Manufacturing apparatus of cement clinker and manufacturing method of cement clinker

Abstract

To stabilize a temperature of an exhaust gas from a clinker cooler.SOLUTION: A manufacturing apparatus of a cement clinker includes a kiln, a clinker cooler, and a controller. The clinker cooler has a plurality of grates for conveying a cement clinker from the upstream to the downstream, a plurality of air chambers for sending a cooling air for cooling the cement clinker via an opening respectively formed for the plurality of grates to above the plurality of grates, a first drive part for driving one or more grates belonging to a first section positioned on the most upstream, an object drive part for driving one or more grates belonging to an object section positioned on the downstream than the first section, and a pressure measurement part for measurement of a wind pressure at an air chamber corresponding to the object section. The controller controls movements of one or more grates belonging to the object section by the object drive part in a manner that a measurement result by the pressure measurement part follows the target wind pressure.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Patent Document 1 discloses an operation control method for a cement burning apparatus. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-158326 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides an apparatus for producing cement clinker and a method for producing cement clinker that are useful for stabilizing the temperature of exhaust gas from a clinker cooler. [Means for solving the problem]

[0005] a control device for controlling the clinker cooler, wherein the clinker cooler has a plurality of grates that support the cement clinker and transport the cement clinker from upstream to downstream, a plurality of air chambers that send cooling air to above the plurality of grates through openings formed in each of the plurality of grates to cool the cement clinker, a first drive unit that drives one or more grates belonging to a first section that is located most upstream of the plurality of grates, a target drive unit that drives one or more grates belonging to a target section that is located downstream of the first section among the plurality of grates, and a pressure measurement unit that measures air pressure in an air chamber corresponding to the target section among the plurality of air chambers, wherein the control device adjusts operation of the one or more grates belonging to the target section by the target drive unit so that a measurement result by the pressure measurement unit follows a target air pressure.

[0006] [2] The cement clinker manufacturing apparatus described in [1] above, wherein the clinker cooler further has a second drive unit that drives one or more grates among the plurality of grates that belong to a second section located between the first section and the target section.

[0007] [3] The cement clinker manufacturing apparatus described in [1] or [2] above, wherein the clinker cooler further has an exhaust pipe for sending the exhaust gas from an exhaust outlet provided at a position corresponding to the target section to a power generation device that generates power using the exhaust gas from the clinker cooler.

[0008] [4] The cement clinker manufacturing apparatus according to any one of [1] to [3] above, wherein the clinker cooler further has another pressure measuring unit that measures the wind pressure in another air chamber corresponding to the first section among the multiple air chambers, and the control device further performs control to adjust the operation of one or more grates belonging to the first section by the first drive unit so that the measurement result by the other pressure measuring unit follows another target wind pressure, and the other target wind pressure is set to a value greater than the target wind pressure.

[0009] [5] The control device adjusts the operating speed of one or more grates belonging to the target section by the target drive unit so that the measurement results by the pressure measuring unit follow the target wind pressure, the clinker cooler further has a third drive unit that drives one or more grates among the plurality of grates that belong to a third section located downstream of the target section, and the control device sets the operating speed of one or more grates belonging to the third section operated by the third drive unit in accordance with the operating speed of one or more grates belonging to the target section. The cement clinker manufacturing apparatus described in any one of [1] to [4] above.

[0010] [6] A method for producing cement clinker, comprising: a generating step of generating cement clinker by burning cement raw materials in a kiln; and a cooling step of cooling the cement clinker discharged from the kiln in a clinker cooler, the cooling step including: a transporting step of transporting the cement clinker from upstream to downstream by a plurality of grates capable of supporting the cement clinker; an air sending step of sending cooling air for cooling the cement clinker from a plurality of air chambers to above the plurality of grates through openings formed in each of the plurality of grates; a first driving step of driving one or more grates belonging to a section located most upstream of the plurality of grates by a first driving unit; a target driving step of driving one or more grates belonging to a target section located downstream of the first section among the plurality of grates by a target driving unit; a measuring step of measuring wind pressure in an air chamber corresponding to the target section among the plurality of air chambers; and an operation control step of adjusting operation of the one or more grates belonging to the target section by the target driving unit so that a measurement result in the measuring step follows a target wind pressure. Effect of the Invention

[0011] According to the present disclosure, there is provided an apparatus for producing cement clinker and a method for producing cement clinker that are useful for stabilizing the temperature of exhaust gas from a clinker cooler. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing an example of a cement clinker production system. [Diagram 2] FIG. 2 is a side view that illustrates a schematic diagram of an example of a clinker cooler. [Diagram 3] FIG. 3 is a top view showing a schematic example of an arrangement of a plurality of grates. [Figure 4] Fig. 4(a) is a side view showing an example of a plurality of grates, and Fig. 4(b) and Fig. 4(c) are top views showing an example of the grates. [Diagram 5]FIG. 5 is a flowchart showing an example of a series of processes executed by the control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment will be described with reference to the drawings. In the description, the same elements or elements having the same functions are denoted by the same reference numerals, and duplicated description will be omitted.

[0014] [Cement clinker manufacturing system] Fig. 1 shows a schematic diagram of a cement clinker manufacturing system according to one embodiment. The manufacturing system 1 (cement clinker manufacturing apparatus) shown in Fig. 1 is a system that manufactures cement clinker. Hereinafter, the cement clinker manufactured by the manufacturing system 1 will be simply referred to as "clinker". Clinker is an intermediate product of cement. The manufacturing system 1 includes a manufacturing apparatus 10 and a control device 50.

[0015] (manufacturing equipment) The manufacturing apparatus 10 is an apparatus for producing clinker by burning cement raw materials. The manufacturing apparatus 10 includes, for example, a preheater 12, a kiln 14, and a clinker cooler 16.

[0016] The preheater 12 preheats the cement raw materials (raw materials for clinker). The preheater 12 is supplied with the cement raw materials from an apparatus that performs the raw material process in the cement manufacturing process. The preheater 12 is, for example, a new suspension preheater (NSP) having a plurality of cyclones constituting a multi-stage cyclone and a calciner. The preheater 12 may have four or five cyclones. Exhaust gas from the kiln 14 is introduced into the preheater 12. The preheater 12 brings high-temperature gas, including the exhaust gas from the kiln 14, into contact with the cement raw materials, and separates the gas from the cement raw materials in the cyclone. Exhaust gas used for heat exchange is discharged from the topmost cyclone of the preheater 12.

[0017] The kiln 14 burns the cement raw materials to generate clinker. The kiln 14 burns the cement raw materials that have been preheated by the preheater 12. The kiln 14 is, for example, a rotary kiln. The kiln 14 (rotary kiln) is configured to rotate about an axis line along its longitudinal direction. The kiln 14 may have a drum body and a burner that introduces combustion gas into the drum body. The kiln 14 discharges the generated clinker to the clinker cooler 16. The temperature of the clinker discharged from the kiln 14 to the clinker cooler 16 is, for example, about 800°C to 1000°C.

[0018] The clinker cooler 16 cools the clinker (high-temperature clinker) discharged from the kiln 14. The clinker cooler 16 cools the clinker using cooling air (gas). The clinker cooler 16 is also called an air quenching cooler. The clinker cooler 16 is configured to transport the clinker through multiple grates while blowing in high-pressure air from the bottom of the grates. The details of the clinker cooler 16 will be described later.

[0019] In the clinker cooler 16, heat exchange between the cooling air and the clinker occurs, thereby cooling (quenching) the clinker. A portion of the air that has become hot through heat exchange with the clinker is introduced into the kiln 14 as secondary air. Another portion of the air that has been used for heat exchange with the clinker may be introduced into the calciner of the preheater 12. Another portion of the air that has been used for heat exchange with the clinker may be used for power generation, from the viewpoint of effectively utilizing the thermal energy of this air.

[0020] A power generation system 90 may be connected to the manufacturing system 1. The power generation system 90 (power generation device) is a system that generates power by utilizing at least exhaust gas (air after heat exchange) from the clinker cooler 16. The power generation system 90 may be provided in a facility (factory) in which the manufacturing system 1 is installed. The power generation system 90 includes, for example, a boiler 92, a turbine 94, a generator 96, and a condenser 98.

[0021] The boiler 92 generates steam by heating water (condensate from the condenser 98) using the exhaust gas introduced from the clinker cooler 16. The turbine 94 is a steam turbine that is rotated by the steam from the boiler 92. The generator 96 converts the kinetic energy generated by the rotation of the rotating shaft of the turbine 94 into electricity. The condenser 98 condenses the steam that has completed its work in the turbine 94 back into water. The condensate obtained in the condenser 98 is returned to the boiler 92.

[0022] <Clinker cooler> 2 is a schematic side view of the clinker cooler 16. The clinker cooler 16 includes a casing 16a, a clinker transport section 20, an air delivery section 40, a wind pressure measuring section 48, and a wind pressure measuring section 49. The casing 16a forms an internal space for transporting and cooling the clinker. The casing 16a forms an internal space that extends in one horizontal direction as a whole, and an end of the internal space that discharges the clinker is connected to one end of the kiln 14.

[0023] The clinker transport unit 20 transports the clinker discharged from the kiln 14. In this disclosure, the terms "upstream" and "downstream" are used based on the direction in which the clinker is transported. That is, the clinker transport unit 20 transports the clinker from upstream to downstream. The direction in which the clinker is transported by the clinker transport unit 20 corresponds to the direction in which the internal space formed by the casing 16a extends.

[0024] As shown in Fig. 3, the clinker transport section 20 includes a plurality of grates 24. In Fig. 3, the plurality of grates 24 are shown in a plan view, and the direction of transport of the clinker is indicated by an outlined arrow. The plurality of grates 24 support the clinker and transport it from upstream to downstream. The grates 24 are members formed in a plate shape, and may be referred to as grate plates or grate plates. The grates 24 are made of, for example, metal.

[0025] The grates 24 are arranged so as to form a portion that supports the clinker in the internal space formed in the casing 16a. In a plan view, the grates 24 are arranged in a matrix along the clinker conveying direction and the width direction perpendicular to the conveying direction. Fig. 4(a) shows a schematic side view of the grates 24 as viewed from the side. In Fig. 4(a), the members that support each of the grates 24 are omitted.

[0026] Each grate 24 is arranged so that its upper surface (main surface) capable of supporting clinker is inclined. Specifically, each grate 24 is inclined so that the upper surface faces upward as it advances in the clinker conveying direction. The inclination angle of the upper surface of each grate 24 from the horizontal direction is, for example, about 10°. When focusing on a pair of grates 24 adjacent to each other in the clinker conveying direction, the downstream end of the upstream grate 24 overlaps with the upstream end of the downstream grate 24.

[0027] The grates 24 include a plurality of movable grates 24a and a plurality of fixed grates 24b. For example, all the grates 24 included in the clinker conveying section 20 are either the movable grate 24a or the fixed grate 24b. When observing the plurality of grates 24 arranged along the clinker conveying direction, one movable grate 24a and one fixed grate 24b are arranged alternately (see also FIG. 3). The movable grate 24a is a grate that is driven (moves) by a drive unit. The movable grate 24a reciprocates by the drive unit along its extension direction so as to be able to push the clinker downstream. The fixed grate 24b is a grate that is not driven by the drive unit and is in a fixed position.

[0028] 4(b) and 4(c) are schematic top views of the upper surface of the grate 24 as viewed perpendicularly to the upper surface. Each of the grates 24 has one or more slits 26 (openings) or one or more holes 28 (openings) formed therein, connecting a space below the grate with a space above the grate. Through the one or more slits 26 or the one or more holes 28, cooling air can be supplied from the space below the grate to the space above the grate.

[0029] Returning to FIG. 2, the clinker conveying section 20 is divided into two or more sections along the clinker conveying direction. The two or more sections in the clinker conveying section 20 are arranged in order from the upstream in the clinker conveying direction. The clinker conveying section 20 is divided into two or more sections depending on the difference in the driving source for driving the one or more movable grates 24a. In one example, the clinker conveying section 20 is divided into four sections along the clinker conveying direction. Hereinafter, the four sections in the clinker conveying section 20 are defined as "section 22A", "section 22B", "section 22C", and "section 22D". In the clinker conveying direction, the sections 22A, 22B, 22C, and 22D are arranged in this order from the upstream.

[0030] The clinker transport section 20 has a drive unit that drives one or more movable grates 24a included in each of the two or more sections in the clinker transport section 20. In one example, the clinker transport section 20 has a drive unit 30A, a drive unit 30B, a drive unit 30C, and a drive unit 30D. Each of the drive units 30A, 30B, 30C, and 30D includes a drive source such as an electric motor, and is controlled by the control device 50.

[0031] The driving unit 30A (first driving unit) drives one or more movable grates 24a belonging to the section 22A (first section) located most upstream among the multiple grates 24 (all grates 24) of the clinker transport section 20. The driving unit 30B (second driving unit) drives one or more movable grates 24a belonging to the section 22B located downstream of the section 22A among the multiple grates 24 of the clinker transport section 20. The section 22B (second section) is located between the section 22A and the section 22C.

[0032] The drive unit 30C (target drive unit) drives one or more movable grates 24a belonging to section 22C (target section) located downstream of section 22A and section 22B among the multiple grates 24 of the clinker transport unit 20. The drive unit 30D (third drive unit) drives one or more movable grates 24a belonging to section 22D (third section) located downstream of section 22A, section 22B, and section 22C among the multiple grates 24 of the clinker transport unit 20.

[0033] Each section may include multiple movable grates 24a. Each of the driving units 30A, 30B, 30C, and 30D may drive all of the movable grates 24a belonging to the corresponding section to operate at approximately the same operating speed and at the same timing. By driving the multiple movable grates 24a by the corresponding driving unit for each section included in the multiple sections in the clinker transport section 20, the operating speed of the movable grates 24a can be adjusted for each section. The operating speed is defined as the amount of displacement of the grate per unit time.

[0034] The air sending section 40 sends out cooling air (hereinafter referred to as "cooling air") from below the multiple grates 24 toward above the multiple grates 24. The cooling air is air for cooling the clinker, and is, for example, air at room temperature. The air sending section 40 includes multiple air chambers and an air supply section 46.

[0035] The air chambers send the cooling air above the grates 24 through openings formed in each of the grates 24. Each of the air chambers forms an independent space (room) below the lower surface of the grates 24, and sends the cooling air from that space to the space above the grates 24. The air chambers are arranged side by side along the clinker conveying direction. That is, the air chambers are arranged side by side from upstream to downstream. Two or more air chambers may be provided for each section in the clinker conveying section 20.

[0036] The air supply unit 46 supplies cooling air to each of the multiple air chambers. The air supply unit 46 may supply cooling air to each air chamber at a flow rate (flow rate per unit time) that is predetermined for that air chamber. The air supply unit 46 may have one or more fans, and cooling space may be supplied to the multiple air chambers from the fans. Although FIG. 2 shows an example in which branch flow paths connected to each of the multiple air chambers are integrated into one common flow path, cooling air may be supplied to each of the multiple air chambers via any flow path.

[0037] In one example, three air chambers are provided for each of the sections 22A, 22B, 22C, and 22D. The three air chambers corresponding to the section 22A are air chamber 41A, air chamber 42A, and air chamber 43A. The air chamber 41A, air chamber 42A, and air chamber 43A are arranged in this order from the upstream in the clinker conveying direction. Each of the air chambers 41A, 42A, and 43A sends out cooling air to the space above the section 22A through the openings of each of the multiple grates 24 included in the section 22A.

[0038] The three air chambers corresponding to the section 22B are air chamber 41B, air chamber 42B, and air chamber 43B. In the clinker conveying direction, air chamber 41B and air chamber 43A are adjacent to each other, and air chamber 41B, air chamber 42B, and air chamber 43B are arranged in this order from the upstream. Each of air chamber 41B, air chamber 42B, and air chamber 43B sends out cooling air to the space above section 22B through the openings of each of the multiple grates 24 included in section 22B.

[0039] The three air chambers corresponding to the section 22C are the air chamber 41C, the air chamber 42C, and the air chamber 43C. In the clinker conveying direction, the air chamber 41C and the air chamber 43B are adjacent to each other, and the air chamber 41C, the air chamber 42C, and the air chamber 43C are arranged in this order from the upstream. Each of the air chambers 41C, 42C, and 43C sends out cooling air to the space above the section 22C through the openings of the grates 24 included in the section 22C.

[0040] The three air chambers corresponding to the section 22D are the air chamber 41D, the air chamber 42D, and the air chamber 43D. In the clinker conveying direction, the air chamber 41D and the air chamber 43C are adjacent to each other, and the air chamber 41D, the air chamber 42D, and the air chamber 43D are arranged in this order from the upstream. Each of the air chambers 41D, the air chamber 42D, and the air chamber 43D sends out cooling air to the space above the section 22D through the openings of the grates 24 included in the section 22D.

[0041] The wind pressure measuring unit 48 (another pressure measuring unit) measures wind pressure in an air chamber (another air chamber) corresponding to the section 22A among the multiple air chambers (all air chambers) included in the air delivery unit 40. The wind pressure measuring unit 48 may measure wind pressure in any form as long as it is a device or sensor capable of measuring wind pressure. The wind pressure measuring unit 48 is disposed, for example, in the air chamber 41A located most upstream among the three air chambers corresponding to the section 22A. The wind pressure measuring unit 48 may measure the wind pressure of the cooling air delivered from the air chamber 41A to the space above the grate 24. The wind pressure measuring unit 48 outputs information indicating the measurement result of the wind pressure to the control device 50.

[0042] The wind pressure measuring unit 49 measures the wind pressure in the air chamber corresponding to the section 22C among the multiple air chambers (all air chambers) included in the air delivery unit 40. The wind pressure measuring unit 49 may measure the wind pressure in any form as long as it is a device or sensor capable of measuring wind pressure. The wind pressure measuring unit 49 is disposed, for example, in the air chamber 41C located most upstream among the three air chambers corresponding to the section 22C. The wind pressure measuring unit 49 may measure the wind pressure of the cooling air delivered from the air chamber 41C to the space above the grate 24. The wind pressure measuring unit 49 outputs information indicating the measurement result of the wind pressure to the control device 50.

[0043] The clinker cooler 16 may further include a discharge pipe 38. The discharge pipe 38 is a pipe for discharging cooling air (exhaust gas) after being used to cool the clinker in the clinker cooler 16 to the outside of the clinker cooler 16. Note that, in addition to the discharge pipe 38, the clinker cooler 16 may be provided with a pipe for discharging the exhaust gas to the outside of the clinker cooler 16.

[0044] The discharge pipe 38 sends out exhaust gas from an exhaust port 38a provided at a position corresponding to the section 22C toward the power generation system 90. For example, the exhaust pipe 38 introduces exhaust gas from the clinker cooler 16 into a boiler 92 of the power generation system 90 (see FIG. 1). In a plan view, at least a portion of the exhaust port 38a overlaps with at least a portion of the multiple grates 24 included in the section 22C.

[0045] (Control device) The control device 50 is a computer that controls at least some of the various devices included in the manufacturing apparatus 10. The control device 50 controls at least the clinker cooler 16. The control device 50 includes hardware such as a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and an input / output interface. The control device 50 may include a driver (driver circuit). The driver of the control device 50 outputs drive power to a drive motor included in each drive unit such as the drive unit 30A.

[0046] The control device 50 adjusts the operation of one or more movable grates 24a belonging to the section 22C by the drive unit 30C so that the measurement result by the wind pressure measurement unit 49 follows the target wind pressure (hereinafter, referred to as "target wind pressure C"). For example, the control device 50 adjusts the operation speed of one or more movable grates 24a belonging to the section 22C by the drive unit 30C so that the measurement result by the wind pressure measurement unit 49 follows the target wind pressure C. The target wind pressure C is set in advance by an operator such as a worker. When the wind pressure measurement unit 49 is arranged in the air chamber 41C, the wind pressure of the cooling air sent out from the air chamber 41C varies depending on the amount of accumulated clinker on the multiple grates 24 at the position corresponding to the section 22C. By adjusting the operation speed of the grate 24 so that the wind pressure of the cooling air sent out from the air chamber 41C becomes the target wind pressure C, the amount of accumulated clinker on the multiple grates 24 in the section 22C can be kept within a certain target range. If the variation in the amount of accumulated clinker on the grates 24 in the section 22C is large, the temperature of the cooling air (exhaust gas) after heat exchange with the clinker in the section 22C also varies greatly. On the other hand, by adjusting the operating speed of the grates 24 so that the wind pressure of the cooling air from the air chamber 41C follows the target wind pressure C and the amount of accumulated clinker falls within a certain target range, it is possible to reduce the variation in the temperature of the exhaust gas after heat exchange with the clinker in the section 22C. Instead of or in addition to adjusting the operating speed, the control device 50 may adjust the number of operations (reciprocation) per unit time of one or more movable grates 24a belonging to the section 22C by the drive unit 30C so that the measurement result by the wind pressure measurement unit 49 follows the target wind pressure C. The amount of accumulated clinker can also be kept within a certain target range by adjusting the number of operations (reciprocation) per unit time.

[0047] The control device 50 may further execute control to adjust the operation of one or more movable grates 24a belonging to the section 22A by the drive unit 30A so that the measurement result by the wind pressure measurement unit 48 follows the target wind pressure (hereinafter, referred to as "target wind pressure A"). The control device 50 further executes control to adjust the operation speed of one or more movable grates 24a belonging to the section 22A by the drive unit 30A so that the measurement result by the wind pressure measurement unit 48 follows the target wind pressure A. The target wind pressure A (another target wind pressure) is set in advance by an operator such as a worker. The target wind pressure A may be set to a value larger than the target wind pressure C. In the following, a case where the operation speed of the movable grate is adjusted as an adjustment of the operation of the movable grate to follow the target wind pressure will be illustrated as an example.

[0048] The control device 50 may set the operating speed of one or more movable grates 24a belonging to section 22D operated by the drive unit 30D according to the operating speed of one or more movable grates 24a belonging to section 22C. The control device 50 may set the operating speed of the movable grates 24a related to section 22D to a value obtained by multiplying the operating speed (setting value of the operating speed) of the grate 24 adjusted based on the measurement result by the wind pressure measurement unit 49 and the target wind pressure C by a set ratio. The set ratio may be set (adjusted) by an operator such as a worker, and in one example, is set within a range of more than 0% and not more than 150%.

[0049] The control device 50 may set the operating speed of one or more movable grates 24a belonging to section 22B operated by the drive unit 30B according to the operating speed of one or more movable grates 24a belonging to section 22A. As in the setting of the operating speed of the grate 24 related to section 22D, the control device 50 may set the operating speed of the movable grate 24a related to section 22B to a value obtained by multiplying the operating speed of the grate 24 adjusted based on the measurement result by the wind pressure measurement unit 48 and the target wind pressure A by a set ratio.

[0050] [Manufacturing method of cement clinker] Next, a description will be given of the clinker manufacturing process (manufacturing method) executed in the manufacturing system 1. This clinker manufacturing process includes a generating process and a cooling process. The generating process is a process in which the cement raw materials are burned in the kiln 14 to generate clinker. The cooling process is a process in which the clinker discharged from the kiln 14 is cooled in the clinker cooler 16. The cooling process includes at least a conveying process, an air sending process, a driving process A, a driving process C, a measuring process, and an operation control process.

[0051] The conveying step is a step of conveying clinker from upstream to downstream by the multiple grates 24. The air sending step is a step of sending cooling air for cooling the clinker from multiple air chambers included in the air sending section 40 to above the multiple grates 24 through openings formed in each of the multiple grates 24. The driving step A (first driving step) is a step of driving one or more movable grates 24a belonging to the section 22A located most upstream among the multiple grates 24 by the driving section 30A.

[0052] The driving step C (target driving step) is a step of driving one or more movable grates 24a belonging to section 22C located downstream of section 22A among the plurality of grates 24 by the driving unit 30C. The measuring step is a step of measuring the wind pressure in an air chamber corresponding to section 22C among the plurality of air chambers included in the air delivery unit 40. In the measuring step, for example, the wind pressure in air chamber 41C corresponding to section 22C is measured by the wind pressure measuring unit 49.

[0053] The operation control process is a process in which the operation of one or more movable grates 24a belonging to the section 22C is adjusted by the drive unit 30C so that the measurement results in the measurement process follow the target wind pressure C. In the operation control process, for example, the operation speed of one or more movable grates 24a belonging to the section 22C is adjusted by the drive unit 30C so that the measurement results in the measurement process follow the target wind pressure C. The operation control process is executed, for example, by the control device 50. FIG. 5 shows a process flow showing a series of processes executed by the control device 50 in the operation control process.

[0054] In this series of processes, the control device 50 first executes step S01. In step S01, for example, the control device 50 waits until a predetermined measurement timing occurs. The measurement timing may be determined in advance, or may be set so that the series of processes from the next step S02 onward are repeated at a predetermined cycle.

[0055] Next, the control device 50 executes step S02. In step S02, for example, the control device 50 acquires information indicating the measurement result of the wind pressure from the wind pressure measuring unit 49. Furthermore, the control device 50 acquires information indicating the measurement result of the wind pressure from the wind pressure measuring unit 48 in addition to the information from the wind pressure measuring unit 49.

[0056] Next, the control device 50 executes step S03. In step S03, for example, the control device 50 calculates the deviation (hereinafter referred to as "deviation C") between the wind pressure measurement value obtained by the wind pressure measurement unit 49 in step S02 and the target wind pressure C. The control device 50 also calculates the deviation (hereinafter referred to as "deviation C") between the wind pressure measurement value obtained by the wind pressure measurement unit 48 in step S02 and the target wind pressure A.

[0057] Next, the control device 50 executes step S04. In step S04, for example, the control device 50 calculates an operating speed of the grate 24 that reduces the deviation C based on the deviation C calculated in step S03. Also, the control device 50 calculates an operating speed of the grate 24 that reduces the deviation A based on the deviation A calculated in step S03. In one example, the control device 50 may calculate the operating speed of the grate 24 by performing a PID (proportional-integral-derivative) calculation based on the deviation A and the deviation C.

[0058] Next, the control device 50 executes step S05. In step S05, for example, the control device 50 adjusts the output value to the drive unit 30C so that the movable grate 24a belonging to the section 22C operates at the calculated value of the operating speed obtained in step S04 (the value calculated based on the deviation C). The control device 50 also adjusts the output value to the drive unit 30A so that the movable grate 24a belonging to the section 22A operates at the calculated value of the operating speed obtained in step S04 (the value calculated based on the deviation A).

[0059] [Variations] The series of processes shown in Fig. 5 is an example and can be modified as appropriate. In the series of processes described above, the control device 50 may execute one step and the next step in parallel, or may execute each step in an order different from the example described above. The control device 50 may omit any step, or may execute a process different from the example described above in any step.

[0060] The clinker cooler 16 illustrated above is just an example. Instead of the air chamber 41C, the wind pressure measuring unit 49 may be disposed in the air chamber 42C or the air chamber 42D corresponding to the section 22C. Even in this case, the control device 50 may control the driving unit 30C so that the measurement result by the wind pressure measuring unit 49 follows the target wind pressure C.

[0061] Instead of or in addition to the section 22C, a wind pressure measuring unit may be provided in any air chamber corresponding to the section 22B (target section). In this case, the control device 50 may control the drive unit 30B (target drive unit) so that the measurement result by the wind pressure measuring unit follows a predetermined target wind pressure. The exhaust port 38a of the exhaust pipe 38 may be provided at a position corresponding to the section 22B.

[0062] Instead of or in addition to the section 22C, a wind pressure measuring unit may be provided in any air chamber corresponding to the section 22D (target section). In this case, the control device 50 may control the drive unit 30D (target drive unit) so that the measurement result by the wind pressure measuring unit follows a predetermined target wind pressure. The exhaust port 38a of the exhaust pipe 38 may be provided at a position corresponding to the section 22D.

[0063] The clinker conveying section 20 may be divided into two sections. For convenience of explanation, the two sections are referred to as section 22A and section 22B. The wind pressure measuring section 49 measures the wind pressure in one of the air chambers corresponding to the downstream (rear) section 22B. The discharge port 38a of the discharge pipe 38 may be provided at a position corresponding to section 22B (target section). The control device 50 may control the drive section 30B (target drive section) corresponding to section 22B so that the measurement result by the wind pressure measuring section 49 follows the target wind pressure.

[0064] The clinker transport section 20 may be divided into three sections. For example, the clinker transport section 20 may be divided into sections 22A, 22B, and 22C, without including the section 22D. The clinker transport section 20 may be divided into five or more sections.

[0065] Each of drive units 30A, 30B, 30C, and 30D may apply driving force to the corresponding multiple movable grates 24a by one driving source (such as an electric motor) or two or more driving sources (such as electric motors).

[0066] [Summary of this disclosure] The manufacturing system 1 described above includes a kiln (14) that burns cement raw materials to produce clinker (cement clinker), a clinker cooler (16) that cools the clinker discharged from the kiln (14), and a control device (50) that controls the clinker cooler (16). The clinker cooler (16) includes a plurality of grates (24) that support the clinker and transport the clinker from upstream to downstream, a plurality of air chambers (41A-43A, 41B-43B, 41C-43C, 41D-43D) that send cooling air for cooling the clinker to above the plurality of grates (24) via openings (26, 28) formed in each of the plurality of grates (24), and a first section (22A) that is located at the most upstream of the plurality of grates (24). The control device (50) includes a first drive unit (30A) that drives one or more grates (24a) that belong to a target section (22C) located downstream of the first section (22A) among the plurality of grates (24), a target drive unit (30C) that drives one or more grates (24a) that belong to a target section (22C) located downstream of the first section (22A) among the plurality of grates (24), and a pressure measurement unit (49) that measures wind pressure in an air chamber (41C-43C) corresponding to the target section (22C) among the plurality of air chambers (41A-43A, 41B-43B, 41C-43C, 41D-43D). The control device (50) adjusts the operation of the one or more grates (24a) that belong to the target section (22C) by the target drive unit (30C) so that the measurement result by the pressure measurement unit (49) follows the target wind pressure (C).

[0067] In the section (20) where clinker is transported by a plurality of grates (24), the amount of clinker transported by one or more grates (24a) varies depending on the operation (e.g., operation speed) of one or more movable grates (24a). This causes the amount of clinker temporarily accumulated on the one or more grates (24a) to vary. In the target section (22C) located downstream of the first section (22A) located at the most upstream position in the section (20), the amount of clinker accumulated on the grates (24) in the section (22C) may vary significantly due to the variation in the amount of clinker discharged from the kiln (14) to the clinker cooler (16) and the variation in the amount of clinker transported in the first section (22A), if the grates (24a) operate at a constant speed or with a constant number of operations. In contrast, in the manufacturing system (1), the operation of one or more grates (24a) is adjusted so that the wind pressure measured by the wind pressure measuring unit (49) in the target section (22C) located downstream follows the target wind pressure. Since the wind pressure in the air chamber (41C-43C) corresponding to the section (22C) varies depending on the amount of clinker accumulated on the grate (24), the amount of clinker accumulated in the section (22C) can be kept within a certain range by adjusting the operation of the grate (24a) as described above. This reduces the temperature fluctuation of the flue gas (flue gas from the clinker cooler) containing air after it has been used to cool the clinker in the section (22C). Therefore, the manufacturing system (1) is useful for stabilizing the temperature of the flue gas from the clinker cooler (16).

[0068] The clinker cooler (16) may further include a second drive unit (30B) for driving one or more grates (24a) belonging to a second section (22B) located between the first section (22A) and the target section (22C) among the plurality of grates (24). In this case, clinker is transported to the target section (22C) via the second section (22B), so that the variation in the amount of accumulated clinker due to the variation in the amount of clinker transported in the first section (22A) located at the most upstream side may become even larger. Therefore, as described above, it is even more useful to adjust the operation of the grate (24) based on the measurement result of the wind pressure in the target section (22C).

[0069] The clinker cooler (16) may further include a discharge pipe (38) for delivering exhaust gas from a discharge outlet (38a) provided at a position corresponding to the target section (22C) to a power generation device (90) that generates power using the exhaust gas from the clinker cooler (16). In this case, the temperature of the exhaust gas delivered from the discharge pipe (38) to the power generation device (90) varies only slightly, so that the power generation device (90) can operate stably.

[0070] The clinker cooler (16) may further include another pressure measuring unit (48) for measuring wind pressure in another air chamber (41A-43A) corresponding to the first section (22A) among the plurality of air chambers (41A-43A, 41B-43B, 41C-43C, 41D-43D). The control device (50) may further perform control for adjusting the operation of one or more grates (24a) belonging to the first section (22A) by the first drive unit (30A) so that the measurement result by the another pressure measuring unit (48) follows another target wind pressure (A). The another target wind pressure (A) may be set to a value higher than the target wind pressure (C). The temperature of the clinker being transported in the first section (22A) located at the most upstream side is higher than that in the section (22C) located downstream. By increasing the wind pressure at the most upstream side as in the above configuration, the clinker can be cooled more efficiently.

[0071] The control device (50) may adjust the operating speed of one or more grates (24a) belonging to the target section (22C) by the target drive unit (30C) so that the measurement result by the pressure measurement unit (49) follows the target wind pressure (C). The clinker cooler (16) may further include a third drive unit (30D) that drives one or more grates (24a) belonging to a third section (22D) located downstream of the target section (22C) among the plurality of grates (24). The control device (50) may set the operating speed of one or more grates (24a) belonging to the third section (22D) operated by the third drive unit (30D) according to the operating speed of one or more grates (24a) belonging to the target section (22C). In the third section (22D), there may be cases where the operating speed of the grate (24a) does not need to be adjusted according to the amount of accumulated clinker, i.e., the wind pressure in the corresponding air chamber. Therefore, in the above configuration, there is no need to measure the air pressure in the air chamber corresponding to the third section (22D), which is useful for simplifying the manufacturing system (1).

[0072] The method for producing cement clinker described above includes a production step of producing clinker by burning the cement raw materials in the kiln (14) and a cooling step of cooling the clinker discharged from the kiln (14) in the clinker cooler (16). The cooling step includes a transport step of transporting the clinker from upstream to downstream by a plurality of grates (24) capable of supporting the clinker, an air delivery step of delivering cooling air for cooling the clinker from a plurality of air chambers (41A to 43A, 41B to 43B, 41C to 43C, 41D to 43D) to above the plurality of grates (24) through openings (26, 28) formed in each of the plurality of grates (24), a first driving step of driving one or more grates (24a) belonging to a section (22A) located most upstream of the plurality of grates (24) by a first driving unit (30A), and a second driving step of driving one or more grates (24a) belonging to a section (22A) located most upstream of the plurality of grates (24) downstream of the first section (22A). The method includes a target driving step of driving one or more grates (24a) belonging to the target section (22B, 22C, 22D) located in the target section (22B, 22C, 22D) by a target driving unit (30B, 30C, 30D), a measurement step of measuring wind pressure in an air chamber (41B-43B, 41C-43C, 41D-43D) corresponding to the target section (22B, 22C, 22D) among the plurality of air chambers (41A-43A, 41B-43B, 41C-43C, 41D-43D), and an operation control step of adjusting the operation of one or more grates (24a) belonging to the target section (22B, 22C, 22D) by the target driving unit (30B, 30C, 30D) so that the measurement result in the measurement step follows the target wind pressure. This manufacturing method is useful for stabilizing the temperature of the exhaust gas from the clinker cooler (16) as in the above manufacturing system (1). [Explanation of symbols]

[0073] 1...cement clinker manufacturing system, 14...kiln, 16...clinker cooler, 20...clinker transport section, 22A, 22B, 22C, 22D...section, 24...grate, 24a...movable grate, 24b...fixed grate, 30A, 30B, 30C, 30D...drive section, 38...discharge piping, 38a...discharge outlet, 41A, 42A, 43A...air chamber, 41B, 42B, 43B...air chamber, 41C, 42C, 43C...air chamber, 41D, 42D, 43D...air chamber, 48, 49...wind pressure measuring section, 50...control device, 90...power generation system.

Claims

1. a kiln for burning cement raw materials to produce cement clinker; a clinker cooler for cooling the cement clinker discharged from the kiln; A control device for controlling the clinker cooler, The clinker cooler comprises: A plurality of grates for supporting the cement clinker and transporting the cement clinker from upstream to downstream; a plurality of air chambers for delivering cooling air to above the plurality of grates through openings formed in each of the plurality of grates for cooling the cement clinker; A first drive unit that drives one or more grates belonging to a first section that is located most upstream among the plurality of grates; a target driving unit that drives one or more grates belonging to a target section that is located downstream of the first section among the plurality of grates; a pressure measuring unit that measures wind pressure in an air chamber corresponding to the target section among the plurality of air chambers, The control device adjusts the operation of one or more grates belonging to the target section using the target drive unit so that the measurement results by the pressure measurement unit follow a target wind pressure.

2. The cement clinker manufacturing apparatus according to claim 1 , wherein the clinker cooler further includes a second drive unit that drives one or more grates among the plurality of grates that belong to a second section located between the first section and the target section.

3. 3. The cement clinker manufacturing apparatus according to claim 1 or 2, wherein the clinker cooler further has an exhaust pipe for sending the exhaust gas from an exhaust outlet provided at a position corresponding to the target section toward a power generation device that generates power using the exhaust gas from the clinker cooler.

4. The clinker cooler further includes another pressure measuring unit that measures wind pressure in another air chamber corresponding to the first section among the plurality of air chambers, The control device further performs control to adjust the operation of one or more grates belonging to the first section by the first driving unit so that the measurement result by the other pressure measuring unit follows another target wind pressure, 3. The cement clinker manufacturing apparatus according to claim 1, wherein the another target wind pressure is set to a value larger than the target wind pressure.

5. The control device adjusts the operating speed of one or more grates belonging to the target section by the target drive unit so that the measurement result by the pressure measurement unit follows the target wind pressure, The clinker cooler further includes a third drive unit that drives one or more grates belonging to a third section located downstream of the target section among the plurality of grates, The cement clinker manufacturing apparatus according to claim 1 or 2, wherein the control device sets the operating speed of one or more grates belonging to the third section operated by the third drive unit according to the operating speed of one or more grates belonging to the target section.

6. a step of burning the cement raw material in a kiln to produce cement clinker; and a cooling step of cooling the cement clinker discharged from the kiln in a clinker cooler, The cooling step includes: a conveying step of conveying the cement clinker from an upstream side to a downstream side by a plurality of grates capable of supporting the cement clinker; an air delivery step of delivering cooling air from a plurality of air chambers to above the plurality of grates through openings formed in each of the plurality of grates for cooling the cement clinker; a first driving step of driving one or more grates belonging to a first section located most upstream among the plurality of grates by a first driving unit; a target driving step of driving one or more grates belonging to a target section located downstream of the first section among the plurality of grates by a target driving unit; a measuring step of measuring wind pressure in an air chamber corresponding to the target section among the plurality of air chambers; and an operation control process of adjusting the operation of one or more grates belonging to the target section by the target drive unit so that the measurement results in the measurement process follow the target wind pressure.

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