Classifier, power generation plant, and method for operating a classifier

Abstract

To simplify fixation work of a reinforcement member and a blade.SOLUTION: A rotary typed classifier 16 rotates around a center axis C extending in a vertical direction, classifies pulverized solid fuel introduced from outside in the radial direction by carrier gas, and introduces the pulverized solid fuel whose grain diameter is a prescribed grain diameter or less into inside. The rotary typed classifier 16 comprises: a body part 70 which rotates around the center axis C; a plurality of tabular blades 60 which extend in a vertical direction and an upper part and a lower part of which are fixed to the body part 70; and a reinforcement member 80 which reinforces the plurality of blades 60. The plurality of blades 60 are arranged at the position maintaining a prescribed distance from the center axis C to outside in a radial direction, and are arrayed in a circumferential direction at a prescribed distance so that plate surfaces of the adjacent blades 60 in a circumferential direction face each other. The reinforcement member 80 is fixed to an inner end part of the blade 60 in a radial direction to connect the blades 60 arrayed in a circumferential direction with each other.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a classifier, a power generation plant, and an operation method of the classifier.

Background Art

[0002] Conventionally, solid fuels such as coal and biomass fuels (carbon-containing solid fuels) are pulverized into fine powders within a predetermined particle size range by a pulverizer (mill) and supplied to a combustion device. The mill sandwiches solid fuels such as coal and biomass fuels input to a pulverizing table between the pulverizing table and a pulverizing roller and pulverizes them. Among the solid fuels pulverized into fine powders (hereinafter, the pulverized solid fuel is referred to as "pulverized fuel"), fine pulverized fuel within a predetermined particle size range (fine powder degree) is selected by a classifier, and is conveyed to a boiler by a conveying gas (primary air) supplied from the outer periphery of the pulverizing table and burned in a combustion device. In a thermal power generation plant, steam is generated by heat exchange with combustion gas generated by burning fine pulverized fuel in a boiler, and power generation is performed by rotationally driving a steam turbine by the steam and rotationally driving a generator connected to the steam turbine.

[0003] As one of the classifiers provided in a mill, for example, a rotary classifier is known. The rotary classifier has a plurality of blades arranged at equal intervals in the circumferential direction around a rotation axis. When the pulverized fuel passes between a plurality of blades rotating around the rotation axis, the coarse pulverized fuel (pulverized fuel larger than a predetermined particle size) on which the weight and centrifugal force act strongly is bounced to the outer peripheral side of the blades, and the fine pulverized fuel (pulverized fuel smaller than a predetermined particle size) on which the weight is small and the conveying force by the airflow of the primary air acts strongly is passed to the inner peripheral side of the blades, thereby performing classification. Further, the rotary classifier has a main body portion that rotates around a rotation axis. The main body portion can revolve the blades around the rotation axis by holding the upper and lower portions of the blades. The main body portion is held by a bearing and rotates at a predetermined rotational speed by a power source such as a motor. By changing this rotational speed, the force acting on the pulverized fuel can be adjusted, and a predetermined fine powder degree can be obtained.

[0004] As a mill equipped with such a rotary classifier, for example, the mill described in Patent Document 1 is known.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, in recent years, mills have been increasing in size. As the mill increases in size, the rotary classifier also becomes larger accordingly. In addition, the radial length (blade width) and the vertical length (blade length) of the blades increase. For this reason, since the centrifugal force acting on the blades when the rotary classifier rotates also increases, the deflection of the blades increases. If the deflection of the blades becomes too large, there is a problem that the blades are permanently deformed and damaged. Further, when the deformation of the blades occurs locally, the balance when the rotary classifier rotates is lost. If the balance is lost, it may generate a large vibration load, leading to damage to bearings and the like.

[0007] In order to prevent the deformation of the blades due to centrifugal force, in a large mill, a reinforcing member for connecting the blades may be provided at substantially the central portion in the vertical direction of the blades. By providing the reinforcing member, even if the blades tend to deflect outward in the radial direction due to centrifugal force, the blades are connected in a ring shape via the reinforcing member, so the reinforcing member pulls the blades back inward in the radial direction. Thereby, the deflection of the blades due to centrifugal force is reduced.

[0008] However, conventional reinforcing members were provided between adjacent blades and were configured to connect the opposing plate surfaces. Therefore, when installing the reinforcing members, it was necessary to fix the reinforcing members in the narrow gaps between the blades, which complicated the operation of fixing the reinforcing members to the blades (hereinafter referred to as the "fixing operation"). In addition, since the conventional reinforcing members were provided to connect the opposing plate surfaces, the number of fixing points between the blades and the reinforcing members became twice the number of blades. As a result, the number of fixing points increased. In particular, since a large number of blades are provided in a rotary classifier, the increase in the number of fixing points is significant. Therefore, there was a problem that the fixing operation became complicated.

[0009] Thus, due to the complication of the fixing operation, there was a problem that the process of manufacturing the rotary classifier took a long time and the cost increased. In addition, the blades wear out during long-term use. When the blades wear out, it is necessary to replace the blades, and the fixing operation is also performed when replacing the blades. Therefore, due to the complication of the fixing operation, there was a problem that the process also took a long time and the cost increased when replacing the blades.

[0010] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a classifier, a power generation plant, and an operation method of the classifier that can simplify the operation of fixing a reinforcing member to a blade.

Means for Solving the Problems

[0011] In order to solve the above problems, the classifier, the power generation plant, and the operation method of the classifier according to the present disclosure employ the following means. A classifier according to an aspect of the present disclosure rotates about a central axis extending in the vertical direction, classifies particles guided by a conveying gas from the outer side in the radial direction, and introduces the particles having a predetermined particle size or less therein. The classifier includes a main body portion that rotates about the central axis, a plurality of plate-shaped blades that extend in the vertical direction and have upper and lower portions fixed to the main body portion, and a reinforcing member that reinforces the plurality of blades. The plurality of blades are arranged side by side at a predetermined interval in the circumferential direction such that the plate surfaces of the blades adjacent in the circumferential direction face each other at a position spaced a predetermined distance from the central axis to the outer side in the radial direction. The reinforcing member is fixed to the inner end portion of the blade in the radial direction and connects the blades arranged in the circumferential direction.

[0012] Moreover, an operation method of a classifier according to an aspect of the present disclosure rotates about a central axis extending in the vertical direction, classifies particles guided by a conveying gas from the outer side in the radial direction, and introduces the particles having a predetermined particle size or less therein. The classifier includes a main body portion that rotates about the central axis, a plurality of plate-shaped blades that extend in the vertical direction and have upper and lower portions fixed to the main body portion, and a reinforcing member that reinforces the plurality of blades. The plurality of blades are arranged side by side at a predetermined interval in the circumferential direction such that the plate surfaces of the blades adjacent in the circumferential direction face each other at a position spaced a predetermined distance from the central axis to the outer side in the radial direction. The reinforcing member is fixed to the inner end portion of the blade in the radial direction and connects the blades arranged in the circumferential direction. The method includes a step of classifying the particles into particles larger than a predetermined particle size and particles having a predetermined particle size or less by the blades. [Advantages of the Invention]

[0013] According to the present disclosure, the operation of fixing the reinforcing member and the blade can be simplified. [Brief Description of the Drawings]

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

MODE FOR CARRYING OUT THE INVENTION

[0015] 〔First Embodiment〕 Hereinafter, the first embodiment of the present disclosure will be described with reference to the drawings. The power generation plant 1 according to the present embodiment includes a solid fuel pulverizer 100 and a boiler 200. In the following description, the upward direction refers to the vertically upward direction, and the "upper" such as the upper part and the upper surface refers to the vertically upper part. Similarly, the "lower" refers to the vertically lower part, and the vertical direction is not strict and includes an error.

[0016] The solid fuel pulverizer 100 of the present embodiment is, for example, a device that pulverizes solid fuels (carbon-containing solid fuels) such as coal and biomass fuels to generate pulverized fuels and supply them to the burner (combustion device) 220 of the boiler 200. The power generation plant 1 including the solid fuel pulverizer 100 and the boiler 200 shown in FIG. 1 is provided with one solid fuel pulverizer 100, but may also be a system provided with a plurality of solid fuel pulverizers 100 corresponding to each of the plurality of burners 220 of one boiler 200.

[0017] The solid fuel pulverizer 100 of the present embodiment includes a mill (pulverizer) 10, a coal feeder (fuel supply device) 20, a blower section (conveying gas supply section) 30, a state detection section 40, and a control section (judgment section) 50.

[0018] The mill 10 that pulverizes solid fuels such as coal and biomass fuel supplied to the boiler 200 into pulverized fuel, which is finely powdered solid fuel, may be of a type that pulverizes only coal, a type that pulverizes only biomass fuel, or a type that pulverizes biomass fuel together with coal. Here, biomass fuel is a renewable bio-derived organic resource, for example, thinned wood, waste wood, driftwood, grasses, waste, sludge, tires, and recycled fuels (pellets and chips) made from these, and is not limited to those presented here. Since biomass fuel captures carbon dioxide during the growth process of biomass, it is considered carbon neutral and does not emit carbon dioxide, which is a global warming gas, and thus its use is being variously studied.

[0019] The mill 10 includes a housing 11, a pulverizing table 12, pulverizing rollers 13, a drive section 14, a mill motor 15 connected to the drive section 14 and rotationally driving the pulverizing table 12, a rotary classifier 16, a fuel supply section 17, and a classifier motor 18 that rotationally drives the rotary classifier 16. Note that the rotary classifier 16 may be installed separately from the mill 10. The housing 11 is formed in a cylindrical shape extending in the vertical direction and is a housing that houses the pulverizing table 12, the pulverizing rollers 13, the rotary classifier 16, and the fuel supply section 17. At the center of the ceiling portion 42 of the housing 11, a fuel supply unit 17 is attached. This fuel supply unit 17 supplies the solid fuel led from the bunker 21 into the housing 11. It is arranged along the vertical direction at the center position of the housing 11, and the lower end portion extends to the inside of the housing 11.

[0020] Near the bottom surface portion 41 of the housing 11, a drive unit 14 is installed, and a pulverizing table 12 that rotates by the driving force transmitted from a mill motor 15 connected to this drive unit 14 is rotatably arranged. The pulverizing table 12 is a member circular in plan view and is arranged so that the lower end portion of the fuel supply unit 17 faces it. The upper surface of the pulverizing table 12 may have, for example, an inclined shape where the center portion is low and it becomes higher toward the outside, and the outer peripheral portion may have a shape that bends upward. The fuel supply unit 17 supplies the solid fuel (for example, coal or biomass fuel in this embodiment) from above toward the lower pulverizing table 12, and the pulverizing table 12 pulverizes the supplied solid fuel between it and the pulverizing roller 13.

[0021] When the solid fuel is introduced from the fuel supply unit 17 toward the substantially central region of the pulverizing table 12, due to the centrifugal force caused by the rotation of the pulverizing table 12, the solid fuel is guided to the outer peripheral side of the pulverizing table 12 and is sandwiched between the pulverizing table 12 and the pulverizing roller 13 and pulverized. The pulverized solid fuel is blown upward by the conveying gas (hereinafter referred to as primary air) led from the conveying gas flow path (hereinafter referred to as the primary air flow path) 100a and is guided to the rotary classifier 16. An air outlet (not shown) is provided on the outer periphery of the grinding table 12 to allow the primary air flowing in from the primary air flow path 100a to flow out into the space above the grinding table 12 in the housing 11. A swirler (not shown) is installed at the air outlet to impart a swirling force to the primary air blown out from the air outlet. The primary air provided with the swirling force by the swirler becomes an air flow having a swirling speed component, and conveys the solid fuel pulverized on the grinding table 12 to the rotary classifier 16 located above in the housing 11. Among the pulverized solid fuels, those larger than a predetermined particle size are classified by the rotary classifier 16 or fall without reaching the rotary classifier 16 and are returned onto the grinding table 12, where they are pulverized again between the grinding table 12 and the grinding roller 13.

[0022] The grinding roller 13 is a rotating body that grinds the solid fuel supplied onto the grinding table 12 from the fuel supply unit 17. The grinding roller 13 is pressed against the upper surface of the grinding table 12 and cooperates with the grinding table 12 to grind the solid fuel. In FIG. 1, only one grinding roller 13 is shown as a representative, but a plurality of grinding rollers 13 are arranged at regular intervals in the circumferential direction so as to press the upper surface of the grinding table 12. For example, three grinding rollers 13 are arranged at equal intervals in the circumferential direction with an angular interval of 120° on the outer peripheral portion. In this case, the portions (pressing portions) where the three grinding rollers 13 contact the upper surface of the grinding table 12 are equidistant from the rotation center axis of the grinding table 12.

[0023] The grinding roller 13 can swing and displace vertically by the journal head 45 and is supported so as to be able to approach and separate from the upper surface of the grinding table 12. When the grinding table 12 rotates with the outer peripheral surface of the grinding roller 13 in contact with the solid fuel on the upper surface of the grinding table 12, the grinding roller 13 receives a rotational force from the grinding table 12 and rotates along with it. When solid fuel is supplied from the fuel supply unit 17, the solid fuel is pressed and ground between the grinding roller 13 and the grinding table 12.

[0024] The support arm 47 of the journal head 45 is supported on the side surface of the housing 11 by a support shaft 48 with a horizontal middle part, such that the grinding roller 13 can swing and displace vertically around the support shaft 48. Also, a pressing device 49 is provided at the upper end of the support arm 47 on the upper vertical side. The pressing device 49 is fixed to the housing 11 and applies a load to the grinding roller 13 via the support arm 47 and the like so as to press the grinding roller 13 against the grinding table 12.

[0025] The drive unit 14 is a device that transmits a driving force to the grinding table 12 and rotates the grinding table 12 around the central axis. The drive unit 14 is connected to the mill motor 15 and transmits the driving force of the mill motor 15 to the grinding table 12.

[0026] The rotary classifier 16 is provided at the upper part of the housing 11 and has a hollow substantially inverted conical outer shape. The rotary classifier 16 is provided with a plurality of blades 60 extending vertically at its outer peripheral position. Each blade 60 is provided at a predetermined interval (equal interval) around the central axis C of the rotary classifier 16. The rotary classifier 16 classifies the solid fuel pulverized by the grinding table 12 and the grinding roller 13 (hereinafter, the pulverized solid fuel is referred to as "pulverized fuel") into those larger than a predetermined particle size (for example, 70 - 100 μm for coal, hereinafter, the pulverized fuel exceeding the predetermined particle size is referred to as "coarse pulverized fuel") and those smaller than or equal to the predetermined particle size (hereinafter, the pulverized fuel smaller than or equal to the predetermined particle size is referred to as "fine pulverized fuel"). The rotary classifier 16 that classifies by rotation is also called a rotary separator, and is rotationally driven by a classifier motor 18 controlled by a control unit 50, and rotates around the fuel supply unit 17 with a cylindrical shaft 71 (see FIG. 2) extending vertically in the housing 11 as the center. Details of the rotary classifier 16 will be described later. Note that as the classifier, a fixed classifier having a fixed hollow inverted conical casing and a plurality of fixed swirling blades instead of the blades 60 at the outer peripheral position of the casing may be used.

[0027] The pulverized fuel that reaches the rotary classifier 16 is, due to the relative balance between the centrifugal force generated by the rotation of the blades 60 and the centripetal force by the airflow of the primary air, such that the coarse pulverized fuel with a large diameter is knocked off by the blades 60, returned to the pulverizing table 12, pulverized again, and the fine pulverized fuel is guided to the outlet port 19 located at the ceiling portion 42 of the housing 11. The fine pulverized fuel classified by the rotary classifier 16 is discharged from the outlet port 19 together with the primary air into the fine pulverized fuel supply flow path 100b and supplied to the burner 220 of the boiler 200. The fine pulverized fuel supply flow path 100b is also called a fine pulverized coal pipe when the solid fuel is coal.

[0028] The fuel supply unit 17 is installed with its lower end extending along the vertical direction through the ceiling portion 42 of the housing 11 to the inside of the housing 11, and supplies the solid fuel input from the upper part of the fuel supply unit 17 to the substantially central region of the pulverizing table 12. The fuel supply unit 17 is supplied with solid fuel from the coal feeder 20. The upper part of the fuel supply unit 17 has a rectangular cross-section in the horizontal direction that changes from rectangular to circular in order to connect the rectangular coal feeder 20 outlet and the cylindrical lower part of the fuel supply unit 17.

[0029] The coal feeder 20 includes a conveying unit 22 and a coal feeder motor 23. The conveying unit 22 is, for example, a belt conveyor, and conveys the solid fuel discharged from the lower end of the downspout 24 directly below the bunker 21 to the upper part of the fuel supply unit 17 of the mill 10 by the driving force given from the coal feeder motor 23 and inputs it into the fuel supply unit 17. Normally, primary air for conveying fine pulverized fuel to the burner 220 is supplied inside the mill 10, and the pressure is higher than that of the coal feeder 20 and the bunker 21. In the downspout 24, which is a pipe extending vertically directly below the bunker 21, fuel is held in a stacked state inside, and the stacked solid fuel layer in the downspout 24 ensures a sealing property so that the primary air and fine pulverized fuel on the mill 10 side do not flow back to the bunker 21 side. The supply amount of the solid fuel supplied to the mill 10 is adjusted, for example, by the moving speed of the belt conveyor of the conveying unit 22.

[0030] The air supply section 30 is a device that dries the pulverized fuel and blows primary air for conveying it to the rotary classifier 16 into the housing 11. In this embodiment, the air supply section 30 includes a primary air fan (PAF) 31, a hot gas flow path 30a, a cold gas flow path 30b, a hot gas damper 30c, and a cold gas damper 30d in order to appropriately adjust the flow rate and temperature of the primary air blown into the housing 11.

[0031] In this embodiment, the hot gas flow path 30a supplies a part of the air (outside air) sent out from the primary air fan 31 as hot gas heated by passing through a heat exchanger 34 such as an air preheater. A hot gas damper 30c is provided on the downstream side of the hot gas flow path 30a. The opening degree of the hot gas damper 30c is controlled by the control section 50. The flow rate of the hot gas supplied from the hot gas flow path 30a is determined by the opening degree of the hot gas damper 30c.

[0032] The cold gas flow path 30b supplies a part of the air sent out from the primary air fan 31 as cold gas at normal temperature. A cold gas damper 30d is provided on the downstream side of the cold gas flow path 30b. The opening degree of the cold gas damper 30d is controlled by the control section 50. The flow rate of the cold gas supplied from the cold gas flow path 30b is determined by the opening degree of the cold gas damper 30d.

[0033] In this embodiment, the flow rate of the primary air is the total flow rate of the hot gas supplied from the hot gas flow path 30a and the cold gas supplied from the cold gas flow path 30b, and the temperature of the primary air is determined by the mixing ratio of the hot gas supplied from the hot gas flow path 30a and the cold gas supplied from the cold gas flow path 30b, and is controlled by the control section 50. Also, a part of the combustion gas discharged from the boiler 200 may be introduced into the hot gas supplied from the hot gas flow path 30a via a gas recirculation fan (not shown) and mixed to adjust the oxygen concentration of the primary air blown from the primary air flow path 100a into the housing 11.

[0034] In this embodiment, the state detection unit 40 of the mill 10 transmits the measured or detected data to the control unit 50. The state detection unit 40 of this embodiment is, for example, differential pressure measurement means, and measures the differential pressure between the pressure at the portion where primary air flows into the inside of the housing 11 from the primary air flow path 100a and the pressure at the outlet port 19 where primary air and pulverized fuel are discharged from the inside of the housing 11 to the pulverized fuel supply flow path 100b as the differential pressure of the mill 10. The increase or decrease of the differential pressure of this mill 10 corresponds to the increase or decrease of the circulation amount of the pulverized fuel circulating between the vicinity of the rotary classifier 16 and the vicinity of the grinding table 12 inside the housing 11 due to the classification effect of the rotary classifier 16. That is, by adjusting the rotational speed of the rotary classifier 16 according to the differential pressure of this mill 10, the amount of pulverized fuel discharged from the outlet port 19 can be adjusted with respect to the supply amount of the solid fuel supplied to the mill 10. Therefore, within a range where the particle size of the pulverized fuel does not affect the combustibility of the burner 220, a stable amount of pulverized fuel corresponding to the supply amount of the solid fuel to the mill 10 can be supplied to the burner 220 provided in the boiler 200. Further, the state detection unit 40 of this embodiment is, for example, temperature measurement means, and detects the temperature of the primary air supplied into the inside of the housing 11 (the primary air temperature at the mill inlet) and the temperature of the primary air from the space above the grinding table 12 inside the housing 11 to the outlet port 19, and controls the blower unit 30 so as not to exceed the upper limit temperature. The upper limit temperature is determined in consideration of the possibility of ignition of the solid fuel and the like. The primary air is cooled by transporting while drying the pulverized fuel inside the housing 11, and the temperature of the primary air at the outlet port 19 is, for example, about 60 to 90 degrees.

[0035] The control unit 50 is a device that controls each part of the solid fuel pulverizing device 100. For example, the control unit 50 may transmit a drive instruction to the mill motor 15 to control the rotational speed of the grinding table 12. The control unit 50 can stably supply the pulverized fuel to the burner 220, for example, by transmitting a drive instruction to the classifier motor 18 to control the rotation speed of the rotary classifier 16 to adjust the classification performance, and optimizing the differential pressure of the mill 10, that is, the circulation amount of the pulverized fuel inside the mill 10 within a predetermined range. Also, the control unit 50 can adjust the supply amount (coal feeding amount) of the solid fuel that the conveying unit 22 conveys and supplies to the fuel supply unit 17, for example, by transmitting a drive instruction to the coal feeder motor 23 of the coal feeder 20. Further, the control unit 50 can control the opening degrees of the hot gas damper 30c and the cold gas damper 30d to adjust the flow rate and temperature of the primary air by transmitting an opening degree instruction to the blower unit 30. Specifically, the control unit 50 controls the opening degrees of the hot gas damper 30c and the cold gas damper 30d so that the flow rate of the primary air supplied into the housing 11 and the temperature of the primary air at the outlet port 19 become predetermined values set corresponding to the coal feeding amount for each type of solid fuel.

[0036] The control unit 50 is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and a computer-readable storage medium, etc. And a series of processes for realizing various functions are stored in a storage medium, etc. in the form of a program as an example. The CPU reads this program into the RAM, etc. and executes information processing and arithmetic processing, thereby realizing various functions. Note that the program may be applied in a form pre-installed in the ROM or other storage media, a form provided in a state stored in a computer-readable storage medium, a form distributed via wired or wireless communication means, etc. The computer-readable storage medium is a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, etc. Also, the HDD may be replaced with a solid state disk (SSD), etc.

[0037] Next, a boiler 200 that generates steam by burning using the pulverized fuel supplied from the solid fuel pulverizer 100 will be described. The boiler 200 includes a furnace 210 and a burner 220.

[0038] The burner 220 is a device that forms a flame by burning the pulverized fuel using primary air containing the pulverized fuel supplied from the pulverized fuel supply passage 100b and secondary air supplied by heating the air (outside air) sent out from a forced draft fan (FDF) 32 with a heat exchanger 34. The combustion of the pulverized fuel is carried out in the furnace 210, and the high-temperature combustion gas is discharged to the outside of the boiler 200 after passing through heat exchangers (not shown) such as an evaporator, a superheater, and a economizer.

[0039] The combustion gas discharged from the boiler 200 is subjected to predetermined treatment by an environmental device (not shown such as a denitration device and an electrostatic precipitator), and heat exchange is performed between the air sent out from the primary air blower 31 and the air sent out from the forced draft fan 32 with a heat exchanger 34 such as an air preheater, and is guided to a chimney (not shown) via an induced draft fan (IDF) 33 and discharged to the outside air. The air sent out from the primary air blower 31 heated by the combustion gas in the heat exchanger 34 is supplied to the aforementioned hot gas flow path 30a. The water supply to each heat exchanger of the boiler 200 is heated in an economizer (not shown), and then further heated by an evaporator (not shown) and a superheater (not shown) to generate high-temperature and high-pressure steam, which is sent to a steam turbine (not shown) that is a power generation unit to rotationally drive the steam turbine, and a generator (not shown) connected to the steam turbine is rotationally driven to generate electricity, thus constituting the power generation plant 1.

[0040] Next, the details of the rotary classifier 16 will be described. In the following description, the "circumferential direction" and the "radial direction" mean the "circumferential direction" and the "radial direction" centered on the central axis C.

[0041] As shown in FIG. 1, the rotary classifier 16 is provided at the upper part of the housing 11. As shown in FIG. 2, the rotary classifier 16 rotates about a central axis C extending in the vertical direction. In the present embodiment, as indicated by the arrow A1 in FIGS. 2 and 3, the rotary classifier 16 rotates clockwise when viewed in plan. The rotation direction of the rotary classifier 16 is opposite to the swirling direction of the primary air formed by the swirling blades installed at the air outlet. The rotary classifier 16 is rotationally driven by a motor (not shown). The rotation speed of the motor is controlled by the control unit 50.

[0042] As shown in FIGS. 2 and 3, the rotary classifier 16 includes a main body portion 70 having a hollow substantially inverted conical outer shape, a plurality of blades 60 provided at the outer peripheral position of the main body portion 70, and a reinforcing member 80 for reinforcing the blades 60.

[0043] The main body portion 70 rotates about the central axis C. A space (internal space S1) is formed inside the main body portion 70. The main body portion 70 integrally has a cylindrical shaft 71 that covers the fuel supply portion 17 and extends along the central axis C, an upper end portion 72 that extends radially from the upper end of the cylindrical shaft 71, and a lower end portion 73 that extends radially from the lower end of the cylindrical shaft 71. The upper end portion 72 partitions the upper end of the internal space S1. Also, the lower end portion 73 partitions the lower end of the internal space S1. An opening 72a to which the outlet port 19 (see FIG. 1) is connected is formed in the upper end portion 72.

[0044] Each blade 60 extends in the vertical direction. Each blade 60 is a flat plate-like member. The upper end of each blade 60 is fixed to the upper end portion 72. Also, the lower end of each blade 60 is fixed to the lower end portion 73. Each blade 60 is inclined such that the lower end side approaches the central axis C more than the upper end side. An opening 72a is formed in the upper end portion 72.

[0045] As shown in FIG. 3, the plurality of blades 60 are arranged at a position radially spaced from the central axis C of the rotary classifier 16 by a predetermined distance. The plurality of blades 60 are provided in parallel at predetermined intervals (equal intervals) in the circumferential direction about the central axis C. Further, each blade 60 is arranged so as to be inclined at a predetermined angle with respect to the radial direction when viewed in plan. Also, a gap is formed between adjacent blades 60 in the circumferential direction. The gap communicates an internal space S1, which is a space inside the plurality of blades 60 in the radial direction, and an external space S2, which is a space outside the blades 60 in the radial direction. Pulverized fuel is guided to each blade 60 together with primary air flowing from the outside in the radial direction toward the inside.

[0046] Each blade 60 has a collision surface 61, which is the front surface in the rotation direction, a back surface 65, which is the rear surface in the rotation direction, and two side surfaces 68 connecting the collision surface 61 and the back surface 65. As shown in FIG. 3, pulverized fuel containing fine powder fuel B2 and coarse powder fuel B1 collides with the collision surface 61. An outward force in the radial direction (a force directed toward the external space S2 due to centrifugal force or the like) indicated by arrow A4 and an inward force in the radial direction (a force directed toward the internal space S1 due to the flow of the primary air) indicated by arrow A5 act on the pulverized fuel that has collided with the collision surface 61. Since the coarse powder fuel B1 has a large weight, an outward force acts strongly on the coarse powder fuel B1 that has collided with the collision surface 61 due to the influence of centrifugal force. As a result, the coarse powder fuel B1 is repelled toward the outside (the external space S2 side) of the blade 60 as shown by arrow A2, against the inward force. On the other hand, since the fine powder fuel B2 has a small weight, the inward force due to the flow of the primary air acts strongly. As a result, since the force acting on the fine powder fuel B2 is dominated by the inward force, the fine powder fuel B2 is repelled toward the inside (the internal space S1 side) of the blade 60 as shown by arrow A3. The rotary classifier 16 classifies the coarse powder fuel B1 and the fine powder fuel B2 based on such a principle.

[0047] As shown in FIG. 3, the reinforcing member 80 is an annular member. As shown in FIG. 2, the shape of the circumferential cross-section (the cross-section when cut along a plane perpendicular to the circumferential direction) of the reinforcing member 80 is substantially circular.

[0048] The outer peripheral surface of the reinforcing member 80 is fixed to all the blades 60 arranged side by side in the circumferential direction. Specifically, the outer peripheral surface of the reinforcing member 80 is fixed to the radially inner end portions of the respective blades 60. The reinforcing member 80 connects all the blades 60 arranged in the circumferential direction to each other.

[0049] As shown in FIG. 4, the reinforcing member 80 and the blade 60 are connected by a welded portion W1. That is, the reinforcing member 80 and the blade 60 are fixed by welding. The welded portion W1 is provided on a part of the radially inner side surface 68 and the back surface 65 of the blade 60. The welded portion W1 is not provided on the collision surface 61.

[0050] As shown in FIG. 2, the reinforcing member 80 is located between the upper end portion 72 and the lower end portion 73 that support and fix the blade 60, and is specifically fixed approximately at the center in the vertical direction.

[0051] When the rotary classifier 16 rotates, centrifugal force acts on each blade 60 (see arrows F1 and F2 in FIG. 2). As described above, the upper and lower ends of each blade 60 are fixed to the main body portion 70. For this reason, a force that tries to bend radially outward acts on the central portion in the vertical direction of each blade 60. At this time, since each blade 60 is connected by the reinforcing member 80, a force that pulls radially inward acts by the reinforcing member 80. Thereby, it is possible to suppress the bending (deformation) of the blade 60 radially outward.

[0052] According to the present embodiment, the following operational effects are achieved. In this embodiment, the reinforcing member 80 is fixed to the inner end portion of the blade 60. Therefore, the number of welding points of the reinforcing member 80 to one blade 60 can be set to one. As a result, the number of welding points between the blade 60 and the reinforcing member 80 can be reduced as compared with the case where a plurality of welding points between the reinforcing member 80 and one blade 60 are provided. Therefore, the operation of fixing the blade 60 and the reinforcing member 80 can be simplified. Consequently, the process of manufacturing the rotary classifier 16 can be shortened, and the operation cost can be suppressed. The case where a plurality of welding points between one blade 60 and the reinforcing member 80 are provided means, for example, as shown as a comparative example in FIG. 10, a case where a plurality of reinforcing members 80' are welded so as to be provided between adjacent blades 60 and connect the plate surfaces of the opposing blades 60. In this example, the reinforcing members 80' are welded to both plate surfaces of each blade 60. That is, two welding points are provided on each blade 60.

[0053] In addition, the blade 60 wears out during long-term use. When the blade 60 wears out, it is necessary to replace the blade 60. However, even when replacing the blade 60, the operation of fixing the blade 60 and the reinforcing member 80 is performed. Therefore, by simplifying the fixing operation, the process can be shortened and the operation cost can be suppressed even when the blade 60 is replaced.

[0054] In addition, since the number of welding points between the blade 60 and the reinforcing member 80 can be reduced, the members used for fixing the blade 60 and the reinforcing member 80 (for example, materials used for welding, etc.) can be reduced, so that the equipment cost can be reduced. Further, due to the reduction in the number of welding points, the cost of non-destructive inspection, the rework time due to repair of welding defects, and the risk of damage due to internal defects can also be reduced.

[0055] In addition, the inner end portion of the blade 60 faces the internal space S1. Thus, since the inner end portion of the blade 60 to which the reinforcing member 80 is fixed faces a relatively wide space, the workability of the operation of fixing the blade 60 and the reinforcing member 80 can be improved.

[0056] Further, in the present embodiment, the reinforcing member 80 is fixed to the inner end portion of the blade 60. As a result, for example, compared with the case where the reinforcing member 80 is fixed to the radially outer end portion or the plate surface (the collision surface 61 or the back surface 65) of the blade 60, it is difficult for the solid fuel guided from the outside in the radial direction to come into contact with the reinforcing member 80. Therefore, wear of the reinforcing member 80 due to the solid fuel can be suppressed.

[0057] Also, the reinforcing member 80 is fixed to the inner end portion of the blade 60. As a result, a structure can be adopted in which the reinforcing member 80 is not fixed to the plate surface (the collision surface 61) of the blade 60. Therefore, it is possible to make it difficult for the reinforcing member 80 to impede the flow of the solid fuel classified by the blade 60. Thus, the classification accuracy can be improved as compared with the case where the reinforcing member 80 is fixed to the plate surface (the collision surface 61) or the outer end portion (for example, the side surface 68 on the outer peripheral side) of the blade 60.

[0058] Also, in the present embodiment, the reinforcing member 80 is formed in an annular shape. As a result, the reinforcing member 80 can receive the tensile force due to the centrifugal force, so that the blade 60 can be more suitably reinforced and deflection can be suppressed. In addition, when the reinforcing member 80 is attached, the operation of cutting the reinforcing member 80 into a plurality of pieces in accordance with the interval between the blades 60 can be omitted.

[0059] 〔Second Embodiment〕 Next, a second embodiment of the present disclosure will be described with reference to FIGS. 5 and 6. In this embodiment, only the reinforcing member is different from the first embodiment. For the same configurations as those in the first embodiment, the same reference numerals are given and the detailed description thereof is omitted.

[0060] As shown in FIG. 5, the reinforcing member 180 according to the present embodiment is formed in an annular shape by connecting a plurality of (three in this embodiment as an example) arc-shaped divided reinforcing members (divided parts) 180a. Each divided reinforcing member 180a has an arc shape of 120 degrees. Each divided reinforcing member 180a does not have to be evenly divided. The plurality of divided reinforcing members 180a are arranged side by side in the circumferential direction to form an annulus. As shown in FIG. 6, the divided reinforcing members 180a are connected at their circumferential ends by a welding portion W2. That is, the divided reinforcing members 180a are connected by welding. Further, a groove 181 is formed at the circumferential end of each divided reinforcing member 180a. Specifically, as shown in FIG. 6, the groove 181 is formed so that a groove recessed from the inner circumferential surface toward the outer circumferential surface is formed when the divided reinforcing members 180a are butted against each other. In this embodiment, as shown in FIG. 6, the divided reinforcing members 180a are fixed by welding so that the welding portion W2 enters the groove 181.

[0061] According to the present embodiment, the following operational effects are achieved. In this embodiment, the reinforcing member 180 has a plurality of divided reinforcing members 180a. In other words, the annular reinforcing member 180 is divided into a plurality of divided reinforcing members 180a. Thereby, compared with the case where the reinforcing member 180 is composed of one member, one member can be miniaturized, so that the work of fixing the reinforcing member 180 and the blade 60 can be simplified.

[0062] Note that the method of connecting the plurality of divided reinforcing members 180a on the arc is not limited to the method described above. For example, as shown in FIG. 7, the divided reinforcing members 180a may be connected by a joint structure 185. The joint structure 185 is a so-called dovetail joint. The joint structure 185 has a convex portion 185a provided at the circumferential end of one of the divided reinforcing members 180a to be connected, and a concave portion 185b provided at the circumferential end of the other divided reinforcing member 180a and fitted with the convex portion 185a. Since the joint structure 185 is a so-called dovetail joint, the concave portion 185b and the convex portion 185a are provided only on the inner circumferential side of each divided reinforcing member 180a. On the outer circumferential side of each divided reinforcing member 180a, only the end faces are butted against each other, and the concave portion 185b and the convex portion 185a are not provided. That is, the concave portion 185b is formed so as to be recessed from the inner circumferential surface and the end face of the divided reinforcing member 180a. The joint structure 185 is configured such that the convex portion 185a can be fitted into the concave portion 185b from the inner circumferential side, but cannot be fitted from the outer circumferential side.

[0063] By providing the convex portion 185a and the concave portion 185b only on the inner circumferential side in this way, even if the reinforcing member 180 wears from the outer circumferential side, it is possible to make it difficult to damage the convex portion 185a and the concave portion 185b. Therefore, it is possible to make it difficult to release the connection between the divided reinforcing members 180a. Note that the joint structure 185 for connecting the divided reinforcing members 180a is not limited to a dovetail joint. The joint structure for connecting the divided reinforcing members 180a may be other joints, for example, a screw joint.

[0064] 〔Third Embodiment〕 Next, the third embodiment of the present disclosure will be described with reference to FIGS. 8 and 9. In this embodiment, the only difference from the first embodiment is that the blade is covered with a wear-resistant material. For the same configuration as that of the first embodiment, the same reference numerals are given and the detailed description thereof is omitted.

[0065] As shown in FIGS. 8 and 9, the blade 60 according to the present embodiment is covered by a hardened build-up plate (wear-resistant portion) 190 formed of a high-hardness material having wear resistance on the entire surface of the collision surface 61. In other words, in the present embodiment, the blade 60 and the hardened build-up plate 190 overlap in the plate thickness direction. The length of the blade 60 in the plate thickness direction and the length of the hardened build-up plate 190 in the plate thickness direction may be substantially the same. The hardened build-up plate 190 is formed of a material having a higher hardness than the material of the blade 60. Examples of the material of the blade 60 include, for example, stainless steel materials. Examples of the material of the hardened build-up plate 190 include, for example, high-chromium cast iron-based materials.

[0066] Note that the welded portion W1 is provided only on the blade 60 and is not provided on the hardened build-up plate 190.

[0067] According to the present embodiment, the following operational effects are achieved. Generally, it is not possible to weld a hardened build-up plate 190 formed of a high-hardness material. However, in the present embodiment, since the reinforcing member 80 is fixed to the inner end portion of the blade 60, the structure can be such that the reinforcing member 80 is not fixed to the collision surface 61 of the blade 60. Therefore, in the blade 60 provided with the reinforcing member 80, the collision surface 61 can be covered with the hardened build-up plate 190.

[0068] Further, in the present embodiment, the collision surface 61 of the blade 60 is covered by a hardened build-up plate 190 formed of a wear-resistant material. Thereby, wear of the collision surface 61 of the blade 60 can be suppressed.

[0069] Further, in the present embodiment, since the reinforcing member 80 is fixed to the inner end portion of the blade 60, the structure can be such that the reinforcing member 80 is not fixed to the collision surface 61 of the blade 60. Therefore, compared with the case where the reinforcing member 80 is fixed to the collision surface 61, the collision surface 61 can be easily covered with the hardened build-up plate 190.

[0070] Note that the present disclosure is not limited to the above-described embodiments, and can be appropriately modified without departing from the gist thereof. For example, in the above-described embodiment, a mill of the present disclosure is used. However, as the solid fuel, biomass fuel or PC (Petroleum Coke) fuel generated during petroleum refining may be used, and these fuels may be used in combination. Also, the high-hardness material having wear resistance on the entire surface of the collision surface 61 is not limited to the hardened build-up plate, and for example, a ceramic plate or the like may be used.

[0071] Also, in the above-described embodiment, an example of applying the classifier of the present disclosure to a mill for pulverizing solid fuel has been described, but the present disclosure is not limited thereto. For example, the classifier of the present disclosure may be applied to a crusher for crushing ore.

[0072] Also, in each of the above-described embodiments, an example of fixing the reinforcing member 80 and the blade 60 by welding has been described, but the present disclosure is not limited thereto. For example, the reinforcing member 80 and the blade 60 may be fixed with a fastener such as a bolt. Also, the reinforcing member 80 and the blade 60 may be fixed via a fixing member such as a bracket.

[0073] Also, in each of the above-described embodiments, an example in which the cross-sectional shape of the reinforcing member 80 is substantially circular has been described, but the present disclosure is not limited thereto. The cross-sectional shape of the reinforcing member may be a cross-sectional shape that can sufficiently suppress deformation due to centrifugal force, and for example, an oval shape or an elliptical shape may be used. Also, a polygonal shape may be used.

[0074] Also, the reinforcing member 80 may be provided with a suspension piece, an eye plate, or the like on the upper surface. By configuring in this way, the reinforcing member 80 can be lifted by engaging a hook or the like provided on a lifting device (not shown) with the suspension piece or the eye plate. Therefore, since the reinforcing member 80 can be lifted to a desired height, the work of fixing the reinforcing member 80 and the blade 60 can be simplified. Note that the lifting device includes, for example, a crane or a winch.

[0075] Also, in each of the above embodiments, an example in which the reinforcing member 80 is annular has been described, but the present disclosure is not limited thereto. For example, the reinforcing member may have an annular shape with a polygonal outer shape in plan view. Specifically, for example, it may be an annular polygon having the same number of blades 60 as the number of vertices.

[0076] Also, in each of the above embodiments, an example in which the reinforcing member 80 is provided at the vertical center of the blade 60 has been described, but the present disclosure is not limited thereto. For example, the reinforcing member 80 may be fixed at a position in the vertical direction where the largest centrifugal force acts on the blade 60. By configuring in this way, the reinforcing member 80 can be fixed at a position where it is most easily deformed by the centrifugal force of the blade 60. Therefore, deformation of the blade 60 can be preferably suppressed.

[0077] Specifically, for example, in each of the above embodiments, as shown in FIG. 2 and the like, the blade 60 is inclined such that the upper part is farther from the central axis C than the lower part. As a result, when the rotary classifier 16 rotates, the centrifugal force F1 (see FIG. 2) acting on the upper part of the blade 60 is larger than the centrifugal force F2 (see FIG. 2) acting on the lower part of the blade 60. Thus, the centrifugal force acting on the blade 60 is not uniform in the vertical direction. Considering this point, the reinforcing member 80 may be provided at the vertical position of the blade 60 where the largest acting centrifugal force acts. By providing it in this way, deformation of the blade 60 can be further suppressed. The position where the centrifugal force acting on the blade 60 is the largest is a position above the vertical center when the blade 60 is inclined such that the upper part is farther from the central axis C than the lower part.

[0078] In addition, in each of the above embodiments, an example in which one reinforcing member 80 is provided has been described, but the present disclosure is not limited thereto. For example, a plurality of reinforcing members 80 may be provided. When a plurality of reinforcing members 80 are provided, they may be arranged at a predetermined interval in the vertical direction. Specifically, for example, when two reinforcing members 80 are provided, one reinforcing member 80 may be provided at a position one-third from the top of the blade 60, and one reinforcing member 80 may be provided at a position two-thirds from the top of the blade 60. Further, when a plurality of reinforcing members 80 are provided, the intervals between the reinforcing members 80 may be equal or unequal. For example, as described above, when the centrifugal force F1 (see FIG. 2) acting on the upper part of the blade 60 is larger than the centrifugal force F2 (see FIG. 2) acting on the lower part of the blade 60, the reinforcing members 80 may be provided so as to be biased toward the upper side.

[0079] The classifier, power generation plant, and operation method of the classifier described in the embodiments described above are understood as follows, for example. A classifier according to one aspect of the present disclosure is a classifier (16) that rotates about a central axis (C) extending in the vertical direction, classifies particles guided by a conveying gas from the outer side in the radial direction, and introduces the particles having a predetermined particle size or less therein. The classifier includes a main body portion (70) that rotates about the central axis (C), a plurality of plate-like blades (60) that extend in the vertical direction and have upper and lower portions fixed to the main body portion (70), and a reinforcing member (80) that reinforces the plurality of blades (60). The plurality of blades (60) are arranged at a predetermined interval in the circumferential direction such that the plate surfaces of the blades (60) adjacent in the circumferential direction face each other at a position spaced a predetermined distance from the central axis (C) to the outer side in the radial direction. The reinforcing member (80) is fixed to the inner end portion of the blade (60) in the radial direction and connects the blades (60) arranged in the circumferential direction.

[0080] In the above configuration, the reinforcing member is fixed to the inner end portion of the blade. Therefore, the number of fixing positions of the reinforcing member to one blade can be set to one. As a result, compared with the case where a plurality of fixing positions of the reinforcing member are provided for one blade, the number of fixing positions between the blade and the reinforcing member can be reduced. Therefore, the work of fixing the blade and the reinforcing member can be simplified. Consequently, the process of manufacturing the rotary classifier can be shortened, and the working cost can be suppressed. Also, since the number of fixing positions between the blade and the reinforcing member can be reduced, the members used for fixing the blade and the reinforcing member (for example, materials used for welding, fasteners, etc.) can be reduced, so that the equipment cost can be reduced. In the above configuration, the reinforcing member is fixed to the inner end portion of the blade. Thereby, for example, compared with the case where the reinforcing member is fixed to the outer end portion in the radial direction of the blade, it is difficult for the solid fuel guided from the outside in the radial direction to come into contact with the reinforcing member. Therefore, wear of the reinforcing member due to the solid fuel can be suppressed. In addition, the reinforcing member is fixed to the inner end portion of the blade. Thereby, a structure can be adopted in which the reinforcing member is not fixed to the blade surface. Therefore, the flow of the solid fuel classified by the blade can be made less likely to be obstructed by the reinforcing member. Thus, the classification accuracy can be improved compared with the case where the reinforcing member is fixed to the blade surface.

[0081] In the classifier according to one aspect of the present disclosure, the reinforcing member (80) is annular, and the outer peripheral surface thereof is fixed to the blade (60).

[0082] In the above configuration, the reinforcing member is annular. Thereby, since the reinforcing member can receive the tensile force due to the centrifugal force, the blade can be more suitably reinforced.

[0083] The classifier according to one aspect of the present disclosure, the reinforcing member (80) has a plurality of divided portions (180a) arranged side by side in the circumferential direction, and the divided portions (180a) are such that the ends of the divided portions (180a) adjacent to each other in the circumferential direction are connected.

[0084] In the above configuration, the reinforcing member has a plurality of divided portions. In other words, the annular reinforcing member is divided into a plurality of divided portions. Thereby, compared with the case where the reinforcing member is composed of one member, one member can be miniaturized, so that the work of fixing the reinforcing member and the blade can be simplified.

[0085] The classifier according to one aspect of the present disclosure, the front surface (61) of the blade (60) in the rotation direction is covered by a wear-resistant portion (190) formed of a wear-resistant material.

[0086] Particles of pulverized solid fuel collide with the front surface of the blade in the rotation direction. In the above configuration, the front surface of the blade in the rotation direction is covered with a wear-resistant material. Thereby, wear of the blade surface can be suppressed. Further, in the above configuration, since the reinforcing member is fixed to the inner end portion of the blade, the structure can be such that the reinforcing member is not fixed to the blade surface. Therefore, compared with the case where the reinforcing member is fixed to the blade surface, the blade surface can be easily covered with a wear-resistant material.

[0087] The classifier according to one aspect of the present disclosure, the reinforcing member (80) is fixed at a position where the largest centrifugal force acts on the blade (60) in the vertical direction.

[0088] When the classifier rotates, a centrifugal force acts on the blade. In the above configuration, the reinforcing member is fixed at a position where the largest centrifugal force acts on the blade in the vertical direction. That is, the reinforcing member is fixed at a position where it is most easily deformed by the centrifugal force. Therefore, deformation of the blade can be suitably suppressed.

[0089] The grinder according to one aspect of the present disclosure includes the classifier (16) described in any of the above.

[0090] The power generation plant according to one aspect of the present disclosure includes the grinder (10) described above, a boiler (200) that burns the pulverized solid fuel which is the particles having a predetermined particle size or less pulverized by the grinder (10) and classified by the classifier (16), and a power generation unit that generates power using the steam generated by the boiler (200).

[0091] The operation method of the classifier according to one aspect of the present disclosure is an operation method of a classifier (16) that rotates about a central axis (C) extending in the vertical direction, classifies the particles of the pulverized solid fuel guided by the conveying gas from the outside in the radial direction, and introduces the pulverized particles having a predetermined particle size or less therein. The classifier (16) includes a main body (70) that rotates about the central axis (C), a plurality of plate-shaped blades (60) that extend in the vertical direction and have upper and lower portions fixed to the main body (70), and a reinforcing member (80) that reinforces the plurality of blades (60). The plurality of blades (60) are arranged at a predetermined distance from the central axis (C) to the outside in the radial direction at a predetermined interval in the circumferential direction such that the plate surfaces of the blades (60) adjacent in the circumferential direction face each other. The reinforcing member (80) is fixed to the inner end portion of the blade (60) in the radial direction and connects the blades (60) arranged in the circumferential direction. The method includes a step of classifying the particles by the blades (60) into particles having a size larger than a predetermined particle size and particles having a size equal to or smaller than the predetermined particle size.

Explanation of Reference Numerals

[0092] 1: Power generation plant 10: Mill 11: Housing 12: Pulverizing table 13: Pulverizing roller 14: Driving unit 15: Mill motor 16: Rotary classifier (classifier) 17: Fuel supply unit 18: Classifier motor 19: Outlet port 20: Coal feeder 21: Bunker 22: Conveyor section 23: Coal feeder motor 24: Down spout 30: Blower section 30a: Hot gas flow path 30b: Cold gas flow path 30c: Hot gas damper 30d: Cold gas damper 31: Primary air blower 32: Press-in blower 34: Heat exchanger 40: State detection section 41: Bottom surface 42: Ceiling section 45: Journal head 47: Support arm 48: Support shaft 49: Pressing device 50: Control section 60: Blade 61: Collision surface 65: Back surface 68: Side surface 70: Main body section 71: Cylindrical shaft 72: Upper end 72a: Opening 73: Lower end 80: Reinforcing member 100: Solid fuel pulverizer 100a: Primary air flow path 100b: Fine powder fuel supply flow path 180: Reinforcing member 180a: Split reinforcing member (split section) 181: Groove 185: Joint structure 185a: Protrusion 185b: Recess 190: Hardened build-up plate (wear-resistant section) 200: Boiler 210: Furnace 220: Burner

Claims

1. A classifier that rotates about a central axis extending in the vertical direction, classifies particles guided by a conveying gas from the outer side in the radial direction, and introduces the particles having a predetermined particle size or less therein, comprising: A main body portion that rotates about the central axis; A plurality of plate-like blades that extend in the vertical direction and have upper and lower portions fixed to the main body portion; A reinforcing member having a constant cross-sectional shape along the circumferential direction and reinforcing the plurality of blades; The plurality of blades are arranged at a predetermined interval in the circumferential direction such that the plate surfaces of the blades adjacent in the circumferential direction face each other at a position spaced a predetermined distance from the central axis to the outer side in the radial direction; The reinforcing member is annular, is fixed to the inner end portion of the blade in the radial direction, and connects the blades arranged in the circumferential direction; The outer peripheral surface of the annular reinforcing member is connected to the inner end portion of the blade in the radial direction by a welded portion formed by welding; The blade has a collision surface that is the plate surface on the front side in the rotation direction, a back surface that is the plate surface on the rear side in the rotation direction, and two side surfaces that connect the collision surface and the back surface; The welded portion is provided on the side surface and the back surface inside the blade in the radial direction.

2. The reinforcing member has a plurality of divided portions arranged side by side in the circumferential direction; The classifier according to claim 1, wherein the end portions of the divided portions adjacent in the circumferential direction are connected to each other.

3. The classifier according to claim 1 or 2, wherein the collision surface on the front side in the rotation direction of the blade is covered with a wear-resistant portion formed of a wear-resistant material.

4. The classifier according to any one of claims 1 to 3, wherein the reinforcing member is fixed at a position where the largest centrifugal force acts on the blade in the vertical direction.

5. A crusher equipped with the classifier according to any one of Claims 1 to 4.

6. The crusher according to Claim 5, and a boiler that burns the crushed solid fuel, which is the particles having a predetermined particle size or less crushed by the crusher and classified by the classifier, and a power generation unit that generates power using the steam generated by the boiler. A power generation plant comprising:

7. An operating method of a classifier that rotates about a central axis extending in the vertical direction, classifies particles guided by a conveying gas from the outer side in the radial direction, and introduces the particles having a predetermined particle size or less therein, wherein the classifier includes a main body that rotates about the central axis, a plurality of plate-like blades that extend in the vertical direction and have upper and lower portions fixed to the main body, and a reinforcing member that has a constant cross-sectional shape along the circumferential direction and reinforces the plurality of blades, the plurality of blades are arranged side by side at a predetermined interval in the circumferential direction such that the plate surfaces of the blades adjacent in the circumferential direction face each other at a position spaced a predetermined distance from the central axis to the outer side in the radial direction, the reinforcing member is annular, is fixed to the inner end portion of the blade in the radial direction, and connects the blades arranged in the circumferential direction, the outer peripheral surface of the annular reinforcing member is connected by a welded portion formed by welding to the inner end portion of the blade in the radial direction, the blade has a collision surface that is the plate surface on the front side in the rotation direction, a back surface that is the plate surface on the rear side in the rotation direction, and two side surfaces that connect the collision surface and the back surface, the welded portion is provided on the side surface and the back surface on the inner side in the radial direction of the blade, and a step of classifying the particles by the blade into particles having a particle size larger than a predetermined particle size and particles having a predetermined particle size or less. An operating method of a classifier.

Images