Chlorine bypass facility, cement clinker manufacturing apparatus, cement clinker manufacturing method, chlorine bypass facility operation method, and waste treatment method

Abstract

To provide a technique capable of transporting coarse powder and enhancing a freedom degree of an installation position of a classification part.SOLUTION: A chlorine bypass facility 90 comprises: an extraction hole 21A for extracting a kiln exhaust gas, from a furnace tail 52 of a cement kiln 50, a rising duct 42 or a space therebetween; a classifying part 22 for separating coarse powder of raw material dust from the extracted gas extracted through the extraction hole 21A, and acquiring a derivation gas having a temperature of 770°C or greater and including fine powder of the raw material dust; and a mixing part 30 for mixing, coarse powder separated by the classifying part 22 and moisture-containing waste W.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a chlorine bypass facility, a cement clinker production apparatus, a cement clinker production method, a chlorine bypass facility operation method, and a waste treatment method. [Background technology]

[0002] In cement clinker manufacturing plants, efforts are being made to use various waste materials as raw materials and thermal energy sources. For these reasons, the amount of chlorine brought into the cement kiln tends to increase. Many cement clinker manufacturing plants are equipped with chlorine bypass equipment to reduce the chlorine in the cement kiln, and technology is being considered to efficiently remove chlorine from the bleed gas bled by this chlorine bypass equipment. Patent Document 1 proposes a technology in which coarse particles are separated from the bleed gas in a classifier while maintaining the temperature of the bleed gas bled from the kiln exhaust gas flow path at 770°C or higher, and then the chlorine bypass dust is separated by cooling the gas to 600°C or lower. Patent Document 1 also shows that the separated coarse particles are returned to the cement kiln system. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-55900 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the coarse powder classified from the bleed gas with the temperature maintained at 770°C or higher is very hot dust, and therefore difficult to handle. Specifically, there is no mechanical or pneumatic conveyor capable of transporting the coarse powder, which can reach temperatures of about 1000°C, making it difficult to transport the coarse powder. It is possible to return the coarse powder to the cement kiln using a chute or the like without using a conveyor, but in this case, there are conditions for the installation position and angle of the chute to move the coarse powder appropriately. This causes a problem of significant restrictions on the installation location of the classifier.

[0005] The present disclosure has been made in consideration of the above, and aims to provide a technology that enables the transport of coarse powder and increases the freedom in the installation location of the classifier. [Means for solving the problem]

[0006] In order to achieve the above object, a chlorine bypass equipment according to one aspect of the present disclosure has an extraction port that extracts kiln exhaust gas from the bottom of a cement kiln, a rising duct, or a space between them, a classification section that separates coarse powder of raw material dust from the extracted gas extracted from the extraction port and obtains an output gas having a temperature of 770°C or higher containing fine powder of the raw material dust, and a mixing section that mixes the coarse powder separated in the classification section with moist waste.

[0007] According to the above-mentioned chlorine bypass facility, the coarse powder separated in the classification section is mixed with the water-containing waste in the mixing section. At this time, the hot coarse powder is cooled by the water-containing waste, making it possible to transport it by a transport vehicle, and increasing the freedom of the installation position of the classification section.

[0008] The water-containing waste may be at least one of sludge and waste liquid. In this case, the mixture of the water-containing waste and the coarse powder has properties suitable for returning to the cement kiln. In addition, by mixing the high-temperature coarse powder and the water-containing waste, the water in the water-containing waste can be volatilized, suppressing deterioration of fuel consumption of the cement kiln, and further suppressing deterioration of draft in the cement kiln due to an increase in the volume of the volatilized water. Therefore, it is possible to suppress operational fluctuations of the cement kiln caused by the input of the water-containing waste, and stable treatment of the water-containing waste is possible.

[0009] The present invention may further include a cooling gas inlet section for introducing a cooling gas into a flow path through which the discharge gas discharged from the classifier flows, and a steam supply section for introducing steam generated in the mixing section into the cooling gas inlet section as a part of the cooling gas. Clinker dust made of fine powder of raw material dust has a very small particle size and is likely to cause clogging of a bag filter and blockage of a flow path. Therefore, by using the steam generated in the mixing section as a part of the cooling gas, the clinker dust can be coarsened, and blockage of the bag filter and the flow path can be suppressed.

[0010] The cooling gas inlet may introduce the cooling gas so as to generate a swirling flow along the inner wall surface of the flow passage, whereby the generated swirling flow acts as an air curtain, and it is possible to prevent the clinker dust from adhering to the inner wall of the flow passage and causing coating.

[0011] An embodiment may further include an oxygen concentration management unit that manages the oxygen concentration in the mixing unit so that the oxygen concentration in the mixing unit is less than the limit oxygen concentration. The mixing unit is an environment in which combustible gases such as methane and / or dust may exist, and gas explosions and dust explosions may occur. Thus, by adopting a configuration having an oxygen concentration management unit as described above, the oxygen concentration in the mixing unit can be made less than the limit oxygen concentration to prevent the occurrence of gas explosions and dust explosions.

[0012] A cement clinker production apparatus according to an aspect of the present disclosure includes any one of the above-mentioned chlorine bypass facilities. Since the above-mentioned cement clinker production apparatus includes the above-mentioned chlorine bypass facility, it is possible to transport coarse powder and increase the degree of freedom in the installation position of the classifier.

[0013] A method for producing cement clinker according to an aspect of the present disclosure produces cement clinker using the above-mentioned cement clinker production apparatus. Since the above-mentioned method for producing cement clinker uses the above-mentioned chlorine bypass facility to produce cement clinker, it is possible to transport coarse powder and increase the degree of freedom in the installation position of the classifier.

[0014] A method for operating a chlorine bypass facility according to one aspect of the present disclosure includes an extraction process for obtaining kiln exhaust gas from the bottom of a cement kiln, a rising duct, or a space between these, a classification process for separating coarse particles of raw material dust from the extracted gas obtained in the extraction process and obtaining an output gas having a temperature of 770°C or higher containing fine particles of the raw material dust, and a mixing process for mixing the coarse particles separated in the classification process with water-containing waste in a mixing section.

[0015] According to the above-mentioned method for operating the chlorine bypass facility, the coarse powder separated in the classification process is mixed with the water-containing waste in the mixing section. At this time, the high-temperature coarse powder is cooled by the water-containing waste, making it possible to transport it by a transport vehicle, and increasing the degree of freedom in the installation position of the classification section that performs the classification process.

[0016] A waste treatment method according to one aspect of the present disclosure is a method for treating waste using a cement clinker manufacturing apparatus, and includes an extraction process for obtaining kiln exhaust gas from the bottom of a cement kiln, a rising duct, or a space between the two; a classification process for separating coarse powder of raw material dust from the extracted gas obtained in the extraction process and obtaining an output gas having a temperature of 770°C or higher containing fine powder of the raw material dust; a mixing process for mixing the coarse powder separated in the classification process with water-containing waste in a mixing section; and a feeding process for feeding the mixture obtained by the mixing process into the cement kiln.

[0017] According to the above waste treatment method, the coarse powder separated in the classification process is mixed with the wet waste in the mixing section. At this time, the high-temperature coarse powder is cooled by the wet waste, making it possible to transport it by a transport vehicle, and increasing the freedom of the installation location of the classification section that performs the classification process. Furthermore, by treating the waste with the above cement clinker production device, it is possible to suppress the operational fluctuation of the cement kiln caused by the input of the wet waste, and therefore it is possible to stably treat the wet waste. Effect of the Invention

[0018] According to the present disclosure, a technology is provided that enables the transport of coarse powder and increases the degree of freedom in the installation position of the classifier. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram showing a chlorine bypass facility according to one embodiment and a cement clinker production apparatus equipped with the facility. [Diagram 2] FIG. 2 is a diagram for explaining the configuration of the coarse particle introduction section in the chlorine bypass facility. [Diagram 3] FIG. 3 is a cross-sectional view showing a radial cross section of an outlet gas flow path to which a cooling gas inlet is connected. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings as needed. However, the following embodiment is an example for explaining the present disclosure, and is not intended to limit the present disclosure to the following content. In the description, the same reference numerals are used for the same elements or elements having the same functions, and redundant descriptions are omitted as needed. In addition, the positional relationships such as up, down, left, right, etc. are based on the positional relationships shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios of each element are not limited to the ratios shown in the drawings.

[0021] 1 is a diagram showing a chlorine bypass equipment according to one embodiment and a cement clinker manufacturing apparatus equipped with the same. The chlorine bypass equipment 90 is connected to a rising duct 42 of a preheating and calcining section 40 of a cement clinker manufacturing apparatus 100. The chlorine bypass equipment 90 recovers volatile matters such as chlorine content in the cement clinker manufacturing apparatus 100 as clinker dust, and reduces the chlorine content in the cement clinker manufacturing apparatus 100. The cement clinker manufacturing apparatus 100 may be configured to include a control unit 10.

[0022] The chlorine bypass equipment 90 has an extraction port 21A for extracting gas from the rising duct 42, and an extraction pipe 21 through which the extraction gas containing raw material dust extracted from the extraction port 21A flows. The chlorine bypass equipment 90 also has a classification section 22 for separating coarse particles of the raw material dust from the extraction gas to obtain an output containing fine particles of raw material dust smaller than the coarse particles, a flow path 24 through which the output gas flows, and a cooling gas introduction section 80 for introducing a cooling gas so as to generate a swirling flow in the flow path 24. The chlorine bypass equipment 90 also has a mixer 30 for mixing the coarse particles classified in the classification section 22 with the water-containing waste.

[0023] The bleed gas bled from the bleed port 21A contains raw material dust and gaseous chlorine. The bleed gas flows through the bleed pipe 21 and is introduced into the classification section 22. The bleed pipe 21 may be one called an bleed probe. The temperature of the bleed gas when introduced into the classification section 22 is preferably higher than 770°C, more preferably 820°C or higher, and even more preferably 860°C or higher, from the viewpoint of preventing volatilized chlorine such as KCl and NaCl from precipitating alone or on the surface of the raw material dust and adhering to the classification section 22 as clinker dust.

[0024] The classifier 22 separates the coarse particles of the raw dust by introducing the bleed gas and classifying it. The classifier 22 may be, for example, a cyclone. In the classifier 22, the bleed gas in the above-mentioned temperature range is classified, so that the coarse particles of the raw dust can be separated from the bleed gas while the chlorine content is contained in the gas phase. This prevents the volatilized chlorine content from precipitating alone or from precipitating on the surface of the raw dust, causing coating and clogging the classifier 22. It also prevents the raw dust from which chlorine has precipitated from returning to the cement kiln side through the circulation flow path.

[0025] From the viewpoint of suppressing the precipitation of chlorine in the coarse powder of raw material dust separated from the bleed gas in the classification section 22, the temperature of the bleed gas when the coarse powder of raw material dust is separated in the classification section 22 is set to 770°C or higher. The temperature of the bleed gas can be preferably 820°C or higher, more preferably 860°C or higher. The temperature of the outlet gas discharged from the classification section 22 is also set to 770°C or higher. The temperature of the outlet gas can be preferably 820°C or higher, more preferably 860°C or higher.

[0026] In addition, in the classification section 22, the exhaust gas from the combustion furnace may be mixed with the bleed gas. In this case, a mixed gas containing the bleed gas and the exhaust gas is obtained in the classification section 22. In addition, an example of a combustion furnace that generates an exhaust gas is a combustion furnace in a waste plastic desalination facility. The combustion furnace is a furnace that burns tar contained in a pyrolysis gas generated by heat treating a raw material containing waste plastic. When the exhaust gas from the combustion furnace is introduced into the classification section 22 and mixed with the bleed gas, the temperature of the gas mixed in the classification section 22 can be stably increased compared to the case of the bleed gas alone. In addition, when the exhaust gas from the combustion furnace and the bleed gas are merged, the flow rate of the gas mixed in the classification section 22 can be increased. Therefore, the classification performance in the classification section 22 is improved, and the coarse powder of the raw material dust can be separated from the mixed gas with higher accuracy.

[0027] The exhaust gas that merges with the bleed gas in the chlorine bypass facility 90 is not limited to the exhaust gas from the combustion furnace of the waste plastic desalination facility, but may be exhaust gas from a combustion furnace other than the combustion furnace of the waste plastic desalination facility. For example, the exhaust gas may be high-temperature exhaust gas from a combustion furnace, an ammonia gasification furnace, a sulfur combustion furnace, or a combustion furnace or melting furnace other than these, which are provided in a biomass pellet carbonization facility. One of these exhaust gases may be used alone, or a combination of multiple exhaust gases may be used.

[0028] The particle size of the coarse powder 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 so that the coarse powder has a size of 14 μm or more, the volatile content can be sufficiently reduced.

[0029] The coarse powder of the raw dust separated from the bleed gas in the classification section 22 is introduced into the mixing section 30. The mixing section 30 is a sealed container that stores the coarse powder of the raw dust. In addition, the water-containing waste W is introduced into the mixing section 30. Inside the mixing section 30, a stirring blade 31 for mixing the coarse powder and the water-containing waste may be provided.

[0030] The water-containing waste refers to waste with a water content of 30% or more, for example. When the water content is 40% to 99%, it is suitable for mixing with coarse powder. The type of waste constituting the water-containing waste is not particularly limited, and may be, for example, either industrial waste or general waste. The water-containing waste may also include, for example, at least one of sludge and waste liquid.

[0031] The mixing ratio of the coarse powder and the water-containing waste in the mixing section 30 is not particularly limited, but for example, the two may be mixed so that the weight ratio of the coarse powder to the water-containing waste is about 1:99 to 70:30. Since the classification in the classification section 22 is performed at a high temperature as described above, the high-temperature coarse powder is introduced into the mixing section 30. On the other hand, the water-containing waste is in a state containing moisture, and its temperature is not particularly limited and may be room temperature. By mixing such water-containing waste and coarse powder, the moisture in the water-containing waste can be volatilized, and the deterioration of the fuel consumption of the cement kiln can be suppressed. In addition, when mixed at the above ratio, the temperature of the mixture of the coarse powder and the water-containing waste can be reduced to, for example, 400°C or less compared to the coarse powder immediately after classification. As a result, the handling of the mixture is improved. In addition, when the water-containing waste contains at least one of sludge and waste liquid, the mixture of the water-containing waste and the coarse powder has properties suitable for returning to the cement kiln.

[0032] In addition, the mixing section 30 may be configured such that, for example, the wet waste is stored in advance, and the coarse powder is dropped from the upper classification section 22, so that the two are mixed in the mixing section 30. In this case, the hot coarse powder is prevented from directly contacting the bottom surface of the mixing section 30, and damage to the container can be prevented.

[0033] The mixing section 30 may also be provided with a sensor 35 for managing the oxygen concentration inside. The sensor 35 measures the oxygen concentration inside. The measurement result by the sensor 35 is sent to the control section 10. The sensor 35 and the control section 10 manage the oxygen concentration inside the mixing section 30 so that it is less than the limit oxygen concentration. The limit oxygen concentration used as a threshold in managing the oxygen concentration is the "dust explosion limit oxygen concentration" and the "gas explosion limit oxygen concentration". Since water-containing waste such as sludge is used inside the mixing section 30, combustible gases such as methane are generated, which may cause a gas explosion. In addition, if the sludge is dried too much by mixing with the coarse powder, there is a risk of a dust explosion occurring inside the mixing section 30. Therefore, the oxygen concentration inside is monitored so that the oxygen concentration does not reach the limit oxygen concentration, which is the oxygen concentration at which a dust explosion and / or a gas explosion may occur. In this way, the sensor 35 and the control section 10 function as an oxygen concentration management section.

[0034] In addition, a coarse powder introduction section 23 may be provided between the classification section 22 and the mixing section 30 as a path for introducing the coarse powder from the classification section 22 into the mixing section 30. FIG. 2 is a schematic diagram of the coarse powder introduction section 23. The coarse powder introduction section 23 may be composed of a pipe formed of a cylindrical member extending in the vertical direction connecting the bottom surface of the classification section 22 and the top surface of the mixing section 30. In addition, two dampers 25a and 25b may be provided in the coarse powder introduction section 23. In this case, the coarse powder is introduced from the classification section 22 into the mixing section 30 via the two-stage dampers 25a and 25b. The dampers 25a and 25b may be controlled by the control section 10, for example, or may be gravity dampers that do not perform control.

[0035] Collision members 27a and 27b that collide with the coarse particles that have passed through the dampers 25a and 25b may be provided below the dampers 25a and 25b, respectively. The collision members 27a and 27b may have any shape as long as they are configured to disperse the coarse particles. For example, a plurality of rod-shaped members (FIG. 2 shows a cross section of a rod-shaped member) may be provided as the collision member 27a. Also, an umbrella-shaped member whose diameter increases from a top provided at the top toward the bottom may be provided as the collision member 27b. Also, the collision member may be formed by combining plate-shaped members. In this way, the collision member may have any shape that disperses the coarse particles. If the collision member 27b is provided below the downstream damper 25b, it is easy to form a state in which the coarse particles are dispersed in the water-containing waste. On the other hand, by providing the collision member 27a above the downstream damper 25b, two collision members 27a, 27b are provided from upstream to downstream, and a state in which the coarse particles are easily dispersed can be created in stages. The arrangement and number of the collision members can be changed as appropriate.

[0036] Returning to FIG. 1, the mixture after mixing in the mixing section 30 is introduced into the kiln end 52 of the cement kiln 50, since it is the raw material for cement clinker. The flow path 29 for returning the mixture may be, for example, a transport vehicle for mechanical transport. In this way, by returning the mixture of the coarse powder of the raw material dust extracted from the extraction port 21A and the water-containing waste to the kiln end 52, the mixture containing the coarse powder of the raw material dust can be used for manufacturing cement clinker. The mixture may be returned to the rising duct 42, the chute connecting the cyclone C4 and the kiln end 52, the calciner 44, or the kiln body 56, instead of the kiln end 52. Also, a plurality of flow paths 29 may be provided to return the mixture to a plurality of places.

[0037] The output gas output from the classifier 22 contains coarse and fine powder of the raw material dust that was not recovered in the classifier 22. When exhaust gas is introduced into the classifier 22, the Ca content contained in the raw material dust that was not recovered in the classifier 22 may react with the chlorine content such as HCl in the exhaust gas to generate solid CaCl2. Such chlorine content can also be recovered as clinker dust in the chlorine bypass facility 90.

[0038] The output gas containing fine raw material dust particles and gaseous chlorine, obtained by separating the coarse raw material dust particles from the bleed gas in the classifier 22, flows through a flow path 24 connected to the classifier 22 and is cooled in a cooling gas inlet 80. In the cooling gas inlet 80, a cooling gas flow path 81 is connected to the flow path 24 formed by a circular pipe 26, and the output gas containing the fine raw material dust particles and chlorine is mixed with the cooling gas and cooled. After cooling, the gas containing the output gas flows through the flow path 24 and is introduced into the cooling section 70.

[0039] The cooling gas may be air at room temperature, or may include exhaust gas of 200°C or less, preferably 100°C or less, generated in a factory or the like. Examples of exhaust gas include odorous gases generated during the reception, storage, and fermentation of water-containing sludge such as sewage sludge brought into a cement manufacturing plant, and exhaust gases discharged from the suction section 74 (see FIG. 1) described below and from the suction sections of other processes. One of these may be used alone, or two or more may be used in combination.

[0040] As an example, FIG. 1 shows a configuration in which room temperature air (outside air) is introduced into the above-mentioned cooling gas flow path 81. In addition to the outside air, steam generated in the mixing section 30 is partially introduced as the cooling gas. That is, as shown in FIG. 1, a flow path 37 for introducing steam from the mixing section 30 is connected to the cooling gas flow path 81 for introducing the outside air. The mixing section 30 is a so-called sealed container. In addition, high-temperature coarse powder is mixed with the water-containing waste, so that moisture evaporates. As a result, steam containing moisture is generated. By introducing this steam into the flow path 81 through the flow path 37, the outside air and steam are mixed and introduced into the cooling gas introduction section 80 as a cooling gas. That is, the flow path 37 and the flow path 81 connected to the flow path 37 function as a steam supply section for introducing the steam generated in the mixing section 30 into the cooling gas introduction section 80 as a part of the cooling gas.

[0041] The mixing ratio of outside air and steam in flow path 81 is not particularly limited. However, for example, since the steam from mixing section 30 is considered to be at a relatively high temperature, the mixing ratio may be adjusted from the standpoint of temperature control so that the temperature of the cooling gas does not become too high.

[0042] The outlet gas is mixed with the cooling gas and cooled in the cooling gas introduction section 80. The temperature of the gas containing the outlet gas after cooling (mixed gas of the outlet gas and the cooling gas) may be 600°C or less, or may be 500°C or less, from the viewpoint of the heat resistance of the equipment.

[0043] In the cooling gas inlet 80, the cooling gas is introduced so as to follow the circumferential direction of the inner wall surface of the flow passage 24 through which the discharge gas containing fine powder of raw material dust and chlorine flows. This generates a swirling flow in the flow passage 24, which can prevent the adhesion of clinker dust to the inner wall surface of the flow passage 24 and the occurrence of coating. Such a swirling flow forms an air curtain on the outer periphery of the flow passage 24, which can protect the inner wall surface of the circular pipe 26 constituting the flow passage 24 from the high-temperature discharge gas.

[0044] FIG. 3 is a cross-sectional view showing a radial cross section of the outlet gas flow path 24 to which the cooling gas introduction part is connected. The flow path 24, through which the outlet gas containing chlorine and fine powder of the raw material dust flows after the coarse powder of the raw material dust is separated, is composed of a circular pipe 26. When viewed in a radial cross section of the flow path 24 (circular pipe 26) as shown in FIG. 3, the flow path wall 28 forming the flow path 81 of the cooling gas introduction part 80 is connected to the circular pipe 26 so as to extend in a direction parallel to the tangential direction of the circular pipe 26. The cooling gas introduction part 80 connected to the circular pipe 26 introduces the cooling gas G flowing in the flow path 81 into the flow path 24. The introduced cooling gas G forms a swirling flow SF while merging with the outlet gas in the flow path 24. The swirling axis of the swirling flow SF coincides with the central axis P of the flow path 24 formed by the circular pipe 26.

[0045] The outlet gas flows through the center of the flow passage 24 along the axial direction of the central axis P, and the cooling gas G flows as a swirling flow SF along the inner wall surface 26W of the circular pipe 26 that constitutes the flow passage 24. In this manner, the gases are caused to flow through different flow passages in the flow passage 24 for the outlet gas and the cooling gas G. A small amount of clinker dust is generated at the boundary between the flow passage of the outlet gas and the flow passage of the cooling gas G, but the swirling flow SF acts as an air curtain, which can prevent the clinker dust from adhering to the inner wall surface 26W and causing coating.

[0046] As shown in Fig. 1, the chlorine bypass facility 90 includes a cooling section 70 for cooling the gas containing the outlet gas downstream of the cooling gas introduction section 80, a recovery section 72 for recovering dust (clinker dust) contained in the gas containing the outlet gas from the gas containing the outlet gas, and a suction section 74 for sucking the outlet gas. The cooling section 70 may be a water-cooled or air-cooled heat exchanger. The suction section 74 may be a normal suction fan such as a sirocco fan or a turbo fan.

[0047] The cooling section 70 cools the gas containing the outlet gas obtained by joining the cooling gas G and the outlet gas, for example, to less than 260°C, preferably less than 200°C. Since this gas containing the outlet gas contains clinker dust, it is introduced into the recovery section 72. The recovery section 72 may be a bag filter or a wet dust collector such as a wet scrubber. The clinker dust recovered in the recovery section 72 may be washed with water and then blended into a cement composition or used as a cement raw material.

[0048] 1 includes a chlorine bypass facility 90, a preheating and calcining unit 40 that preheats and calcines the cement raw materials, a cement kiln 50 that burns the preheated and calcined cement raw materials to obtain cement clinker, and a clinker cooler 60 that cools the cement clinker obtained in the cement kiln 50. The preheating and calcining unit 40 has four cyclones C1, C2, C3, and C4 (preheaters) and a calciner 44.

[0049] The bottom end 52 of the cement kiln 50 and the calciner 44 of the preheating calcination section 40 are connected by a rising duct 42. Near the connection between the rising duct 42 and the bottom end 52, an extraction port 21A of a chlorine bypass equipment 90 is provided, which extracts the kiln exhaust gas generated in the cement kiln 50 and recovers the dust contained in the kiln exhaust gas. An extraction pipe 21 is connected to the extraction port 21A. By providing the chlorine bypass equipment 90, the cement clinker production apparatus 100 can reduce the chlorine content in the cement clinker production apparatus 100.

[0050] The cement raw materials introduced from the connection between cyclone C1 and cyclone C2 flow through cyclone C1, cyclone C2, cyclone C3, rising duct 42, calciner 44, and cyclone C4, and are introduced into the kiln end 52 of the cement kiln 50. In the cement kiln 50, the preheated and calcined cement raw materials are heated by combustion in a burner 54 provided on the opposite side of the kiln end 52, and become cement clinker. The obtained cement clinker is cooled in a clinker cooler 60. After being cooled in the clinker cooler 60, cement clinker is obtained.

[0051] As described above, the control unit 10 has a function as an oxygen concentration management unit that manages the oxygen concentration in the mixing unit 30 to be less than the limit oxygen concentration based on the oxygen concentration measured by the sensor 35. When the oxygen concentration is likely to be the limit oxygen concentration or more, the control unit 10 may be configured to, for example, warn an administrator or the like who manages the cement clinker manufacturing apparatus 100. In addition, when the mixing unit 30 has a water sprinkling mechanism inside, the oxygen concentration may be reduced by sprinkling water inside under the control of the control unit 10. In addition, when the mixing unit 30 has a mechanism for introducing an inert gas such as nitrogen inside, the oxygen concentration may be reduced by introducing an inert gas inside under the control of the control unit 10. In this way, the control unit 10 functions as an oxygen concentration management unit that manages the oxygen concentration inside the mixing unit 30.

[0052] The control unit 10 may control each part of the cement clinker manufacturing apparatus 100, not limited to the mixing unit 30. The control unit 10 may control the cement clinker manufacturing apparatus 100 based on information measured by a measuring unit provided in each part of the cement clinker manufacturing apparatus 100. Examples of operation information measured by the measuring unit include temperature, pressure, gas components, gas flow rate, dust concentration, and images. Taking the chlorine bypass as an example, specific examples include the temperature inside or on the surface of the extraction pipe 21, the classification unit 22, and the flow path 24, the temperature of the kiln exhaust gas at the rising duct 42 and the kiln end 52, the temperature of the kiln exhaust gas flowing into the extraction pipe 21 from the extraction port 21A, the pressure of the kiln exhaust gas and the extraction gas, the gas components of the kiln exhaust gas and the extraction gas, the dust concentration contained in the kiln exhaust gas and the extraction gas, and images of the inside of the extraction pipe 21 and the classification unit 22. Examples of the measuring unit include a temperature sensor, a pressure sensor, a gas component sensor, a flow rate sensor, and a camera.

[0053] The control unit 10 may output a control signal for adjusting the flow rate of the exhaust gas based on the operating information measured by the above-mentioned measuring unit. The control unit may be a normal computer system, and may include, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and an input / output interface.

[0054] The control unit 10 may also have a function of automatically controlling the flow rate of the exhaust gas from the combustion furnace. For example, the temperature of the exhaust gas discharged from the classifier 22 may be measured by a measuring unit, and the flow rate of the exhaust gas that merges with the bleed gas may be controlled to increase according to the measurement result. This makes it possible to prevent the temperature of the classifier 22 from dropping too much.

[0055] The cement clinker production apparatus 100 is equipped with the chlorine bypass equipment 90, and therefore can operate stably and produce cement clinker stably. In addition, the yield of cement clinker can be increased by effectively utilizing raw material dust. In addition, the amount of clinker dust is reduced, and the cost of treating the clinker dust can be reduced.

[0056] [Manufacturing method of cement clinker] A method for producing cement clinker according to an embodiment can be performed using a cement clinker production apparatus 100. These methods may include a preheating and calcining step of preheating and calcining the cement raw material in the preheating and calcining section 40, a firing step of introducing the preheated and calcined cement raw material from the kiln bottom 52 into the kiln body 56 to produce cement clinker, an extraction step of extracting the kiln exhaust gas generated in the firing step to obtain an extraction gas, a classification step of separating coarse powder of the raw material dust from the extraction gas containing the raw material dust in the classification section 22, a cooling gas introduction step of introducing a cooling gas so as to generate a swirling flow in a flow path through which the outlet gas in which the coarse powder of the raw material dust is reduced and which is discharged from the classification section 22 flows, a cooling step of cooling the gas containing the outlet gas, and a dust recovery step of recovering the clinker dust contained in the gas containing the outlet gas cooled in the cooling step. The method may also include a mixing step in which the coarse powder of the raw material dust separated in the classification step is mixed with the water-containing waste in a mixing section 30, and a charging step in which the mixture obtained in the mixing step is returned to the cement kiln 50. The method may also include a clinker cooling step in which the cement clinker obtained in the burning step is cooled in a clinker cooler 60.

[0057] In the preheating and calcining process, the cement raw material is introduced from a flow path between cyclones C1 and C2. The cement raw material is preheated by flowing through cyclones C1, C2, and C3. It is then introduced into a calciner 44 and calcined. The calciner 44 may be provided with a burner that burns a thermal energy source such as coal. The cement raw material calcined in the calciner 44 (calcined raw material) is introduced into cyclone C4 and heated.

[0058] In the firing process, the calcined raw material heated in the cyclone C4 is introduced into the kiln end 52. It is then fired in the kiln body 56 to become cement clinker. In the extraction process, the kiln exhaust gas generated in the firing process is extracted from the extraction port 21A. In the classification process, the coarse powder of the raw material dust can be separated while the chlorine content is contained in the extracted gas as a gas phase. This prevents the volatilized chlorine content from precipitating alone or on the surface of the raw material dust, causing coating and clogging the classification section 22. It also prevents the raw material dust from precipitating chlorine from returning to the cement kiln side through the circulation flow path.

[0059] In the mixing process, the coarse powder of the raw material dust obtained in the classification process is mixed with the wet waste. By performing the mixing process, the temperature of the high-temperature coarse powder obtained in the classification process can be lowered, improving the handling of the mixture. In addition, by performing a circulation process in which the mixture is returned to the kiln end 52 of the cement kiln 50, the production amount of cement clinker can be efficiently increased. In addition, by mixing the coarse powder and the wet waste, the moisture in the wet waste can be volatilized, which can suppress the deterioration of the fuel consumption of the cement kiln, and further suppress the deterioration of the draft in the cement kiln due to the increase in the volume of the volatilized moisture. Therefore, the operational fluctuation of the cement kiln caused by the input of the wet waste can be suppressed, and stable processing of the wet waste can be achieved.

[0060] In the cooling gas introduction step, the cooling gas is mixed with the outlet gas discharged from the classification section 22 to cool the outlet gas. At this time, the steam generated in the mixing section 30 may be introduced into the cooling gas introduction section 80 as a part of the cooling gas.

[0061] Also, a swirling flow may be generated by introducing a cooling gas along the circumferential direction of the inner wall surface of the flow path 24 for the gas containing the outlet gas, which is constituted by the circular pipe 26. This makes it possible to prevent the adhesion of clinker dust to the flow path 24 and the occurrence of coating. The temperature of the gas containing the outlet gas cooled by mixing the cooling gas G in the cooling gas introduction step may be 600°C or less, or may be 500°C or less, from the viewpoint of the heat resistance of the equipment. By cooling the outlet gas in this way, the volatilized chlorine component precipitates alone or on the surface of the raw material dust to form clinker dust.

[0062] In the cooling step, the gas containing the outlet gas is cooled, for example, to less than 260°C, preferably less than 200°C, in a cooling section 70 equipped with a heat exchanger. In the dust recovery step, dust contained in the gas containing the cooled outlet gas is recovered in a recovery section 72. The dust recovered in this manner is called clinker dust. This manufacturing method allows the chlorine bypass facility 90 and the cement clinker manufacturing apparatus 100 to be stably operated. In addition, the raw material dust can be effectively utilized to efficiently manufacture cement clinker. In addition, the amount of clinker dust is reduced by separating the coarse powder of the raw material dust in the classification step, and the cost of treating the clinker dust can be reduced.

[0063] [Bypass facility operation method] The operating method of the chlorine bypass facility according to one embodiment may include the above-mentioned gas extraction process, classification process, mixing process, cooling process, and dust recovery process. It may also include the above-mentioned feeding process, or may further include any of the processes in the above-mentioned cement clinker manufacturing method. This operating method can be performed using the chlorine bypass facility 90 provided in the cement clinker manufacturing apparatus 100. Therefore, the content of each process may be the same as that in the above-mentioned cement clinker manufacturing method.

[0064] [Waste disposal method] The above-mentioned method for producing cement clinker can also be called a method for treating waste. That is, the method for treating waste according to one embodiment is a method for treating waste in the above-mentioned cement clinker production apparatus 100, and may include the above-mentioned feeding step, air extraction step, classification step, mixing step, and feeding step. It may further include a cooling step and a dust recovery step. It may also further include any of the steps of the above-mentioned method for producing cement clinker.

[0065] [Effect] According to the above example, the coarse powder separated in the classification unit 22 is mixed with the wet waste W in the mixer 30. At this time, the high-temperature coarse powder is cooled by the wet waste W, making it possible to transport it by a transport vehicle, and thus increasing the degree of freedom in the installation position of the classification unit.

[0066] Conventionally, it has been considered to classify the bleed gas under conditions in which an outlet gas of 770°C or more is discharged. At this time, the coarse powder obtained by classification may also be at a high temperature. The coarse powder obtained by classification may be returned to the preheating calcination section 40. However, it has been difficult to transport high-temperature coarse powder using conventional conveyors. Specifically, there is a problem that it is difficult to transport the coarse powder because there is no mechanical or pneumatic conveyor capable of transporting coarse powder that may be at about 1000°C. To address this issue, it is possible to return the coarse powder to the cement kiln using a chute or the like without using a conveyor. In this case, it is necessary to design the chute so that the coarse powder can be reliably returned, and strict conditions are imposed, particularly on the installation position and design of the classifier. Thus, there has been a problem that it is difficult to design the device due to the poor handleability of the high-temperature coarse powder after classification.

[0067] In contrast, by adopting the above-mentioned configuration, the coarse powder is mixed with the water-containing waste W in the mixer 30. The resulting mixture is cooled compared to the coarse powder, and therefore reaches a temperature at which it can be transported using a transport vehicle. Therefore, it is possible to adopt an arrangement of the classifier 22 that takes into account transportation using a transport vehicle, and the design freedom of the chlorine bypass equipment 90 including the classifier 22 is increased.

[0068] In addition, when the wet waste W contains at least one of sludge and waste liquid, the mixture of the wet waste and coarse powder has properties suitable for returning to the cement kiln. In addition, by mixing the high-temperature coarse powder with the wet waste, the water in the wet waste is evaporated, which can suppress deterioration of fuel consumption of the cement kiln and can also suppress deterioration of draft in the cement kiln due to an increase in the volume of evaporated water. Therefore, it is possible to suppress operational fluctuations of the cement kiln caused by the input of the wet waste, and stable processing of the wet waste is possible.

[0069] Furthermore, in the above example, the embodiment may further include a cooling gas inlet 80 for introducing a cooling gas into the flow path through which the derived gas discharged from the classifier 22 flows, and flow paths 37 and 81 that function as steam supplying parts for introducing steam generated in the mixer 30 into the cooling gas inlet as part of the cooling gas. Clinker dust made from fine powder of raw material dust has a very small particle size and is likely to cause clogging of the bag filter and blockage of the flow path. Therefore, by using the steam generated in the mixer as part of the cooling gas, the clinker dust can be coarsened, and blockage of the bag filter and the flow path can be suppressed.

[0070] The cooling gas inlet 80 may also introduce the cooling gas so that a swirling flow is generated along the inner wall surface of the flow passage. This makes it possible to prevent the clinker dust from adhering to the inner wall of the flow passage and causing coating by the generated swirling flow acting as an air curtain.

[0071] Furthermore, the mixing section 30 may further include a sensor 35 and a control section 10 as an oxygen concentration control section that controls the oxygen concentration in the mixing section 30 so that the oxygen concentration in the mixing section 30 becomes the limit oxygen concentration. The mixing section 30 is an environment in which combustible gases such as methane and / or dust may exist, and there is a possibility of a gas explosion or dust explosion occurring. Therefore, by configuring the mixing section 30 to include an oxygen concentration control section as described above, it is possible to prevent the occurrence of a gas explosion or dust explosion in the mixing section 30.

[0072] In the above example, the cement clinker production apparatus 100 has the above-mentioned chlorine bypass equipment 90. Since the above-mentioned cement clinker production apparatus 100 includes the above-mentioned chlorine bypass equipment 90, it is possible to transport coarse powder and increase the degree of freedom in the installation position of the classifier.

[0073] Moreover, the above-mentioned method for producing cement clinker produces cement clinker using the above-mentioned cement clinker production apparatus 100. The above-mentioned method for producing cement clinker produces cement clinker using the above-mentioned chlorine bypass facility 90, so that it is possible to transport coarse powder and increase the degree of freedom in the installation position of the classifier.

[0074] The operating method of the chlorine bypass equipment 90 includes an extraction process of obtaining kiln exhaust gas from the bottom of the cement kiln, a rising duct, or between them, a classification process of separating coarse powder of raw material dust from the extracted gas obtained in the extraction process to obtain an output gas having a temperature of 770°C or higher containing fine powder of raw material dust, and a mixing process of mixing the coarse powder separated in the classification process with water-containing waste in a mixing section. According to this operating method of the chlorine bypass equipment, the coarse powder separated in the classification process is mixed with water-containing waste in the mixing section. At this time, the high-temperature coarse powder is cooled by the water-containing waste, making it possible to transport it by a transport machine, and increasing the degree of freedom in the installation position of the classification section for performing the classification process.

[0075] Furthermore, the above waste treatment method is a method for treating waste by the cement clinker manufacturing apparatus 100, and includes an extraction process for obtaining kiln exhaust gas from the bottom of the cement kiln, a rising duct, or a gap between them, a classification process for separating coarse powder of raw material dust from the extracted gas obtained in the extraction process to obtain an output gas having a temperature of 770°C or higher containing fine powder of raw material dust, a mixing process for mixing the coarse powder separated in the classification process with water-containing waste in a mixing section, and a charging process for charging the mixture obtained in the mixing process into the cement kiln. According to the above waste treatment method, the coarse powder separated in the classification process is mixed with the water-containing waste in the mixing section. At this time, the high-temperature coarse powder is cooled by the water-containing waste, making it possible to transport it by a transport machine, and increasing the degree of freedom in the installation position of the classifier 22 for performing the classification process. In addition, by mixing the high-temperature coarse powder with the wet waste, the moisture in the wet waste is evaporated, which suppresses deterioration of fuel consumption of the cement kiln and suppresses deterioration of the draft in the cement kiln due to an increase in the volume of evaporated moisture. Therefore, the operation fluctuation of the cement kiln caused by the input of the wet waste can be suppressed, and the above-mentioned cement clinker production apparatus 100 enables stable processing of the wet waste.

[0076] [Variations] The disclosure in this specification should be considered to be illustrative and not restrictive in all respects. Various omissions, substitutions, modifications, etc. may be made to the above examples without departing from the scope of the claims and the gist thereof.

[0077] In the above embodiment, the air extraction port 21A is provided in the rising duct 42, but is not limited thereto. For example, the air extraction port 21A may be provided in the kiln end 52, or may be provided between the kiln end 52 and the rising duct 42 (or at the boundary).

[0078] Furthermore, when exhaust gas generated from a combustion furnace is used, the joining position with the bleed gas is not limited to the classifier 22. For example, the bleed gas and exhaust gas may join to become a mixed gas between the classifier 22 and the bleed port 21A, for example, in a flow path inside the bleed pipe 21. As another modified example, the flow path of the exhaust gas may be branched so that the exhaust gas is divided into a plurality of locations and joined with the bleed gas or the mixed gas. In this case, the flow rate of the exhaust gas joining at the plurality of joining sections may be individually adjustable.

[0079] In the above embodiment, the control unit 10 functions as an oxygen concentration control unit to control the oxygen concentration in consideration of the possibility of dust explosion and gas explosion in the mixing unit 30. However, instead of or in addition to this configuration, a configuration may be provided in which the dust concentration in the mixing unit 30 is monitored so that the dust concentration is below the "lower explosion limit concentration." Furthermore, instead of or in addition to the above configuration, a configuration may be provided in which the possibility of a steam explosion in the mixing unit 30 is considered.

[0080] The above-mentioned description of the chlorine bypass facility 90 and the cement clinker production apparatus 100 also applies to the above-mentioned description of the cement clinker production method and the operation method of the chlorine bypass facility. The above-mentioned description of the production method and the operation method also applies to the above-mentioned description of the chlorine bypass facility 90 and the cement clinker production apparatus 100.

[0081] Although several embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-mentioned embodiments. For example, in the above-mentioned embodiment, the coarse powder of the raw material dust separated in the classifier 22 is returned to the cement kiln 50 side through the flow path 27, but the present disclosure is not limited to this. For example, it may be placed in a tank of cement raw material and supplied to the preheating calcination section 40 as a cement raw material. In addition, the circular pipe 26 constituting the flow path 24 of the output gas may be arranged inclined with respect to the horizontal direction instead of being arranged horizontally. The chlorine bypass equipment may have a mixing chamber between the cooling gas introduction section 80 and the cooling section 70. [Explanation of symbols]

[0082] 10...control section, 21...air extraction pipe, 21A...air extraction port, 22...classification section, 24...flow path, 26...circular pipe, 25a, 25b...damper, 26W...inner wall surface, 27a, 27b...collision member, 28...flow path wall, 29...flow path, 30...mixing section, 31...agitating blade, 35...sensor, 37...flow path, 40...preheating calcination section, 42...rising duct, 44...calcination furnace, 50...cement kiln, 52...kiln bottom, 70...cooling section, 72...recovery section, 74...suction section, 80...cooling gas introduction section, 81...flow path, 90...chlorine bypass equipment, 100...cement clinker manufacturing apparatus, G...cooling gas, SF...swirling flow, W...moisture waste.

Claims

1. A method for producing cement clinker, comprising the steps of: producing cement clinker using a cement clinker production apparatus having a chlorine bypass facility, The chlorine bypass equipment includes an extraction port for extracting kiln exhaust gas from the bottom of a cement kiln, a rising duct, or a space between the two, a classification section for separating coarse particles of the raw material dust from the bleed gas bled from the bleed port to obtain an output gas containing fine particles of the raw material dust; A mixing section that mixes the coarse powder separated in the classification section with the wet waste; having The moisture content of the water-containing waste is 30% or more, an extraction step of obtaining the kiln exhaust gas from the bottom of the cement kiln, the rising duct, or a space between them; a classification step of separating the coarse particles of the raw material dust from the extracted gas obtained in the extraction step to obtain an output gas having a temperature of 770° C. or more and containing the fine particles of the raw material dust; a mixing step of mixing the coarse powder separated in the classification step and the water-containing waste in the mixing section; A method for producing cement clinker, comprising:

2. The manufacturing method described in claim 1, wherein the aqueous waste includes sludge.

3. A cooling gas introducing step of introducing a cooling gas into a flow path through which the outlet gas discharged from the classifier flows; a steam supplying step of introducing the steam generated in the mixing section into a cooling gas inlet section as a part of the cooling gas; The method of claim 1 or 2, further comprising:

4. A manufacturing method as described in claim 3, wherein in the cooling gas introduction process, the cooling gas is introduced so as to generate a swirling flow along the inner wall surface of the flow path.

5. A manufacturing method described in any one of claims 1 to 4, wherein the chlorine bypass equipment further has an oxygen concentration control section that controls the oxygen concentration in the mixing section so that the oxygen concentration in the mixing section is less than a limit oxygen concentration.

6. A method for operating a chlorine bypass system, comprising: The chlorine bypass equipment includes an extraction port for extracting kiln exhaust gas from the bottom of a cement kiln, a rising duct, or a space between the two, a classification section for separating coarse particles of the raw material dust from the bleed gas bled from the bleed port to obtain an output gas containing fine particles of the raw material dust; A mixing section that mixes the coarse powder separated in the classification section with the wet waste; having The moisture content of the water-containing waste is 30% or more, an extraction step of obtaining the kiln exhaust gas from the bottom of the cement kiln, the rising duct, or a space between them; a classification step of separating the coarse particles of the raw material dust from the extracted gas obtained in the extraction step to obtain an output gas having a temperature of 770° C. or more and containing the fine particles of the raw material dust; a mixing step of mixing the coarse powder separated in the classification step and the water-containing waste in the mixing section; A method for operating a chlorine bypass facility, comprising:

7. 1. A method for treating wet waste by a cement clinker manufacturing plant, comprising: an extraction process for extracting kiln exhaust gas from the bottom of the cement kiln, a rising duct, or a space between them; a classification step of separating coarse particles of the raw material dust from the extracted gas obtained in the extraction step to obtain an output gas having a temperature of 770° C. or more and containing fine particles of the raw material dust; a mixing step of mixing the coarse powder separated in the classification step with water-containing waste in a mixing section; A step of charging the mixture obtained by the mixing step into the cement kiln; Including, A method for treating wet waste, wherein the wet waste has a moisture content of 30% or more.

Images