Method for producing cement clinker, cement clinker production system, sludge supply method, and sludge supply device

Abstract

To stabilize quality of cement clinker.SOLUTION: A cement clinker manufacturing method according to one aspect of the present disclosure includes a heating step, a suction step, and a feeding step. At the heating step, a cement raw material is heated in a heating section to which sludge is fed. At the suction step, the sludge is sucked from a storage section by moving a piston of a pomp pressure feeding section. At the feeding step, the sludge having been sucked is delivered into a feed pipe connected to the heating unit by moving the piston from a first position to a second position, The feeding step includes moving the piston from the first position to an intermediate position between the first position and the second position, stopping the piston at the intermediate position, and moving the piston from the intermediate position to the second position.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing cement clinker, a manufacturing system for cement clinker, a sludge supply method, and a sludge supply device.

Background Art

[0002] Patent Document 1 discloses a method for transporting low-moisture sludge. This transportation method includes a step of crushing sludge into lumps, a step of adding a lubricant to the lumps, and a step of transporting the lumps added with the lubricant through a pressure feed pump. Further, in the above transportation method, the moisture content of the lumps is adjusted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a method for manufacturing cement clinker, a manufacturing system for cement clinker, a sludge supply method, and a sludge supply device that are useful for stabilizing the quality of cement clinker.

Means for Solving the Problems

[0005] The method for manufacturing cement clinker according to one aspect of the present disclosure includes a heating step, a suction step, and a supply step. The heating step heats the cement raw material in a heating section to which sludge is supplied. The suction step sucks the sludge from the storage section by moving the piston of the pump pressure feeding section. The supply step sends out the sucked sludge into a supply pipe connected to the heating section by moving the piston from the first position to the second position. The supply step includes moving the piston from the first position to an intermediate position between the first position and the second position, stopping the piston at the intermediate position, and moving the piston from the intermediate position to the second position.

[0006] When the water content rate of the sludge introduced into the supply pipe becomes low, instead of the sludge being introduced into the heating section by one reciprocating operation of the piston, a large amount of sludge mass can be introduced into the heating section by a plurality of reciprocating operations of the piston. If the amount of the sludge mass introduced into the heating section is large, a part of the sludge mass may not be incinerated, which may affect the heating of the cement raw material in the heating section. In contrast, in the above manufacturing method, the piston is stopped at the intermediate position while moving the piston from the first position to the second position. As a result, the amount of sludge sent out into the supply pipe decreases as the piston continuously moves toward the second position. Therefore, the water content rate of the sludge becomes low, and even when the sludge mass is introduced into the heating section by a plurality of reciprocating operations of the piston, the amount of the sludge mass introduced into the heating section decreases. As a result, it is possible to suppress the influence on the heating in the heating section caused by the non-incineration of the sludge. Therefore, it is useful for stabilizing the quality of the cement clinker.

[0007] In the above manufacturing method, in the supply step, the piston may be stopped at the intermediate position by stopping the piston when a predetermined time has elapsed from the timing of the start of the movement of the piston from the first position. In this case, it is not necessary to install a sensor or the like to stop the piston at the intermediate position. Therefore, it is useful for simplifying the device configuration.

[0008] In the above manufacturing method, in the supply process, when the arrival of the piston is detected by a sensor arranged at a position corresponding to the intermediate position, the piston may be stopped, so that the piston may be stopped at the intermediate position. In this case, when repeatedly executing the reciprocating motion of the piston, the piston can be stably stopped at the target position between the first position and the second position, and the possibility of an increase in the amount of sludge lumps is further reduced. Therefore, it is more useful for stabilizing the quality of cement clinker.

[0009] The supply process may further include driving the piston in a first operation mode in which the piston is moved from the first position to the second position without stopping between the first position and the second position. The above manufacturing method may switch from the first operation mode to a second operation mode in which the piston is moved from the first position to the intermediate position and stopped at the intermediate position, and then the piston is moved to the second position, based on a user instruction regarding the switching of the operation mode. In this case, during a period when it is determined that there is no influence on the heating in the heating part due to sludge, the piston can be operated in the first operation mode. Therefore, it is useful for achieving both simplification of the piston operation and stabilization of the quality of cement clinker.

[0010] The supply process may further include driving the piston in a first operation mode in which the piston is moved from the first position to the second position without stopping between the first position and the second position. The above manufacturing method may switch from the first operation mode to a second operation mode in which the piston is moved from the first position to the intermediate position and stopped at the intermediate position, and then the piston is moved to the second position, based on information indicating the pressure in the supply pipe. The moisture content of the sludge in the supply pipe can be estimated from the pressure in the supply pipe. Therefore, in the above method, when the moisture content of the sludge in the supply pipe becomes low, the operation mode can be switched to the second operation mode. As a result, during a period when the moisture content of the sludge is high and it is determined that there is no such influence on the heating in the heating part caused by the sludge, the piston can be operated in the first operation mode. Therefore, it is useful for achieving both simplification of the piston operation and stabilization of the quality of cement clinker.

[0011] The supply process may further include driving the piston in a first operation mode in which the piston is moved from the first position to the second position without stopping between the first position and the second position. The manufacturing method may switch from the first operation mode to a second operation mode in which the piston is moved from the first position to an intermediate position, stopped at the intermediate position, and then moved to the second position, based on information indicating the heating state of the cement raw material in the heating section. From the heating state of the cement raw material, it is possible to estimate the influence on heating in the heating section caused by the sludge already introduced into the heating section. Therefore, in the above method, when there is an influence on heating in the heating section caused by the sludge, it is possible to switch to the second operation mode to reduce or eliminate the influence. As a result, during a period when it is estimated that there is no such influence on heating in the heating section caused by the sludge, the piston can be operated in the first operation mode. Therefore, it is useful for achieving both simplification of the piston operation and stabilization of the quality of the cement clinker.

[0012] The information indicating the heating state of the cement raw material in the heating section may include one or more types of information selected from the group consisting of the temperature of the heating section, the temperature of the cement raw material after being heated in the heating section, the concentration of a predetermined component contained in the exhaust gas discharged from the heating section, and the supply amount of the energy source supplied to the heating section. These information vary due to the above influence on heating in the heating section caused by the sludge already introduced into the heating section. Therefore, it becomes possible to control the operation of the piston after grasping the influence of the sludge on heating in the heating section.

[0013] The above manufacturing method may further include a feeding step of feeding the sludge contained in the tank toward the downstream region including the above accommodating portion by a screw feeder. The water content of the sludge contained in the tank may be 80% or less. When the water content of the sludge contained in the tank is low, there is a high possibility that a phenomenon occurs in which a large amount of sludge mass is introduced into the heating portion by a plurality of reciprocating motions of the piston without the sludge being introduced into the heating portion by one reciprocating motion of the piston. In the above manufacturing method, the piston once stops at the intermediate position, and the amount of the sludge mass introduced into the heating portion decreases, so that the influence on the heating in the heating portion due to the sludge not being incinerated can be suppressed. Therefore, it is useful for stabilizing the quality of the cement clinker.

[0014] The cement clinker manufacturing system according to one aspect of the present disclosure includes a cement clinker manufacturing apparatus, a sludge supply apparatus, and a control apparatus for controlling the sludge supply apparatus. The cement clinker manufacturing apparatus has a heating portion for heating a cement raw material and generates a cement clinker. The sludge supply apparatus includes an accommodating portion for accommodating sludge, a supply pipe connected to the heating portion, and a pump pressure feeding portion for sucking the sludge from the accommodating portion by the reciprocating movement of the piston and feeding the sludge into the supply pipe, and supplies the sludge to the heating portion. The control apparatus executes supply control for feeding the sludge sucked from the accommodating portion into the supply pipe by moving the piston from the first position to the second position. The supply control includes moving the piston from the first position to an intermediate position between the first position and the second position, stopping the piston at the intermediate position, and moving the piston from the intermediate position to the second position. In this manufacturing system, the piston stops at the intermediate position while moving from the first position to the second position. Therefore, similarly to the above manufacturing method, it is useful for stabilizing the quality of the cement clinker.

[0015] The sludge supply method according to one aspect of the present disclosure is a method of supplying sludge to a heating unit that heats cement raw materials. The sludge supply method includes a suction step of sucking sludge from a storage unit by moving a piston of a pump pressure-feeding unit, and a supply step of sending the sucked sludge into a supply pipe connected to the heating unit by moving the piston from a first position to a second position. The supply step includes moving the piston from the first position to an intermediate position between the first position and the second position, stopping the piston at the intermediate position, and moving the piston from the intermediate position to the second position. In this sludge supply method, the piston is stopped at the intermediate position while moving the piston from the first position to the second position. Therefore, similar to the above manufacturing method, it is useful for stabilizing the quality of cement clinker.

[0016] The sludge supply device according to one aspect of the present disclosure includes a storage unit that stores sludge, a supply pipe connected to a heating unit that heats cement raw materials, and a pump pressure-feeding unit that sucks sludge from the storage unit and sends the sludge into the supply pipe by the reciprocating movement of a piston. The pump pressure-feeding unit executes a supply operation of sending the sludge sucked from the storage unit into the supply pipe by moving the piston from a first position to a second position. The supply operation includes the piston moving from the first position to an intermediate position between the first position and the second position, the piston stopping at the intermediate position, and the piston moving from the intermediate position to the second position. In this sludge supply device, the piston is stopped at the intermediate position while moving the piston from the first position to the second position. Therefore, similar to the above manufacturing method, it is useful for stabilizing the quality of cement clinker.

Advantages of the Invention

[0017] According to the present disclosure, there are provided a method for manufacturing cement clinker, a manufacturing system for cement clinker, a sludge supply method, and a sludge supply device that are useful for stabilizing the quality of cement clinker.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

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Figure 5

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Figure 10

Figure 11

DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment will be described with reference to the drawings. In the description, the same reference numerals are given to the same elements or elements having the same function, and redundant descriptions are omitted. Also, the positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings unless otherwise specified, and the dimensional ratios of the respective elements are not limited to the ratios shown in the drawings.

[0020] [Cement Clinker Manufacturing System] Figure 1 schematically shows a cement clinker manufacturing system according to an embodiment. The manufacturing system 1 (cement clinker manufacturing system) shown in Figure 1 is a system for manufacturing cement clinker by firing cement raw materials. The manufacturing system 1 includes a cement clinker manufacturing apparatus 2 and a control device 90.

[0021] The cement clinker manufacturing apparatus 2 is an apparatus for heating cement raw materials to produce cement clinker. The cement clinker manufacturing apparatus 2 includes, for example, a preheater 10, a rotary kiln 30, a clinker cooler 38, and a sludge supply device 40. Hereinafter, each apparatus included in the cement clinker manufacturing apparatus 2 and the control device 90 will be described respectively.

[0022] The preheater 10 is a new suspension preheater (NSP). Before firing the cement raw materials in the rotary kiln 30, the preheater 10 preheats and calcines the cement raw materials using high-temperature gas (hereinafter simply referred to as "high-temperature gas") containing exhaust gas from the rotary kiln 30. The high-temperature gas has a temperature sufficient to preheat and calcine the cement raw materials. The preheater 10 includes a plurality of cyclones, a calcining furnace 14, a rising duct 16, and a raw material supply section 17. The plurality of cyclones includes, for example, cyclones C1, C2, C3, and C4. Different from the example shown in Figure 1, the number of cyclones may be 5 or more or 3 or less.

[0023] The cyclones C1, C2, C3, and C4 are arranged in this order from top to bottom, and each cyclone separates the cement raw materials (preheated raw materials) from the high-temperature gas. The calcining furnace 14 is a furnace body for calcining cement raw materials with high-temperature gas containing exhaust gas from the rotary kiln 30. The calcining furnace 14 functions as a heating section for heating the cement raw materials. The heating temperature in the calcining furnace 14 is, for example, about 700°C to 900°C.

[0024] The calciner 14 is connected to the kiln end 32 of the rotary kiln 30 via a rising duct 16. At the lower end of the calciner 14, an air vent 14a connected to one end of the rising duct 16 is provided. The rising duct 16 guides the exhaust gas from the rotary kiln 30 into the calciner 14 through the air vent 14a. The exhaust gas from the kiln end 32 of the rotary kiln 30 flows upward in the rising duct 16 and in the calciner 14.

[0025] The calciner 14 has a burner (not shown) that mixes an energy source such as coal (e.g., pulverized coal) and air to supply combustion gas into the interior of the calciner 14. The high-temperature gas includes the exhaust gas from the rotary kiln 30 and the combustion gas from the burner of the calciner 14. Inside the calciner 14, a swirling flow that rises while swirling may be formed by the combustion gas from the burner. The high-temperature gas (exhaust gas discharged from the calciner 14) generated in the calciner 14 flows to the cyclone C4, and then flows upward so as to pass through the cyclones C3, C2, C1 in this order.

[0026] The raw material supply unit 17 inputs the cement raw material generated in the previous process (raw material process) into the gas duct between the cyclones C1 and C2. The supplied cement raw material descends in the order of cyclones C1, C2, C3 while repeating heat exchange with the high-temperature gas in the gas duct between the cyclones and separation from the high-temperature gas in the cyclones. The cement raw material separated from the high-temperature gas in the cyclone C3 is introduced into the interior of the calciner 14. By heat exchange with the high-temperature gas in the calciner 14, decarbonation of the limestone (calcium carbonate: CaCO3) contained in the cement raw material is performed. The calcined (decarbonated) cement raw material is introduced into the cyclone C4 together with the high-temperature gas, and after being separated from the high-temperature gas in the cyclone C4, it is supplied to the kiln end 32 of the rotary kiln 30.

[0027] The rotary kiln 30 is a device for firing cement raw materials that have been preheated and calcined in the preheater 10. The heating temperature in the rotary kiln 30 is, for example, about 1000°C to 1500°C. The rotary kiln 30 has a main body 34 and a burner 36 provided at the rear end of the main body 34. The rotary kiln 30 generates cement clinker by heating the cement raw materials with combustion gas from the burner 36. The rotary kiln 30 discharges the generated cement clinker to the clinker cooler 38. The clinker cooler 38 cools the cement clinker using cooling air or the like.

[0028] The sludge supply device 40 is a device for supplying sludge to the calciner 14. When the sludge is supplied into the calciner 14, some components of the sludge (for example, Al2O3) are used as cement raw materials. The sludge has a property of being easy to burn. The sludge supply device 40 may introduce the sludge into the calciner 14 from a supply port provided at any location in the upper half of the calciner 14. The sludge introduced from the sludge supply device 40 into the calciner 14 is incinerated by the high-temperature gas while falling in the calciner 14.

[0029] The sludge supply device 40 may supply any type of sludge to the calciner 14. The sludge supply device 40 may supply sludge in which a plurality of types of sludge are mixed to the calciner 14. The sludge supplied by the sludge supply device 40 may include undigested sludge with a high water content and digested sludge with a low water content. In one example, the water content of the undigested sludge is 83% to 85%, and the water content of the digested sludge is 78 to 79%, or less than 78%. The sludge supplied by the sludge supply device 40 may include sludge with a strong odor. The odor of organic sludge (organic sewage sludge) tends to be strong. Specific examples of organic sludge include sewage sludge, fecal sludge, and excess sludge.

[0030] FIG. 2 schematically shows an example of the sludge supply device 40. In the sludge supply device 40 shown in FIG. 2, to prevent leakage of odor to the outside, the sludge is accommodated in a sealed space and transported to the calciner 14 in a sealed state. The sludge supply device 40 includes, for example, a sealed facility 42, a tank 44, a screw feeder 46, a liquid injection unit 48, a hopper 49, a pump pressure feeding unit 50, and a supply pipe 52.

[0031] The sealed facility 42 is a facility that forms a sealed space so as to prevent leakage of the odor of the sludge. The sealed facility 42 houses a part of the tank 44, the screw feeder 46, the liquid injection unit 48, the hopper 49, the pump pressure feeding unit 50, and a part of the supply pipe 52. An entrance for loading may be provided on one side wall of the sealed facility 42 and can be opened and closed by a shutter. Various sludges may be supplied into the tank 44 from the entrance for loading using a truck or the like.

[0032] The sludge accommodated in the tank 44 may contain at least one selected from the group consisting of sewage sludge, night soil sludge, and surplus sludge. The water content of the sludge accommodated in the tank 44 may be 80% or less. In one example, the upper limit value of the water content of the sludge accommodated in the tank 44 is 78%, 76%, or 75%. The water content of the sludge in the tank 44 can be calculated by the following formula (1) based on the weight of the sludge sample before and after drying the sludge sample in a furnace at 40°C for 24 hours. Water content (%) = (weight before drying - weight after drying) / weight before drying × 100 (1)

[0033] The screw feeder 46 is a device that sends out the sludge in the tank 44 downstream. The sludge sent out from the screw feeder 46 is transported to the hopper 49. The present disclosure uses the terms "upstream" and "downstream" based on the flow of the transported sludge. That is, the sludge is transported from upstream to downstream. Other hoppers and other feeders may be provided between the screw feeder 46 and the pump pressure feeding unit 50. The liquid injection unit 48 supplies a liquid to the sludge being sent out by the screw feeder 46 so as to increase the water content of the sludge.

[0034] The hopper 49 (accommodating section) receives the sludge sent out from the screw feeder 46 and temporarily accommodates the sludge. The hopper 49 is arranged in a region downstream of the screw feeder 46. The hopper 49 forms a space for accommodating sludge (hereinafter referred to as "accommodating space S"). The hopper 49 includes, for example, a bottom wall and side walls, and forms an accommodating space S with an open upper end.

[0035] The pump pressure feeding section 50 is a piston pump that sucks sludge from the hopper 49 by the reciprocating movement of a piston and pressure-feeds the sludge toward the calcining furnace 14. The pump pressure feeding section 50 and the calcining furnace 14 are connected by a supply pipe 52. In the supply pipe 52, the inside of the pipe is sealed so that the odor of the sludge does not leak to the outside. The sludge pressure-fed from the pump pressure feeding section 50 is guided into the calcining furnace 14 through the supply pipe 52.

[0036] After the operation of the manufacturing system 1 (sludge supply device 40) is started, the pump pressure feeding section 50 gradually sends out the sludge into the pipe from one end 52a of the supply pipe 52. As a result, the supply pipe 52 is filled with sludge. When the pump pressure feeding section 50 further sends out a certain amount of sludge from the end 52a into the supply pipe 52 in a state where the supply pipe 52 is filled with sludge, the sludge located at the other end 52b connected to the calcining furnace 14 of the supply pipe 52 and in the vicinity of the end 52b can be introduced into the calcining furnace 14. The pump pressure feeding section 50 repeatedly executes an operation (reciprocating movement of the piston) of sending out a certain amount of sludge into the supply pipe 52 and introducing a part of the sludge in the supply pipe 52 into the calcining furnace 14.

[0037] FIG. 3 schematically shows an example of the pump feeding unit 50. The pump feeding unit 50 includes a pump unit 60, a switching unit 70, and an on-off valve 78. The pump unit 60 has a function of sucking the sludge in the hopper 49 and sending out the sucked sludge. The pump unit 60 may have two sets of (one set of) piston mechanisms. The pump unit 60 includes, for example, a container 62A, a piston 64A, a piston driving unit 66A, and position sensors 68A and 69A, and a container 62B, a piston 64B, a piston driving unit 66B, and position sensors 68B and 69B.

[0038] The container 62A is configured to be able to accommodate sludge therein. The container 62A is formed in a cylindrical shape so as to extend along one direction. Hereinafter, the extending direction of the container 62A is denoted as "direction D". One end of the container 62A in the direction D is open and connected to one side wall of the hopper 49. The sludge in the hopper 49 can be introduced into the container 62A from one end of the container 62A in the direction D.

[0039] The piston 64A is provided in the container 62A and forms a suction space in the container 62A that is connected to the accommodation space S in the hopper 49. The volume of the suction space partitioned by the container 62A and the piston 64A changes according to the position of the piston 64A in the direction D. The piston 64A has a shape capable of closing the cross section of the container 62A in the direction D2. The piston 64A may be connected to the piston driving unit 66A via a piston rod extending along the direction D.

[0040] The piston driving unit 66A is a driving unit configured to reciprocate the piston 64A along the direction D based on an operation instruction from the control device 90. The piston driving unit 66A is, for example, a hydraulic cylinder. The piston driving unit 66A may reciprocate the piston 64A between a predetermined retracted position P1 and a predetermined advanced position P2 in the direction D. In the direction D, the hopper 49, the advanced position P2, and the retracted position P1 are arranged in this order. In the present disclosure, the distance between the retracted position P1 (the first position) and the advanced position P2 (the second position) is defined as "one stroke". The distance of one stroke may be about 0.5 m to 2.0 m.

[0041] In the present disclosure, moving the piston from the retracted position P1 to the advanced position P2 is referred to as "advancing", and moving the piston from the advanced position P2 to the retracted position P1 is referred to as "retracting". As the piston 64A retracts from the advanced position P2 toward the retracted position P1, the volume of the suction region in the container 62A increases, and sludge is suctioned from the storage space S of the hopper 49 into the container 62A. As the piston 64A advances from the retracted position P1 toward the advanced position P2, the volume of the suction region in the container 62A decreases, and sludge is pushed out from the container 62A.

[0042] The position sensor 68A is a sensor that detects (senses) that the piston 64A has reached the retracted position P1. For example, when the piston 64A retracts from the advanced position P2 toward the retracted position P1, the position sensor 68A generates a signal indicating the arrival of the piston 64A when the piston 64A reaches the retracted position P1. The position sensor 68A may be any type of sensor as long as it can detect the arrival of the piston 64A at the retracted position P1, and it may be arranged at any position. The position sensor 68A may directly detect the arrival of the piston 64A at the retracted position P1, or may detect the arrival of the piston 64A at the retracted position P1 by detecting the arrival of a part of a member (for example, the piston rod) connected to the piston 64A.

[0043] The position sensor 69A is a sensor that detects (senses) that the piston 64A has reached the forward position P2. For example, when the piston 64A moves forward from the retracted position P1 towards the forward position P2, the position sensor 69A generates a signal indicating the arrival of the piston 64A when the piston 64A reaches the forward position P2. The position sensor 69A may be any type of sensor and may be arranged at any position as long as it can detect the arrival of the piston 64A at the forward position P2. The position sensor 69A may directly detect the arrival of the piston 64A at the forward position P2, or may detect the arrival of the piston 64A at the forward position P2 by detecting the arrival of a part of the member connected to the piston 64A.

[0044] The container 62B has the same configuration and the same functions as the container 62A. The piston 64B has the same configuration and the same functions as the piston 64A. The piston drive unit 66B has the same configuration and the same functions as the piston drive unit 66A. The position sensors 68B, 69B have the same functions as the position sensors 68A, 69A, respectively. The piston drive unit 66B advances the piston 64B from the retracted position P1 towards the forward position P2 while sludge is being sucked into the container 62A due to the retraction of the piston 64A. The piston drive unit 66B retracts the piston 64B from the forward position P2 towards the retracted position P1 while sludge is being discharged from the container 62A due to the advancement of the piston 64A.

[0045] The switching unit 70 switches the pumping state from the pump pumping unit 50 between a first state and a second state. The first state is a state in which sludge can be discharged from the container 62A to the supply pipe 52 and sludge can be sucked from the storage space S of the hopper 49 into the container 62B. In the first state, sludge cannot be discharged from the container 62B to the supply pipe 52, and sludge cannot be sucked from the storage space S of the hopper 49 into the container 62A.

[0046] The second state is a state in which sludge can be sent from the container 62B to the supply pipe 52 and sludge can be sucked from the storage space S of the hopper 49 into the container 62A. In the second state, sludge cannot be sent from the container 62A to the supply pipe 52, and sludge cannot be sucked from the storage space S of the hopper 49 into the container 62B. The switching unit 70 has, for example, a connection pipe 72 and a switching drive unit 74.

[0047] The connection pipe 72 is a pipe that connects between the open end of the container 62A and the end 52a of the supply pipe 52, and between the open end of the container 62B and the end 52a of the supply pipe 52 at different timings. The connection pipe 72 is provided so that the connection destination of its end 72a can be switched between the end of the container 62A and the end of the container 62B. The end 72b of the connection pipe 72 on the side opposite to the end 72a is connected to the end 52a of the supply pipe 52 regardless of the connection destination of the end 72a. When the end 72a of the connection pipe 72 is connected to the end of the container 62A, the first state is achieved, and when the end 72a is connected to the end of the container 62B, the second state is achieved.

[0048] Based on an operation instruction from the control device 90, the switching drive unit 74 drives the connection pipe 72 so as to switch between a first state in which the space between the end of the container 62A and the end 52a of the supply pipe 52 is connected, and a second state in which the space between the end of the container 62B and the end 52a of the supply pipe 52 is connected. When the space between the end of the container 62A and the end 52a of the supply pipe 52 is connected via the connection pipe 72, the storage space S in the hopper 49 and the space (the above-mentioned suction space) in the container 62B are connected. When the space between the end of the container 62B and the end 52a of the supply pipe 52 is connected via the connection pipe 72, the storage space S and the space (the above-mentioned suction space) in the container 62A are connected.

[0049] The on-off valve 78 is a valve that switches the open / closed state of the flow path in the supply pipe 52 based on an operation instruction from the control device 90. The on-off valve 78 may be provided in the supply pipe 52 near the end portion 52a connected to the hopper 49. The on-off valve 78 switches the flow path in the supply pipe 52 from the closed state to the open state based on an operation instruction from the control device 90. The on-off valve 78 switches the flow path in the supply pipe 52 from the open state to the closed state based on an operation instruction from the control device 90. When the on-off valve 78 is in the open state, it is possible to introduce sludge into the supply pipe 52 (more specifically, the downstream portion of the supply pipe 52 from the on-off valve 78), and the sludge is supplied from the supply pipe 52 into the calciner 14. The on-off valve 78 may be any type of valve as long as it can switch the open / closed state in the supply pipe 52.

[0050] As shown in FIG. 1, the cement clinker manufacturing apparatus 2 may include an acquisition device 82. The acquisition device 82 is a device that acquires information indicating the heating state of the cement raw material in the calciner 14 (hereinafter referred to as "heating information"). The acquisition device 82 outputs the acquired heating information to the control device 90. The acquisition device 82 measures, for example, the temperature indicating the heating state of the cement raw material in the calciner 14. The acquisition device 82 may measure the temperature of the calciner 14. The temperature of the calciner 14 varies depending on the heating state of the cement raw material in the calciner 14. The acquisition device 82 may measure the temperature of the outer surface of the calciner 14 by detecting infrared rays or the like radiated from the outer surface of the calciner 14.

[0051] As shown in FIG. 2, the cement clinker manufacturing apparatus 2 may include a pressure gauge 84. The pressure gauge 84 measures the pressure in the supply pipe 52. The pressure gauge 84 outputs information indicating the pressure in the supply pipe 52 (hereinafter referred to as "pressure information") to the control device 90. The pressure in the supply pipe 52 can vary depending on the water content rate of the sludge filled in the supply pipe 52. When the water content rate of the sludge in the supply pipe 52 decreases, the pressure in the supply pipe 52 tends to increase, and when the water content rate of the sludge in the supply pipe 52 increases, the pressure in the supply pipe 52 tends to decrease.

[0052] The control device 90 is a computer that controls at least the sludge supply device 40. The control device 90 may be a computer that controls the entire cement clinker manufacturing device 2. Hereinafter, the case where the control device 90 is a computer that controls the entire cement clinker manufacturing device 2 will be exemplified. As shown in FIG. 4, the control device 90 has a circuit 91. The circuit 91 includes at least one processor 92, a memory 93, a storage 94, an input / output port 95, and a timer 96. The storage 94 records a program for controlling each element included in the cement clinker manufacturing device 2. The storage 94 is a computer-readable recording medium such as a hard disk, a non-volatile semiconductor memory, a magnetic disk, or an optical disk.

[0053] The memory 93 temporarily stores a program loaded from the storage 94, the calculation results of the processor 92, and the like. The processor 92 executes control over each element included in the cement clinker manufacturing device 2 by executing a program in cooperation with the memory 93. The input / output port 95 inputs and outputs electrical signals between the piston drive units 66A and 66B, the position sensors 68A, 68B, 69A, and 69B, the switching drive unit 74, the on-off valve 78, and the like in response to a command from the processor 92. The timer 96 measures the elapsed time by counting clock pulses of a predetermined period according to a command from the processor 92.

[0054] An input / output device 98 may be connected to the control device 90. The input / output device 98 is a device for inputting an instruction from an operator such as a worker to the control device 90 and notifying the operator of information from the control device 90. The input / output device 98 may include a keyboard, an operation panel, or a mouse as an input device, and may include a monitor (for example, a liquid crystal display) as an output device. The input / output device 98 may be a touch panel in which an input device and an output device are integrated. The control device 90 and the input / output device 98 may be integrated.

[0055] The control device 90 may adjust the supply amount of pulverized coal (supply amount per unit time) supplied to the calciner 14 according to the measurement result of the temperature of the calciner 14. The control device 90 may adjust the supply amount of pulverized coal so that the temperature of the calciner 14 is included in a predetermined target range (so as to approach the target temperature). The control device 90 may control the pump feeding unit 50 so that the supply amount of sludge (supply amount per unit time) supplied from the pump feeding unit 50 is included in a predetermined target range. In one example, the control device 90 controls the pump feeding unit 50 so that the operations including the suction and delivery of sludge by the reciprocating motions of the pistons 64A and 64B are repeated at a predetermined cycle.

[0056] The control device 90 may be configured to switch the operation mode of the pump feeding unit 50. The control device 90 may control the pump feeding unit 50 in an operation mode (hereinafter referred to as the "first operation mode") in which the pistons 64A and 64B are operated without being stopped during one stroke between the retracted position P1 and the advanced position P2. The control device 90 may control the pump feeding unit 50 in an operation mode (hereinafter referred to as the "second operation mode") in which the pistons 64A and 64B are once stopped and then operated during one stroke.

[0057] In the first operation mode, the control device 90 drives the piston 64A by the piston driving unit 66A so that the piston 64A moves from the retracted position P1 to the advanced position P2 without being stopped between the retracted position P1 and the advanced position P2. In the first operation mode, the control device 90 also drives the piston 64B by the piston driving unit 66B in the same manner as the driving of the piston 64A.

[0058] In the second operation mode, the control device 90 controls the piston drive unit 66A to move the piston 64A from the retracted position P1 to the intermediate position Pm between the retracted position P1 and the advanced position P2 and stop at the intermediate position Pm. Thereafter, the control device 90 controls the piston drive unit 66A to move the piston 64A from the intermediate position Pm to the advanced position P2. In the second operation mode, the control device 90 controls the piston drive unit 66B for the piston 64B in the same manner as the control for the piston 64A.

[0059] In the supply of sludge from the supply pipe 52 to the calciner 14, an amount of sludge corresponding to the moving distance from the start of the forward movement to the stop of the pistons 64A and 64B can be introduced into the calciner 14. In the second operation mode, since the piston stops once at the intermediate position Pm, an amount of sludge corresponding to the moving distance from the start of the forward movement of the pistons 64A and 64B to the stop at the intermediate position Pm can be introduced into the calciner 14. Thereafter, an amount of sludge corresponding to the moving distance from the resumption of the forward movement to the stop at the advanced position P2 of the pistons 64A and 64B can be introduced into the calciner 14. Therefore, in the second operation mode, the supply amount of sludge (the amount of sludge introduced in one supply operation) associated with one operation from the movement to the stop of the piston can be smaller than the supply amount associated with one operation in the first operation mode.

[0060] The control device 90 may control the pump pressure-feeding unit 50 in the first operation mode unless an operator such as a worker gives an instruction. The control device 90 may switch from the first operation mode to the second operation mode based on a switching instruction (user instruction) from the operator. If the water content rate of the sludge sent to the calcining furnace 14 is low, the ventilation opening 14a of the calcining furnace 14 may be blocked. When the water content rate of the sludge is low, the following phenomena are considered to occur. When the water content rate becomes low and the sludge in the supply pipe 52 becomes hard, the sludge may not be pushed into the calcining furnace 14 by one reciprocating motion of the piston. In this case, after executing a plurality of reciprocating motions of the piston, a large amount of sludge may be pushed into the calcining furnace 14 at once in a lump. When a large amount of sludge is introduced into the calcining furnace 14 in a lump, part of the sludge may not be incinerated, and there is a risk that part of the ventilation opening 14a may be clogged. If the ventilation opening 14a of the calcining furnace 14 is blocked by sludge, a ventilation obstacle of the high-temperature gas from the rising duct 16 may occur, and a trouble may occur in which the temperature of the calcining furnace 14 decreases.

[0061] When the operator estimates that the ventilation opening 14a is blocked or estimates that the water content rate of the sludge is decreasing, the operator may switch the operation mode of the pump pressure-feeding unit 50. The operator may determine whether control in the second operation mode is necessary while checking the transition of the temperature measurement result by the acquisition device 82 or the transition of the measurement result by the pressure gauge 84. When the operator determines that switching is necessary, the operator may input a switching instruction to the control device 90 via the input / output device 98. After switching to the second operation mode, the control device 90 may switch from the second operation mode to the first operation mode based on an instruction from the operator.

[0062] [Method for manufacturing cement clinker] Using the above manufacturing system 1, cement clinker can be manufactured from cement raw materials. The method for manufacturing cement clinker in the manufacturing system 1 includes a preheating and calcining process (heating process), a firing process, a cooling process, and a sludge supply process. Cement is manufactured by subjecting the cement clinker generated by the above processes to a finishing process including pulverization and the like.

[0063] In the preheating and calcining process, the cement raw materials are preheated and calcined by the preheater 10. In the preheating and calcining process, calcination (heating) of the cement raw materials may be performed in the calciner 14 to which pulverized coal and sludge are supplied. In the firing process, the cement raw materials are fired by the rotary kiln 30, and as a result, cement clinker is produced. In the firing process, in the rotary kiln 30, the cement raw materials after being preheated and calcined are fired (heated). In the cooling process, the cement clinker produced in the rotary kiln 30 is cooled by the clinker cooler 38.

[0064] The sludge supply process is executed during at least a part of the period overlapping with the period during which the preheating and calcining process, the firing process, and the cooling process are being executed. In the sludge supply process (sludge supply method), sludge is supplied to the calciner 14 by the sludge supply device 40. The sludge supply process includes, for example, a receiving process, a sending process, a liquid injection process, and a pressure feeding process. In the receiving process, sludge having a water content of 80% or less is supplied into the tank 44, and the sludge is stored in the tank 44.

[0065] In the sending process, the sludge in the tank 44 is sent out by the screw feeder 46 toward the downstream area including the hopper 49 and the pump pressure feeding section 50. In the liquid injection process, liquid is supplied to the sludge being sent out by the screw feeder 46. Through the sending process and the liquid injection process, the sludge is stored in the hopper 49.

[0066] In the pressure feeding process, the sludge in the hopper 49 is pressure fed through the supply pipe 52 into the calciner 14 by the pump pressure feeding section 50. In a state where the supply pipe 52 is filled with sludge, by introducing sludge from the pump pressure feeding section 50 into the supply pipe 52 in the pressure feeding process, a part of the sludge filled in the supply pipe 52 is introduced into the calciner 14. The pressure feeding process includes a suction process and a supply process.

[0067] In the suction process, the piston 64A is moved from the forward position P2 to the backward position P1 by the piston driving unit 66A, so that sludge is sucked from the hopper 49 into the container 62A. In the suction process, the piston 64B is moved from the forward position P2 to the backward position P1 by the piston driving unit 66B, so that sludge is sucked from the hopper 49 into the container 62B. The suction of sludge into the container 62A and the suction of sludge into the container 62B are executed alternately.

[0068] In the supply process, with the sludge filled in the container 62A, the piston 64A is moved from the backward position P1 to the forward position P2 by the piston driving unit 66A, so that the sludge is sent into the supply pipe 52. In the supply process, with the sludge filled in the container 62B, the piston 64B is moved from the backward position P1 to the forward position P2 by the piston driving unit 66B, so that the sludge is sent into the supply pipe 52. The sending out of sludge from the container 62A and the sending out of sludge from the container 62B are executed alternately.

[0069] The details of the execution content of the supply process vary depending on the setting (switching result) of the operation mode of the pump pressure feeding unit 50. When set to the first operation mode, in the supply process, the piston driving units 66A and 66B are controlled so that the pistons 64A and 64B move forward to the forward position P2 without stopping between the backward position P1 and the forward position P2. When set to the second operation mode, in the supply process, the piston driving units 66A and 66B are controlled so that the pistons 64A and 64B move from the backward position P1 to the intermediate position Pm, stop at the intermediate position Pm, and then move forward from the intermediate position Pm to the forward position P2.

[0070] Next, with reference to FIGS. 5 to 10, an example of the control method by the control device 90 in the second operation mode will be described. FIG. 5 is a flowchart showing a series of processes executed when the piston 64A is advanced by one stroke when the operation mode of the pump pressure-feeding unit 50 is switched to the second operation mode. This series of processes is executed after the start of operation of the manufacturing system 1 in a state where the supply pipe 52 is filled with sludge. In the initial state of this series of processes, the piston 64A is located at the retracted position P1, and the piston 64B is located at the advanced position P2. Also, the on-off valve 78 is in the open state, and the container 62A and the supply pipe 52 are connected via the connecting pipe 72.

[0071] The control device 90 first executes step S01. In step S01, the control device 90 controls the piston drive unit 66A so as to start the forward movement of the piston 64A, and controls the piston drive unit 66B so as to start the backward movement of the piston 64B. FIG. 6(a) schematically shows the state after step S01 is started. By the execution of step S01, the introduction of the sludge in the container 62A into the supply pipe 52 via the connecting pipe 72 is started, and the suction of the sludge from the storage space S of the hopper 49 into the container 62B is started.

[0072] Next, the control device 90 executes steps S02 and S03. In step S02, the control device 90 waits until a predetermined set time (predetermined time) elapses from the execution of step S01. In step S03, the control device 90 controls the piston drive unit 66A so as to interrupt the forward movement of the piston 64A, and controls the piston drive unit 66B so as to interrupt the backward movement of the piston 64B. The above set time may be set in advance by the operator. The above set time is set so that the pistons 64A and 64B stop between the retracted position P1 and the advanced position P2 when the movement is interrupted.

[0073] FIG. 6(b) schematically shows the state after the execution of step S03. The intermediate position Pm corresponds to the position where the piston 64A stops when the set time has elapsed from the timing of the start of the movement of the piston 64A from the retracted position P1 and the piston 64A is stopped. After the execution of step S03, the position where the piston 64A stops and the position where the piston 64B stops may substantially coincide with each other, or may be different from each other. At a timing substantially the same as the execution of step S03, the control device 90 may control the on-off valve 78 so as to switch from the open state to the closed state.

[0074] Next, the control device 90 executes step S04. In step S04, the control device 90 waits until a predetermined stop time has elapsed after the execution of step S03. The stop time may be set in advance by the operator. The stop time may be set to a time such that the mass of sludge that can be introduced from the end 52b of the supply pipe 52 into the calciner 14 is interrupted. The stop time may be about 1 / 4 to 3 / 4 of the time for moving the piston one stroke in the first operation mode, and in one example, it is about 1.0 second to 3.0 seconds.

[0075] Next, the control device 90 executes step S05. In step S05, the control device 90 controls the piston drive unit 66A so as to resume the forward movement of the piston 64A, and controls the piston drive unit 66B so as to resume the backward movement of the piston 64B. At a timing substantially the same as the execution of step S05, or before the execution of step S05, the control device 90 may control the on-off valve 78 so as to switch from the closed state to the open state. FIG. 7(a) schematically shows the state after the movement of the pistons 64A and 64B is resumed.

[0076] Next, the control device 90 executes steps S06 and S07. In step S06, the control device 90 waits until the piston 64A reaches the forward position P2. The control device 90 may wait until it receives a signal from the position sensor 69A indicating that the piston 64A has reached the forward position P2. In step S07, the control device 90 controls the piston drive unit 66A to stop the forward movement of the piston 64A. Through the above steps, the piston 64A moves from the intermediate position Pm to the forward position P2, and the sludge in the container 62A is further introduced into the supply pipe 52 through the connection pipe 72.

[0077] In parallel with the execution of steps S06 and S07, the control device 90 executes steps S08 and S09. In step S08, for example, the control device 90 waits until the piston 64B reaches the retracted position P1. The control device 90 may wait until it receives a signal from the position sensor 68B indicating that the piston 64B has reached the retracted position P1. In step S09, the control device 90 controls the piston drive unit 66B to stop the retraction of the piston 64B. Through the above steps, the piston 64B moves to the retracted position P1, and the container 62B is filled with sludge.

[0078] Next, the control device 90 executes steps S11, S12, and S13. In step S11, the control device 90 controls the on-off valve 78 to switch from the open state to the closed state. In step S12, the control device 90 controls the switching drive unit 74 of the switching unit 70 to switch from the first state in which the container 62A and the supply pipe 52 are connected to the second state in which the container 62B and the supply pipe 52 are connected through the connection pipe 72. FIG. 7(b) illustrates the state of switching the connection by the connection pipe 72. In step S13, the control device 90 controls the on-off valve 78 to switch from the closed state to the open state.

[0079] FIG. 8 is a flowchart showing a series of processes executed when the piston 64A is retracted by one stroke when the operation mode of the pump delivery unit 50 is switched to the second operation mode. The series of processes shown in FIG. 8 is continuously executed after the execution of step S13 described above is completed.

[0080] After the execution of step S13, the control device 90 executes step S21. In step S21, the control device 90 controls the piston drive unit 66A so as to start the retraction of the piston 64A, and controls the piston drive unit 66B so as to start the forward movement of the piston 64B. FIG. 9(a) schematically shows the state after step S21 is started. By the execution of step S21, the suction of sludge from the storage space S of the hopper 49 into the container 62A is started, and the sludge in the container 62B is started to be introduced into the supply pipe 52 through the connection pipe 72.

[0081] Next, the control device 90 executes steps S22 and S23. In step S22, the control device 90 waits until a predetermined set time elapses from the execution of step S21. In step S23, the control device 90 controls the piston drive unit 66A so as to interrupt the retraction of the piston 64A, and controls the piston drive unit 66B so as to interrupt the forward movement of the piston 64B. The above set time may be preset to the same time as the set time used in step S02 described above.

[0082] FIG. 9(b) schematically shows the state after the execution of step S23. The intermediate position Pm corresponds to the position where the piston 64B stops when the set time elapses from the timing of starting the movement of the piston 64B from the retracted position P1 and the piston 64B is stopped. The position where the piston 64B stops after the execution of step S23 and the position where the piston 64A stops after the execution of step S03 described above may substantially coincide with each other or may be different from each other. At a timing substantially the same as the execution of step S23, the control device 90 may control the on-off valve 78 so as to switch from the open state to the closed state.

[0083] Next, the control device 90 executes step S24. In step S24, the control device 90 waits until a predetermined stop time elapses after the execution of step S23. The above stop time may be preset to the same time as the stop time used in step S04 described above.

[0084] Next, the control device 90 executes step S25. In step S25, the control device 90 controls the piston drive unit 66A so as to resume the backward movement of the piston 64A, and controls the piston drive unit 66B so as to resume the forward movement of the piston 64B. At substantially the same timing as the execution of step S25, or before the execution of step S25, the control device 90 may control the on-off valve 78 so as to switch from the closed state to the open state. FIG. 10(a) schematically shows the state after the movement of the pistons 64A and 64B is resumed.

[0085] Next, the control device 90 executes steps S26 and S27. In step S26, the control device 90 waits until the piston 64A reaches the backward position P1. The control device 90 may wait until it receives a signal indicating the arrival of the piston 64A at the backward position P1 from the position sensor 68A. In step S27, the control device 90 controls the piston drive unit 66A so as to stop the backward movement of the piston 64A. Through the above steps, the piston 64A moves to the backward position P1, and the container 62A is filled with sludge.

[0086] In parallel with the execution of steps S26 and S27, the control device 90 executes steps S28 and S29. In step S28, for example, the control device 90 waits until the piston 64B reaches the forward position P2. The control device 90 may wait until it receives a signal indicating the arrival of the piston 64B at the forward position P2 from the position sensor 69B. In step S29, the control device 90 controls the piston drive unit 66B so as to stop the forward movement of the piston 64B. Through the above steps, the piston 64B moves from the intermediate position Pm to the forward position P2, and the sludge filled in the container 62B is introduced into the supply pipe 52 through the connection pipe 72.

[0087] Next, the control device 90 executes steps S31, S32, and S33. In step S31, the control device 90 controls the on-off valve 78 so as to switch from the open state to the closed state. In step S32, the control device 90 controls the switching drive unit 74 of the switching unit 70 so as to switch from the second state in which the container 62B and the supply pipe 52 are connected to the first state in which the container 62A and the supply pipe 52 are connected via the connection pipe 72. FIG. 10(b) illustrates how the connection state is switched by the connection pipe 72. In step S33, the control device 90 controls the on-off valve 78 so as to switch from the closed state to the open state.

[0088] In the series of processes (supply process) exemplified above, the control device 90 executes supply control to send the sludge sucked from the hopper 49 to the supply pipe 52 by moving the piston 64A from the retracted position P1 to the advanced position P2. In the supply control, the control device 90 moves the piston 64A from the retracted position P1 to the intermediate position Pm by the piston drive unit 66A, stops the piston 64A at the intermediate position Pm by the piston drive unit 66A, and moves the piston 64A from the intermediate position Pm to the advanced position P2 by the piston drive unit 66B. In the supply control, the control device 90 controls the piston drive unit 66B so that the piston 64B performs the same operation as the piston 64A.

[0089] The control device 90 executes a series of processes from step S01 to step S13 and a series of processes from step S21 to step S33 at predetermined intervals. As a result, sludge is supplied from the supply pipe 52 to the calciner 14 at predetermined intervals. When the operation mode of the pump pressure feeding unit 50 is set to the first operation mode in which the piston is not stopped at the intermediate position Pm, the control device 90 executes a series of processes in which the execution of steps S02 to S05 and the execution of steps S22 to S25 are omitted in the above series of processes.

[0090] [Modification example] The above series of processes is an example and can be changed as appropriate. In the above series of processes, the control device 90 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 90 may omit any step, or may execute a process different from the above example in any step.

[0091] Instead of or in addition to the temperature of the calciner 14, the acquisition device 82 may acquire information indicating the temperature of the cement raw material after being heated in the calciner 14 as heating information indicating the heating state of the cement raw material in the calciner 14. The acquisition device 82 may measure, for example, the temperature of the cement raw material immediately before being charged into the kiln end 32 near the outlet of the cement raw material of the cyclone C4. The temperature of the cement raw material after being heated in the calciner 14 varies depending on the heating state of the cement raw material in the calciner 14.

[0092] Instead of or in addition to the temperature of the calciner 14, the acquisition device 82 may acquire information indicating the concentration of a predetermined component contained in the exhaust gas discharged from the calciner 14 as the above heating information. The acquisition device 82 may measure the concentration of carbon monoxide contained in the exhaust gas from the calciner 14. The concentration of a predetermined component (for example, carbon monoxide) contained in the exhaust gas from the calciner 14 varies depending on the heating state of the cement raw material in the calciner 14.

[0093] When the control device 90 adjusts the supply amount of an energy source such as pulverized coal other than sludge to the calciner 14 so as to maintain the temperature of the calciner 14 within the target range, the supply amount varies depending on the heating state of the cement raw material in the calciner 14. That is, when the temperature of the calciner 14 drops from the target range, the supply amount of pulverized coal or the like is increased, and when the temperature of the calciner 14 exceeds the target range, the supply amount of pulverized coal or the like is decreased. The control device 90 may acquire information indicating the supply amount of the energy source to the calciner 14 as the above heating information.

[0094] In the above example, based on the switching instruction from the operator, the operation mode of the pump pumping unit 50 is switched from the first operation mode to the second operation mode in which the piston is stopped at the intermediate position Pm. However, the method of switching the operation mode is not limited to this example. The control device 90 may switch from the first operation mode to the second operation mode based on the heating information indicating the heating status of the cement raw material in the calciner 14.

[0095] The control device 90 may switch from the first operation mode to the second operation mode based on one or more types of information selected from the group consisting of the temperature of the calciner 14, the temperature of the cement raw material after being heated in the calciner 14, the concentration of a predetermined component contained in the exhaust gas discharged from the calciner 14, and the supply amount of the energy source supplied to the calciner 14. The control device 90 may switch from the first operation mode to the second operation mode according to the comparison result between any heating information and a predetermined threshold value.

[0096] In one example, the control device 90 may switch from the first operation mode to the second operation mode when the temperature of the calciner 14 or the temperature of the cement raw material after heating falls below a predetermined threshold value. The control device 90 may switch from the first operation mode to the second operation mode when the concentration of carbon monoxide in the exhaust gas from the calciner 14 exceeds a predetermined threshold value. The control device 90 may switch from the first operation mode to the second operation mode when the supply amount of the energy source (for example, pulverized coal) to the calciner 14 exceeds a predetermined threshold value. After switching to the second operation mode, the control device 90 may switch from the second operation mode to the first operation mode based on any heating information.

[0097] Instead of or in addition to the heating information, the control device 90 may switch from the first operation mode to the second operation mode based on the pressure information indicating the pressure in the supply pipe 52 obtained by the pressure gauge 84. In one example, the control device 90 may switch from the first operation mode to the second operation mode when the measured value of the pressure in the supply pipe 52 exceeds a predetermined threshold value.

[0098] The control device 90 may operate the pump pressure-feeding unit 50 in the second operation mode while the manufacturing system 1 is operating, without executing the control for the pump pressure-feeding unit 50 in the first operation mode. In the suction process of retracting the pistons 64A and 64B from the forward position P2 to the retracted position P1, the control device 90 may not stop the pistons 64A and 64B between the retracted position P1 and the forward position P2.

[0099] FIG. 11(a) shows another example of the pump pressure-feeding unit 50. Instead of the elapse of the set time from the start timing of the movement from the retracted position P1, when the arrival of the piston 64A is detected (sensed) by the position sensor 79A disposed at a position corresponding to the intermediate position Pm, the piston drive unit 66A may be controlled to stop the piston 64A. The intermediate position Pm may substantially coincide with the position where the position sensor 79A detects the arrival of the piston 64A.

[0100] The position sensor 79A generates a signal indicating the arrival of the piston 64A, for example, when the piston 64A reaches a detectable position when the piston 64A advances from the retracted position P1 toward the forward position P2. The position sensor 79A may be any type of sensor as long as it can detect the arrival of the piston 64A, and may be disposed at any position. The position sensor 79A may be disposed between the retracted position P1 and the forward position P2 to directly detect the arrival of the piston 64A. The position sensor 79A may detect the arrival of the piston 64A by detecting the arrival of a part of a member (for example, the piston rod) connected to the piston 64A. The control device 90 may also stop the piston 64B between the retracted position P1 and the forward position P2 according to the detection result by the position sensor.

[0101] FIG. 11(b) shows another example of the method of driving the piston in the second operation mode. When the control device 90 moves the piston 64A forward from the retracted position P1 toward the advanced position P2, the control device 90 may stop the piston 64A at two or more intermediate positions between the retracted position P1 and the advanced position P2. The control device 90 may also stop the piston 64A at two or more intermediate positions between the retracted position P1 and the advanced position P2 for the piston 64B.

[0102] In one example, the control device 90 controls the piston drive unit 66A to move the piston 64A from the retracted position P1 to the first intermediate position pm1 and stop the piston 64A at the first intermediate position pm1. Then, the control device 90 controls the piston drive unit 66A to move the piston 64A from the first intermediate position pm1 to the second intermediate position pm2 and stop the piston 64A at the second intermediate position pm2. Thereafter, the control device 90 controls the piston drive unit 66A to move the piston 64A from the second intermediate position pm2 to the advanced position P2.

[0103] The pump feeding unit 50 may have one system (single) piston mechanism instead of the two-system piston mechanism. The sludge supply device 40 may supply sludge to the rotary kiln 30 (heating unit) instead of or in addition to the calcining furnace 14.

[0104] [Effects of the Embodiment] In the method for manufacturing a cement clinker described above, while moving the pistons 64A and 64B from the retracted position P1 to the advanced position P2, the pistons 64A and 64B are stopped at the intermediate position Pm. As a result, the amount of sludge sent out into the supply pipe 52 decreases as the pistons 64A and 64B continuously move toward the advanced position P2. Therefore, the water content rate of the sludge decreases, and even when lumps of sludge are introduced into the calciner 14 by multiple reciprocating operations of the pistons 64A and 64B, the amount of the lumps of sludge introduced into the calciner 14 decreases. As a result, it is possible to suppress the influence on heating in the calciner 14 caused by the sludge not being incinerated (for example, a temperature drop in the calciner 14 due to an air flow obstruction of high-temperature gas). Therefore, it is useful for stabilizing the quality of the cement clinker.

[0105] In the manufacturing method described above, in the supply process, the pistons 64A and 64B may be stopped at the intermediate position Pm by stopping the pistons 64A and 64B when a predetermined set time has elapsed since the timing of the start of the movement of the pistons 64A and 64B from the retracted position P1. In this case, it is not necessary to install a position sensor or the like to stop the pistons 64A and 64B at the intermediate position Pm. Therefore, it is useful for simplifying the device configuration of the pump pressure feeding unit 50.

[0106] In the manufacturing method described above, in the supply process, the pistons 64A and 64B may be stopped at the intermediate position Pm by stopping the pistons 64A and 64B when the arrival of the pistons 64A and 64B is detected by a sensor arranged at a position corresponding to the intermediate position Pm. In this case, when repeatedly executing the reciprocating operation of the pistons 64A and 64B, the pistons 64A and 64B can be stably stopped at a target position between the retracted position P1 and the advanced position P2, and the possibility of an increase in the amount of lumps of sludge is further reduced. Therefore, it is more useful for stabilizing the quality of the cement clinker.

[0107] The above-described manufacturing method may be switched from the first operation mode to the second operation mode based on a user instruction regarding the switching of the operation mode. In this case, during a period in which it is determined that there is no such influence on the calciner 14 caused by sludge, the pistons 64A and 64B can be operated in the first operation mode. Therefore, it is useful for achieving both the simplification of the operation of the pistons 64A and 64B and the stabilization of the quality of the cement clinker.

[0108] The above-described manufacturing method may be switched from the first operation mode to the second operation mode based on information indicating the pressure in the supply pipe. The water content of the sludge in the supply pipe 52 can be estimated from the pressure in the supply pipe 52. Therefore, in the above method, when the water content of the sludge in the supply pipe 52 becomes low, the operation mode can be switched to the second operation mode. As a result, during a period in which the water content of the sludge is high and it is determined that there is no such influence on the heating in the calciner 14 caused by the sludge, the pistons 64A and 64B can be operated in the first operation mode. Therefore, it is useful for achieving both the simplification of the operation of the pistons 64A and 64B and the stabilization of the quality of the cement clinker.

[0109] The above-described manufacturing method may be switched from the first operation mode to the second operation mode based on information indicating the heating state of the cement raw material in the calciner 14. From the heating state of the cement raw material, the above influence on the heating in the calciner 14 caused by the sludge already introduced into the calciner 14 can be estimated. Therefore, in the above method, when there is such an influence on the heating in the calciner 14 caused by the sludge, the operation mode can be switched to the second operation mode in order to reduce or eliminate the influence. As a result, during a period in which it is estimated that there is no influence on the heating in the calciner 14 caused by the sludge, the pistons 64A and 64B can be operated in the first operation mode. Therefore, it is useful for achieving both the simplification of the operation of the pistons 64A and 64B and the stabilization of the quality of the cement clinker.

[0110] Information indicating the heating status of the cement raw material in the calciner 14 (heating information) may include one or more types of information selected from the group consisting of the temperature of the calciner 14, the temperature of the cement raw material after being heated in the calciner 14, the concentration of a predetermined component contained in the exhaust gas discharged from the calciner 14, and the supply amount of the energy source supplied to the calciner 14. These pieces of information vary due to the above-mentioned influence on the heating in the calciner 14 caused by the sludge already introduced into the calciner 14. Therefore, it becomes possible to control the operations of the pistons 64A and 64B after grasping the influence of the sludge on the calciner 14.

[0111] The above-described manufacturing method may further include a feeding step of feeding the sludge accommodated in the tank 44 toward the downstream region including the hopper 49 by the screw feeder 46. The water content of the sludge accommodated in the tank 44 may be 80% or less. When the water content of the sludge accommodated in the tank 44 is low, there is a high possibility that a phenomenon occurs in which a large amount of sludge lumps are introduced into the calciner 14 by a plurality of reciprocating operations of the pistons 64A and 64B without the sludge being introduced into the calciner 14 by one reciprocating operation of the pistons 64A and 64B. In the above manufacturing method, the pistons 64A and 64B are temporarily stopped at the intermediate position Pm, and the amount of the sludge lumps introduced into the calciner 14 is reduced, so that the influence on the heating in the calciner 14 due to the sludge not being incinerated can be suppressed. Therefore, it is useful for stabilizing the quality of the cement clinker.

Explanation of Reference Numerals

[0112] 1... Cement clinker manufacturing system, 2... Cement clinker manufacturing apparatus, 14... Calciner, 40... Sludge supply device, 44... Tank, 46... Screw feeder, 49... Hopper, 50... Pump pressure feeding section, 52... Supply pipe, 64A, 64B... Pistons, P1... Retracted position, P2... Advanced position, Pm... Intermediate position, 79A... Position sensor, 90... Control device.

Claims

1. A heating step of heating a cement raw material in a heating section to which sludge is supplied; A suction step of sucking sludge from a storage section by moving a piston of a pump pressure-feeding section; A supply step of sending the sucked sludge into a supply pipe connected to the heating section by moving the piston from a first position to a second position, the supply step including: The supply step includes: Moving the piston from the first position to an intermediate position between the first position and the second position; Stopping the piston at the intermediate position; Moving the piston from the intermediate position to the second position, a method for manufacturing cement clinker.

2. The method for manufacturing cement clinker according to claim 1, wherein in the supply step, the piston is stopped at the intermediate position by stopping the piston when a predetermined time has elapsed from the timing of starting the movement of the piston from the first position.

3. The method for manufacturing cement clinker according to claim 1, wherein in the supply step, the piston is stopped at the intermediate position by stopping the piston when the arrival of the piston is detected by a sensor arranged at a position corresponding to the intermediate position.

4. The supply step further includes driving the piston in a first operation mode in which the piston is moved from the first position to the second position without stopping between the first position and the second position, and switching from the first operation mode to a second operation mode in which the piston is moved from the first position to the intermediate position, stopped at the intermediate position, and then moved to the second position based on a user instruction regarding switching of the operation mode. The method for manufacturing cement clinker according to any one of claims 1 to 3. Based on a user instruction regarding switching of the operation mode, switching from the first operation mode to a second operation mode in which the piston is moved from the first position to the intermediate position, stopped at the intermediate position, and then moved to the second position. The method for manufacturing cement clinker according to any one of claims 1 to 3.

5. The supply step further includes driving the piston in a first operation mode in which the piston is moved from the first position to the second position without stopping between the first position and the second position, and switching from the first operation mode to a second operation mode in which the piston is moved from the first position to the intermediate position, stopped at the intermediate position, and then moved to the second position based on information indicating the pressure in the supply pipe. The method for manufacturing cement clinker according to any one of claims 1 to 3. Based on information indicating the pressure in the supply pipe, switching from the first operation mode to a second operation mode in which the piston is moved from the first position to the intermediate position, stopped at the intermediate position, and then moved to the second position. The method for manufacturing cement clinker according to any one of claims 1 to 3.

6. The supply process further includes driving the piston in a first operation mode in which the piston is moved from the first position to the second position without stopping between the first position and the second position. Based on information indicating the heating state of the cement raw material in the heating unit, switching from the first operation mode to a second operation mode in which the piston is moved from the first position to the intermediate position and stopped at the intermediate position, and then the piston is moved to the second position. The method for manufacturing cement clinker according to any one of claims 1 to 3.

7. The information indicating the heating state of the cement raw material in the heating unit includes one or more types of information selected from the group consisting of the temperature of the heating unit, the temperature of the cement raw material after being heated in the heating unit, the concentration of a predetermined component contained in the exhaust gas discharged from the heating unit, and the supply amount of the energy source supplied to the heating unit. The method for manufacturing cement clinker according to claim 6.

8. The method further includes a feeding step of feeding the sludge contained in the tank toward the downstream region including the accommodating portion by a screw feeder. The water content of the sludge contained in the tank is 80% or less. The method for manufacturing cement clinker according to any one of claims 1 to 7.

9. A cement clinker manufacturing apparatus having a heating unit for heating a cement raw material and generating cement clinker, An accommodating portion for accommodating sludge, a supply pipe connected to the heating unit, and a pump pressure feeding portion that sucks sludge from the accommodating portion by the reciprocating movement of a piston and sends the sludge into the supply pipe. A sludge supply apparatus for supplying sludge to the heating unit, A control device for controlling the sludge supply apparatus, The control device executes supply control for sending the sludge sucked from the accommodating portion into the supply pipe by moving the piston from the first position to the second position. The supply control includes: Moving the piston from the first position to an intermediate position between the first position and the second position; Stopping the piston at the intermediate position; Moving the piston from the intermediate position to the second position. A cement clinker manufacturing system.

10. A sludge supply method for supplying sludge to a heating unit that heats a cement raw material, A suction step of sucking sludge from the accommodating portion by moving the piston of the pump pressure feeding portion. A supply step of sending the sucked sludge into a supply pipe connected to the heating unit by moving the piston from the first position to the second position, is included. The supply step includes: moving the piston from the first position to an intermediate position between the first position and the second position; stopping the piston at the intermediate position; moving the piston from the intermediate position to the second position. A sludge supply method.

11. A storage unit for storing sludge; A supply pipe connected to a heating unit for heating a cement raw material; A pump pressure feeding unit for sucking sludge from the storage unit and sending the sludge into the supply pipe by a reciprocating movement of a piston, is provided. The pump pressure feeding unit executes a supply operation of sending the sludge sucked from the storage unit into the supply pipe by moving the piston from the first position to the second position. The supply operation includes: the piston moving from the first position to an intermediate position between the first position and the second position; the piston stopping at the intermediate position; the piston moving from the intermediate position to the second position. A sludge supply device.

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