Cement clinker manufacturing method, cement clinker manufacturing device, and program

Abstract

To detect falling off of a coating at an early stage.SOLUTION: The method of producing cement clinker, comprises a step of acquiring temperature information showing the temperature of the outer surface of a rotary kiln when cement clinker is being produced by the rotary kiln calcining a cement raw material, a step of detecting falling off of a coating from the inner wall of the rotary kiln, and a step of outputting the result of detecting the falling off of a coating.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for producing cement clinker, an apparatus for producing cement clinker, and a program. [Background technology]

[0002] Patent Document 1 discloses a cement manufacturing apparatus having a clinker cooler. This manufacturing apparatus has an image recognition means for recognizing an image of the clinker discharged from the clinker cooler, and switches the destination of the clinker depending on the whiteness of the clinker. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-73917 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a cement clinker manufacturing method, a cement clinker manufacturing device, and a program capable of detecting coating fall-off at an early stage. [Means for solving the problem]

[0005] A method for producing cement clinker according to one aspect of the present disclosure includes a step of acquiring temperature information indicating a temperature of an outer surface of a rotary kiln while cement clinker is being produced by the rotary kiln, which burns cement raw materials, a step of detecting falling of a coating from an inner wall of the rotary kiln based on the temperature information, and a step of outputting a detection result of the falling of the coating.

[0006] The coating on the inner wall of the rotary kiln has thermal insulation properties. Therefore, the temperature on the outer surface of the rotary kiln changes between when the coating is present on the inner wall of the rotary kiln and when at least a part of the coating falls off the inner wall. The present manufacturing method utilizes this temperature change property to detect the falling of the coating. This makes it possible to detect the falling of the coating at an early stage because the falling of the coating can be detected before it falls and is discharged from the rotary kiln.

[0007] The step of acquiring temperature information may include acquiring section temperature information indicating the temperature of the outer surface of the rotary kiln for each of a plurality of sections obtained by dividing the rotary kiln along the longitudinal direction of the rotary kiln. The step of detecting the coating drop may include detecting the coating drop for each of the plurality of sections based on the section temperature information. In this case, by identifying the section in which the coating drop was detected, it is possible to know in which area of ​​the rotary kiln the coating drop occurred.

[0008] The step of acquiring temperature information may include acquiring information indicative of the temperature of the outer surface of the rotary kiln at a plurality of points aligned along the direction of rotation of the rotary kiln. The step of detecting coating fall may include detecting coating fall based on the maximum value of the temperatures at the plurality of points. When coating fall occurs, the temperature of the point where the coating has fallen becomes higher than that of other points in the direction of rotation. In the above method, by measuring the temperature at a plurality of points and evaluating the presence or absence of coating fall at the maximum value, it becomes possible to accurately detect coating fall.

[0009] The step of detecting the falling of the coating may include determining that the coating has fallen when the amount of change per unit time of the temperature indicated by the temperature information exceeds a first threshold value, or when the temperature indicated by the temperature information exceeds a second threshold value. In this case, it is determined that the coating has fallen when at least one of the temperature change and the temperature itself exceeds a corresponding threshold value, so that the falling of the coating can be detected more reliably.

[0010] The method may further include detecting a coating drop based on information indicating the power supplied to the motor that rotates the rotary kiln. When the coating drop occurs, the power supplied to the motor that rotates the rotary kiln fluctuates. In the method, the power fluctuation is used to further detect the coating drop, making it possible to evaluate the validity of the detection result of the coating drop based on the temperature information.

[0011] The manufacturing method may further include a step of detecting the falling of the coating based on information indicating the wind pressure of a cooling gas used in a clinker cooler that cools the cement clinker produced by burning in the rotary kiln. When the fallen coating is sent to the clinker cooler, fluctuations occur in the wind pressure of the cooling gas. In the method, the falling of the coating is further detected using the fluctuations in the wind pressure, making it possible to evaluate the validity of the detection result of the falling of the coating based on the temperature information.

[0012] The above manufacturing method may further include a step of imaging the cement clinker discharged from a clinker cooler that cools the cement clinker produced by burning in the rotary kiln, and a step of determining whether or not the discharge of the coating from the clinker cooler is completed based on an image obtained by imaging the cement clinker discharged from the clinker cooler when the falling of the coating is detected. In this method, when it is determined that the discharge of the coating is completed, it can be estimated that the cement clinker discharged from the clinker cooler does not contain the coating, and therefore the possibility that the cement clinker containing the coating is shipped as a product can be reduced.

[0013] The above manufacturing method may further include a step of transporting the cement clinker produced by burning in the rotary kiln to a predetermined switching point, a step of switching the destination of the cement clinker at the switching point, a step of calculating the arrival time of the dropped coating at the switching point when the drop of the coating is detected, and a step of outputting the calculated arrival time. In this case, since the timing of the arrival of the coating at the switching point can be grasped, the destination can be switched according to that timing. As a result, the possibility that cement clinker mixed with the coating is shipped as a product can be reduced.

[0014] A cement clinker manufacturing apparatus according to one aspect of the present disclosure includes a rotary kiln for burning cement raw materials, a temperature measuring unit for measuring the temperature of the outer surface of the rotary kiln, a temperature information acquiring unit for acquiring temperature information indicating the temperature of the outer surface of the rotary kiln from the temperature measuring unit while the cement clinker is being produced by the rotary kiln, a drop detecting unit for detecting a coating falling from an inner wall of the rotary kiln based on the temperature information, and an output unit for outputting a detection result of the coating falling. As with the above-described manufacturing method, this manufacturing apparatus allows the coating to fall and the falling of the coating to be detected before it is discharged from the rotary kiln, making it possible to detect the coating falling at an early stage.

[0015] A program according to one aspect of the present disclosure is a program for causing a computer to execute the steps of acquiring temperature information indicating the temperature of the outer surface of a rotary kiln that burns cement raw materials and produces cement clinker, detecting falling of a coating from an inner wall of the rotary kiln based on the temperature information, and outputting a detection result of the falling of the coating. As with the above-described manufacturing method, this program allows the falling of the coating to be detected before it is discharged from the rotary kiln, thereby making it possible to detect the falling of the coating at an early stage. Effect of the Invention

[0016] According to the present disclosure, there are provided a cement clinker manufacturing method, a cement clinker manufacturing device, and a program capable of detecting coating fall-off at an early stage. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic diagram showing an example of a cement clinker production system. [Diagram 2] 2(a) and 2(b) are schematic diagrams showing an example of how the temperature is measured on the outer surface of a rotary kiln. [Diagram 3] FIG. 3 is a block diagram illustrating an example of a hardware configuration of the control device. [Figure 4] FIG. 4 is a block diagram illustrating an example of a functional configuration of the control device. [Diagram 5] FIG. 5 is a flowchart showing an example of a method for producing cement clinker. [Figure 6] FIG. 6 is a flow chart illustrating an example of a coating drop detection method. [Figure 7] FIG. 7 is a flow chart showing an example of a method for switching the destination when a coating drop is detected. [Figure 8] FIG. 8 is a graph showing an example of the measurement result of the temperature information. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment will be described with reference to the drawings. In the description, the same elements or elements having the same functions are designated by the same reference numerals, and duplicated description will be omitted.

[0019] [Cement clinker manufacturing equipment] Fig. 1 shows a manufacturing system including a cement clinker manufacturing apparatus according to one embodiment. The manufacturing system 1 shown in Fig. 1 is a system for manufacturing cement clinker. The manufacturing system 1 includes, for example, a cement clinker manufacturing apparatus 2, a product silo 4, a non-standard product silo 6, and a control device 100.

[0020] The manufacturing apparatus 2 produces cement clinker (hereinafter simply referred to as "clinker") from cement raw materials, and transports the produced clinker to a product silo 4 or a non-standard product silo 6. The manufacturing apparatus 2 includes, for example, a preheater 10, a rotary kiln 20, a clinker cooler 30, a transport device 40, and an imaging unit 80.

[0021] The preheater 10 preheats the cement raw materials (clinker raw materials) supplied from a device performing a previous process. The preheater 10 is, for example, a new suspension preheater (NSP). In this case, the preheater 10 has a plurality of cyclones constituting a multi-stage cyclone and a calcination furnace. The preheater 10 successively drops the clinker raw materials fed from the inlet of the topmost cyclone into the cyclones below, and heats the clinker raw materials so that the temperature gradually increases. The preheater 10 also heats the cement raw materials (calcines them) using a burner in the calcination furnace. The preheater 10 supplies the preheated cement raw materials to a rotary kiln 20.

[0022] The rotary kiln 20 burns the cement raw materials supplied from the preheater 10. The rotary kiln 20 is a rotary kiln configured to rotate about an axis along its longitudinal direction. The longitudinal direction of the rotary kiln 20 is the extension direction of the rotary kiln 20. The rotary kiln 20 has, for example, a drum body 22 inclined toward the downstream side to which the cement raw materials are fed, and a burner (not shown) that burns the cement raw materials fed into the drum body 22.

[0023] A drive unit 28 that generates a driving force is connected to the rotary kiln 20, and the rotary kiln 20 rotates about an axis along its longitudinal direction by the driving force from the drive unit 28. As a result, the rotary kiln 20 moves and stirs the supplied cement raw materials while burning them with a burner. As a result, clinker is produced by the rotary kiln 20. The rotary kiln 20 discharges the produced clinker to the clinker cooler 30.

[0024] A coating formed by burning the cement raw materials is attached to the inner wall of the rotary kiln 20 (more specifically, the inner wall of the drum body 22). For example, before the production of clinker is started using the production system 1, a coating (coating layer) is formed on the inner wall of the rotary kiln 20 by burning the cement raw materials. This coating has heat insulating properties and functions to protect the refractory material used in the inner wall of the rotary kiln 20.

[0025] The coating may fall off the inner wall of the rotary kiln 20 due to various factors while the manufacturing equipment 2 is operating to produce clinker. One example of a factor that may cause the coating to fall off is a fluctuation in the operating state of the manufacturing equipment 2. The amount of chlorine and sulfur components contained in the coating is greater than the amount of the corresponding components contained in the clinker produced by the rotary kiln 20. Therefore, when the coating is mixed into the clinker, the clinker must be treated as a non-standard product.

[0026] The clinker cooler 30 cools the clinker produced by burning in the rotary kiln 20. The clinker cooler 30 may cool the high-temperature clinker discharged from the rotary kiln 20 using cooling air (gas). The clinker cooler 30 has, for example, a grate device 32 and a plurality of air chambers 34. The grate device 32 transports the clinker to be cooled by a plurality of grate plates provided with slits for passing cooling air. The plurality of air chambers 34 are provided below the plurality of grate plates of the grate device 32, and send cooling air to the space above the grate plates. The clinker cooler 30 discharges the cooled clinker to a transport device 40.

[0027] The conveying device 40 conveys the clinker generated by burning in the rotary kiln 20 to the product silo 4 or the non-standard silo 6. The clinker to be conveyed by the conveying device 40 may be clinker that has been crushed after being discharged from the clinker cooler 30 by a crusher device provided between the clinker cooler 30 and the conveying device 40. The conveying device 40 switches the destination of the clinker in response to an operation instruction from the control device 100. For example, the conveying device 40 switches the destination of the clinker to either the product silo 4 or the non-standard silo 6.

[0028] The conveying device 40 has, for example, a main conveying section 42, a product conveying section 44, a nonstandard product conveying section 46, and a switching section 48. In the conveying device 40, the main conveying section 42 is connected to either the product conveying section 44 or the nonstandard product conveying section 46 at a switching point SP where the switching section 48 is provided.

[0029] The main conveying section 42 conveys the clinker discharged from the clinker cooler 30 to the switching point SP. The product conveying section 44 conveys the clinker from the switching point SP to the product silo 4. The non-standard product conveying section 46 conveys the clinker from the switching point SP to the non-standard product silo 6. The switching section 48 switches between a state in which the main conveying section 42 and the product conveying section 44 are connected to each other (hereinafter referred to as the "first conveying state") and a state in which the main conveying section 42 and the non-standard product conveying section 46 are connected to each other (hereinafter referred to as the "second conveying state") in response to an operational instruction from the control device 100.

[0030] When the switching unit 48 has switched to the first conveying state, the clinker conveyed to the switching point SP is conveyed to the product silo 4 by the product conveying unit 44. When the switching unit 48 has switched to the second conveying state, the clinker conveyed to the switching point SP is conveyed to the non-standard product silo 6 by the non-standard product conveying unit 46. In the manufacturing system 1, when a coating drop is detected, the switching unit 48 can switch from the first conveying state to the second conveying state. This prevents the dropped coating from being mixed into the clinker conveyed to the product silo 4.

[0031] The main conveying section 42 and the nonstandard product conveying section 46 (the members of these conveying sections that come into contact with the clinker to be conveyed) may be made of a material having high heat resistance. In one example, the heat resistance of the material constituting the main conveying section 42 and the nonstandard product conveying section 46 may be higher than the heat resistance of the material constituting the product conveying section 44. The dropped coating lumps tend to be larger than the clinker lumps discharged from the rotary kiln 20. Therefore, compared to the clinker, the dropped coating may be discharged without being sufficiently cooled by the clinker cooler 30. By providing the materials constituting the main conveying section 42 and the nonstandard product conveying section 46 that convey the dropped coating with heat resistance, the risk of fire caused by the coating can be eliminated.

[0032] The imaging unit 80 images the clinker discharged from the clinker cooler 30. The clinker to be imaged by the imaging unit 80 may be clinker crushed after being discharged from the clinker cooler 30 by a crusher device provided between the clinker cooler 30 and the conveying device 40. The imaging unit 80 is disposed, for example, above the main conveying section 42 of the conveying device 40, and images the clinker being conveyed by the main conveying section 42. The imaging unit 80 may image the clinker by setting the upstream end of the main conveying section 42 as the imaging range. In one example, the imaging unit 80 has a digital camera capable of generating color still images. The digital camera of the imaging unit 80 may image the clinker on the main conveying section 42 at a predetermined cycle in response to an operation instruction from the control device 100.

[0033] The manufacturing apparatus 2 has various measuring units for grasping the operating state of the manufacturing apparatus 2. The manufacturing apparatus 2 has, for example, a temperature measuring unit 50, a power measuring unit 60, and a wind pressure measuring unit .

[0034] The temperature measuring unit 50 measures the temperature of the outer surface of the rotary kiln 20. The temperature measuring unit 50 is provided, for example, around the rotary kiln 20 at a distance from the rotary kiln 20. The temperature measuring unit 50 measures the temperature of the outer surface of the rotary kiln 20 (more specifically, the shell constituting the outer wall of the drum body 22). The temperature measuring unit 50 may measure the temperature of the outer surface of the rotary kiln 20 by any method. In one example, the temperature measuring unit 50 may measure the temperature of the outer surface by detecting infrared rays or the like radiated from the outer surface of the rotary kiln 20. The temperature measuring unit 50 may measure the temperature of the outer surface of the rotary kiln 20 by measuring the temperature in the vicinity of the outer surface of the rotary kiln 20.

[0035] As shown in Fig. 2(a), the temperature measurement unit 50 may measure the temperature of the outer surface of the rotary kiln 20 in each of a plurality of sections R obtained by dividing at least a part of the rotary kiln 20 along the longitudinal direction of the rotary kiln 20. In other words, the temperature measurement unit 50 may measure the temperature of the outer surface of the rotary kiln 20 for each section R. The multiple sections R are virtual regions, and in one example, are regions obtained by dividing the rotary kiln 20 in units of several meters.

[0036] The temperature measuring unit 50 may have a measuring sensor corresponding to each of the multiple sections R, or may use one sensor (e.g., an infrared thermo camera) to measure the temperature of the outer surface of the rotary kiln 20 at approximately the same timing for each of the multiple sections R. The measurement range of the temperature measuring unit 50 may be a part of the rotary kiln 20 in the longitudinal direction of the rotary kiln 20, or may be the entire rotary kiln 20.

[0037] As shown in Fig. 2(b), the temperature measuring unit 50 may measure the temperature of the outer surface of the rotary kiln 20 at multiple points MP arranged in the rotation direction TD of the rotary kiln 20 in one section. For example, the temperature measuring unit 50 measures the temperature of the outer surface of the rotary kiln 20 at each of the multiple points MP during one rotation of the rotary kiln 20 (drum body 22) by the drive unit 28 in accordance with an operation instruction of the control device 100. In one example, the multiple points MP are arranged at equal intervals in the circumferential direction around the axis about which the rotary kiln 20 rotates, and are set at tens to hundreds of points.

[0038] Returning to Fig. 1, the power measurement unit 60 is provided in the drive unit 28 and measures the power for rotating the rotary kiln 20. More specifically, the power measurement unit 60 measures the power supplied to the motor 28a of the drive unit 28.

[0039] The wind pressure measuring unit 70 is provided in the clinker cooler 30 and measures the wind pressure of the air sent out to cool the clinker. For example, the wind pressure measuring unit 70 measures the pressure in the air chamber 34 that sends air out to the space above the grate device 32. In one example, the wind pressure measuring unit 70 has a wind pressure sensor provided in one of the air chambers 34 that is close to the rotary kiln 20 among the multiple air chambers 34 that are aligned in the clinker transport direction.

[0040] The control device 100 is a computer device that controls the manufacturing device 2 to manufacture clinker. The control device 100 is configured to execute at least the steps of acquiring temperature information indicating the temperature of the outer surface of the rotary kiln 20 while the rotary kiln 20 is producing clinker, detecting the falling of the coating from the inner wall of the rotary kiln 20 based on the temperature information, and outputting the detection result of the falling of the coating. The control device 100 includes, for example, a computer main body 102, an input device 104, and an output device 106.

[0041] The computer main body 102 is the main body of a computer device. The computer main body 102 has a circuit 110 as shown in Fig. 3. The circuit 110 includes at least one processor 112, a memory 114, a storage 116, and an input / output port 118. The storage 116 records programs for configuring each functional module described below. The storage 116 is a computer-readable recording medium such as a hard disk, a non-volatile semiconductor memory, a magnetic disk, an optical disk, or the like.

[0042] The memory 114 temporarily stores programs loaded from the storage 116, calculation results of the processor 112, etc. The processor 112 configures each functional module by executing programs in cooperation with the memory 114. The input / output port 118 inputs and outputs electrical signals between the manufacturing apparatus 2, the input device 104, the output device 106, etc. in response to commands from the processor 112. The timer 122 counts clock pulses at a predetermined cycle in response to commands from the processor 112 to measure the elapsed time.

[0043] The input device 104 is a device for inputting information to the computer main body 102. More specifically, the input device 104 inputs input information indicating instructions from an operator to the computer main body 102. The input device 104 may be any device capable of inputting desired information, and specific examples thereof include a keyboard, an operation panel, and a mouse.

[0044] The output device 106 is a device for outputting information output from the computer main body 102. The output device 106 is, for example, a monitor on which an operator can check information from the computer main body 102. This monitor may be any device capable of displaying information on a screen, and a specific example thereof is a liquid crystal panel.

[0045] 4, the computer main body 102 of the control device 100 has, as functional components (hereinafter referred to as "functional modules"), a temperature information acquisition unit 152, a power information acquisition unit 154, a wind pressure information acquisition unit 156, an input information acquisition unit 158, a drop detection unit 162, an output unit 164, a switching control unit 166, and a timing calculation unit 168. The processes executed by these functional modules correspond to the processes executed by the computer main body 102.

[0046] The temperature information acquisition unit 152 is a functional module that acquires information indicating the temperature of the outer surface of the rotary kiln 20 (hereinafter referred to as "temperature information") from the temperature measurement unit 50 while clinker is being produced by the rotary kiln 20. The temperature information acquisition unit 152 may acquire information indicating the temperature of the outer surface of the rotary kiln 20 for each section R obtained by dividing the rotary kiln 20 along the longitudinal direction. Hereinafter, the temperature information for each section R is referred to as "section temperature information". The temperature information acquisition unit 152 may acquire information indicating the temperatures of the outer surface at multiple points MP arranged along the rotation direction of the rotary kiln 20 for each section R.

[0047] The power information acquisition unit 154 is a functional module that acquires information indicating the power supplied to the motor 28a of the drive unit 28 that rotates the rotary kiln 20. The wind pressure information acquisition unit 156 is a functional module that acquires information indicating the wind pressure of the cooling gas (air) for cooling the clinker in the clinker cooler 30.

[0048] The input information acquisition unit 158 ​​is a functional module that acquires input information via the input device 104. The input information acquisition unit 158 ​​acquires, from the input device 104, input information indicating an instruction by an operator, for example.

[0049] The drop detection unit 162 is a functional module that detects the drop of the coating from the inner wall of the rotary kiln 20 (the fact that the coating has fallen) based on the above temperature information. The drop detection unit 162 may determine whether or not the coating has fallen based on the temperature information when clinker is being generated by the rotary kiln 20. The drop detection unit 162 may determine whether or not the coating has fallen for each of the multiple sections R based on the section temperature information. In this case, the drop detection unit 162 may identify in which section of the multiple sections R the coating has fallen. The drop detection unit 162 may select the maximum value of the temperatures of the multiple locations MP in one section R as the section temperature information, and determine whether or not the coating has fallen in that section R based on the section temperature information (maximum temperature).

[0050] In one example, the drop detection unit 162 determines whether or not the coating has fallen off by comparing the section temperature information with a predetermined threshold for each of the multiple sections R. The drop detection unit 162 may determine that the coating has fallen off when the amount of change per unit time in the temperature indicated by the section temperature information exceeds a predetermined threshold Th1 (first threshold) or when the temperature exceeds a predetermined threshold Th2 (second threshold).

[0051] The drop detection unit 162 may detect the drop of the coating based on information indicating the power supplied to the motor 28a, in addition to detecting the drop of the coating based on the temperature information. The drop detection unit 162 may determine that the coating has fallen when the fluctuation per unit time of the power supplied to the motor 28a exceeds a predetermined threshold.

[0052] The drop detection unit 162 may detect the drop of the coating based on information indicating the wind pressure of the cooling gas (air) for cooling the clinker, in addition to detecting the drop of the coating based on the temperature information. The drop detection unit 162 may determine that the coating has fallen when the fluctuation of the wind pressure of the air per unit time exceeds a predetermined threshold value.

[0053] The output unit 164 is a functional module that outputs a detection result of the coating falling. For example, when the fall detection unit 162 determines that the coating has fallen, the output unit 164 outputs information indicating that the coating has fallen. The output unit 164 may output the information to another functional module of the computer main body 102, or may output the information to the outside of the computer main body 102. In one example, the output unit 164 outputs the information indicating that the coating has fallen to the output device 106. In this case, the output device 106 may display the information indicating that the coating has fallen on a screen.

[0054] The switching control unit 166 is a functional module that controls the switching unit 48 to switch the destination of the clinker discharged from the clinker cooler 30. The switching control unit 166 controls the switching unit 48 in response to, for example, input information from an operator via the input device 104. In one example, when a switching instruction is input from the operator in a first conveying state in which the clinker is conveyed to the product silo 4, the switching control unit 166 switches from the first conveying state to a second conveying state in which the clinker is conveyed to the non-standard product silo 6. On the other hand, when a switching instruction is input from the operator in the second conveying state, the switching control unit 166 switches from the second conveying state to the first conveying state.

[0055] The timing calculation unit 168 is a functional module that calculates the timing at which the dropped coating reaches a switching point SP where the destination of the clinker can be switched (hereinafter referred to as "arrival timing"). The timing calculation unit 168 may calculate the arrival timing at the switching point SP by, for example, referring to a table that associates the position of the section where the dropped coating occurred with the timing at which the coating reaches the switching point SP.

[0056] [Manufacturing method of cement clinker] Next, a control method of the manufacturing apparatus 2 executed by the control device 100 will be described as an example of a method for manufacturing cement clinker. FIG. 5 is a flowchart showing an example of the control method of the manufacturing apparatus 2. In this control method, for example, the control device 100 executes step S01 in response to an instruction from an operator to start the operation of the manufacturing apparatus 2. In step S01, for example, the control device 100 controls the manufacturing apparatus 2 to start the input of cement raw materials and start the production of clinker. In the subsequent processing, the input of cement raw materials and the production of clinker are continued until the operation of the manufacturing apparatus 2 is stopped. In the initial state, the conveying state of the clinker is set to a first conveying state in which the conveying destination is the product silo 4.

[0057] Next, the control device 100 executes step S02. In step S02, for example, the control device 100 executes a process for determining whether or not the coating has fallen inside the rotary kiln 20 (hereinafter referred to as a "fall determination process"). In the fall determination process of step S02, the fall detection unit 162 determines whether or not the coating has fallen based on temperature information indicating the temperature of the outer surface of the rotary kiln 20. Then, when it is determined that the coating has fallen, the output unit 164 outputs the determination result to the output device 106. The operator can know that the coating has fallen by monitoring the output device 106. The fall determination process of step S02 will be described in detail later.

[0058] Next, the control device 100 executes step S03. In step S03, for example, the control device 100 determines whether or not to end the production of clinker by the production device 2. In one example, when an instruction to stop the operation of the production device 2 is input by an operator, the control device 100 ends the production of clinker by the production device 2. In this case, a series of processes by the control device 100 ends.

[0059] On the other hand, if it is determined that the production of clinker by the manufacturing apparatus 2 is not to be terminated, the control device 100 repeats the processes of steps S02 and S03. That is, the control device 100 repeatedly executes the process of step S02 while continuing the production of clinker by the rotary kiln 20 until an instruction to stop the operation of the manufacturing apparatus 2 is received. The control device 100 repeatedly executes the process of step S02 at predetermined intervals (for example, every tens of seconds to several minutes). In this case, the control device 100 judges whether or not the coating has fallen at each predetermined interval. As described above, the control device 100 continuously executes monitoring for the falling of the coating in parallel with the control for the production of clinker by the manufacturing apparatus 2.

[0060] 6 is a flow chart showing an example of the fall determination process of step S02. In this fall determination process, the control device 100 first executes step S11. In step S11, for example, the temperature information acquisition unit 152 acquires information indicating the temperature of one of the multiple points MP set on the outer surface of the rotary kiln 20 from the temperature measurement unit 50. The temperature information acquisition unit 152 acquires information indicating the temperature of one point for each of the multiple sections R.

[0061] Next, the control device 100 executes step S12. In step S12, for example, the temperature information acquisition unit 152 determines whether or not the temperatures of all of the multiple locations MP have been measured. If it is determined in step S12 that the temperatures of all of the multiple locations MP have not been measured (step S12: NO), the control device 100 repeats the processes of steps S11 and S12. The control device 100 repeatedly executes step S11 at a timing according to the rotation speed of the rotary kiln 20 and the set positions of the multiple locations MP.

[0062] On the other hand, if it is determined in step S12 that the temperatures of all of the multiple locations MP have been measured (step S12: YES), the process executed by the control device 100 proceeds to step S13. By executing steps S11 and S12, information indicating all of the temperatures of the multiple locations MP is acquired for each of the multiple sections R. In step S13, for example, the temperature information acquisition unit 152 selects, for each section R, the maximum temperature among the temperatures of the multiple locations MP as section temperature information indicating the temperature of that section R.

[0063] Next, the control device 100 executes step S14. In step S14, for example, the drop detection unit 162 determines whether the change in temperature per unit time indicated by the section temperature information (hereinafter simply referred to as "temperature change") for each of the multiple sections R is greater than a threshold value Th1. The drop detection unit 162 may calculate the temperature change for each section R based on the section temperature information obtained in the current period and the section temperature information obtained in multiple periods immediately preceding the current period. The target range (period) and threshold value Th1 for calculating the temperature change are stored in advance in the control device 100. The threshold value Th1 is set in advance based on, for example, past performance values ​​of temperature changes when coating drop actually occurs.

[0064] If it is determined that the temperature change in any of the sections R is greater than the threshold value Th1 (step S14: YES), the drop detection unit 162 determines that a coating drop has occurred, and the process executed by the control device 100 proceeds to step S16. On the other hand, if it is determined that the temperature change per unit time in all of the sections R is equal to or less than the threshold value Th1 (step S14: NO), the process executed by the control device 100 proceeds to step S15.

[0065] In step S15, for example, the drop detection unit 162 determines whether the temperature indicated by the section temperature information for each of the multiple sections R is greater than a threshold value Th2. The threshold value Th2 is pre-stored in the control device 100. The threshold value Th2 is set in advance based on, for example, a past performance value of the temperature when the coating drop actually occurred (the maximum temperature in one section).

[0066] If it is determined that the temperature indicated by the section temperature information is greater than the threshold value Th2 in any section R (step S15: YES), the drop detection unit 162 determines that a coating drop has occurred, and the process executed by the control device 100 proceeds to step S16. As described above, if the temperature change in any section R exceeds the threshold value Th1 in step S14, or if the temperature itself in any section R exceeds the threshold value Th2 in step S15, the control device 100 executes step S16. When executing steps S14 and S15, if the section temperature information in multiple sections R satisfies any of the above conditions, the drop detection unit 162 may determine that a coating drop has occurred in the multiple sections R. The drop detection unit 162 identifies the section R in which the temperature change or temperature exceeds the threshold value as the section R in which a coating drop has occurred.

[0067] In step S16, for example, the timing calculation unit 168 calculates (predicts) the arrival timing at which the dropped coating reaches the switching point SP in the transport device 40. The timing calculation unit 168 may calculate the arrival timing corresponding to the section R identified as the section where the dropped coating occurred, by referring to a table in which each section R is associated with the arrival time to the switching point SP. This table is stored in advance in the control device 100, and is created, for example, based on simulation results or the like. The timing calculation unit 168 may calculate, as the arrival timing, a predicted period during which the dropped coating passes the switching point SP (a predicted time of passing start and a predicted time of passing completion).

[0068] Next, the control device 100 executes step S17. In step S17, for example, the output unit 164 outputs information indicating that a coating drop has occurred to the output device 106. This allows the operator to understand that a coating drop has occurred. The output unit 164 may output to the output device 106, in addition to the above information indicating the occurrence of a coating drop, information indicating the section R in which the coating drop has occurred and information indicating the arrival timing at which the dropped coating reaches the switching point SP.

[0069] If it is determined in step S14 that the temperature change is equal to or less than the threshold Th1 for all sections R, and if it is determined in step S15 that the temperature is equal to or less than the threshold Th2 for all sections R, the control device 100 does not execute steps S16 and S17. In these cases, the drop detection unit 162 determines that no coating drop has occurred in any of the sections R.

[0070] This ends the drop determination process of step S02. In this drop determination process, when information indicating that the coating has fallen is notified to the operator via the output device 106, the operator may input an instruction to switch the destination of the clinker to the control device 100 via the input device 104. For example, the operator may input an instruction to switch the destination to the control device 100 depending on the arrival timing when the fallen coating is predicted to reach the switching point SP.

[0071] When an instruction to switch the destination is input to the control device 100, the switching control unit 166 controls the switching unit 48 to switch from the first conveying state, in which the destination of the clinker is the product silo 4, to the second conveying state, in which the destination of the clinker is the non-standard product silo 6. Then, when the operator determines that all the dropped coating has passed, he or she may input an instruction to switch the destination to the control device 100 again. In this case, the switching control unit 166 controls the switching unit 48 to switch from the second conveying state to the first conveying state. As a result, the clinker discharged from the clinker cooler 30 is conveyed again toward the product silo 4.

[0072] [Variations] The above-described series of processes is an example and can be modified as appropriate. In the above-described series of processes, the control device 100 may execute one step and the next step in parallel, or may execute each step in an order different from the above-described example. The control device 100 may omit any step, or may execute a process different from the above-described example in any step. For example, the execution order of steps S14 and S15 may be reversed from the above-described example.

[0073] The method of determining whether the coating has fallen is not limited to the above example. The drop detection unit 162 may determine that the coating has fallen when the amount of change per unit time of the temperature indicated by the temperature information (temperature change) is greater than a threshold value Th1 and the temperature is greater than a threshold value Th2 for each section R. The drop detection unit 162 may determine that the coating has fallen when the temperature change is greater than the threshold value Th1 without comparing the temperature with a threshold value. The drop detection unit 162 may determine that the coating has fallen when the temperature indicated by the temperature information is greater than the threshold value Th2 without comparing the temperature change with a threshold value.

[0074] In the above example, the drop detection unit 162 determines that the coating has fallen when the temperature change and the temperature itself become greater than the corresponding thresholds at the same timing (cycle). In addition, the drop detection unit 162 may determine that the coating has fallen when the temperature change and the temperature itself become greater than the corresponding thresholds at different timings within a predetermined period. For example, the drop detection unit 162 may also determine that the coating has fallen when the temperature exceeds the threshold Th2 in a period several periods after the period in which the temperature change exceeds the threshold Th1.

[0075] When the drop determination process of step S02 is performed, the drop detection unit 162 may further determine whether or not the coating has fallen based on information indicating the power supplied to the motor 28a that rotates the rotary kiln 20. For example, the drop detection unit 162 may determine that the coating has fallen when the amount of change per unit time of the power supplied to the motor 28a exceeds a predetermined threshold value, separately from the detection of the coating falling based on the temperature information. The drop detection unit 162 may output the detection result of the coating falling based on the power supplied to the motor 28a to the output device 106.

[0076] The operator may determine whether or not it is necessary to switch the destination of the clinker by comprehensively determining the detection result of the coating drop based on the temperature information and the detection result of the coating drop based on the information indicating the power supplied to the motor 28a. The drop detection unit 162 may detect the coating drop based on the temperature information and the information indicating the power supplied to the motor 28a. For example, the drop detection unit 162 may detect that the coating has fallen when both the temperature information and the information indicating the power satisfy the drop detection conditions corresponding to each other.

[0077] When the drop determination process of step S02 is executed, the drop detection unit 162 may further determine whether or not the coating has fallen based on information indicating the wind pressure of the cooling air used in the clinker cooler 30. For example, the drop detection unit 162 may determine that the coating has fallen when the amount of change per unit time of the wind pressure of the cooling air exceeds a predetermined threshold value, separately from the detection of the coating falling based on the temperature information. The drop detection unit 162 may output the detection result of the coating falling based on the wind pressure of the cooling air to the output device 106.

[0078] For the same coating drop, the detection of the coating drop based on the temperature information and the detection of the coating drop based on the information indicating the wind pressure are different in detection position, so there is a difference in timing. Therefore, the output of the drop detection based on the temperature information and the output of the drop detection based on the information indicating the wind pressure are output at different timings. The operator may determine whether or not it is necessary to switch the destination of the clinker by comprehensively judging the detection result of the coating drop based on the temperature information and the detection result of the coating drop based on the information indicating the wind pressure. The drop detection unit 162 may detect the coating drop based on the temperature information and the information indicating the wind pressure. For example, the drop detection unit 162 may detect that the coating has fallen when both the temperature information and the information indicating the wind pressure satisfy the drop detection conditions corresponding to each other.

[0079] In the above example, after the drop of the coating is detected, the destination of the clinker is switched by the instruction of the operator, but the control device 100 may automatically switch the destination (transport state) of the clinker depending on the detection result of the drop of the coating. In this case, the output unit 164 may output information indicating that the coating has dropped to the switching control unit 166. At this time, the output unit 164 may further output information indicating the calculation result of the timing at which the dropped coating will reach the switching point SP to the switching control unit 166. This information indicating the calculation result includes, for example, a predicted arrival time indicating the time at which the dropped coating is predicted to reach the switching point SP.

[0080] Based on an image of the clinker discharged from the clinker cooler 30, it may be determined whether or not the discharge of the dropped coating from the clinker cooler 30 has been completed. For example, as shown in Fig. 4, the control device 100 may have an image information acquisition unit 172 and a discharge completion determination unit 174 as functional modules. The image information acquisition unit 172 is a functional module that acquires an image of the clinker discharged from the clinker cooler 30 by causing the imaging unit 80 to capture the image of the clinker. The discharge completion determination unit 174 is a functional module that determines whether or not the discharge of the dropped coating from the clinker cooler 30 has been completed based on the image of the clinker obtained by the image information acquisition unit 172.

[0081] 7 is a flow chart showing an example of a method for switching the destination executed after it is detected that the coating has fallen. In this switching method, the control device 100 executes steps S31 and S32. In step S31, for example, the switching control unit 166 waits until the predicted arrival time. In step S32, for example, the switching control unit 166 controls the switching unit 48 so that the destination of the clinker is switched from the product silo 4 to the non-standard product silo 6 (so that the first conveying state is switched to the second conveying state). As a result, the clinker that may contain the fallen coating is conveyed to the non-standard product silo 6.

[0082] Next, the control device 100 executes steps S33 and S34. In step S33, for example, the image information acquisition unit 172 acquires an image of the clinker discharged from the clinker cooler 30 and being transported by the main transport unit 42 of the transport device 40 from the imaging unit 80. In step S34, for example, the discharge completion determination unit 174 calculates the whiteness from the image acquired in step S33, and determines whether the calculated whiteness is smaller than a predetermined threshold value Th3.

[0083] In the present disclosure, "whiteness" refers to the degree of whiteness of the clinker image, and is determined by the degree of brightness of each pixel. The whiteness tends to increase as the amount of coating mixed into the clinker increases. The discharge completion determination unit 174 may compare the average value, median value, or mode value of the whiteness of multiple pixels with the above threshold value Th3. The threshold value Th3 is stored in the control device 100. The threshold value Th3 may be preset based on the whiteness of the clinker image when the falling of the coating is actually observed.

[0084] If it is determined in step S34 that the whiteness is equal to or greater than the threshold value Th3 (step S34: NO), the control device 100 repeats steps S33 and S34. In this case, the discharge completion determination unit 174 determines that the discharge of the dropped coating is not complete. The control device 100 may repeat steps S33 and S34 at a predetermined cycle until it is determined that the whiteness is smaller than the threshold value Th3. In order to determine the completion of the discharge of the coating, the discharge completion determination unit 174 may compare the number of pixels among the multiple pixels whose whiteness is smaller than the threshold value Th3 with a predetermined threshold value, instead of comparing a statistical value such as an average value with the threshold value Th3.

[0085] If it is determined in step S34 that the whiteness is less than the threshold value Th3 (step S34: YES), the discharge completion determination unit 174 determines that discharge of the dropped coating is complete, and the processing of the control device 100 proceeds to step S35. In step S35, for example, the switching control unit 166 controls the switching unit 48 so that the destination of the clinker is switched from the non-standard product silo 6 to the product silo 4 (so that the second conveying state is switched to the first conveying state). As a result, the clinker that is likely not mixed with the dropped coating is conveyed again to the product silo 4. With the above, a series of processes for switching the destination after detection of dropped coating is completed.

[0086] The temperature measuring unit 50 may measure the temperature of the outer surface in one section in the longitudinal direction of the rotary kiln 20 instead of measuring in multiple sections R. In this case, the drop detection unit 162 may detect the drop of the coating based on information indicating the temperature of the outer surface in the one section. The temperature measuring unit 50 may measure the temperature of the outer surface at one location in one section R instead of multiple locations MP. In this case, the drop detection unit 162 may use information indicating the temperature of the outer surface at the one location as the section temperature information. When the temperature of the outer surface is measured at multiple locations MP, the drop detection unit 162 may use the average value, median value, or mode value of the temperatures at the multiple locations MP as the section temperature information instead of the maximum value.

[0087] The drop detection unit 162 may not use the measurement results of at least one of the power measurement unit 60 and the wind pressure measurement unit 70 to detect the drop of the coating. For example, the measurement results (measurement values) of the power measurement unit 60 and the wind pressure measurement unit 70 may be output to the output device 106. Then, the operator may check the result of the coating drop detection based on the temperature information and the measurement results of the power measurement unit 60 and the wind pressure measurement unit 70 to determine whether or not it is necessary to switch the destination of the clinker. Alternatively, the manufacturing apparatus 2 may not have at least one of the power measurement unit 60 and the wind pressure measurement unit 70.

[0088] [Effects of the embodiment] The method for producing cement clinker described above includes a step of acquiring temperature information indicating the temperature of the outer surface of the rotary kiln 20, which burns cement raw materials, while clinker is being produced by the rotary kiln 20, a step of detecting falling of a coating from the inner wall of the rotary kiln 20 based on the temperature information, and a step of outputting the detection result of the falling of the coating.

[0089] The coating applied to the inner wall of the rotary kiln 20 has heat insulating properties. Therefore, the temperature on the outer surface of the rotary kiln 20 changes between when the coating is present on the inner wall of the rotary kiln 20 and when at least a part of the coating has fallen off the inner wall. The manufacturing method according to the above embodiment utilizes this temperature change characteristic to detect the falling of the coating. In this case, the falling of the coating can be detected before it falls and is discharged from the rotary kiln 20 (for example, immediately after the coating falls), making it possible to detect the falling of the coating at an early stage.

[0090] In the above manufacturing method, the step of acquiring temperature information may include acquiring section temperature information indicating the temperature of the outer surface of the rotary kiln 20 for each of a plurality of sections R obtained by dividing the rotary kiln 20 along the longitudinal direction of the rotary kiln 20. The step of detecting the coating drop may include detecting the coating drop for each of the plurality of sections R based on the section temperature information. In this case, by identifying the section R in which the coating drop was detected, it is possible to know in which region of the rotary kiln 20 the coating drop occurred.

[0091] In the above manufacturing method, the step of acquiring temperature information may include acquiring information indicating the temperature of the outer surface of the rotary kiln 20 at multiple points MP arranged along the rotation direction TD of the rotary kiln 20. The step of detecting coating drop may include detecting coating drop based on the maximum value of the temperatures at the multiple points MP. When coating drop occurs, the temperature at the point where the coating has fallen becomes higher than other points in the above rotation direction TD. In the above method, the temperature is measured at multiple points MP and the presence or absence of coating drop is evaluated at the maximum value, making it possible to accurately detect coating drop.

[0092] The step of detecting the falling of the coating may include determining that the coating has fallen when the amount of change per unit time of the temperature indicated by the temperature information exceeds a threshold value Th1 or when the temperature indicated by the temperature information exceeds a threshold value Th2. In this case, it is determined that the coating has fallen when at least one of the temperature change and the temperature itself exceeds a corresponding threshold value, so that the falling of the coating can be detected more reliably.

[0093] The manufacturing method may further include a step of detecting coating drop based on information indicating the power supplied to the motor 28a that rotates the rotary kiln 20. When coating drop occurs, the power supplied to the motor 28a fluctuates. In the method, the power fluctuation is used to further detect coating drop, making it possible to evaluate the validity of the detection result of coating drop based on the temperature information.

[0094] The above manufacturing method may further include a step of detecting the falling of the coating based on information indicating the wind pressure of the cooling gas used in the clinker cooler 30 that cools the clinker generated by the burning in the rotary kiln 20. When the fallen coating is sent to the clinker cooler 30, a fluctuation occurs in the wind pressure of the cooling gas. In the above method, the fall of the coating is further detected using the fluctuation in the wind pressure, making it possible to evaluate the validity of the detection result of the falling of the coating based on the temperature information.

[0095] The above manufacturing method may further include a step of imaging the clinker discharged from the clinker cooler 30, and a step of judging whether or not the discharge of the coating from the clinker cooler 30 has been completed based on the image obtained by imaging the clinker discharged from the clinker cooler 30 when the falling of the coating is detected. In this method, when it is judged that the discharge of the coating has been completed, it can be estimated that the clinker discharged from the clinker cooler 30 does not contain the coating, and therefore the possibility that the clinker containing the coating is shipped as a product can be reduced.

[0096] The above manufacturing method may further include a step of transporting the clinker generated by burning in the rotary kiln 20 to a predetermined switching point SP, a step of switching the destination of the clinker at the switching point SP, a step of calculating the arrival timing of the dropped coating to the switching point SP when a drop of the coating is detected, and a step of outputting the calculated arrival timing. In this case, since the arrival timing of the coating at the switching point SP can be grasped, the destination can be switched from the non-standard product silo 6 to the product silo 4 in accordance with the arrival timing. As a result, it is possible to suppress the unnecessary transport of clinker not mixed with the coating to the non-standard product silo 6, while reducing the possibility that clinker mixed with the coating is shipped as a product.

[0097] As a method for detecting (detecting) the falling of the coating, for example, it is possible to detect the falling of the coating based on image data obtained by imaging the clinker discharged from the clinker cooler and being transported by a transport device. However, with this detection method, the time from when the fall is detected based on the image data to when the coating is transported to the switching point where the destination is switched is short, and there is a risk that the destination will not be switched in time and the coating will be mixed in with the clinker heading to the product silo 4. To eliminate this risk, it is possible to lengthen the transport path to the switching point SP, but this would result in an increase in the size of the device.

[0098] In contrast, in the above-mentioned manufacturing method, since the falling of the coating can be detected early, it is possible to avoid an increase in the size of the equipment and to prevent the coating from being mixed into the clinker heading to the product silo 4. Even if the destination cannot be switched in time after the completion of the coating discharge is detected from the image data, only a part of the clinker that is estimated not to have the coating mixed in will be transported to the non-standard product silo 6, and no particular problem will occur.

[0099] Here, an example of the relationship between the measurement results of the temperature information and the measured values ​​of the chlorine component contained in the clinker will be described with reference to FIG. 8. FIG. 8 is a graph showing the measurement results with the horizontal axis representing time (date and time) and the vertical axis representing temperature change and temperature. In this graph, the measurement results of the temperature change in one section R are shown in graph "D1", and the measurement results of the temperature in the same section R are shown in graph "D2". In both graphs, the maximum value of the temperatures of multiple points MP is selected as the measurement value. In graphs D1 and D2, the display range and scale of the vertical axis are adjusted so that the threshold values ​​Th1 and Th2 are approximately equal to each other. In this graph, the measurement results for three days are shown.

[0100] The chlorine content of the clinker was measured in the period indicated by "P1" and the period indicated by "P2" in the graph. Since there is a time lag between when the coating falls and when the clinker that may contain the coating is discharged, the evaluation was performed over a certain period of time rather than time. In the period P1, neither the temperature change nor the temperature exceeded the threshold values ​​Th1 and Th2, respectively. When the concentration of the chlorine content of the clinker discharged from the rotary kiln 20 was measured in this period P1, it was several tens to several hundreds of ppm.

[0101] In period P2, both the temperature change and the temperature exceed the threshold values ​​Th1 and Th2, respectively. When the concentration of the chlorine component contained in the clinker discharged from the rotary kiln 20 was measured in period P2, the measured value was ten to several tens of times higher than the measured value in period P1. In other words, it was confirmed that the coating fell in period P2 and was mixed into the clinker. From the above measurement results, it was confirmed that when the coating falls, at least one of the temperature change and the temperature increases, and therefore, by continuously monitoring these pieces of information, the falling of the coating can be detected. [Explanation of symbols]

[0102] 1... manufacturing system, 2... manufacturing equipment, 4... product silo, 6... non-standard product silo, 10... preheater, 20... rotary kiln, 28... drive unit, 28a... motor, 30... clinker cooler, 40... conveying device, 42... main conveying unit, 44... product conveying unit, 46... non-standard product conveying unit, 48... switching unit, 50... temperature measurement unit, 60... power measurement unit, 70... wind pressure measurement unit, 80... imaging unit, 100... control device, 152... temperature information acquisition unit, 154... power information acquisition unit, 156... wind pressure information acquisition unit, 162... fall detection unit, 164... output unit, 166... ​​switching control unit, 168... timing calculation unit, 172... image information acquisition unit, 174... discharge completion determination unit.

Claims

1. A step of acquiring temperature information indicating a temperature of an outer surface of a rotary kiln that burns cement raw materials while cement clinker is being produced by the rotary kiln; detecting a coating falling off an inner wall of the rotary kiln based on the temperature information; and outputting a detection result of the coating falling off, In the process of detecting the fall of the coating, a first comparison for comparing a change amount per unit time of the temperature indicated by the temperature information with a first threshold value set so that a drop of the coating can be detected from the change amount; and a second comparison of comparing the temperature indicated by the temperature information with a second threshold value set so that a drop of the coating can be detected from the temperature; Detecting the drop of the coating by performing at least one of the following: A method for producing cement clinker.

2. The step of acquiring the temperature information includes acquiring the temperature of the outer surface of the rotary kiln in each of a plurality of sections obtained by dividing the rotary kiln along the longitudinal direction of the rotary kiln, The manufacturing method according to claim 1 , wherein in the step of detecting falling of the coating, at least one of the first comparison and the second comparison is performed for each of the plurality of sections to detect falling of the coating.

3. The step of acquiring the temperature information includes acquiring information indicating the temperature of the outer surface of the rotary kiln at a plurality of points arranged along the rotation direction of the rotary kiln, The manufacturing method according to claim 1 or 2, wherein in the step of detecting falling of the coating, a maximum value among the temperatures at the plurality of locations is used as the temperature indicated by the temperature information.

4. In the step of detecting the drop of the coating, both the first comparison and the second comparison are performed, The manufacturing method according to any one of claims 1 to 3, wherein the step of detecting falling of the coating includes determining that the coating has fallen when a change in temperature per unit time indicated by the temperature information exceeds the first threshold value or when the temperature indicated by the temperature information exceeds the second threshold value.

5. The method according to any one of claims 1 to 4, further comprising a step of detecting coating drop by comparing a fluctuation per unit time of the power supplied to the motor that rotates the rotary kiln with a threshold value set so that coating drop can be detected from the fluctuation. The manufacturing method according to any one of claims 1 to 4.

6. The manufacturing method according to any one of claims 1 to 5, further comprising a step of detecting coating drop by comparing a fluctuation per unit time in the wind pressure of a cooling gas used in a clinker cooler that cools the cement clinker produced by burning in the rotary kiln with a threshold value set so that coating drop can be detected from the fluctuation.

7. Taking an image of cement clinker discharged from a clinker cooler that cools the cement clinker produced by burning in the rotary kiln; The manufacturing method according to any one of claims 1 to 6, further comprising: a step of determining whether or not the discharging of the coating from the clinker cooler is completed by calculating a whiteness degree in an image obtained by photographing the cement clinker discharged from the clinker cooler when the falling of the coating is detected.

8. A step of transporting cement clinker produced by burning in the rotary kiln to a predetermined switching point; Switching the destination of the cement clinker at the switching point; calculating, when a drop of the coating is detected, a timing at which the dropped coating reaches the switching point; The manufacturing method according to claim 1 , further comprising: outputting the calculated arrival timing.

9. A rotary kiln for burning cement raw materials; A temperature measuring unit that measures the temperature of the outer surface of the rotary kiln; A temperature information acquisition unit that acquires temperature information indicating a temperature of an outer surface of the rotary kiln from the temperature measurement unit while cement clinker is being produced by the rotary kiln; A drop detection unit that detects the drop of the coating from the inner wall of the rotary kiln based on the temperature information; an output unit that outputs a detection result of the coating falling off, The drop detection unit is a first comparison for comparing a change amount per unit time of the temperature indicated by the temperature information with a first threshold value set so that a drop of the coating can be detected from the change amount; and a second comparison of comparing the temperature indicated by the temperature information with a second threshold value set so that a drop of the coating can be detected from the temperature; Detecting the drop of the coating by performing at least one of the following: Cement clinker manufacturing equipment.

10. A step of acquiring temperature information indicating a temperature of an outer surface of a rotary kiln that burns cement raw materials while cement clinker is being produced by the rotary kiln; detecting a coating falling off an inner wall of the rotary kiln based on the temperature information; and outputting a detection result of the falling of the coating. In the process of detecting the fall of the coating, a first comparison for comparing a change amount per unit time of the temperature indicated by the temperature information with a first threshold value set so that a drop of the coating can be detected from the change amount; and a second comparison of comparing the temperature indicated by the temperature information with a second threshold value set so that a drop of the coating can be detected from the temperature; Detecting the drop of the coating by performing at least one of the following: program.

Images