composition of 50 to 95% by weight of MgO and C.
r ₂ O ₃ is a refractory composed mainly of 1 to 40% by weight, and spinel bricks are those containing spinel clinker in a range of 50% by weight or less, magnesia clinker and alumina clinker. As the main component,
A refractory material in which spinel (MgO.Al ₂ O ₃ ) is generated in the manufacturing process.

As the refractory bricks 12 of the firing zone 2, it is general to use mag-chromic bricks or mag-dolomite bricks due to thermal load, corrosion resistance to external components, stability of coating and the like. Further, as the refractory brick 13 of the coating / removal zone 3, it is common to use a spinel brick having resistance to spalling caused by repeated coating / removal due to temperature change. In the example of FIG. 1, the bricks 12 and 13 are alternately arranged and lined (1: 1), but these combinations can be changed depending on the conditions of use of the kiln. Further, in the example shown in the figure, the mag-chromic bricks 12 and the spinel bricks 13 are arranged in the axially striped zebra structure with the material boundary line 1 as the center.

When using a mag-domite brick for the firing zone 12, it is preferable to avoid contact with the spinel brick 13 and to use a mag-chrom brick for the contact portion with the spinel brick.

FIG. 3 shows a modified example of the zebra structure in which the mutual arrangement of the mag-chromic bricks 12 and the spinel bricks 13 is gradually decreased in the kiln axis direction before and after the material boundary line 1. This is an example of a lining that best serves the purpose. As the gradual decrease method, mag-chromic bricks: spinel bricks are arranged and lined from the firing zone 2 to the coating / decoupling zone 3 in a ratio of, for example, 5: 1 → 1: 5. Therefore, the ratio of the spinel bricks 13 increases toward the coaching attachment / detachment zone 3.

FIG. 4 is a vertical cross-sectional view of the rotary kiln in the structure of FIG. 1 showing the state where the material is coated around the material boundary line 1 of the rotary kiln. The inner surface of the spinel brick 13 is coated with the coating layer 4 to ensure stable operation. It is ensured that abrasion of each brick is suppressed and the life of the lining brick is extended.

In this case, the adhesion of the coating in the zebra structure naturally adheres preferentially to the mag-chromic brick, but the coating layer gradually grows and develops from that portion, which promotes the adhesion of the coating on the spinel surface and further The integration of coaching on the brick surface progresses.

Although the cement rotary kiln has been described in detail above, it is obvious to those skilled in the art that the present invention can be applied to the rotary kiln for other purposes.

[0019]

EFFECTS OF THE INVENTION (1) According to the present invention, it is possible to suppress the damage of the lining bricks near the material boundary line due to the fluctuation of the operation, and the firing zone refractory bricks and the detachable zone refractory bricks can be freely selected and combined. Is possible.

(2) That is, by adopting a striped zebra structure: 1) It is possible to cope with changes in the operating conditions of the rotary kiln, and it is possible to prolong the life of the lining brick near the boundary.

2) The ideal raw material flow due to the adhered coating will not only reduce the abrasion damage of the refractory bricks, but also contribute to the increase of the amount of cement raw material flowing out.

[Brief description of drawings]

FIG. 1 is a development view in which the zebra structure of the present invention is arranged in the circumferential direction.

FIG. 2 is a development view in which the zebra structure of the present invention is arranged in the axial direction of the kiln.

FIG. 3 is a development view showing an example in which the zebra structure of the present invention is gradually reduced in the axial direction of the kiln.

FIG. 4 is a vertical cross-sectional view showing an attached state of a coating.

[Explanation of symbols] 1 Material boundary line 2 Firing zone 3 Coating attachment / detachment zone 4 Coating layer 5 Iron skin 12 Mag-chromic brick 13 Spinel brick

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

Claims (5)

[Claims] 1. A zebra structure in which two or more types of refractory bricks are laminated in a striped manner at a boundary portion of a refractory material lined in each of a firing zone and a coaching attachment / detachment zone in a lining of a rotary kiln. , Rotary kiln lining structure. 2. The lining structure of a rotary kiln according to claim 1, wherein the zebra structure is circumferentially arranged in a ring unit of the rotary kiln lining. 3. The lining structure of a rotary kiln according to claim 1, wherein the zebra structure is in the axial direction of the rotary kiln. 4. The lining structure for a rotary kiln according to claim 1, wherein the different types of bricks having the zebra structure gradually decrease in the axial direction of the rotary kiln. 5. The rotary kiln lining structure according to claim 1, wherein the zebra structure is a checkered structure.