JP2022099641A - Chlorine bypass equipment and operation method thereof, cement clinker production apparatus, and cement clinker production method - Google Patents

Abstract

To provide chlorine bypass equipment that is made compatible by small-scale equipment modification and is operable efficiently even when existing equipment is used.SOLUTION: Chlorine bypass equipment 90 includes: a first bleed air outlet 11A and a second bleed air outlet 21A that bleed kiln exhaust gas from a kiln butt 52 of a cement kiln 50 or a rising duct 42 or from between them; and a first flow path 10 and a second flow path 20 in which the bleed gas extracted from the first bleed air outlet 11A and the second bleed air outlet 21A is blown at different temperatures, respectively. The first flow path 10 has a cooling unit 13 that cools the temperature of the bleed air gas to less than 770°C, and the second flow path 20 has a classification unit 22 that separates raw material dust contained in the bleed air gas from the bleed air gas in a state in which the temperature of the bleed air gas is maintained at 770°C or higher.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a chlorine bypass facility and its operation method, a cement clinker manufacturing apparatus, and a cement clinker manufacturing method.

Efforts are underway to use various types of waste as raw materials and fuel in cement clinker manufacturing equipment. Under these circumstances, the amount of chlorine brought into the cement kiln tends to increase. Many cement cleaner manufacturing equipment are equipped with a chlorine bypass facility to reduce chlorine in the cement kiln, and a technique for efficiently removing chlorine from the extracted gas extracted by this chlorine bypass facility is being studied. There is. In Patent Document 1, a technique for separating coarse powder from bleed gas while maintaining the temperature of bleed gas extracted from the kiln exhaust gas flow path at 770 ° C. or higher, and then cooling to 600 ° C. or lower to separate chlorine bypass dust. Has been proposed. By using this technique, it becomes possible to recover high chlorine chlorine bypass dust by separating the coarse powder from the bleed air gas.

Japanese Unexamined Patent Publication No. 2019-55900

However, in the technique of Patent Document 1, a large heat insulating structure is required to maintain the total amount of bleed gas at a temperature of 770 ° C. or higher, and if the heat insulating structure is not conventionally provided, a large-scale equipment modification is required. become. In addition, the amount of coarse powder (raw material dust) contained in the bleed air gas changes greatly depending on the operating conditions of the cement kiln. Factors that change the amount of raw material dust contained in the extracted gas include, for example, changes in the flow of raw material dust due to changes in the refractory construction status of the slide under the rising duct and shape changes due to dust adhesion, the amount of passing gas, and the shape of the slide table. Differences in gas flow velocity due to changes, scattering of raw material dust from the C1 chute when landing, and the like can be mentioned. Depending on these situations, the amount of raw material dust contained in the bleed air gas may be small. The technique of Patent Document 1 is inefficient because the entire amount of the bleed air gas is introduced into the classification device even when the amount of the raw material dust contained in the bleed air gas is small.

Therefore, the present disclosure provides a chlorine bypass facility and an operation method thereof, which can be dealt with by small-scale equipment modification even when the existing equipment is used and can be operated efficiently. Further, the present disclosure provides a cement clinker manufacturing apparatus and a cement clinker manufacturing method capable of stably operating and efficiently manufacturing a cement clinker by providing such a chlorine bypass facility. do.

The chlorine bypass facility according to one aspect of the present disclosure circulates a bleeding port for extracting kiln exhaust gas from a kiln butt, a rising duct, or between them, and an bleeding gas extracted from the bleeding port at different temperatures. A plurality of flow paths are provided, and the plurality of flow paths include a first flow path having a cooling unit for cooling the temperature of the bleed gas to less than 770 ° C. It has a second flow path having a classifying portion for separating the raw material dust contained in the gas from the bleed air gas.

In the first flow path in the chlorine bypass facility, raw material dust and volatilized chlorine such as KCl and NaCl are extracted and cooled promptly to precipitate KCl and NaCl in the extracted gas or precipitate on the surface of the raw material dust. Let and get chlorine dust. On the other hand, the second flow path has a classification unit for separating the raw material dust contained in the bleed air gas while maintaining the temperature of the bleed air gas at 770 ° C. or higher. At this time, since the temperature of the classifying portion is maintained at 770 ° C. or higher, the raw material dust can be separated from the bleed air gas while the chlorine content is contained in the gas phase. Therefore, even when the amount of raw material dust in the extracted gas increases, the amount of raw material dust can be separated at the classification part before KCl, NaCl, etc. are deposited on the surface of the raw material dust, so that the amount of chlorine dust increases. It is possible to suppress a decrease in the chlorine concentration of the cleanse dust. As a result, it is possible to suppress an increase in the amount of clinker dust to be treated in the water washing facility and to suppress the treatment cost of clinker dust.

As described above, in the chlorine bypass facility, the first flow path for precipitating KCl, NaCl, etc. in the extracted gas or precipitating the surface of the raw material dust to obtain the cleana dust, and the KCl, NaCl, etc. in the extracted gas are the raw material dust. Since it also has a second flow path that separates raw material dust in the classification section before it precipitates on the surface of the chloride, it can flexibly respond even if the amount of raw material dust extracted due to changes in the operating state of the cement kiln fluctuates. Is possible. For example, the flow rate of the bleed gas in each of the first flow path and the second flow path can be adjusted according to the amount of clinker dust in the recovery unit and the chlorine concentration of the clinker dust, or the bleed gas in one of the flow paths can be adjusted. It is also possible to stop the distribution of. As described above, according to the chlorine bypass equipment, the operating state can be flexibly adjusted. Therefore, it is possible to provide a chlorine bypass facility capable of operating stably and efficiently. In addition, if the existing first flow path is utilized, it can be dealt with by small-scale equipment modification. However, it is not limited to the chlorine bypass equipment to be modified, and the entire chlorine bypass equipment may be newly installed.

The chlorine bypass equipment is preferably provided with a plurality of bleed air ports. Further, it is preferable that the first flow path and the second flow path draw bleed air from bleed air ports different from each other. The bleed air port (first bleed air port) to which the first flow path is connected is preferably installed in a place where raw material dust is difficult to be bleeded, and the bleed air port (second bleed air port) to which the second flow path is connected is It is preferable to install it in a place where raw material dust is easily extracted in the vicinity of the first bleed air port. As a result, the amount of bleed air in the first bleed air is increased, and even when a large amount of raw material dust is easily extracted from the first bleed air, the first bleed air is extracted by extracting the raw material dust through the second bleed air port. The amount of raw material dust extracted from the mouth can be reduced. This makes it possible to recover clinker dust having a high chlorine concentration in both the first flow path and the second flow path, and the chlorine content can be efficiently discharged from the cement kiln. In addition, it is possible to suppress an increase in the amount of clinker dust treated by the water washing facility and suppress the treatment cost of clinker dust.

The area of the second bleeding port to which the second flow path is connected is preferably smaller than the area of the first bleeding port to which the first flow path is connected. In the second flow path, it is sufficient that there is an area of an air extraction port capable of collecting raw material dust. By making the second flow path small, the heat insulating structure can be made small, and it becomes easy to install this equipment even in places where space is limited.

It is preferable that the chlorine bypass facility is provided with a circulation flow path for returning the raw material dust separated in the classification section to the cement kiln side. In this case, since the raw material dust contained in the extracted gas is separated and returned to the cement kiln side in the circulation flow path while the temperature of the extracted gas is maintained at 770 ° C. or higher, the chlorine content is in a volatile state and the raw material dust is removed. It can be effectively used as a raw material for cement clinker.

The chlorine bypass facility collects a mixing section that obtains a mixed gas by merging the first extracted gas that has flowed through the first flow path and the second extracted gas that has flowed through the second flow path, and the cleana dust contained in the mixed gas. It is preferable to provide a recovery unit for sucking the mixed gas and a suction unit for sucking the mixed gas on the downstream side of the recovery unit. In the second bleed gas flowing through the second flow path, the raw material dust is reduced in the classification section, and the chlorine concentration of the clinker dust can be increased. By providing the mixing section and the recovery section and the suction section downstream thereof, the chlorine content contained in the first bleed air gas and the second bleed air gas can be collectively recovered as clinker dust. This makes it possible to reduce equipment costs and operating costs.

It is preferable to provide a flow rate adjusting unit for adjusting the flow rate of at least one of the first bleed gas and the second bleed gas. As a result, even when the above-mentioned mixing portion is provided, when the operating state in the cement kiln changes and the amount of raw material dust extracted changes, air is extracted into the first flow path and the second flow path, respectively. The amount of bleed air can be adjusted flexibly and quickly. This makes it possible to stabilize the operating state of the cement clinker manufacturing apparatus. When the mixing unit is not provided, it is preferable that both the first bleed air gas and the second bleed air gas are provided with a flow rate adjusting unit for adjusting the flow rate. This makes it possible to flexibly and quickly adjust the amount of bleed air drawn into the first flow path and the second flow path when the operating state in the cement kiln changes and the amount of raw material dust changes.

The first flow path and the second flow path include a recovery unit for collecting clinker dust contained in the bleed air gas cooled to preferably below 260 ° C., more preferably less than 200 ° C., and a suction unit for sucking the bleed air gas. , May be provided respectively. By providing such a first flow path and a second flow path, clinker dust can be stably recovered. Further, even if the operation of one of the first flow path and the second flow path is stopped, the operation of the other flow path can be continued. Therefore, the reliability of the chlorine bypass equipment can be sufficiently increased.

The cement clinker manufacturing apparatus according to one aspect of the present disclosure is provided with any of the above chlorine bypass equipment. Therefore, stable operation is possible, and cement clinker can be efficiently manufactured.

The method for manufacturing cement clinker according to one aspect of the present disclosure is to manufacture cement clinker using the above-mentioned cement clinker manufacturing apparatus. Therefore, stable operation is possible, and cement clinker can be efficiently manufactured.

The operation method of the chlorine bypass facility according to one aspect of the present disclosure includes an extraction step of extracting the kiln exhaust gas generated when the cement raw material is fired in a cement kiln to obtain a first extraction gas and a second extraction gas, and a first. 2 A classification step of classifying the extracted gas while maintaining a temperature of 770 ° C. or higher to separate the raw material dust contained in the extracted gas, and a cooling step of cooling the first extracted gas to less than 770 ° C. without classifying. It has a second extraction gas from which raw material dust has been separated and a dust recovery step for recovering the cleaner dust contained in the first extraction gas cooled to less than 770 ° C.

In the above operation method, in the classification step, the raw material dust can be separated from the second bleed gas in a state where chlorine such as KCl and NaCl in the bleed gas is contained in the gas phase. Then, the clinker dust is recovered from the second bleed air gas after the raw material dust is separated in the dust recovery step. Therefore, even when a large amount of raw material dust is extracted with the second bleed air gas, it is possible to suppress an increase in the amount of clinker dust in the dust recovery step. Further, the separated raw material dust can be used as a raw material for cement clinker.

As described above, the operation method of the chlorine bypass facility described above includes a cooling step of cooling the first extracted gas to less than 770 ° C. without classifying the second extracted gas and classifying the second extracted gas while maintaining the temperature of 770 ° C. or higher. Since it has a classification step of separating the raw material dust contained in the second extracted gas, it is possible to flexibly respond to changes in the operating state of the cement kiln. For example, the flow rate ratio of the first bleed gas and the second bleed gas can be adjusted in the bleeding step according to the amount of clinker dust collected by the recovery unit and the chlorine concentration of the clinker dust. As described above, according to the operation method of this chlorine bypass equipment, the operating state can be flexibly adjusted. Therefore, the chlorine bypass equipment can be operated stably and efficiently.

Even when the existing equipment is used, it is possible to provide a chlorine bypass equipment and an operation method thereof, which can be dealt with by small-scale equipment modification and can be operated efficiently. Further, by providing such a chlorine bypass facility, it is possible to provide a cement clinker manufacturing apparatus and a cement clinker manufacturing method capable of stable operation and efficiently manufacturing a cement clinker. ..

It is a figure which shows the chlorine bypass equipment which concerns on one Embodiment, and the cement clinker manufacturing apparatus provided with this. It is a figure which shows an example of the connection | connection point between the bleed air pipe of a chlorine bypass equipment, and a rising duct. (A), (B), (C), and (D) are diagrams showing examples of the shape of the bleed air port of the chlorine bypass equipment, respectively. (A), (B), (C), and (D) are diagrams showing examples of the shape of the bleed air port of the chlorine bypass equipment, respectively. It is a figure which shows the chlorine bypass equipment which concerns on another Embodiment, and the cement clinker manufacturing apparatus provided with this.

Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings as the case may be. However, the following embodiments are examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following contents. In the description, the same reference numerals are used for the same elements or elements having the same function, and duplicate description may be omitted in some cases. In addition, the positional relationship such as up, down, left, and right shall be based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratio of each element is not limited to the ratio shown in the figure. Further, the terms "upstream", "downstream", "upstream side" and "downstream side" in the present specification are based on the flow direction of the extracted gas, the cooling gas or a mixed gas thereof.

FIG. 1 is a diagram showing a chlorine bypass facility according to an embodiment and a cement clinker manufacturing apparatus including the chlorine bypass facility. The chlorine bypass equipment 90 is connected to the rising duct 42 of the preheating and calcining portion 40 of the cement clinker manufacturing apparatus 100. The chlorine bypass facility 90 precipitates volatile chlorine components such as KCl and NaCl in the cement clinker manufacturing apparatus 100, precipitates them on the surface of raw material dust, collects them as clinker dust, and collects them as clinker dust, and chlorine in the cement clinker manufacturing apparatus 100. Reduce minutes.

The chlorine bypass facility 90 includes a first bleed air port 11A and a second bleed air port 21A for extracting gas from the rising duct 42, a first flow path 10 through which the bleed air extracted from the first bleed air port 11A flows, and a second. A second flow path 20 through which the bleed air gas extracted from the bleed air port 21A flows is provided. The first flow path 10 connects the first bleed pipe 11 and the cooling unit 13 connected to the first bleed air port 11A along the flow direction of the bleed air gas (first bleed air gas) from the first bleed air port 11A. Prepare in order. The second flow path 20 includes a second bleed pipe 21, a classification unit 22, and a cooling unit connected to the second bleed air port 21A along the flow direction of the bleed air gas (second bleed air gas) from the second bleed air port 21A. 25 and 25 are provided in this order. Further, in the chlorine bypass equipment 90, the first bleed gas cooled by the cooling unit 13 and the raw material dust are separated by the classification unit 22, and then the second bleed gas cooled by the cooling unit 25 is mixed. A unit 30 is provided.

The first bleed gas drawn from the first bleed air port 11A contains volatile chlorine content such as KCl and NaCl and raw material dust. The first bleed gas flows through the first bleed pipe 11 and is cooled to less than 770 ° C. by the cooling unit 13. As a result, volatilized chlorine such as KCl and NaCl is precipitated or precipitated on the surface of the raw material dust to become clinker dust. The first bleed air tube 11 may be called an bleed air probe. The cooling temperature of the first bleed gas in the cooling unit 13 may be 600 ° C. or lower, or 500 ° C. or lower, from the viewpoint of heat resistance of the equipment. Cooling by the cooling unit 13 may be performed, for example, by mixing the cooling gas with the first bleed air gas. The cooling gas may be air at room temperature and may include exhaust gas generated in a factory or the like. Exhaust gas includes, for example, odorous gas generated during reception, storage and fermentation of sewage sludge and other sewage sludge brought into a cement manufacturing plant, exhaust gas discharged from the suction unit 38 described later and the suction unit of another process, and the like. Can be mentioned. One of these can be used alone or in combination of two or more. Further, the first bleed air cooled by the cooling unit 13 may be introduced into the classifier to separate the coarse powder of clinker dust. The classifier may be, for example, a cyclone. The chlorine concentration of clinker dust varies depending on the particle size, and the coarse powder of clinker dust has a lower chlorine concentration than the fine powder. Therefore, by separating the coarse powder of clinker dust having a low chlorine concentration and returning the separated coarse powder of clinker dust to the cement kiln side, it is possible to suppress an increase in the amount of clinker dust washed with water.

The first bleed gas cooled by the cooling unit 13 is introduced into the mixing unit 30. The mixing unit 30 may be, for example, a chamber for merging the first bleed gas and the second bleed gas. In the mixing unit 30, the clinker dust associated with the first bleed air gas and the second bleed air gas may be collected. Further, a cooling gas may be introduced into the mixing portion. Examples of the cooling gas include those similar to those used for the cooling unit 13.

The second bleed gas drawn from the second bleed air port 21A contains volatile chlorine components such as KCl and NaCl and raw material dust. The second bleed gas flows through the second bleed pipe 21 and is introduced into the classification unit 22. The second bleed air tube 21 may be called an bleed air probe. The shape and size of the second bleeding pipe 21 and the first bleeding pipe 11 may be the same or different. The second bleed air separates the raw material dust in the classification unit 22 while maintaining the temperature of 770 ° C. or higher. The classification unit 22 may be, for example, a cyclone. The particle size of the raw material dust may be, for example, 18 μm or more, preferably 16 μm or more, and more preferably 14 μm or more. By classifying the raw material dust to 14 μm or more, the volatile content can be sufficiently reduced. As a result, even when the raw material dust is returned to the cement kiln side by the circulation flow path 26, the carry-in of chlorine can be reduced.

The second bleed gas having a temperature of 770 ° C. or higher contains volatile chlorine components such as KCl and NaCl and raw material dust. Since the raw material dust is a raw material for the cement clinker, it flows through the circulation flow path 26 and is introduced into the kiln tail 52 of the cement kiln 50. By returning the raw material dust extracted from the second bleed air port 21A to the kiln tail 52 in this way, the raw material dust contained in the second bleed air gas can be used for the production of the cement clinker. The raw material dust may be returned to the rising duct 42, the calcining furnace 44, or the kiln main body 56 instead of the kiln tail 52. Further, a plurality of circulation flow paths 26 may be provided to return the raw material dust to a plurality of locations. From the viewpoint of suppressing the precipitation of volatilized chlorine such as KCl and NaCl on the surface of the raw material dust separated from the second bleed air gas in the classification unit 22, the temperature of the bleed air gas when separating the raw material dust is preferable. Is preferably maintained at 820 ° C, more preferably 860 ° C or higher.

Since the second bleed gas in the classification unit 22 has a sufficiently high temperature, the chlorine content is contained as a gas. The second bleed gas from which the raw material dust is separated in the classification unit 22 is cooled by the cooling unit 25. The cooling temperature of the second bleed gas in the cooling unit 25 may be 600 ° C. or lower, or 500 ° C. or lower, from the viewpoint of heat resistance of the equipment. Cooling in the cooling unit 25 may be performed by mixing the cooling gas with the second bleed air gas in the same manner as in the cooling unit 13. The cooling gas used here may be the same as the cooling gas used in the cooling unit 13. In the modified example, the cooling unit 25 may not be provided and may be cooled by mixing with the first bleed air gas in the mixing unit 30.

By cooling the second bleed air gas, volatilized chlorine components such as KCl and NaCl are deposited on the surface of the raw material dust that has not been separated by the classification unit 22, and becomes clinka dust. The second bleed gas cooled by the cooling unit 25 is introduced into the mixing unit 30 and merges with the first bleed gas. The mixed gas generated by the confluence of the first bleed gas and the second bleed gas in the mixing unit 30 contains clinker dust. A part of the clinker dust may be separated in the mixing section 30.

The chlorine bypass facility 90 includes a cooling unit 35 for cooling the mixed gas, a recovery unit 37 for recovering the cleana dust contained in the mixed gas from the mixed gas, and a suction unit 38 for sucking the mixed gas downstream of the mixing unit 30. To prepare for. The cooling unit 35 may be a water-cooled type or an air-cooled type heat exchanger. Examples of the suction unit 38 include ordinary suction fans such as a sirocco fan and a turbo fan. The mixed gas obtained in the mixing unit 30 is cooled to, for example, less than 260 ° C., preferably less than 200 ° C. by the cooling unit 35 provided downstream of the mixing unit 30, and then introduced into the recovery unit 37. The collection unit 37 may be a bug filter. Further, the collection unit 37 is not limited to a dry dust collector such as a bag filter, and may be a wet dust collector such as a wet scrubber. The clinker dust collected by the collection unit 37 may be used as a cement raw material in the same manner as a normal clinker after being washed with water.

FIG. 2 is a diagram showing an example of a connection point between an air extraction pipe of a chlorine bypass facility and a rising duct. The first bleeding pipe 11 and the second bleeding pipe 21 are connected to one side and the other side of the rising duct 42, respectively. A first bleeding port 11A is provided on the first side surface of the rising duct 42, and a second bleeding port 21A is provided on the second side surface of the rising duct 42 (the left side surface of the first side surface in FIG. 2). For example, if a large amount of raw material dust is present on the second side surface side due to the operating condition of the cement kiln, if the amount of bleed air of the first bleed air gas is increased, the raw material dust passing through the second side surface side from the first bleed air port is bleeded. As a result, the chlorine concentration of the cleana dust of the first bleed air gas decreases.

Therefore, by providing the second bleed air port 21A on the second side surface, even if a large amount of raw material dust is easily extracted from the first bleed air port 11A, the raw material dust is extracted by the second bleed air port 21A and the first bleed air port 21A is used. The amount of raw material dust extracted from the bleed air port 11A can be reduced. In this way, the amount of clinker dust collected by the recovery unit 37 can be reduced while reducing the chlorine content in the kiln main body 56.

The first bleeding port 11A and the second bleeding port 21A do not necessarily have to be provided on the side surfaces of the rising duct 42 adjacent to each other, and may be provided on the same side surface. The first bleeding port 11A and the second bleeding port 21A may be provided side by side in the vertical direction or may be provided side by side in the horizontal direction. Further, three or more bleed air ports may be provided, and bleed air gas may be drawn from the plurality of bleed air ports into the first flow path 10 and the second flow path 20. The number and shape of the first bleed air port 11A and the second bleed air port 21A are not particularly limited. Further, the rising duct is not limited to the shape shown in FIG. 2, and may have a cylindrical shape or a polygonal pillar shape other than a square pillar.

3 and 4 are views showing an example of the shape of the bleed air port when the bleed air port of the chlorine bypass equipment is viewed from the center of the inside of the flow path of the kiln exhaust gas (inside the rising duct 42 or the kiln tail 52). In the example of FIG. 3A, as shown in FIG. 1, a second bleeding port 21A is provided below the first bleeding port 11A. With such an arrangement, when the amount of raw material dust that rises along with the kiln exhaust gas from the kiln main body 56 and the kiln tail 52 increases, the raw material dust is collected in advance by the second bleed air port 21A. It is possible to prevent a large amount of raw material dust from being drawn from the first bleeding port 11A. Further, by introducing the raw material dust extracted from the second bleed air port 21A into the classification unit 22, the raw material dust can be separated from the bleed air gas and returned to the kiln tail 52 by the circulation flow path 26.

That is, the raw material dust is circulated in the flow path composed of the second bleeding port 21A, the second bleeding pipe 21, the classification unit 22, and the circulation flow path 26. As a result, the yield of cement clinker is increased, and the cement clinker can be efficiently produced. Further, by extracting the raw material dust from the second bleed air port 21A together with the kiln exhaust gas, the amount of the raw material dust extracted from the first bleed air port 11A can be reduced, and the processing cost of the cleaner dust can be reduced. For example, when the wear of the refractory progresses at the chute of the preheating and calcining portion 40, the raw material dust does not flow as expected and winds up, and the raw material dust accompanying the kiln exhaust gas increases. By increasing the amount of air drawn from the second air extraction port 21A at such a timing, the circulation of raw material dust to the cement kiln 50 side (kiln tail 52) can be promoted, and the production of cement clinker can be made efficient. The first bleeding port 11A has a circular shape and the second bleeding port 21A has a rectangular shape, but both are not limited to such a shape.

In the example of FIG. 3B, the second bleeding port 21A is provided above the first bleeding port 11A. By arranging in such an arrangement, the raw material dust (falling-out dust) that has fallen out of the calcination furnace 44 is collected in advance by the second bleed air port, thereby preventing a large amount of bleeding dust from the first bleed air port. be able to. By introducing such fall-off dust into the classification portion 22 of the second flow path 20, the fall-off dust can be separated and returned to the kiln tail 52 by the circulation flow path 26. As a result, the yield of cement clinker is increased, and the cement clinker can be efficiently produced.

In the example of FIG. 3C, a pair of second bleeding ports 21B are provided on both sides of the first bleeding port 11A. That is, the first bleed air port 11A is provided between the pair of second bleed air ports 21B. A second bleeding pipe 21 may be connected to each of the plurality of second bleeding ports 21B, and a plurality of second bleeding pipes 21 may be connected to the classification unit 22. It may be connected to 22. In this respect, in the following example, the one having a plurality of second bleeding openings may be the same as this example.

Inside the rising duct 42 and the kiln tail 52, the flow velocity of the kiln exhaust gas is not uniform, and there is a flow velocity distribution. For example, when the rising duct 42 and the kiln tail 52 have corners as shown in FIG. 2, the flow velocity of the kiln exhaust gas is slower in the vicinity of the corners than in the center, and the dust that has fallen out of the calciner 44 passes through. Easy to do. Therefore, as shown in FIG. 3C, by arranging the second bleed air port 21B closer to the corner than the first bleed air port 11A, the dust falling out of the calciner 44 is removed from the second bleed air port 21B. It can be easily bleeded together with the kiln exhaust gas. As a result, the yield of cement clinker is increased, and the cement clinker can be efficiently produced. In addition, the amount of bleeding dust extracted from the first bleeding port 11A is reduced, and the processing cost of clinker dust can be reduced. The first bleeding port 11A has a circular shape and the second bleeding port 21B has a rectangular shape, but both are not limited to such a shape.

In the example of FIG. 3D, a second bleeding port 21C is provided around the first bleeding port 11A so as to surround the first bleeding port 11A. As described in the description of FIGS. 3 (A), (B), and (C), the raw material dust is drawn from various directions such as above, below, and from the side of the kiln exhaust gas flow path at the bleed air port. In such a case, by arranging the first bleed air port 11A and the second bleed air port 21C as shown in FIG. 3 (D), the raw material dust is given priority from the second bleed air port 21C instead of the first bleed air port. You can bleed air. As a result, the amount of raw material dust returned to the kiln tail 52 by the circulation flow path 26 increases, the yield of cement clinker increases, and the cement clinker can be efficiently manufactured. Further, the amount of raw material dust extracted from the first bleed air port 11A is reduced, and the processing cost of clinker dust can be reduced. In this example, the first bleeding port 11A has a circular shape and the second bleeding port 21C has a ring shape, but both are not limited to such a shape.

In the example of FIG. 4A, a pair of second bleeding ports 21D are provided above and below the first bleeding port 11A, and a pair of second bleeding ports 21E are provided on both sides of the first bleeding port 11A. There is. That is, a total of four second bleeding ports 21D and 21E are provided so as to surround the first bleeding port 11A. Even with such an arrangement, the yield of the cement clinker is increased and the cement clinker can be efficiently produced, as in FIG. 3D. In addition, the processing cost of clinker dust can be reduced.

Further, in the example of FIG. 4A, the flow rate of the bleed gas drawn by the four second bleed air ports can be individually adjusted. For example, a flow rate adjusting portion such as a valve or a damper may be provided in the bleeding pipe connected to the second bleeding ports 21D and 21E, or in the connecting portion between the bleeding pipe and the classification portion. As a result, the amount of bleed air of each of the second bleeding ports 21D and 21E is adjusted according to the operating state inside the rising duct 42 and the kiln butt 52, and the amount of raw material dust circulated to the kiln butt 52 is further increased. The amount of clinker dust can be reduced. In this example, the first bleeding port 11A has a circular shape and the second bleeding port 21D has a rectangular shape, but both are not limited to such a shape.

In the example of FIG. 4B, the second bleed air port 21A is provided above the first bleed air port 11A, and the second bleed air port 21F is provided below the first bleed air port 11A. That is, the first bleed air port 11A is provided between the second bleed air ports 21A and 21F. In this example, as in the example of FIG. 3A, the raw material dust that rises along with the kiln exhaust gas can be extracted at the second extraction port 21F. Further, similarly to FIG. 3B, the bleeding dust can be drawn out at the second bleeding port 21A. Here, the second bleed air port 21A is larger than the second bleed air port 21F. Therefore, when there is more fall-off dust than the raw material dust that rises with the kiln exhaust gas, the raw material dust can be efficiently taken into the second flow path 20 and circulated. When the amount of raw material dust that rises with the kiln exhaust gas is larger than that of the dust that falls out, the magnitude relationship between the second bleed air port 21A and the second bleed air port 21F may be reversed. In this example, the first bleeding port 11A has a circular shape, and the second bleeding ports 21A and 21F have a rectangular shape, but both are not limited to such a shape. The bleed air amount of the second bleed air ports 21A and 21F may be individually adjusted by the flow rate adjusting unit.

In the example of FIG. 4C, two second bleeding ports 21G are provided diagonally above the first bleeding port 11A so as to form a figure eight. In this example, similarly to FIG. 3B, the bleeding dust can be extracted at the second bleed air port 21G. As a result, the yield of cement clinker is increased, and the cement clinker can be efficiently produced. In addition, the processing cost of clinker dust can be reduced. The bleeding amount of the two second bleeding ports 21G may be individually adjusted by the flow rate adjusting unit.

In the example of FIG. 4D, as in the example of FIG. 3D, a second bleeding port 21H is provided around the first bleeding port 11A so as to surround the first bleeding port 11A. By arranging the second bleed air port 21H around the first bleed air port 11A, the raw material dust can be preferentially extracted from the second bleed air port 21H. Further, the flow path of the bleed air of the second bleed air port 21H is divided into a plurality of sections by the partition plate 21h. The flow rate of each of the plurality of compartments may be individually adjustable. By adjusting the flow rate (bleed air amount) in each section flow path according to the operating state inside the rising duct 42 and the kiln butt 52, the amount of raw material dust circulated to the kiln butt 52 is further increased, and the amount of raw material dust is further increased to the clinker dust. It is possible to further reduce the amount of raw material dust mixed in.

The area of the second bleed air ports 21A to 21H may be smaller than the area of the first bleed air port 11A. By making the second flow path small, the heat insulating structure can be made small, and it becomes easy to install this equipment even in places where space is limited. Although some examples of the first bleed air port and the second bleed air port have been given with reference to FIGS. 3 and 4, the number and shape of the first bleed air port and the second bleed air port are not limited to the above examples.

The cement clinker manufacturing apparatus 100 of FIG. 1 includes a chlorine bypass facility 90, a preheated preheating section 40 for preheating and preheating the cement raw material, and a cement clinker 50 for calcining the preheated and preheated cement raw material to obtain a cement clinker. And a clinker cooler 60 for cooling the cement clinker obtained in the cement kiln 50. The preheating calcining unit 40 has four cyclones C1, C2, C3, C4 (preheaters) and a calcining furnace 44.

The kiln tail 52 of the cement kiln 50 and the calcination furnace 44 of the preheating calcination section 40 are connected by a rising duct 42. In the vicinity of the connection between the rising duct 42 and the kiln tail 52, the kiln exhaust gas generated in the cement kiln 50 is extracted, and the dust contained in the kiln exhaust gas is collected. A mouth 21A is provided. The first bleeding pipe 11 is connected to the first bleeding port 11A, and the second bleeding pipe 21 is connected to the second bleeding port 21A. The cement clinker manufacturing apparatus 100 can reduce the volatile content in the cement clinker manufacturing apparatus 100 by providing the chlorine bypass equipment 90.

The cement raw material introduced from the connection portion between the cyclone C1 and the cyclone C2 is distributed through the cyclone C1, the cyclone C2, the cyclone C3, the rising duct 42, the calcination furnace 44, and the cyclone C4 to the kiln tail 52 of the cement kiln 50. be introduced. In the cement kiln 50, the preheated and calcined cement raw material is heated by the combustion of the burner 54 provided on the opposite side of the kiln tail 52 to become a cement clinker. The obtained cement clinker is cooled by the clinker cooler 60. After cooling by the clinker cooler 60, a cement clinker is obtained.

Since the cement clinker manufacturing apparatus 100 is provided with the chlorine bypass equipment 90, stable operation is possible and the cement clinker can be efficiently manufactured. In addition, the cement clinker can be efficiently produced by effectively utilizing the raw material dust. In addition, clinker dust is reduced, and the processing cost of clinker dust can be reduced. In the present embodiment, both the first bleeding port 11A and the second bleeding port 21A are provided in the rising duct 42, but the present invention is not limited to this. For example, at least one of the first bleeding port 11A and the second bleeding port 21A may be provided in the kiln butt 52, or may be provided between (or a boundary portion) between the kiln butt 52 and the rising duct 42.

The method for manufacturing a cement clinker according to an embodiment can be performed using the cement clinker manufacturing apparatus 100. In this manufacturing method, a preheating calcination step of preheating and calcination of the cement raw material in the preheating calcination section 40 and a preheating and calcination of the cement raw material are introduced from the kiln tail 52 into the kiln main body 56 to manufacture a cement clinker. The firing step, the extraction step of extracting the kiln exhaust gas generated in the firing step, and a part of the extracted gas (second extracted gas) are introduced into the classification unit 22, and the extracted air is maintained at a temperature of 770 ° C. or higher. The raw material dust is separated into a classification step for separating the raw material dust contained in the gas, a cooling step for cooling the temperature to less than 770 ° C. without introducing another part of the extracted gas (first extracted gas) into the classification unit 22. The dust recovery step of recovering the cleaner dust and the raw material dust separated in the classification step from the extracted gas and the extracted gas cooled to less than 770 ° C. without being introduced into the classification unit 22 are returned to the cement kiln 50 side. It has a circulation process. Further, it may have a clinker cooling step in which the cement clinker obtained in the firing step is cooled by the clinker cooler 60.

In the preheating calcination step, the cement raw material is introduced from the flow path between the cyclones C1 and the cyclone C2. The cement raw material is preheated by circulating cyclone C1, cyclone C2 and cyclone C3. After that, it is introduced into the calcining furnace 44 and calcined. The calcination furnace 44 may be provided with a burner for burning fuel such as coal. The cement raw material (temporary firing raw material) that has been calcined in the calcining furnace 44 is introduced into the cyclone C4 and heated.

In the firing step, the calcining raw material heated by the cyclone C4 is introduced into the kiln tail 52. After that, it is fired in the kiln body 56 to become a cement clinker. In the bleeding step, the kiln exhaust gas generated in the firing step is bleeded from the first bleeding port 11A and the second bleeding port 21A. In the classification step, the raw material dust contained in the second bleed gas extracted from the second bleed air port 21A is separated from the second bleed gas by the classification unit 22. The temperature of the second bleed gas when separating the raw material dust from the second bleed gas in the classification unit 22 is maintained at 770 ° C. or higher, preferably 820 ° C., more preferably 860 ° C. or higher, so that chlorine such as KCl and NaCl is maintained. Minutes are in a volatile state. By performing a circulation step of returning the raw material dust separated from the second bleed gas in the classification unit 22 to the kiln tail 52 of the cement kiln 50, it can be effectively used as a raw material for cement clinker.

In the cooling step, the first bleed air gas is cooled to less than 770 ° C. without being introduced into the classification unit 22. As a result, volatilized chlorine such as KCl and NaCl contained in the first bleed air gas is precipitated or precipitated on the surface of the raw material dust to become clinker dust. The cooling temperature of the first bleed gas in the cooling step may be 600 ° C. or lower, or 500 ° C. or lower, from the viewpoint of heat resistance of the equipment. Another cooling step may be performed to cool the second bleeding step after separating the raw material dust in the classification step. Also in this case, the second bleed air gas is cooled to less than 770 ° C., preferably 600 ° C. or lower, more preferably 500 ° C. or lower. As a result, the volatilized chlorine contained in the second bleed air gas is deposited on the surface of the raw material dust to become clinker dust.

In the mixing unit 30, the first bleed gas and the second bleed gas may be merged to obtain a mixed gas. Then, the mixed gas is cooled to, for example, less than 260 ° C., preferably less than 200 ° C. in the cooling unit 35, and then the clinker dust is collected in the recovery unit 37. By this manufacturing method, the chlorine bypass equipment 90 and the cement clinker manufacturing apparatus 100 can be stably operated. In addition, the cement clinker can be efficiently produced by effectively utilizing the raw material dust. In addition, clinker dust is reduced, and the processing cost of clinker dust can be reduced. The order of cooling and mixing the first bleed gas and the second bleed gas, and the number of times of cooling are not particularly limited.

The operation method of the chlorine bypass equipment according to one embodiment may include the above-mentioned bleeding step, classification step, cooling step and dust recovery step. Further, it may have the above-mentioned circulation step, or may further have any step of the above-mentioned method for producing cement clinker. The content of each step may be the same as the content in the above-mentioned method for producing cement clinker.

The above-mentioned description of the chlorine bypass equipment 90 and the cement clinker manufacturing apparatus 100 also applies to the above-mentioned description of the method for manufacturing the cement clinker and the method for operating the chlorine bypass equipment. Further, the description of the manufacturing method and the operation method is also applied to the description of the chlorine bypass equipment 90 and the cement clinker manufacturing apparatus 100 described above.

FIG. 5 is a diagram showing a chlorine bypass facility according to another embodiment and a cement clinker manufacturing apparatus including the chlorine bypass facility. The chlorine bypass equipment 92 and the cement clinker manufacturing apparatus 102 of the present embodiment are provided with one bleeding port 70A in the rising duct 42, and the bleeding pipe 70 is connected to the bleeding port 70A. The bleeding pipe 70 branches into two, a first bleeding pipe 11 and a second bleeding pipe 21 at the branching portion 72. As a result, the bleed air drawn by the bleed air port 70A is divided into a first bleed air gas that flows through the first bleed air pipe 11 and a second bleed air gas that circulates through the second bleed air pipe 21.

The first flow path 10A collects the first bleed pipe 11, the cooling unit 13 that cools the temperature of the first bleed gas to less than 770 ° C., and the dust contained in the first bleed gas downstream of the cooling unit 13. It has a collection unit 37 (first collection unit) and a suction unit 38 (first suction unit) that sucks the first bleed air gas downstream of the collection unit 37.

The second flow path 20A includes a second bleed pipe 21, a classification unit 22 to which the second bleed pipe 21 is connected, a cooling unit 27 that cools the second bleed gas downstream of the classification unit 22, and a cooling unit 27. A recovery unit 37A (second collection unit) that collects dust contained in the second bleed air gas downstream from the collection unit 37A, and a suction unit 38A (second suction unit) that sucks the second bleed air gas downstream from the collection unit 37A. , Have. The collection unit 37A and the suction unit 38A may have the same device configuration as the collection unit 37 and the suction unit 38.

The chlorine bypass equipment 92 has only one bleed air port 70A. Therefore, even if the space around the rising duct 42 and the kiln tail 52 is limited, it is possible to provide a plurality of flow paths through which the bleed air gas flows. That is, the chlorine bypass equipment 92 and the cement clinker manufacturing apparatus 102 also include a first flow path 10A and a second flow path 20A having a classification unit 22 for separating raw material dust from the bleed air gas. Therefore, it is possible to flexibly respond to fluctuations in the operating state. For example, the flow rate of the bleed gas flowing through each of the first flow path 10A and the second flow path 20A can be adjusted according to the amount of cleana dust in the recovery unit and the chlorine concentration of the cleanka dust, or the flow rate of one of the bleed gas can be adjusted. It is also possible to stop the distribution. As described above, according to the chlorine bypass equipment 92 and the cement clinker manufacturing apparatus 102 provided with the chlorine bypass equipment 92, the operating state can be flexibly adjusted according to the amount and properties of the clinker dust. Therefore, the chlorine bypass equipment 92 and the cement clinker manufacturing apparatus 102 can be operated stably and efficiently.

As described above, the chlorine bypass equipment 92 has one bleeding port 70A and is branched into the first flow path 10A and the second flow path 20A at the branch portion 72, as well as the first flow path 10A and the first flow path 20A. The second flow path 20A differs from the chlorine bypass equipment 90 in FIG. 1 in that the second flow path 20A has a recovery unit (collection unit 37, 37A) and a suction unit (suction unit 38, suction unit 38A), respectively. Since the other points are the same as those of the chlorine bypass equipment 90 and the cement clinker manufacturing apparatus 100, the description of the chlorine bypass equipment 90 and the cement clinker manufacturing apparatus 100 is applied.

The cement clinker manufacturing method may be carried out using the cement clinker manufacturing apparatus 102. The chlorine bypass operation method may be performed using the chlorine bypass facility 92. In these cases, in the bleeding step, the kiln exhaust gas generated in the firing step is bleeded from the bleeding port 70A, and then a branching step of separating the first bleeding gas and the second bleeding gas at the branching portion is performed. In the dust recovery step, the first bleed air gas obtained in the branching step is cooled to less than 770 ° C. As a result, volatilized chlorine such as KCl and NaCl contained in the first bleed air gas is precipitated or precipitated on the surface of the raw material dust to become clinker dust. Further, the second bleed gas obtained in the branching step is classified by the classification unit 22, and the second bleed gas with reduced raw material dust is also cooled to less than 770 ° C. in a cooling step. As a result, volatilized chlorine such as KCl and NaCl contained in the second bleed air gas is precipitated or precipitated on the surface of the raw material dust to become clinker dust. The first bleed air gas and the second bleed air gas are cooled to, for example, less than 260 ° C., preferably less than 200 ° C. in the cooling units 35 and 27, respectively, and then the clinker dust is collected in the collection units 37 and 37A. Other steps are the same as when the cement clinker manufacturing apparatus 100 and the chlorine bypass equipment 90 are used. Further, the description of the chlorine bypass facility 92 and the cement clinker manufacturing apparatus 102 described above also applies to the description of the manufacturing method and the operating method. Further, the description of the manufacturing method is also applied to the description of the chlorine bypass equipment 92 and the cement clinker manufacturing apparatus 102.

According to this manufacturing method or operating method, the chlorine bypass equipment 92 and the cement clinker manufacturing apparatus 102 can be stably operated, and the cement clinker can be efficiently manufactured. Further, since the first flow path 10A and the second flow path 20A downstream of the branch portion 72 can operate independently, even if one of the first flow path 10A and the second flow path 20A stops. , The other operation can be continued. Therefore, the reliability of the chlorine bypass equipment 92 and the cement clinker manufacturing apparatus 102 can be sufficiently increased.

Although some embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. For example, each configuration of each embodiment and each modification may be combined or interchanged. For example, the chlorine bypass equipment 92 may include a mixing unit 30 like the chlorine bypass equipment 90. As a result, the cooling unit, the recovery unit, and the suction unit on the downstream side of the mixing unit 30 can be integrated into one system.

For example, the chlorine bypass facility 90 may have one bleed air port and a branch portion like the chlorine bypass facility 92. Further, at the branch portion, the bleed air gas may be divided into three or more. A recovery unit and a suction unit may be individually provided in the flow path through which the separated bleed air gas flows, as in the chlorine bypass equipment 92, or a mixing unit may be provided in the flow path in which the separated bleed air gas flows. The cleaner dust may be collected by merging.

According to the present disclosure, a chlorine bypass facility capable of operating stably and efficiently is provided. Further, in the present disclosure, a cement clinker manufacturing apparatus and a cement clinker manufacturing method capable of stably operating and efficiently manufacturing a cement clinker by providing such a chlorine bypass facility are provided. Will be done.

10,10A ... 1st flow path, 11 ... 1st bleeding tube, 11A ... 1st bleeding port, 13,25,27,35 ... cooling unit, 20,20A ... 2nd flow path, 21 ... 2nd bleeding tube, 21A, 21B, 21C, 21D, 21E, 21F, 21G, 21H ... 2nd air extraction port, 21h ... partition plate, 22 ... classification section, 26 ... circulation flow path, 30 ... mixing section, 37, 37A ... recovery section, 38 , 38A ... Suction part, 40 ... Preheating calcining part, 42 ... Rising duct, 44 ... Temporary firing furnace, 50 ... Cement kiln, 52 ... Kiln butt, 54 ... Burner, 56 ... Kiln body, 60 ... Clinker cooler, 70A ... Extraction port, 70 ... Extraction pipe, 72 ... Branch part, 90, 92 ... Chlorine bypass equipment, 100, 102 ... Cement clinker manufacturing equipment, C1, C2, C3, C4 ... Cyclone.

Claims (10)

A cement kiln kiln butt, a rising duct, or an air outlet for extracting kiln exhaust gas from between them,
It is provided with a plurality of flow paths for circulating the bleed air gas drawn from the bleed air port at different temperatures.
The plurality of flow paths include a first flow path having a cooling unit for cooling the temperature of the bleed air gas to less than 770 ° C., and a raw material contained in the bleed air gas in a state where the temperature of the bleed air gas is maintained at 770 ° C. or higher. A chlorine bypass facility comprising a second flow path having a classifying portion for separating dust from the bleed gas. It is equipped with a plurality of the above-mentioned bleed air ports.
The chlorine bypass facility according to claim 1, wherein the first flow path and the second flow path draw bleed air from the bleed air ports that are different from each other. The chlorine bypass facility according to claim 2, wherein the area of the second bleed air port to which the second flow path is connected is smaller than the area of the first bleed air port to which the first flow path is connected. The chlorine bypass facility according to any one of claims 1 to 3, further comprising a circulation flow path for returning the raw material dust separated in the classification section to the cement kiln side. A mixing section that merges the first extracted gas that has flowed through the first flow path and the second extracted gas that has flowed through the second flow path to obtain a mixed gas, and a recovery unit that collects the chlorine dust contained in the mixed gas. The chlorine bypass facility according to any one of claims 1 to 4, further comprising a section and a suction section for sucking the mixed gas on the downstream side of the recovery section. The chlorine bypass facility according to claim 5, further comprising a flow rate adjusting unit for adjusting the flow rate of at least one of the first bleed gas and the second bleed gas. The first flow path and the second flow path are provided with a recovery unit for collecting dust contained in the bleed air gas cooled to less than 260 ° C. and a suction unit for sucking the bleed air gas, respectively. The chlorine bypass equipment according to any one of 4 to 4. A cement clinker manufacturing apparatus provided with the chlorine bypass equipment according to any one of claims 1 to 7. A method for manufacturing a cement clinker, which manufactures a cement clinker using the cement clinker manufacturing apparatus according to claim 8. The extraction process of extracting the kiln exhaust gas generated when the cement raw material is fired in the cement kiln to obtain the first extraction gas and the second extraction gas, and
A classification step of classifying the second bleed gas while maintaining a temperature of 770 ° C. or higher to separate raw material dust contained in the second bleed gas.
A cooling step of cooling the first bleed air gas to less than 770 ° C. without classifying the first bleed air gas.
A method for operating a chlorine bypass facility, comprising: a dust recovery step of recovering clinker dust contained in the second bleed gas from which the raw material dust has been separated and the first bleed gas cooled to less than 770 ° C.

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