WO2020045276A1

WO2020045276A1 - Solid fuel crushing device, power plant equipped with same, and solid fuel crushing method

Info

Publication number: WO2020045276A1
Application number: PCT/JP2019/033017
Authority: WO
Inventors: 聡太朗山口; 昇吾澤
Original assignee: 三菱日立パワーシステムズ株式会社
Priority date: 2018-08-27
Filing date: 2019-08-23
Publication date: 2020-03-05
Also published as: JP7134787B2; JP2020032313A

Abstract

Provided is a solid fuel crushing device which is capable of maintaining a desired classifying performance even when classifying a plurality of types of solid fuels, such as coal fuels or biomass fuels. According to the present invention, a crusher (16) is provided with a seal part (57) having a gap flow passage (GF) formed between a rotary frame (56) and a facing wall part (52). The gap flow passage (GF) of the seal part (57) is provided with: a first flow passage (GF1) that has an inlet opening (GFin) open in the outer periphery of the seal part (57) and extends from the outer peripheral side toward the inner peripheral side; a second flow passage (GF2) of which the upper end is connected to the inner peripheral end section of the first flow passage (GF1) so as to have a first bent part (BD1), and which extends downward; and a third flow passage (GF3) that has an outlet opening (GFout) open in the inner periphery of the seal part (57) and extends from the outer peripheral side toward the inner peripheral side, wherein the other end in the outer peripheral side of the third flow passage (GF3) is connected to the lower end of the second flow passage (GF2) so as to have a second bent part (BD2).

Description

Solid fuel grinding apparatus, power plant equipped with the same, and solid fuel grinding method

The present disclosure relates to a solid fuel pulverizing apparatus suitable for pulverizing, for example, biomass fuel or coal fuel, a power plant including the same, and a solid fuel pulverizing method.

Conventionally, solid fuels such as coal fuel and biomass fuel are pulverized by a mill (pulverizer) into fine powder having a particle size smaller than a predetermined particle size, and supplied to a combustion device. The mill pulverizes solid fuel, such as coal fuel or biomass fuel, injected into the rotary table by chewing between the rotary table and the rollers, and is pulverized by a carrier gas supplied from the outer periphery of the rotary table to a fine powder. The resulting fuel is sorted by a classifier into small-sized particles, transported to a boiler, and burned by a combustion device. In a thermal power plant, steam is generated by heat exchange with combustion gas generated by burning in a boiler, and power is generated by driving a turbine with the steam.

(4) The pulverized fuel that has been pulverized by the mill is classified into fine particles and coarse particles by a rotary classifier installed above the mill. The fine-grained fine fuel passes through the blades of the rotary classifier and is sent to the subsequent process, and the coarse-grained fuel collides with the blades of the rotary classifier, falls on the rotary table, and is pulverized again.

However, a part of the coarse particles that would normally be repelled by the rotary classifier short-passes the gap between the rotary classifier and the blade guide, which is the stationary wall facing the rotary classifier. May be discharged from exit. When such a short path occurs, a desired classification efficiency cannot be obtained. In order to solve this problem, it has been proposed to provide an air seal supply or a labyrinth seal structure as described in Patent Documents 1 to 3 below to suppress a short path.

JP 2018-79424 A JP-A-10-76171 JP-A-8-192066

中でも Among carbon-containing solid fuels, woody biomass fuels are more difficult to pulverize than coal fuels. On the other hand, biomass fuel has a property of being highly flammable as compared with coal fuel and capable of being suitably burned even with a relatively large particle size. Therefore, when a biomass fuel is used as a solid fuel, it is generally supplied from a mill to a combustion device in a state of a particle size that is about 5 to 10 times larger than that of a coal fuel.

As described above, since the particle size supplied to the combustion device differs between the coal fuel and the biomass fuel, the mill for crushing and classifying the solid fuel has a different design between the biomass fuel crushing application and the coal fuel crushing application (for example, the housing). It is inherently preferable to individually design the shape, the rotation speed of the rotary table, the rotation speed of the rotary classifier, and the like. However, from the viewpoint of equipment cost and installation space, a mill that can handle both solid fuels such as biomass fuel and coal fuel is desired.

However, in each of the above patent documents, it is premised that the coal fuel is pulverized, and therefore, it may not be suitable for the pulverization of biomass fuel having a larger particle size after the pulverization than the coal fuel. For example, if the size of the gap between the rotary classifier and the blade guide is set for coal fuel, the biomass fuel may be too narrow and the fuel may adhere or accumulate after pulverization. Alternatively, if a labyrinth seal structure is used as in Patent Document 1, in the case of biomass fuel, there is a possibility that the fuel after grinding may accumulate when passing through a plurality of irregularities.

The present disclosure has been made in view of such circumstances, and even for a plurality of types of solid fuels such as coal fuel and biomass fuel, coarse particles are formed from the gap between the classifier and the blade guide. It is an object of the present invention to provide a solid fuel pulverizer capable of classifying while suppressing a short path in which fuel after pulverization is discharged from a mill outlet while maintaining desired classification performance, a power plant including the same, and a solid fuel pulverization method. I do.

A solid fuel crushing apparatus according to one aspect of the present disclosure is a rotary table, a crushing roller that crushes solid fuel between the rotary table, and a classifier that classifies the crushed fuel crushed by the crushing roller, The classifier comprises a plurality of blades extending in the vertical direction and arranged along a circumferential direction around the rotation axis, and the rotation axis line supporting the upper ends of the plurality of blades. A rotating frame that rotates around, and a seal portion having a gap flow path formed between the rotating frame and an opposing wall portion arranged to face the rotating frame, The gap flow path has an inlet opening that opens to the outer circumference of the seal portion and has a first flow path from the outer circumference to the inner circumference, and a first bend with respect to the inner circumference end of the first flow path. The upper end is connected to have a lower part A second flow path, and an outlet opening at the inner circumference of the seal portion, and the outer flow path is directed from the outer circumference to the inner circumference and has a second bent portion with respect to the lower end of the second flow path. A third flow path to which the other end is connected.

The pulverized fuel pulverized by the pulverizing roller is sealed by a seal provided between a rotating frame of a classifier that rotates about a vertical axis of rotation in a vertical direction and an opposing wall. That is, the gap between the rotating frame and the opposing wall portion is controlled so as to suppress the passage of the post-pulverized fuel that passes between the rotating frame and the opposing wall portion without passing through the blade after the pulverized fuel. A seal is formed by the flow path.
The gap flow passage of the seal portion has an inlet opening that opens to the outer periphery of the seal portion and is connected to the inner peripheral end of the first flow passage from the outer peripheral side to the inner peripheral side, and is connected to the inner peripheral end portion of the first flow passage to be downward. And a third flow passage having an outlet opening connected to the lower end of the second flow passage and opening from the outer periphery toward the inner periphery toward the inner periphery of the seal portion.
Since the second flow path is provided from the upper side to the lower side, the pulverized fuel that has flowed in from the inlet opening is only generated by the fluid force of the fluid flowing from the upper side to the lower side in the second flow path. Without gravity, the discharge can be promoted. Thereby, it becomes easy to discharge the fuel after the pulverization existing in the gap flow path.
Since the gap flow path of the seal portion has the first bent portion and the second bent portion, an appropriate pressure loss is given at these bent portions to crush the gap between the opposed wall portion and coarse particles. By suppressing the post-fuel from being discharged from the outlet of the mill through a short pass, desired sealing properties can be ensured.

Furthermore, in the solid fuel pulverizer according to one aspect of the present disclosure, the cross-sectional area of the third flow path is larger than the cross-sectional area of the second flow path.

Since the cross-sectional area of the third flow path is larger than the cross-sectional area of the second flow path, it is possible to easily discharge the pulverized fuel present in the gap flow path to the outlet opening of the third flow path. it can.

Furthermore, in the solid fuel crushing device according to an aspect of the present disclosure, the cross-sectional area of the first flow path is larger than the cross-sectional area of the second flow path.

(4) Since the flow path cross-sectional area of the first flow path is larger than the flow path cross-sectional area of the second flow path, a gap can be provided on the first flow path GF1 side so as not to interfere with each other.

Furthermore, in the solid fuel crushing device according to an aspect of the present disclosure, the gap dimension D1 between the rotating frame and the opposed wall portion in the second flow path is such that when the solid fuel is a biomass pellet, The particle size is not less than the particle diameter of the constituent particles of the biomass pellet and not more than the particle diameter of the biomass pellet before pulverization.

By setting the gap size of the second flow path to be equal to or larger than the particle diameter of the constituent particles of the biomass pellet and equal to or smaller than the particle diameter of the biomass pellet, it is possible to avoid the accumulation of the fuel after the biomass pellet is pulverized in the second flow path.
The constituent particles of the biomass pellet mean particles (fine particles) that are constituent units of the biomass pellet that is compression-molded into a predetermined shape. Further, the particle size of the biomass pellet means that the biomass pellet that is compression-molded into a predetermined shape is often not a spherical shape but a cylindrical shape, and means the shorter dimension of the outer shape.

Furthermore, in the solid fuel crushing device according to an aspect of the present disclosure, the length from the first bent portion to the second bent portion in the up-down direction of the second flow path is the rotation frame in the second flow path. The gap is between 5 and 10 times the gap between the first and second facing walls.

では If the vertical length of the second flow path is less than 5 times the gap size, a sufficient pressure loss cannot be obtained and the sealing performance may be reduced. If the length from the first bent portion to the second bent portion in the vertical direction of the second flow path exceeds 10 times the gap size, the fuel after pulverization may adhere or accumulate on the second flow path. Therefore, it is preferable that the length of the second flow path in the vertical direction is not less than 5 times and not more than 10 times the gap dimension.

Furthermore, in the solid fuel crushing device according to an aspect of the present disclosure, a rib extending in a radial direction is provided on an outer periphery of the rotating frame.

リブ Ribs extending in the radial direction are provided on the outer periphery of the rotating frame. This allows the ribs that rotate with the rotating frame to remove the coarsely ground fuel that floats in the vicinity of the seal inlet, thereby reducing the amount of fuel after flowing in through the inlet opening and passing through the seal, reducing the coarse particles. Classification performance can be improved by suppressing a short path in which post-fuel is discharged from the mill outlet.

Further, in the solid fuel crushing device according to an aspect of the present disclosure, a chamfered portion or a curved surface portion is provided on an inner peripheral surface side of the rotating frame corresponding to the second bent portion and / or the opposed wall portion. ing.

By providing a chamfered portion or a curved surface portion on the inner peripheral surface side and / or the opposing wall portion of the rotating frame at a position corresponding to the second bent portion, the flow is smoothed, and the dischargeability of the pulverized fuel existing in the gap flow path is improved. Can be improved.

Furthermore, in the solid fuel crushing device according to an aspect of the present disclosure, an upward spiral in which the flow flows from the lower side to the upper side on the inner peripheral surface side of the rotary frame and / or the opposing wall portion corresponding to the second flow path. A groove is formed.

Since the upward spiral groove from which the flow flows upward from below is formed on the inner peripheral surface side and / or the opposing wall portion of the rotating frame corresponding to the second flow path, the pressure loss with respect to the flow of the second flow path is formed. Can be added, and the sealing property can be improved. Since the upward spiral groove has a smaller particle size as compared with the biomass fuel, the gap between the upper wall and the opposed wall portion is prevented from being discharged from the mill outlet by short-passing the fuel after crushing the coarse particles, It is preferable to use it in a form in which a large amount of coal fuel that requires more sealing properties is used.

Furthermore, in the solid fuel crushing device according to an aspect of the present disclosure, the rotating frame and / or the opposing wall corresponding to the second flow path are formed with a downward spiral groove in which a flow flows downward from above. I have.

Since a downward spiral groove is formed in the rotating frame and / or the stationary wall portion corresponding to the second flow path so that the flow is directed downward from above, the flow in the second flow path can be energized, and solid fuel can be supplied. Discharge performance can be improved. The downward spiral groove is preferably used for a biomass fuel that requires a high discharge property because of its larger particle size than coal fuel.

Further, a power plant according to one aspect of the present disclosure is a solid fuel crusher described in any of the above, a boiler that generates steam by burning solid fuel crushed by the solid fuel crusher, A power generation unit that generates power using the steam generated by the boiler.

Further, a solid fuel pulverizing method according to an aspect of the present disclosure includes a rotary table, a pulverizing roller that pulverizes the solid fuel between the rotary table, and a classifier that classifies the pulverized fuel pulverized by the pulverizing roller. The classifier comprises a plurality of blades extending in a vertical direction and arranged along a circumferential direction around a rotation axis, and a state in which upper ends of the plurality of blades are supported. A rotating frame that rotates about a rotation axis, and a solid body that includes a seal portion having a gap flow path formed between the rotating frame and an opposing wall portion disposed to face the rotating frame. A solid fuel pulverization method for a fuel pulverizer, wherein the gap flow path of the seal portion has an inlet opening that opens to an outer periphery of the seal portion and a first flow passage that extends from an outer peripheral side to an inner peripheral side; Inner circumference end of first flow path A second flow path having an upper end connected so as to have a first bent portion with respect to the second flow path, and an outlet opening which opens to the inner periphery of the seal portion, and which is directed from the outer peripheral side to the inner peripheral side, and A third flow path connected to the lower end of the two flow paths so that the other end on the outer peripheral side has a second bent portion.

In the gap flow path formed between the rotating frame and the opposing wall, coarse particles from the gap between the classifier and the blade guide are obtained by obtaining appropriate pulverized fuel dischargeability and a desired pressure loss. A short path in which the fuel after the pulverization is discharged from the mill outlet can be suppressed, and a plurality of types of solid fuels can be classified while maintaining desired classification performance.

1 is a schematic configuration diagram illustrating a power plant according to an embodiment of the present disclosure. It is the seal structure of a classifier, and is the elements expanded longitudinal sectional view which showed the A section of FIG. It is the partial perspective view which showed the rotating frame. It is a seal structure of a classifier according to a second embodiment of the present disclosure, and is a partially enlarged longitudinal sectional view corresponding to FIG. 2. It is a seal structure of a classifier according to a third embodiment of the present disclosure, and is a partially enlarged longitudinal sectional view corresponding to FIG. 2.

Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings.
As shown in FIG. 1, a power plant 1 according to the present embodiment includes a solid fuel crusher 100, a boiler 200 that generates steam, and a power generation unit (not shown) that generates power using the steam generated by the boiler 200. ).

The solid fuel crushing device 100 is a device that crushes a solid fuel such as a coal fuel or a biomass fuel as an example, generates fine powder fuel, and supplies it to the burner unit (combustion device) 220 of the boiler 200. The power plant 1 includes one solid fuel crusher 100. However, the power plant 1 may include a plurality of solid fuel crushers 100 corresponding to each of the plurality of burner units 220 of one boiler 200. Good.

The solid fuel crushing apparatus 100 includes a mill (crushing unit) 10, a coal feeder (fuel feeder) 20, a blowing unit 30, a state detecting unit 40, and a control unit 50.
In the present embodiment, “upward” refers to a vertically upward direction, and “upper” such as an upper portion or an upper surface refers to a vertically upward portion. Similarly, “below” indicates a vertically lower portion.

The mill 10 that pulverizes a solid fuel such as a coal fuel or a biomass fuel supplied to the boiler 200 into a pulverized fuel, which is a pulverized solid fuel, is configured to pulverize not only the coal fuel but also the biomass fuel.
Here, the biomass fuel is a renewable organic resource derived from living organisms, such as thinned wood, waste wood, driftwood, grass, waste, sludge, tires, and recycled fuel (pellet or pellet) made from these. Chip) and the like, and are not limited to those presented here. Since biomass fuel takes in carbon dioxide during the growth process of biomass, it is considered to be carbon neutral which does not emit carbon dioxide which is a global warming gas.

The mill 10 includes a housing 11, a rotary table 12, a roller (crushing roller) 13, a driving unit 14, a classifier 16, a fuel supply unit 17, and a motor 18 for driving the classifier 16 to rotate. I have.
The housing 11 is a casing that is formed in a cylindrical shape extending in the vertical direction and houses the turntable 12, the rollers 13, the classifier 16, and the fuel supply unit 17.
The fuel supply unit 17 is attached to the center of the ceiling 42 of the housing 11. The fuel supply unit 17 supplies the solid fuel guided from the bunker 21 into the housing 11. The fuel supply unit 17 is disposed at the center of the housing 11 along the vertical direction, and has a lower end extending into the housing 11. ing.

The drive unit 14 is installed near the bottom surface 41 of the housing 11, and the turntable 12 that is rotated by the driving force transmitted from the drive unit 14 is rotatably arranged.
The turntable 12 is a member having a circular shape in plan view, and is arranged such that the lower end of the fuel supply unit 17 faces the turntable. The upper surface of the turntable 12 may have, for example, an inclined shape in which a center portion is low and becomes high toward the outside, and an outer peripheral portion may be bent upward. The fuel supply unit 17 supplies the solid fuel (for example, coal or biomass fuel in the present embodiment) from above to the lower rotary table 12, and the rotary table 12 pulverizes the supplied solid fuel with the rollers 13. It is also called a crushing table.

When the solid fuel is supplied from the fuel supply unit 17 toward the center of the turntable 12, the solid fuel is guided to the outer peripheral side of the turntable 12 by centrifugal force due to the rotation of the turntable 12, and is interposed between the solid fuel and the roller 13. Crushed and crushed. The pulverized solid fuel becomes pulverized fuel, and is wound up by a carrier gas (hereinafter, referred to as “primary air”) guided from a carrier gas passage (hereinafter, referred to as “primary air passage”) 100a, It is led to the classifier 16. That is, at a plurality of locations on the outer peripheral side of the turntable 12, outlets (not shown) through which the primary air flowing from the primary air flow path 100 a flows out into the space above the turntable 12 in the housing 11 are provided. . A vane (not shown) is provided above the outlet to apply a turning force to the primary air blown out from the outlet. The primary air to which the swirling force is given by the vane becomes an airflow having a swirling velocity component, and guides the solid fuel pulverized on the rotary table 12 to the upper classifier 16 in the housing 11. Among the solid fuel pulverized products mixed with the primary air, those having a particle size larger than a predetermined particle size are classified by the classifier 16 or dropped and returned to the rotary table 12 without reaching the classifier 16. And crushed again.

The roller 13 is a rotator that crushes the solid fuel supplied from the fuel supply unit 17 to the turntable 12. The roller 13 is pressed against the upper surface of the turntable 12 and cooperates with the turntable 12 to pulverize the solid fuel.
In FIG. 1, only one roller 13 is shown as a representative, but a plurality of rollers 13 are arranged facing each other at a certain interval in the circumferential direction so as to press the upper surface of the rotary table 12. You. For example, three rollers 13 are evenly arranged in the circumferential direction at an angular interval of 120 ° on the outer peripheral portion. In this case, the portions where the three rollers 13 are in contact with the upper surface of the rotary table 12 (the portions to be pressed) are equidistant from the rotation center of the rotary table 12.

The roller 13 is swingable up and down by a journal head 45, and is supported so as to be able to approach and separate from the upper surface of the rotary table 12. When the rotary table 12 rotates in a state where the outer peripheral surface is in contact with the upper surface of the rotary table 12, the roller 13 receives the rotational force from the rotary table 12 and rotates. When the solid fuel is supplied from the fuel supply unit 17, the solid fuel is pressed between the roller 13 and the rotary table 12 to be pulverized to be pulverized.

支持 The support arm 47 of the journal head 45 is supported by a support shaft 48 whose middle portion extends in the horizontal direction. That is, the support arm 47 is supported on the side surface of the housing 11 so as to be able to swing up and down around the roller around the support shaft 48. A pressing device 49 is provided at an upper end portion of the support arm 47 located vertically above. The pressing device 49 is fixed to the housing 11 and applies a load to the roller 13 via the support arm 47 or the like so as to press the roller 13 against the rotary table 12.

The drive unit 14 is a device that transmits a driving force to the rotary table 12 and rotates the rotary table 12 around a central axis. The driving unit 14 generates a driving force for rotating the rotary table 12.

The classifier 16 is provided on the upper portion of the housing 11 and has a hollow inverted-cone shape. The classifier 16 includes a plurality of blades 16a extending vertically in the outer peripheral position. The blades 16a are provided in parallel at predetermined intervals (equal intervals) around the central axis of the classifier 16. The classifier 16 pulverizes the solid fuel pulverized by the rollers 13 into a material having a particle size larger than a predetermined particle size (for example, 70 to 100 μm for coal and 0.6 to 1.0 mm for biomass fuel) (hereinafter, pulverization exceeding the predetermined particle size). This is a device that classifies the solid fuel that has been pulverized into a “coarse fuel” and a solid fuel of a predetermined particle size or less (hereinafter, a solid fuel pulverized to a predetermined particle size or less is referred to as a “fine powder fuel”). Among the classifiers 16, a rotary classifier that classifies by rotating as a whole is also called a rotary separator. A rotational driving force is applied to the classifier 16 by a motor 18.

The crushed solid fuel that has reached the classifier 16 crushes large-diameter coarse powder fuel by the blade 16a due to the relative balance between the centrifugal force generated by the rotation of the blade 16a and the centripetal force generated by the airflow of the primary air. It is dropped, returned to the turntable 12 and crushed again, and the pulverized fuel is guided to the outlet 19 in the ceiling 42 of the housing 11.
The pulverized fuel classified by the classifier 16 is discharged from the outlet 19 to the supply channel 100b, and is conveyed together with the primary air. The pulverized fuel flowing out to the supply flow path 100b is supplied to the burner section 220 of the boiler 200.

The fuel supply unit 17 has a lower end extending vertically to the inside of the housing 11 so as to penetrate the upper end of the housing 11 and is attached. The solid fuel supplied from the upper part of the fuel supply unit 17 is supplied to a substantially central area of the turntable 12. Solid fuel is supplied to the fuel supply unit 17 from the coal feeder 20.

The coal feeder 20 includes a bunker 21, a transport unit (fuel feeder) 22, and a motor (fuel feeder) 23. The transport unit 22 transports the solid fuel discharged from the lower end of the downspout unit 24 immediately below the bunker 21 by the driving force given by the motor 23. The solid fuel transferred by the transfer unit 22 is guided to the fuel supply unit 17 of the mill 10.

Usually, the inside of the mill 10 is supplied with primary air for conveying pulverized fuel, which is pulverized solid fuel, and the pressure is higher than the atmospheric pressure. The fuel is held in a stacked state inside the downspout part 24 which is a tube extending in the vertical direction immediately below the bunker 21, and the fuel layer stacked in the downspout part 24 causes the fuel on the side of the mill 10. The sealability is ensured so that the primary air and the fuel after pulverization do not flow back. The supply amount of the solid fuel to be supplied to the mill 10 may be adjusted by adjusting the belt speed of the belt conveyor of the transport unit 22 by the motor 23.

The chips and pellets of the biomass fuel before pulverization have a constant particle size as compared with coal fuel (that is, the particle size of the coal before pulverization is, for example, about 2 to 50 mm) (the size of the pellet is For example, the diameter is about 6 to 8 mm and the length is about 40 mm or less. For this reason, when the biomass fuel is stored in the down spout section 24, the gap formed between the biomass fuels is larger than in the case of the coal fuel. As described above, since there is a gap between the chips and pellets of the biomass fuel in the down spout portion 24, the primary air blown up from the inside of the mill 10 and the pulverized fuel pass through the gap formed between the biomass fuels. As a result, the pressure inside the mill 10 may decrease. Also, when the primary air blows into the storage section of the bunker 21, if the transportability of the biomass fuel is deteriorated, dust is generated, the downspout section 24 is ignited, and the pressure inside the mill 10 is reduced, the transport amount of the fine powder fuel is reduced. , And various problems may occur in the operation of the mill 10. For this reason, a rotary valve (not shown) may be provided in the middle of the fuel supply unit 17 from the coal feeder 20 to suppress the backflow due to the blowing up of the primary air and the pulverized fuel.

The blower 30 is a device that blows primary air for drying the solid fuel pulverized by the rollers 13 and supplying the solid fuel to the classifier 16 into the housing 11. The blower unit 30 includes a hot gas blower 30a, a cold gas blower 30b, a hot gas damper 30c, and a cold gas damper 30d to adjust the primary air blown to the housing 11 to an appropriate temperature.

The hot gas blower 30a is a blower that blows heated primary air supplied from a heat exchanger (heater) such as an air preheater. A hot gas damper 30c (first blower) is provided downstream of the hot gas blower 30a. The opening degree of the hot gas damper 30c is controlled by the control unit 50. The flow rate of the primary air blown by the hot gas blower 30a is determined by the opening degree of the hot gas damper 30c.

(4) The cold gas blower 30b is a blower that blows primary air that is ambient air at normal temperature. A cold gas damper (second blower) 30d is provided downstream of the cold gas blower 30b. The opening of the cold gas damper 30d is controlled by the control unit 50. The flow rate of the primary air blown by the cold gas blower 30b is determined by the opening of the cold gas damper 30d.

The flow rate of the primary air is the total flow rate of the primary air flow blown by the hot gas blower 30a and the flow rate of the primary air blown by the cold gas blower 30b, and the temperature of the primary air is the primary air blown by the hot gas blower 30a And the mixing ratio of the primary air blown by the cold gas blower 30b is controlled by the control unit 50.
In addition, by introducing a part of the combustion gas discharged from the boiler 200 that has passed through an environmental device such as an electric dust collector to the primary air blown by the hot gas blower 30a through a gas recirculating blower, and thereby forming a mixture, The oxygen concentration of the primary air flowing from the primary air flow path 100a may be adjusted.

In the present embodiment, data measured or detected by the state detection unit 40 of the housing 11 is transmitted to the control unit 50. The state detection unit 40 of the present embodiment is, for example, a differential pressure measuring unit, and includes a portion where the primary air flows from the primary air flow path 100a into the mill 10 and the primary air and the fine powder fuel from the mill 10 to the supply flow path 100b. Is measured as a differential pressure in the mill 10 with respect to the outlet 19 from which the gas is discharged. The classifying performance of the classifier 16 changes the increase / decrease of the circulating amount of the pulverized fuel of the solid fuel circulating inside the mill 10 and the increase / decrease of the differential pressure inside the mill 10 corresponding thereto. That is, the fine fuel discharged from the outlet 19 can be adjusted and managed with respect to the solid fuel supplied to the inside of the mill 10, so that the particle size of the fine fuel does not affect the combustibility of the burner 220, A large amount of fine fuel can be supplied to the burner section 220 provided in the boiler 200.

Further, the state detection unit 40 of the present embodiment is, for example, a temperature measurement unit, and a blower that blows primary air for supplying the solid fuel pulverized by the rollers 13 to the classifier 16 into the housing 11. The temperature of the primary air in the housing 11 whose temperature is adjusted by the temperature detecting unit 30 is detected, and the blowing unit 30 is controlled so as not to exceed the upper limit temperature. The primary air is cooled by transporting the pulverized material in the housing 11 while drying it, so that the temperature of the upper space of the housing 11 is, for example, about 60 to 80 ° C.

The control unit 50 is a device that controls each unit of the solid fuel crusher 100. The control unit 50 can control the rotation of the turntable 12 with respect to the operation of the mill 10 by transmitting a driving instruction to the driving unit 14, for example. The control unit 50 adjusts the classifying performance by transmitting a driving instruction to the motor 18 of the classifier 16 to control the number of revolutions, thereby optimizing the differential pressure in the mill 10 and supplying the fine powder fuel. Can be stabilized. Further, the control unit 50 adjusts the supply amount of the solid fuel supplied from the transport unit 22 to the fuel supply unit 17 by transmitting the drive instruction to the motor 23 of the coal feeder 20, for example. Can be. In addition, by transmitting the opening degree instruction to the blower unit 30, the control unit 50 can control the opening degree of the hot gas damper 30c and the cold gas damper 30d to control the flow rate and temperature of the primary air.

The control unit 50 includes, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and a computer-readable storage medium. For example, a series of processes for realizing various functions are stored in a storage medium or the like in the form of a program as an example, and the CPU reads the program into a RAM or the like, and executes information processing and arithmetic processing. Thereby, various functions are realized. The program may be installed in advance in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or delivered via a wired or wireless communication unit. Etc. may be applied. The computer-readable storage medium is a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like.

Next, the boiler 200 that performs combustion using the pulverized fuel supplied from the solid fuel crusher 100 to generate steam will be described. The boiler 200 includes a furnace 210 and a burner section 220.

The burner unit 220 burns the pulverized fuel using the primary air containing the pulverized fuel supplied from the supply flow path 100b and the secondary air supplied from a heat exchanger (not shown) to generate a flame. It is. The combustion of the pulverized fuel is performed in the furnace 210, and the high-temperature combustion gas is discharged outside the boiler 200 after passing through a heat exchanger (not shown) such as an evaporator, a superheater, and an economizer.

The combustion gas discharged from the boiler 200 is subjected to predetermined processing in an environmental device (for example, a denitration device, an electric dust collector, etc .: not shown), and heat exchange with the outside air is performed by a heat exchanger (not shown) such as an air preheater. Is performed, and guided to a chimney (not shown) via an induction ventilator (not shown), and is discharged to the atmosphere. The outside air heated by heat exchange with the combustion gas in the heat exchanger is sent to the above-described hot gas blower 30a.

Water supplied to each heat exchanger of the boiler 200 is heated by an economizer (not shown), and further heated by an evaporator (not shown) and a superheater (not shown) to generate high-temperature and high-pressure steam. The power is sent to a turbine (not shown), and a generator (not shown) is rotated to generate power.

[Seal structure of classifier]
Next, the seal structure of the classifier 16 will be described.
As shown in FIG. 1, since the classifier 16 rotates around the rotation axis, a gap flow path is provided between the classifier 16 and the ceiling 42 of the stationary housing 11. After the pulverized fuel flows from the outer peripheral side to the inner peripheral side of the classifier 16 via the gap flow path, and the coarse-grained pulverized fuel flowing from the gap flow path GF is short-passed, the fuel is not separated by the blade 16a. Not only the fine fuel but also the coarse fuel is discharged from the mill outlet, and the classification performance is reduced. Therefore, a seal structure for sealing the gap flow path is required. However, if the sealing structure is set for coal fuel by focusing only on the sealing properties, the biomass fuel has a larger particle size than the coal fuel, so the gap flow path is too narrow for biomass fuel, and May adhere or accumulate in the gap flow path, which may hinder the rotation of the classifier 16.

FIG. 2 shows the details of the portion A in FIG. A blade guide (opposing wall) 52 is fixed to the lower surface of the ceiling 42. The blade guide 52 has an annular shape centered on the rotation axis L1. The rotation axis L1 is a center axis on which the classifier 16 rotates. Although the rotation axis L1 is shown relatively close to the blade guide 52 in FIG. 2 for easy understanding, the rotation axis L1 is actually farther away. The blade guide 52 is fixed to a mounting part 54 fixed to the lower surface of the ceiling part 42 by bolts or welding. Therefore, the blade guide 52 is a stationary portion that does not rotate similarly to the ceiling portion 42. The blade guide 52 includes a disk portion 52a provided at an upper portion, and a cylindrical portion 52b continuously extending downward at an inner circumferential position of the disk portion 52a. Therefore, the vertical cross-sectional shape of the blade guide 52 is an L-shape which is turned upside down in FIG.

回転 A rotating frame 56 is provided below the blade guide 52. The rotating frame 56 is a frame that supports upper ends of a plurality of blades 16a (see FIG. 1) arranged in parallel in the circumferential direction. The rotating frame 56 has an annular shape, and rotates around the rotation axis L1 together with each blade 16a. The rotating frame 56 includes an upper cylindrical portion 56a on the upper side and a lower cylindrical portion 56b provided continuously below the upper cylindrical portion 56a. The lower cylindrical portion 56b has an outer peripheral surface 56b1 having the same diameter as the outer peripheral surface 56a1 of the upper cylindrical portion 56a, while having an inner peripheral surface 56b2 located on the inner peripheral side of the inner peripheral surface 56a2 of the upper cylindrical portion 56a. are doing. Therefore, the thickness (radial dimension) of the lower cylindrical portion 56b is larger than that of the upper cylindrical portion 56a.

円 A disk portion 56c is fixed to the outer peripheral surface 56b1 of the lower cylindrical portion 56b so as to extend in the radial direction. The disk portion 56c is fixed to the lower cylindrical portion 56b by welding or the like. A rib 58 is provided on the upper surface of the disk portion 56c.

The rib 58 is a plate-like body having a substantially right triangle when viewed from the side as shown in FIG. The lower side of the rib 58 is fixed to the upper surface of the disk portion 56c by welding or the like, and the left side perpendicular to the lower side of the rib 58 is welded to the outer peripheral surfaces of the upper cylindrical portion 56a and the lower cylindrical portion 56b. And so on. The oblique side of the rib 58 is located on the outer peripheral side.

FIG. 3 is a perspective view showing a part of the rotating frame 56. It should be noted that, in FIG. 2, the inner peripheral side and the outer peripheral side are opposite to each other with respect to the rotation axis L1 in FIG. As shown in the figure, the rib 58 is provided at a predetermined position in the circumferential direction. Preferably, a plurality of ribs 58 are provided at predetermined regular intervals. When the rib 58 rotates together with the rotary frame 56, a part of the airflow flowing from the lower side to the upper side in the mill 10 floats near the inlet opening GFin of the gap flow passage GF described later by the side surface 58a of the rib 58. Powder fuel can be removed.

(2) As shown in FIG. 2, a clearance channel GF is formed between the rotary frame 56 and the blade guide 52 facing the rotary frame 56, and a seal portion 57 is provided. The outer and inner diameters of the rotating frame 56 are substantially the same as the outer and inner diameters of the blade guide 52. The gap flow path GF is provided with a first flow path GF1, a second flow path GF2, and a third flow path GF3 in order from the outer peripheral side to the inner peripheral side, that is, from the upstream side to the downstream side. As will be described below, the gap channel GF has a first channel GF1, a second channel GF2, and a third channel GF3, and has a vertical channel shape having a crank shape. Constitutes the seal portion 57.

The first flow path GF1 is formed between the upper end 56a3 of the upper cylindrical portion 56a of the rotating frame 56 and the lower surface 52a3 of the disk portion 52a of the blade guide 52 facing the upper end. The first flow path GF1 is formed substantially horizontally from the outer peripheral side toward the inner peripheral side. The first flow path GF1 has an inlet opening GFin that opens above the outer peripheral surface 56a1 of the rotating frame 56.

The second flow path GF2 is formed between the inner peripheral surface 56a2 of the upper cylindrical portion 56a of the rotating frame 56 and the outer peripheral surface 52b1 of the cylindrical portion 52b of the blade guide 52 facing the inner peripheral surface 56a2. The second flow path GF2 is connected to the inner peripheral end of the first flow path GF1, and is a flow path extending in a substantially vertical direction from above to below. The connection between the first flow path GF1 and the second flow path GF2 is a first bent portion BD1 bent at a substantially right angle.

The third flow path GF3 is formed between the upper end 56b3 of the lower cylindrical portion 56b of the rotating frame 56 and the lower end 52b3 of the cylindrical portion 52b of the blade guide 52 facing the upper end 56b3. The outer peripheral end of the third flow path GF3 is connected to the lower end of the second flow path GF2, and is a flow path formed from the outer peripheral side toward the inner peripheral side. In the present embodiment, the connecting portion between the second flow path GF2 and the third flow path GF3 is bent at a substantially right angle, and forms a second bent portion BD2. The third flow path GF3 has an outlet opening GFout that opens above the inner peripheral surface 56b2 of the lower cylindrical portion 56b of the rotating frame 56.

The gap D2 in the radial direction between the inner circumference 56a2 of the upper cylindrical portion 56a of the rotating frame 56 and the outer circumferential surface 52b1 of the cylindrical portion 52b of the blade guide 52 is determined by the gap of the second flow path GF2. In the case where the biomass pellet is used, the particle size is equal to or larger than the particle size of the constituent particles of the biomass pellet and equal to or smaller than the particle size of the biomass pellet before pulverization. The constituent particles of the biomass pellet mean particles (fine particles) that are constituent units of the biomass pellet that has been compression-molded into a predetermined shape. For example, the particle diameter of the constituent particles of the biomass pellet is set to 0.6 to 1.0 mm. Further, the particle size of the biomass pellet means that the biomass pellet that is compression-molded into a predetermined shape is often not a spherical shape but a cylindrical shape, and means the shorter dimension of the outer shape. For example, the particle size of the cylindrical biomass pellet is 6 to 8 mm, and the length is 30 to 40 mm. For example, in the case of the biomass pellet as described above, the gap dimension D1 is set to be 0.6 mm or more and 8 mm or less.
In the case where the fuel is used by switching to coal fuel, or when the biomass fuel is included in the coal fuel, the gap size D1 is equal to or larger than the particle diameter of the constituent particles of the biomass pellet and equal to or smaller than the particle diameter of the biomass pellet before pulverization as described above. It has been. For coal fuel, the gap size D1 (for example, 0.6 mm or more and 8 mm or less) is a numerical value several times larger. However, due to the pressure loss in the first bent portion BD1 bent at a substantially right angle and the second flow passage GF2, the gap flow passage GF of the seal portion 57 between the rotary frame 56 and the blade guide 52 is subjected to coarse pulverized fuel. Is suppressed from being discharged from the outlet 19 of the mill 10 through a short pass, whereby the sealing property is ensured.

The vertical length D2 of the second flow path GF2, which is the length between the inlet opening GFin and the outlet opening GFout, is set to be not less than 5 times and not more than 10 times the gap dimension D1. For example, in the case of the specific size of the biomass pellet described above, the length D2 in the vertical direction is 3 mm or more and 80 mm or less.

流路 The cross-sectional area of the first flow path GF1 is larger than the cross-sectional area of the second flow path GF2. That is, the gap dimension D3 of the first channel GF1 is larger than the gap dimension D1 of the second channel GF2.

流路 The cross-sectional area of the third flow path GF3 is larger than the cross-sectional area of the second flow path GF2. That is, the clearance dimension D4 of the third flow path GF3 is larger than the clearance dimension D1 of the second flow path GF2.

According to the present embodiment, the following operation and effect can be obtained.
The pulverized fuel pulverized by the rollers 13 is sealed by the gap flow path GF between the rotary frame 56 of the classifier 16 and the blade guide 52. That is, in order to prevent the fuel after pulverization from passing between the rotary frame 56 and the blade guide 52 without passing between the blades 16a, a seal is provided by the gap flow path GF between the rotary frame 56 and the blade guide 52. A portion 57 is formed.
The gap flow path GF has an inlet opening GFin that opens to the outer circumference of the classifier 16 and is connected to the first flow path GF1 that goes from the outer circumference to the inner circumference, and to the inner circumference end of the first flow path GF1. Of the classifier 16 connected to the lower end of the second flow path GF2 from the outer peripheral side toward the inner peripheral side (specifically, the rotating frame 56 serving as the seal portion 57). A third flow path GF3 having an outlet opening GFout that opens on the inner peripheral side.
Since the second flow path GF2 is provided from the upper side to the lower side, not only the fluid force by the fluid flowing from the top to the bottom in the second flow path GF2 but also gravity can be used. Thus, the pulverized fuel that has flowed in from the inlet opening GFin can be easily discharged without retaining the pulverized fuel existing in the gap flow path GF.
Since the gap flow path GF has the first bent portion BD1 and the second bent portion BD2, an appropriate pressure loss is given to these bent portions BD1 and BD2, and the pressure loss in the second flow passage GF2. To secure desired sealing properties.

(4) It is necessary to provide a gap that does not interfere with each other due to a difference in thermal expansion due to a temperature difference due to a rise in the temperature inside the classifier 16 and a machining accuracy. At this time, the gap flow path of the seal portion 57 between the rotating frame 56 and the blade guide 52 causes the fuel after coarse pulverization of the fuel due to the pressure loss in the first bent portion BD1 bent at a substantially right angle and the second flow path GF2. Can be prevented from being discharged from the outlet 19 of the mill 10 through a short pass. Since the flow path cross-sectional area of the first flow path GF1 is larger than the flow path cross-sectional area of the second flow path GF2, it is possible to provide a gap on the first flow path GF1 side so as not to interfere with each other.

Since the cross-sectional area of the third flow path GF3 is larger than the cross-sectional area of the second flow path GF2, the pulverized fuel that has flowed in from the inlet opening GFin is the pulverized fuel existing in the gap flow path GF. Can be more easily discharged to the outlet opening GFout of the third flow path GF3.

By setting the gap size D1 of the second flow path GF2 to be equal to or larger than the particle diameter of the constituent particles of the biomass pellet and equal to or smaller than the particle diameter of the biomass pellet, it is possible to avoid accumulation of the fuel after pulverization of the biomass pellet in the second flow path GF2. it can.

(4) The length D2 of the second flow path GF2 in the vertical direction is set to 5 times or more and 10 times or less of the gap dimension D1 of the second flow path GF2. If the length D2 of the second flow path GF2 in the up-down direction is less than 5 times the gap dimension D1, sufficient pressure loss cannot be obtained, and the sealing performance may be reduced. If the vertical length D2 of the second flow path GF2 exceeds 10 times the gap dimension D1, the fuel after pulverization may adhere or accumulate on the second flow path GF2. Therefore, in order to provide an appropriate pressure loss in the second flow path GF2, it is preferable that the vertical length D2 of the second flow path GF2 is 5 times or more and 10 times or less of the gap dimension D1.

リブ A rib 58 extending in the radial direction is provided on the outer periphery of the rotating frame 56. Thereby, the coarse fuel floating near the entrance of the entrance opening GFin of the clearance channel GF of the seal portion 57 can be removed by the rib 58 rotating together with the rotating frame 56, thereby suppressing the inflow from the entrance opening (GFin). However, it is possible to prevent the coarse powder fuel from being short-passed through the gap flow path GF and being discharged from the outlet 19 of the mill 10, thereby improving the classification performance.

[Second embodiment]
Next, a second embodiment of the present disclosure will be described with reference to FIG.
This embodiment differs from the first embodiment in the shape of the second bent portion BD2 that connects the first flow path GF1 and the second flow path GF2. Therefore, in the following description, differences from the first embodiment will be described, and other configurations and operational effects are the same as those of the first embodiment, and a description thereof will be omitted.

FIG. 4 is a longitudinal sectional view of this embodiment corresponding to FIG. 2 of the first embodiment.
A chamfered portion 52d is formed between the outer peripheral surface 52b1 and the lower end 52b3 of the cylindrical portion 52b of the blade guide 52. The chamfered portion 52d is provided continuously in the circumferential direction around the rotation axis L1. The chamfered portion 52d may have an arcuate curved surface portion.
A curved surface portion 56d is formed between the inner peripheral surface 56a2 of the upper cylindrical portion 56a of the rotating frame 56 and the upper end 56b3 of the lower cylindrical portion 56b. The curved surface portion 56d has an arc shape (R shape) in which the center of curvature is located on the inner peripheral side of the inner peripheral surface 56a2 of the upper cylindrical portion 56a when viewed in cross section as shown in FIG. It is provided continuously in the circumferential direction around L1. The curved surface portion 56d may have a chamfered shape.
In the present embodiment, the second bent portion BD2 'connecting the second flow passage GF2 and the third flow passage GF3 is formed between the chamfered portion 52d and the curved surface portion 56d.

According to the present embodiment, by providing the chamfered portion 52d and the curved surface portion 56d at positions corresponding to the second bent portion BD2 ', the flow is smoothed, and the dischargeability of the pulverized fuel existing in the gap flow path GF is further improved. Can be improved.
In particular, by providing the blade guide 52 with the chamfered portion 52d and the rotating frame 56 with the curved surface portion 56d, the flow path in the second bent portion BD2 'is widened, so that the fuel after the pulverization can easily flow. . However, the degree to which the flow path of the second bent portion BD2 'is widened is such that the pressure loss given by the second bent portion BD2' is smaller than the pressure loss of the first bent portion BD1 and the pressure loss of the second flow passage GF2. In order to prevent the pressure loss in the first bent portion BD1 and the pressure loss in the second flow path GF2, for example, the pressure loss is appropriately set so as not to be 1/10 or less.

In the present embodiment, the blade guide 52 is provided with the chamfered portion 52d and the rotating frame 56 is provided with the curved surface portion 56d. However, the present disclosure is not limited to this, and the blade guide 52 may be provided with the curved surface portion. May be provided, or a chamfer may be provided on the rotating frame 56. Alternatively, a chamfer or a curved portion may be provided for either the blade guide 52 or the rotating frame 56.

[Third embodiment]
Next, a third embodiment of the present disclosure will be described with reference to FIG.
This embodiment differs from the first embodiment in the shape of the outer peripheral surface 52b1 of the cylindrical portion 52b of the blade guide 52. Therefore, in the following description, differences from the first embodiment will be described, and other configurations and operational effects are the same as those of the first embodiment, and a description thereof will be omitted.

FIG. 5 is a longitudinal sectional view of this embodiment corresponding to FIG. 2 of the first embodiment.
A spiral groove 52e is formed on the outer peripheral surface 52b1 of the cylindrical portion 52b of the blade guide 52. The number of the spiral groove 52e may be one or plural. Further, the cross-sectional shape of the spiral groove 52e may be rectangular as shown in FIG. 5, or may be arc-shaped.
The spiral groove 52e can be used for a case where the spiral groove 52e is formed so as to go upward from below with respect to the flow flowing through the second flow path GF2, and a case where the spiral groove 52e is formed so as to go downward from above.

(4) When the spiral groove 52e is directed upward from the lower side to the upper side, a pressure loss can be added to the flow of the second flow path GF2, and the sealing performance can be improved. The upward spiral groove 52e has a smaller particle size than biomass fuel, so it is preferable to use the spiral groove 52e in a mode in which a large amount of coal fuel requiring sealing properties is used.

(4) When the spiral groove 52e is directed downward from the upper side to the lower side, the flow of the second flow path GF2 can be energized, and the dischargeability of the fuel after pulverization can be improved. The downward spiral groove 52e is preferably used when the biomass fuel is required to be discharged, because of its larger particle size than coal fuel.

In this embodiment, the spiral groove 52e is formed in the blade guide 52. However, the spiral groove 52e may be formed only in the inner peripheral surface 56a2 of the upper cylindrical portion 56a of the rotating frame 56, or the blade guide 52 and the It may be provided on both of the rotating frames 56.

In each of the embodiments described above, the second flow path GF2 is a flow path extending in the vertical direction. However, the present disclosure is not limited to this, and the second flow path GF2 is not limited to the second flow path GF2 as long as gravity can be effectively used. The extending direction of the flow path GF2 may be inclined with respect to the vertical direction.
In addition, as for the bent portions BD1 and BD2, the bent angle is not limited to 90 ° as long as an appropriate pressure loss can be given. For example, the bent angle is set to an obtuse angle even if it is set to 70 ° or more and 110 ° or less. May be.

1 power plant 10 mill (crushing unit)
11 Housing 12 Rotary table 13 Roller (crushing roller)
14 drive unit 16 classifier 16a blade 17 fuel supply unit 18 motor 19 outlet 20 coal supply machine (fuel supply machine)
21 Bunker 22 Transport unit (fuel supply machine)
23 Motor (fuel supply machine)
24 Down spout section 30 Blow section 30a Hot gas blower 30b Cold gas blower 30c Hot gas damper (first blow section)
30d cold gas damper (second blowing unit)
40 state detecting section (temperature detecting means, differential pressure detecting means)
41 bottom part 42 ceiling part 45 journal head 47 support arm 48 support shaft 49 pressing device 50 control part 52 blade guide (opposing wall part)
52a Disk portion 52a3 Lower surface 52b Cylindrical portion 52b1 Outer peripheral surface 52b3 Lower end 52d Beveled portion 52e Spiral groove 54 Mounting portion 56 Rotating frame 56a Upper cylindrical portion 56a1 Outer peripheral surface 56a2 Inner peripheral surface 56a3 Upper end 56b Lower cylindrical portion 56b1 Outer peripheral surface 56b2 Inner peripheral Surface 56b3 Upper end 56c Disk portion 56d Curved surface portion 57 Seal portion 58 Rib 58a Side surface 100 Solid fuel pulverizer 100a Primary air flow path (transport gas flow path)
100b Supply channel 200 Boiler 210 Furnace 220 Burner unit (combustion device)
L1 Rotation axis GF Gap flow path GF1 First flow path GF2 Second flow path GF3 Third flow path GFin Inlet opening GFout Outlet opening BD1 First bent portion BD2, BD2 'Second bent portion D1 (for second flow path) Dimension D2 Vertical length (of second flow path) D3 Gap size (of first flow path) D4 Gap size (of third flow path)

Claims

A rotating table,
A grinding roller for grinding the solid fuel between the rotary table and
A classifier for classifying the fuel after pulverization pulverized by the pulverizing roller,
With
The classifier, a plurality of blades extending vertically and arranged along a circumferential direction around the rotation axis,
A rotating frame that rotates around the rotation axis while supporting the upper ends of the plurality of blades,
The rotating frame, comprising a seal portion having a gap flow path formed between the opposed wall portion disposed opposite to the rotating frame,
The gap flow passage of the seal portion has an inlet opening that opens to the outer periphery of the seal portion and a first flow passage that goes from the outer periphery to the inner periphery, and an inner peripheral end of the first passage. A second flow path having an upper end connected so as to have a first bent portion and having a downward direction, and an outlet opening which is opened to the inner periphery of the seal portion, and which is directed from the outer peripheral side to the inner peripheral side and the second flow path. And a third flow path connected to the lower end of the path so as to have a second bent portion at the other end on the outer peripheral side.
The solid fuel pulverizer according to claim 1, wherein the cross-sectional area of the third flow path is larger than the cross-sectional area of the second flow path.
The solid fuel pulverizer according to claim 1, wherein the cross-sectional area of the first flow path is larger than the cross-sectional area of the second flow path.
The gap dimension D1 between the rotating frame and the opposed wall portion in the second flow path is, when the solid fuel is a biomass pellet, not less than the particle diameter of the constituent particles of the biomass pellet and before the pulverization. The solid fuel pulverizer according to any one of claims 1 to 3, wherein the particle size of the biomass pellet is not more than the particle diameter of the biomass pellet.
The length of the second flow path from the first bent portion to the second bent portion in the up-down direction is at least five times the gap size between the rotating frame and the opposed wall portion in the second flow channel. The solid fuel crushing device according to any one of claims 1 to 4, wherein the crushing ratio is 10 times or less.
The solid fuel pulverizer according to any one of claims 1 to 5, wherein a rib extending in a radial direction is provided on an outer periphery of the rotary frame.
The solid fuel according to any one of claims 1 to 6, wherein a chamfered portion or a curved portion is provided on an inner peripheral surface side of the rotating frame corresponding to the second bent portion and / or on the facing wall portion. Crushing equipment.
The solid fuel pulverizer according to any one of claims 1 to 7, wherein the rotary frame and / or the opposing wall corresponding to the second flow path has an upward spiral groove in which a flow is directed upward from below. apparatus.
The solid fuel pulverizer according to any one of claims 1 to 8, wherein a downward spiral groove is formed in the rotary frame and / or the opposing wall corresponding to the second flow path, the downward spiral groove being formed so that a flow is directed downward from above. apparatus.
A solid fuel crushing device according to any one of claims 1 to 9,
A boiler that generates steam by burning solid fuel pulverized by the solid fuel pulverizer,
A power generation unit that generates power using steam generated by the boiler,
A power plant equipped with:
A rotating table,
A grinding roller for grinding the solid fuel between the rotary table and
A classifier for classifying the fuel after pulverization pulverized by the pulverizing roller,
With
The classifier, a plurality of blades extending vertically and arranged along a circumferential direction around the rotation axis,
A rotating frame that rotates around the rotation axis while supporting the upper ends of the plurality of blades,
The solid fuel pulverization method of a solid fuel pulverizer, comprising: a rotating frame, and a seal portion having a gap flow path formed between an opposing wall portion disposed to face the rotating frame,
The gap flow passage of the seal portion has an inlet opening that opens to the outer periphery of the seal portion and a first flow passage that goes from the outer periphery to the inner periphery, and an inner peripheral end of the first passage. A second flow path having an upper end connected so as to have a first bent portion and having a downward direction, and an outlet opening which is opened to the inner periphery of the seal portion, and which is directed from the outer peripheral side to the inner peripheral side and the second flow path. A third flow path connected to the lower end of the path so as to have a second bent portion at the other end on the outer peripheral side.