KR20190050284A - Mill and method of operating the mill - Google Patents

Abstract

The present invention relates to a method for operating a pulverizer, which aims to avoid dependence on properties of a supplied solid fuel, maintain a differential pressure inside a pulverizer at or below a fixed differential pressure, and conduct very appropriate treatment. The pulverizer comprises: a pulverizing unit which pulverizes a supplied solid fuel; a transport gas supply pipe which supplies transport gas transporting the pulverized fuel pulverized from the solid fuel in the pulverizing unit; a classifying unit (60) which includes a plurality of blades (59) placed around a central axis line (C) at regular intervals, and rotates around the central axis line (C); a rotary separator (53) which classifies particles sizes of the pulverized fuel transported by the transport gas; a discharging hole which is installed inside the classifying unit (60) and discharges the pulverized fuel classified by the classifying unit (60) to the outside; and a reverse gear which changes the rotating direction of the classifying unit (60) around the central axis line (C). In addition, the plurality of blades (59) are respectively inclined toward a tangent line (A) of a rotational trace of the external end unit in a radial direction in a plan view.

Description

[0001] MILL AND METHOD OF OPERATING THE MILL [0002]

This disclosure relates to a method of operating a mill and a mill.

As a carbon-containing solid fuel to be supplied to a boiler or the like, a biomass fuel such as a wood-based fuel may be used. Biomass fuels are difficult to crush finely, and are highly combustible and can burn very well even with relatively large particle sizes. Further, when the biomass fuel is used as a solid fuel, it is supplied to the burner provided in the boiler in a particle size of about 5 to 10 times larger than that of coal from the pulverizing property.

As described above, since the coal and the biomass fuel have different diameters to be supplied to the burner, the pulverizer for pulverizing and classifying the solid fuel has different designs for the biomass fuel pulverization use and the coal pulverization use (for example, , The rotation speed of the crushing table, the rotation speed of the rotary classifier, etc.). However, from the viewpoints of facility cost and installation space, it is possible to cope with the solid fuel of both biomass fuel and coal with the same crusher without any modification, and it is possible to cope with biomass fuel by using a crusher capable of sharing coal and biomass fuel. It is desired to be applicable to mass fuel.

Patent Document 1 discloses that coal and biomass fuel are shared. Patent Document 1 discloses an apparatus for stabilizing the pressure difference in a pulverizer, in which the pulverizer has a coal chain mode and a biomass pulverizer mode, and the classifier is almost stopped in the case of a biomass chain mode.

Japanese Patent Application Laid-Open No. 2015-1347

However, when the biomass fuel which is difficult to be crushed is pulverized by the pulverizer, the granules classified by the rotary classifier are returned to the pulverizing section and pulverized again to increase the amount of the biomass fuel circulating in the pulverizer And there is a possibility that the pressure difference in the pulverizer rises with increase. If the differential pressure in the pulverizer rises, various problems arise in the operation of the pulverizer, which is not preferable. Therefore, in order to suppress the rise of the pressure difference in the pulverizer, the classification performance is adjusted by adjusting the rotation of the rotary classifier, and the assembly of the biomass fuel is easily supplied to the boiler through the rotary classifier, It is considered to reduce the amount of biomass fuel circulating in the pulverizer.

In the apparatus described in Patent Document 1, the rotary classifier is almost stopped in the biomass shear chain mode. However, simply stopping the rotation of the rotary classifier could not very well reduce the biomass fuel circulating in the mill and could not very well suppress the differential pressure in the mill.

The present disclosure has been made in view of the above circumstances and provides a method of operating a crusher and a crusher that can be suitably treated by setting the differential pressure inside the crusher below a predetermined differential pressure without depending on the nature of the solid fuel to be supplied .

In order to solve the above problems, the pulverizer and pulverizer of the present invention employ the following means.

The pulverizer according to some embodiments of the present invention includes a crusher for crushing the supplied solid fuel and a crusher having a plurality of blades provided at a predetermined interval around the central axis to rotate around the central axis A rotary type classifier for classifying the pulverized pulverized fuel in the pulverizing part, a discharge part provided inside the pulverized part and discharging the pulverized fuel classified by the pulverized part to the outside, And a rotation direction changing means for controlling a rotation direction around the axis, wherein the plurality of blades are provided so as to be inclined with respect to a tangent to a rotation locus of the radially outer end portion when viewed from a plane.

In the above configuration, since the tangential line and the blade form an inclined angle with respect to the tangent to the rotation locus of the plurality of blades, an obtuse angle (greater than 90 degrees) and an acute angle (less than 90 degrees) exist.

When the classification unit is rotated so that the angle of acute angle is forward of the rotation direction (that is, when the classification unit is rotated so that the inner circumferential end of the outer circumferential end of the wing is forward of the rotation direction, ), The front face of the wing in the rotating direction is directed to the outward direction of the branch portion. As a result, the pulverized solid fuel, the pulverized fuel, is likely to collide with the blade, and the pulverized fuel impinging on the blade acts strongly on the centrifugal force, so that the pulverized fuel jumps outwardly of the pulverized portion. Particularly among the pulverized fuels, the assembly having a large mass and inertia force and a high linearity is more likely to be repelled outwardly because the centrifugal force due to the collision acts more strongly than in the case of fine particles, . On the other hand, the fine particles in the pulverized fuel are less likely to collide with the blades because the mass and the inertia force are small and the linearity is low, and the centrifugal force acting on the collision is small. In this way, when the classifying portion rotates in the first direction, the assembly is likely to be returned to the crushing portion, and the fine particles are likely to enter the inside of the classifying portion, so that the classifying performance is relatively improved.

On the other hand, when the classifier rotates in a direction opposite to the first direction and the angle at which the obtuse angle is forward of the rotational direction (that is, when the classifier rotates such that the inner circumferential end of the classifier is positioned rearward of the outer peripheral end of the vane in the rotational direction , Hereinafter referred to as " second direction "), and the front face of the vane in the rotational direction is directed toward the inside of the classified section. As a result, the pulverized solid fuel, which is impinged on the blade, is liable to be repelled toward the inner side of the branch portion. Therefore, compared with the case where the front face in the rotating direction of the vane is directed to the outside of the classifying portion, the fine powder fuel easily flows into the inside of the classifying portion and is easily discharged from the discharging portion. Even if the mass and inertia force of the differential fuel is large and the assembly has a high linearity, it is easy to flow into the inside of the classifying portion. Therefore, when the classifying portion rotates in the second direction, compared with the case of rotating in the first direction, Can be suppressed. In this way, when the classifying portion rotates in the second direction, the classifying performance is suppressed, and not only the fine particles of the pulverized fuel but also the granules are easily discharged from the discharging portion to the outside of the pulverizer, . When the amount of the pulverized fuel circulating in the pulverizer is reduced, an increase in the pressure difference in the pulverizer is suppressed. As a result, even when biomass fuel such as wood is used for the solid fuel supplied to the inside of the pulverizer, the amount of the circulating finely fuels decreases, so that the differential pressure in the pulverizer can be made to be a predetermined value or less have. Therefore, when the classifying portion rotates in the second direction, it is possible to increase the solid fuel supplied to the inside of the pulverizer, and to discharge more finely divided fuel from the discharging portion. Therefore, when the particulate fuel discharged from the discharge portion is supplied to the boiler or the like, the particulate fuel can be supplied to the boiler or the like within a range in which the particle size of the particulate fuel does not affect the combustibility of the boiler or the like.

Thus, in the above-described structure, the classification performance can be accurately determined according to the properties of the solid fuel to be supplied, by the rotation direction of the classifying portion. Therefore, for example, in the case of pulverizing a solid fuel which is easy to be pulverized, such as coal, and which is not particularly high in the combustion property and needs to be pulverized to a small particle diameter, to make the pulverized fuel, the drive unit rotates the pulverized portion in the first direction So that the coal can be pulverized until it becomes a predetermined small particle size. On the other hand, for example, in the case of pulverizing a solid fuel which is hard to be finely crushed and has a high combustion characteristic and does not need to be crushed to a small particle size, such as biomass fuel, as a pulverized fuel, It is possible to suppress the rise of the differential pressure in the pulverizer, so that more biomass fuel is supplied into the pulverizer while the differential pressure in the pulverizer is maintained at a predetermined value or less, and the pulverized fuel discharged from the discharge portion is increased .

As described above, in the above configuration, the classifying performance of the rotary classifier can be adjusted by changing the rotational direction of the classifying portion, so that the classifying performance can be achieved according to the properties of the supplied solid fuel. This makes it possible to set the differential pressure inside the pulverizer to a predetermined differential pressure or less and to treat it very well in a range in which the particle size of the pulverized fuel does not affect the combustibility of the boiler or the like without depending on the properties of the solid fuel to be supplied have. Therefore, the pulverizer can be made common to a plurality of solid fuels having different properties.

In addition, since a plurality of the solid fuels having different properties can be made common, it is possible to greatly reduce the facility cost and reduce the installation space, as compared with the case where the pulverizer is provided for each of the solid fuels having different properties can do.

The pulverizer according to any one of the embodiments of the present invention is characterized in that the pulverizer has a conveying gas supply part for supplying a conveying gas for conveying the pulverized fuel from the crushing part to the discharge part, And the rotational direction of the classifying portion may be determined based on the differential pressure measured by the differential pressure measuring means.

When the pressure difference in the pulverizer is higher than a predetermined value, various problems arise in the operation of the pulverizer, such as lowering of the supply flow rate necessary as the transporting gas. However, Thereby determining the rotation direction of the classifier. Thus, by determining the rotational direction of the classifying portion based on the pressure difference inside the pulverizer, the pressure difference in the pulverizer can be made to be a certain value or less more reliably.

The pulverizer according to any one of the embodiments of the present invention may further include a drive unit for supplying a drive force to the classifying unit of the rotary classifier and a drive force measuring unit for measuring a drive force of the drive unit, The rotational direction of the classifier may be determined based on the driving force.

In the above configuration, when the driving force of the driving portion is high, it can be judged that the pulverized fuel circulating in the pulverizer is increasing. Therefore, the amount of circulating pulverized fuel in the pulverizer can be reduced by changing the rotating direction .

The pulverizer according to any one of the embodiments of the present invention may be provided with a rotation number control means for controlling the number of revolutions of the classifier.

In the above arrangement, the classification performance of the classified section can be adjusted by controlling the number of revolutions of the classification section.

The pulverizer according to any one of the embodiments of the present invention may include a drive unit for supplying a drive force to the classifying unit of the rotary classifier and a separating unit for bringing the rotary classifier into a state in which no driving force is supplied from the drive unit .

In the above configuration, when the rotary classifier is set in a state in which no driving force is supplied from the driving unit, a load from the driving unit is not applied to the classifying unit, so that the classifying unit rotates in the second direction by the flow of the carrying gas. As described above, since the classifying section is rotated only by the flow of the transporting gas, confusion of the flow of the transporting gas due to the rotation of the distributing section is suppressed as much as possible, and the flow of the transporting gas can be rectified.

In addition, since the classifying portion rotates in the second direction only by the flow of the conveying gas, the rotation of the classifying portion makes the most flow of the pulverized fuel conveyed by the conveying gas and the conveying gas. As a result, the pressure loss caused when the transporting gas and the fine particle fuel pass through the partitioning portion can be suppressed as much as possible. Therefore, it is possible to discharge the pulverized fuel to the outside of the pulverizer very suitably, and suppress the rise of the pressure difference in the pulverizer.

In addition, it is possible to suppress the rise of the differential pressure in the pulverizer only by making the drive unit not to be supplied with the driving force. Therefore, the cost can be reduced as compared with the case where the special control is continuously executed to suppress the rise of the differential pressure and the case where the apparatus is continuously operated.

The pulverizer according to some embodiments of the present invention includes a crusher for crushing the supplied solid fuel and a crusher having a plurality of blades provided at a predetermined interval around the central axis to rotate around the central axis A rotary classifier for classifying the pulverized pulverized fuel in the pulverizing section, a discharge section provided inside the pulverizing section for discharging the pulverized fuel classified by the pulverizing section to the outside, And a separating means for bringing the classifying portion into a state in which the driving force is not supplied from the driving portion, wherein each of the plurality of vanes has a radially outer end portion But may be provided so as to be inclined with respect to the tangent to the rotation locus.

When the driving force is supplied from the driving unit and the classifying unit is rotating, the particulate matter is guided to the outlet by the classifying unit and the solid fuel is classified by returning the assembly to the crushing unit.

On the other hand, when the driving force is not supplied to the classifying portion from the driving portion, the load from the driving portion is not applied to the classifying portion, so that the classifying portion rotates in the second direction by the flow of the carrying gas. Since the classifying portion rotates in the second direction only by the flow of the carrier gas in this way, disruption of the airflow of the carrier gas due to rotation of the classifying portion is suppressed as much as possible and the flow of the carrier gas can be rectified .

Further, since the classifying portion is rotated only by the flow of the conveying gas, the rotation of the classifying portion is the most likely to allow the differential fuel conveyed by the conveying gas and the conveying gas to pass most easily. As a result, the pressure loss caused when the transporting gas and the solid fuel pass through the distributor can be suppressed as much as possible. Therefore, it is possible to discharge the solid fuel to the outside of the pulverizer very suitably, and suppress the increase of the pressure difference in the pulverizer. Therefore, the solid fuel to be supplied to the inside of the pulverizer can be increased, and more finely divided fuel can be discharged from the discharge portion. Therefore, when the particulate fuel discharged from the discharge portion is supplied to the boiler or the like, the particulate fuel can be supplied to the boiler or the like within a range in which the particle size of the particulate fuel does not affect the combustibility of the boiler or the like.

As described above, according to the above-described configuration, whether or not the driving force is supplied to the classifier can be accurately obtained by classifying performance according to the properties of the solid fuel to be supplied. Therefore, for example, in the case of pulverizing a solid fuel which is easy to crush finely and which is not particularly high in burning property and needs to be crushed to a small particle size, such as coal, as a pulverized fuel, a driving force is supplied to the pulverized portion, By rotating the feed, the coal can be crushed until a small particle size is achieved. On the other hand, in the case of pulverizing a solid fuel which is difficult to crush finely, such as biomass fuel, and which does not need to be crushed to a small particle size with high combustion property, as a pulverized fuel, It is possible to suppress the rise of the differential pressure in the pulverizer so that the particle size of the pulverized fuel is maintained at a predetermined value or lower while the particle size of the pulverized fuel does not affect the burnability of the boiler or the like A large amount of biomass fuel can be supplied into the crusher and the solid fuel discharged from the discharge portion can be increased.

As described above, in the above-described configuration, the drive force is not supplied to the distributor from the drive section, so that the increase of the differential pressure in the grinder can be suppressed. Thereby, the differential pressure inside the crusher can be set to a predetermined differential pressure or less without being dependent on the properties of the solid fuel to be supplied, and can be suitably treated. Therefore, the pulverizer can be made common to a plurality of solid fuels having different properties. In addition, since a plurality of solid fuels having different properties can be used in common, it is possible to greatly reduce the facility cost and reduce the installation space, as compared with the case where the pulverizer is provided for each of the solid fuels having different properties can do.

In addition, it is possible to suppress the rise of the differential pressure in the pulverizer only by making the drive unit not to be supplied with the driving force. Therefore, the cost can be reduced as compared with the case where the special control is continuously executed to suppress the rise of the differential pressure and the case where the apparatus is continuously operated.

The pulverizer according to any one of the embodiments of the present invention is characterized in that the pulverizer has a conveying gas supply part for supplying a conveying gas for conveying the pulverized fuel from the crushing part to the discharge part, Pressure measuring means for measuring the differential pressure, and the separating means may be operated on the basis of the differential pressure measured by the differential pressure measuring means.

When the pressure difference in the pulverizer is higher than a predetermined value, various problems arise in the operation of the pulverizer, such as lowering of the supply flow rate necessary as the transporting gas. However, And the separating means is operated. In this manner, by detecting the pressure difference inside the pulverizer and controlling the separating means based on the pressure difference, the pressure difference in the pulverizer can be reliably set to a predetermined value or less.

The pulverizer according to any one of the embodiments of the present invention may include driving force measuring means for measuring the driving force of the driving portion and may operate the separating means based on the driving force measured by the driving force measuring means.

In the above arrangement, when the driving force of the driving portion is high, it can be judged that the pulverized fuel circulating in the pulverizer is increasing, so that the circulating amount of the pulverized fuel in the pulverizer can be reduced by operating the separating means .

A method of operating a pulverizer according to some embodiments of the present invention is a method of operating a pulverizer including a crusher for crushing a supplied solid fuel and a distributor comprising a plurality of blades provided at a predetermined interval around a central axis, A rotary classifier for classifying the pulverized pulverized fuel in the pulverizing section by rotating the pulverizer, a discharge section provided inside the pulverizer for discharging the pulverized fuel classified by the pulverizer to the outside, And a rotating direction changing means for controlling the rotating direction around the central axis of the crankshaft, wherein the plurality of blades are each provided with a crusher provided so as to be inclined with respect to a tangent to a rotation locus of a radially outer end portion, And changing the rotating direction of the classifying portion by the rotating direction changing means.

A method of operating a pulverizer according to any one of the embodiments of the present invention is characterized in that it comprises a crushing section for crushing the supplied solid fuel and a classifier section having a plurality of blades provided at predetermined intervals around the central axis, A rotary classifier for classifying the pulverized pulverized fuel in the pulverizing section, a discharge section provided inside the pulverizing section for discharging the pulverized fuel classified by the pulverizing section to the outside, A driving unit for supplying a driving force to the classifying unit of the rotary classifier; and a separating unit for bringing the classifying unit into a state in which no driving force is supplied from the driving unit, wherein the plurality of vanes, A method of operating a pulverizer provided so as to be inclined with respect to a tangent to a rotation locus of a radially outer end, Then, a step of the minute payment in the state that the driving force is supplied from the driving unit.

According to the present disclosure, the differential pressure inside the crusher can be made to be a predetermined differential pressure or less without being dependent on the properties of the solid fuel to be supplied, and can be treated very suitably.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a longitudinal sectional view showing a pulverizer according to some embodiments. FIG.
Figure 2 is a cross-sectional view of the rotary classifier of Figure 1;

Hereinafter, an operation method of the crusher and the crusher according to some embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]

Hereinafter, a first embodiment of the present disclosure will be described with reference to Figs. 1 and 2. Fig.

Fig. 1 shows a boiler facility 1 equipped with a crusher according to the present embodiment. Further, in the present embodiment, the upper side indicates a vertically upper direction and the lower side indicates a vertically lower direction.

In the present embodiment, the boiler facility 1 is provided with a crusher 5 for crushing a solid fuel such as coal or biomass fuel to be supplied to the boiler body 3 into a differential fuel, which is a solid-state solid fuel.

The crusher 5 may be a type of crushing only coal, a crushing of only biomass fuel, or a crushing of biomass fuel together with coal. Here, the biomass fuel is an organic resource derived from a renewable biological organism, for example, thinning material, waste wood, driftwood, grass, waste, sludge, tires and recycled fuel (pellets or chips) The present invention is not limited thereto. The use of biomass fuels has been investigated since the biomass fuel becomes carbon neutral that does not emit carbon dioxide, which is a global warming gas, from taking in the carbon dioxide in the course of the biomass.

A plurality of pulverized fuel feed pipes 7 are connected to the pulverizer 5 so that pulverized pulverized fuel pulverized by the pulverizer 5 is supplied to the boiler body 3 via a plurality of pulverized fuel feed pipes 7 together with a heat- And is guided to the burner 9 provided.

In the crusher 5, the solid fuel stored in the hopper 11 is guided via the fuel conveying conveyor 13.

A flame is formed by the furnace burner 9 in the boiler body 3 and steam is generated by a heat exchanger not shown in the boiler body 3. [ The generated steam is led to a steam turbine (not shown) to generate electricity.

Next, the details of the crusher 5 will be described. The pulverizer (5) pulverizes solid fuel such as coal or biomass fuel to make a fine powder.

The housing 41 constituting the outer periphery of the crusher 5 has a substantially cylindrical hollow shape and a fuel supply pipe 43 is mounted at the center of the ceiling portion 42. This fuel supply pipe 43 supplies the solid fuel derived from the hopper 11 into the housing 41 and is arranged in the vertical direction (vertical direction) at the center position of the housing 41 and the lower end is connected to the housing 41 ).

A base 44 is provided on the bottom surface portion 40 of the housing 41 and a crushing table (crushing portion) 45 is rotatably disposed on the base 44. And the lower end of the fuel supply pipe 43 is opposed to the center of the crush table 45 so as to face each other. The fuel supply pipe 43 supplies the solid fuel from above to the lower grinding table 45.

The grinding table 45 is rotatable about the central axis of the up-and-down direction (vertical direction), and is driven by a driving device (not shown). The upper surface of the crush table 45 may have an inclined shape such as a lower center portion and a higher outward portion, for example, and the outer peripheral portion may be bent upward.

A plurality of (for example, three) crushing rollers 46 are disposed opposite to each other above the crushing table 45. Each of the crushing rollers 46 is arranged above the outer periphery of the crushing table 45 at equal intervals in the circumferential direction (also, in FIG. 1, only one crushing roller 46 and its peripheral devices ). The crushing roller 46 is vertically swingable by the journal head 47 and is supported so as to be able to move away from the upper surface of the crushing table 45. When the crushing table 45 rotates in a state where the outer circumferential surface of the crushing roller 46 is in contact with the upper surface of the crushing table 45, the crushing roller 46 receives torque from the crushing table 45, When the solid fuel is supplied from the fuel supply pipe 43, the solid fuel is pressed and crushed between the crushing roller 46 and the crushing table 45 to be the pulverized fuel.

A conveying gas supply unit 50 is connected to the lower portion of the housing 41. The conveying gas supply part 50 supplies the conveying gas sent from the conveying gas supplying device (not shown) to the inside of the housing 41. As the transporting gas, for example, air blown from an air blower (not shown) is used. The heated air supplied via the heat exchanger (heater) such as an air preheater (not shown) using the combustion gas of the boiler body 3 as a heat source may be mixed to adjust the temperature of the transportation gas.

On the upper portion of the housing 41, a rotary separator (rotary classifier) 53 is provided. The rotary separator 53 is disposed so as to surround the fuel supply pipe 43 and rotates around the fuel supply pipe 43 by the driving force from the driving device (driving portion)

The rotary separator 53 includes a cylindrical rotary shaft portion (not shown) extending in the vertical direction (vertical direction) so as to surround the periphery of the fuel supply pipe 43. The rotary shaft is rotatably supported around a central axis C extending in the vertical direction at the center of the cylindrical shape.

The rotary separator 53 is provided with a frame body 54. The frame body 54 has a circular upper support frame 55 and a lower support frame 56 disposed at a position spaced downward from the upper support frame 55 and having a substantially inverted conical shape in a hollow shape, . The upper support frame 55 and the lower support frame 56 are supported on the rotation axis by being disposed on the central axis C of the rotation shaft as viewed in a plan view.

The frame body 54 is configured to be closed up and down by the upper support frame 55 and the lower support frame 56. The upper support frame 55 is formed with a plurality of (for example, four) ejection holes (ejection portions) 57 provided at equal intervals along the circumferential direction about the central axis C . Each of the discharge holes 57 is a hole penetrating in the vertical direction and each communicates with the differential fuel supply pipe 7.

A plurality of vanes 59 extending in the vertical direction are provided on the outer peripheral side of the upper support frame 55 and the lower support frame 56 at predetermined intervals (equally spaced) around the central axis C Is installed. The plurality of blades (59) constitute the classifying portion (60). In the present embodiment, the plurality of blades 59 are formed in a flat plate shape, and are provided so as to be inclined with respect to the central axis C so that the upper end is away from the rotation axis and the lower end is closer to the rotation axis. A space between the upper support frame 55 and the lower support frame 56 is formed between the vane 59 and the adjacent vane 59, And an opening 58 communicating with the outer space 62 of the classifying portion 60 in a space on the side of the rotating shaft rather than the inner peripheral end of the plurality of vanes 59 are formed.

2, each of the plurality of vanes 59 is provided so as to be inclined with respect to the tangent line A with respect to the rotational locus of the radially outer end portion when viewed in a plan view. That is, the angle formed between the tangent line A and each blade 59 is set so that? 1, which is an acute angle (less than 90 degrees), and? 2, which is an obtuse angle (greater than 90 degrees) exist.

The drive device 52 includes an electric motor (not shown), an inverter (not shown), and a reverse gear (rotation direction changing means) 69.

The reversing gear 69 is interposed between the electric motor of the drive unit 52 and the rotary separator 53. The reversing gear 69 is controlled by the control device 64 so that the rotational direction of the classifying portion 60 of the rotary separator 53 is rotated forward by the clockwise rotation when the rotary separator 53 is viewed from above (A second direction, which is a counterclockwise rotation when the rotary separator 53 is viewed from above). If the electric motor is a DC motor, the reverse rotation may be performed by changing the electric supply without using the reverse gear 69. [

1, the boiler facility 1 according to the present embodiment includes a differential pressure sensor (differential pressure measurement means) 65, a driving force measurement device (driving force measurement means) 66, a combustion state detection device 67 and a control device 64. [

The differential pressure sensor 65 is provided in the vicinity of the carrying gas supply part 50 and the discharge hole 57 in the present embodiment and is provided in the vicinity of the carrying gas supply part 50 and the discharge hole 57 . The driving force measuring device 66 is provided in the driving device 52 of the rotary separator 53 and measures the driving force of the driving device 52. [ The combustion state detecting device 67 is provided in the burner 9 and detects the burning state of the burner 9. [ The differential pressure sensor 65, the driving force measuring device 66 and the combustion state detecting device 67 transmit the measured or detected data to the control device 64.

The control device 64 is included in the drive device 52 and the drive device 52 based on the data measured or detected by the differential pressure sensor 65, the drive force measurement device 66 and the combustion state detection device 67 The control of the reverse gear 69 is performed. The control device 64 also controls the state in which the driving force of the driving device 52 is supplied to the rotary separator 53 and the state in which the driving force of the driving device 52 is not supplied to the rotary separator 53 (Separating means) that is not provided with a switch. The switching control section controls the inverter of the driving device 52 so as not to apply a load to the rotary separator 53 so that the driving force of the driving device 52 is not supplied to the rotary separator 53 .

At this time, the rotary separator 53 rotates in the reverse rotation direction (second direction) described later by the flow of the transportation gas.

The control device 64 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. A series of processes for realizing various functions are stored in the form of a program in a storage medium or the like as an example. The CPU reads the RAM and the like, and executes processing and calculation processing of information, . The program may be installed in advance in a ROM or other storage medium, a form provided in a state stored in a computer-readable storage medium, a form transferred via a communication means by wire or wireless, or the like good. The computer-readable storage medium is a magnetic disk, an optical magnetic disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like.

The crusher 5 having the above-described construction operates as follows.

When the solid fuel is fed from the fuel supply pipe 43 toward the center of the grinding table 45, the solid fuel is guided to the outer peripheral side of the grinding table 45 by the centrifugal force due to the rotation of the grinding table 45, 46, and is crushed. The pulverized solid fuel becomes a pulverized fuel and is taken up by the transporting gas derived from the transporting gas supply part 50 and guided to the rotary separator 53. The pulverized fuel that has passed through the branched portion 60 of the rotary separator 53 is led to the pulverized fuel feed pipe 7 together with the feed gas and is supplied to the burner 9 of the boiler body 3. The pulverized fuel is mixed with the carrier gas as the primary air, and burned in the burner 9.

Next, the operation of the rotary separator 53 will be described in detail.

[Exhibition]

A case where the classifying portion 60 of the rotary separator 53 rotates in the normal rotation direction (first direction) as indicated by the broken arrow in Fig. 2 will be described. The front face of the vane 59 in the rotational direction of the vane 59 rotates in the direction of rotation of the vane 59 in the direction of rotation of the vane 59, Toward the outer space 62 side. When the front face of the vane 59 in the rotational direction is directed to the side of the outer space 62, the fine fuel tends to collide with the vane 59 and the centrifugal force strongly acts on the collided fine fuel, It is liable to be thrown into the outer space 62 of the branch portion 60. Particularly, the assembly with high mass and inertia force and high linearity of the pulverized fuel is more likely to be repelled toward the outer space 62 side because the centrifugal force due to the collision is stronger than that of the fine particles, ). ≪ / RTI > On the other hand, the fine particles in the fine fuels are less likely to collide with the vanes 59 because of their small mass and inertial force and low in straightness. Therefore, compared to the assembly, It is easy to enter the inner space 61. The assembly is repelled by the blade 59 and is easily returned to the grinding table 45 and the fine particles are likely to enter the inner space 61 of the classifying portion 60. In this case, Therefore, the classification performance can be enhanced.

[Reverse rotation]

A case where the classifying portion 60 of the rotary separator 53 rotates in the reverse rotation direction (second direction) as indicated by the solid arrow in Fig. 2 will be described. The front face of the vane 59 in the rotational direction of the vane 59 rotates in the direction of rotation of the vane 59 so that the front face of the vane 59 rotates in a direction opposite to the direction of rotation of the vane 59, Toward the inner space 61 side. The pulverized fuel is less likely to collide with the blades 59 and the collided fission fuel is injected into the inner space 61 of the classifying portion 60. As a result, . The pulverized powdered fuels are more likely to flow into the inner space 61 of the branched section 60 as compared with the case of forward rotation in which the front surface of the blade 59 faces the outer space 62, And is easily discharged from the discharge hole 57 provided in the inner space 61 because it is easy to flow into the inner space 61. Even if the differential fuel is large in mass and inertia and has high linearity, it easily flows into the inner space 61 of the classifying portion 60. Therefore, when the classifying portion 60 is rotating in the reverse direction, The classification performance is suppressed. The classification performance is suppressed, so that the amount of the pulverized fuel circulating in the pulverizer is reduced as compared with the forward rotation. Therefore, at the time of the reverse rotation, the rise of the differential pressure in the pulverizer is suppressed as compared with the forward rotation. When the classifying portion 60 is rotated in the reverse direction, it is preferable to rotate the classifying portion 60 at a rotational speed of 5% to 30% of the maximum rotational speed of the forward rotation. Depending on the type of solid fuel such as biomass fuel, the number of revolutions in the reverse direction may be selected from minus 1 rpm to minus 50 rpm.

In addition, when the classifying portion 60 is rotating in the reverse direction, the airflow of the conveying gas for conveying the pulverized fuel by the vane 59 is rectified. When the transporting gas is rectified, the pressure loss in the classifying portion 60 can be reduced, so that the pressure difference in the pulverizer 5 is further suppressed. Further, when the transporting gas is rectified, the transporting gas and the fine particle fuel are more uniformly mixed.

In addition, when the classifying portion 60 is rotating in reverse, as described above, the pressure loss caused by the classifying portion 60 is reduced. However, as long as the classifying portion 60 exists, 60 are secured. That is, the pressure difference between the outer space 62 and the inner space 61 is secured to some extent. By securing a certain pressure difference between the outer space 62 and the inner space 61 in this manner, the flow rate of the transporting gas and the differential fuel discharged from the plurality of discharge holes 57 provided in the inner space 61 becomes So that the conveying gas mixed with the pulverized fuel can be more uniformly distributed and transported to the plurality of pulverized fuel feed pipes (7).

Further, as described above, when the classifying portion 60 is rotating in the reverse direction, the amount of the powdery fuel circulating in the pulverizer 5 decreases, and the rise of the differential pressure is suppressed. Thus, even when biomass fuel such as wood is used for the solid fuel supplied from the hopper 11 into the crusher 5, the amount of the circulating finely divided fuel is reduced, It is possible to make the differential pressure within the range equal to or smaller than a predetermined value. Therefore, when the classifying portion 60 is rotating in the reverse direction, the solid fuel to be supplied to the inside of the crusher 5 can be increased, and more finely divided fuel can be discharged from the discharge hole 57. Therefore, it is possible to supply a large amount of the differentiated fuel to the burner 9 provided in the boiler body 3, within the range in which the particle size of the differential fuel does not affect the combustibility of the burner 9. [

[Separate operation]

When the driving force of the drive unit 52 is not supplied to the rotary separator 53, that is, when the load is not applied to the rotary separator 53, the flow distributor 60 is rotated freely do. Specifically, the impeller 59 rotates in the opposite direction (second direction) due to collision between the pulverized fuel and the carrier gas. As in the case of the above-mentioned reverse rotation, the increase of the differential pressure in the crusher 5 is suppressed.

Further, during the separation operation, the classifying portion 60 rotates at a rotational speed at which the pulverized fuel and the carrying gas are most likely to pass (the pressure loss is small). As a result, the pressure loss caused when the transporting gas and the fine particle fuel pass through the classifying portion 60 is suppressed as much as possible. Therefore, the rise of the pressure difference in the crusher 5 is suppressed.

Also in the separation operation, as in the case of reversely rotating the classifying portion 60, the transporting gas is rectified, so that the transporting gas and the pulverized fuel are more uniformly mixed. Since the pressure loss due to the classifying portion 60 is secured to a certain degree as long as the classifying portion 60 is present, the conveying gas discharged from the plurality of the discharging holes 57 provided in the inner space 61 and / The flow rate of the pulverized fuel is uniformed and the transport gas mixed with the pulverized fuel can be more uniformly distributed and transported to the plurality of pulverized fuel feed pipes 7.

Next, the operation method in the present embodiment will be described.

The control device 64 includes a forward rotation operation mode for forward rotation of the classifying portion 60 of the rotary separator 53, a reverse rotation operation mode for reversely rotating the classifying portion 60 of the rotary separator 53, And has a separate operation mode in which the driving force of the device 52 is not supplied to the rotary separator 53. [ When the pulverizer 5 of the present embodiment for example is pulverized and the pulverized coal is supplied to the burner 9, the operation is performed in the forward rotation mode. Since the coal is easily crushed finely and the combustibility is not particularly high and it is necessary to crush to a small particle diameter, the operation is carried out in the forward rotation operation mode with high classification performance, so that the pulverized coal, .

Next, a case where, for example, the biomass fuel is pulverized by the pulverizer 5 of the present embodiment and the pulverized biomass fuel is supplied to the burner 9 will be described. Biomass fuels are difficult to crush finely because they have a lot of fiber, and have a property of being highly combustible and easy to burn. In such a biomass fuel, it is not necessary to crush to a small particle size in the crusher 5. If the classifying performance of the rotary separator 53 is high, the fine fuels of the biomass fuel returned to the crushing table 45 increase, and the biomass circulating in the crusher 5 increases, The differential fuel of the fuel increases. When the circulation amount increases, the pressure difference in the crusher 5 rises. For this reason, when the biomass fuel is pulverized, the differential pressure tends to increase.

From the above, for example, when the biomass fuel is pulverized, the following operation method is performed.

At first, the differential pressure sensor 65 measures the differential pressure in the crusher 5 while operating in the normal rotation mode. The differential pressure sensor 65 measures a pressure difference between, for example, the vicinity of the delivery gas supply part 50 and the discharge hole 57. When the control device 64 determines that the differential pressure measured by the differential pressure sensor 65 exceeds a predetermined value at the time of operation in the normal rotation mode, the control device 64 controls the rotation speed control section The number of rotations of the classifying portion 60 is reduced. When the differential pressure in the crusher 5 does not become equal to or smaller than the predetermined value even when the revolution speed of the classifier 60 is set to the minimum revolution speed (for example, 10% of the maximum revolution speed) , The switching control section is operated and the operation mode is switched from the normal rotation operation mode to the operation mode.

The differential pressure in the crusher 5 is measured by the differential pressure sensor 65 while the operation is being performed in the separate operation mode. When the control device 64 determines that the differential pressure measured by the differential pressure sensor 65 exceeds a predetermined value in the separate operation mode, the control device 64 determines whether or not the drive force of the drive device 52 The rotary separator 53 is changed to a state where it is supplied to the rotary separator 53 and the reversing gear 69 reversely rotates the classifying portion 60. That is, the operation mode is changed from the separate operation mode to the reverse rotation operation mode. If the electric motor is a DC motor, the reverse rotation may be performed by changing the electric supply without using the reverse gear 69. [

The above-described operating method is an example, and the present disclosure is not limited thereto.

For example, in the case of pulverizing coal, the operation may be performed in the separate operation mode or in the reverse rotation operation mode within a range in which the grain size of the differential fuel discharged from the pulverizer 5 is acceptable.

In the case of pulverizing the biomass fuel, the operation mode may be changed to the reverse rotation operation mode when the operation is started in the separate operation mode and the differential pressure thereafter exceeds a predetermined value.

Further, in the case of pulverizing the biomass fuel, the operation may be started in the reverse rotation operation mode.

In the case of pulverizing the biomass fuel, the operation is started in the normal rotation operation mode. Thereafter, when the differential pressure exceeds the predetermined value, the operation mode is changed to the reverse rotation operation mode without going through the separate operation mode good.

Further, the driving force measured by the driving force measuring device 66 may be used as the data for determining the switching of the operation mode. When the driving force of the drive device 52 is high, it can be determined that the powdery fuel circulating in the crusher 5 is increasing. Therefore, by changing the operation mode, the amount of circulation of the powdery fuel can be reduced. The combustion state detected by the combustion state detecting device 67 provided in the burner 9 may be used as the data for determining the switching of the operation mode. The particle size of the differential fuel discharged from the crusher 5 by adding the combustion state of the burner 9 to the combustion state of the burner 9 (whether or not it is fired) And the operation mode may be changed.

The present embodiment achieves the following operational effects.

In the present embodiment, in the case of pulverizing coal, since the classifying portion 60 is rotated in the forward direction, the predetermined particle size is set to be small The pulverized coal may be pulverized into a pulverized fuel.

On the other hand, the biomass fuel is difficult to be crushed finely, and the biomass fuel is highly combustible and does not need to be crushed to a small particle diameter. In the present embodiment, in the case of pulverizing the biomass fuel, since the classifying portion 60 is rotated in the reverse direction, the increase of the differential pressure in the pulverizer 5 can be suppressed. Therefore, it is possible to supply more biomass fuel into the crusher 5 and increase the amount of the differential fuel discharged from the discharge hole 57, while maintaining the differential pressure in the crusher 5 at a predetermined value or less.

As described above, in this embodiment, the classifying performance of the rotary separator 53 can be adjusted by changing the rotating direction of the classifying portion 60, so that the classifying performance can be achieved according to the properties of the supplied solid fuel. Thereby, the differential pressure inside the crusher 5 can be made to be equal to or lower than the predetermined differential pressure, and can be suitably treated without depending on the properties of the solid fuel to be supplied. Therefore, the crusher 5 can be made common to a plurality of solid fuels having different properties.

Further, since the crusher 5 can be made common to different solid fuels, compared to the case where the crusher 5 is provided for each of the solid fuels having different properties, The installation space can be reduced.

If the differential pressure in the crusher 5 is higher than a predetermined value, it is not desirable to cause various problems when the crusher 5 is operated. However, in the present embodiment, based on the differential pressure measured by the differential pressure sensor 65 Thereby determining the rotational direction of the classifier 60. In this way, by determining the direction of rotation of the classifying portion 60 based on the differential pressure inside the crusher 5, the pressure difference within the crusher 5 can be made to be a certain value or less more reliably.

Further, when the classifying portion 60 is rotating in the reverse rotation mode (in the reverse rotation mode), the flow of the transporting gas for transporting the pulverized fuel by the blades 59 is rectified and a plurality of discharge holes The flow rates of the carrier gas and the non-fuels fuel discharged from the adsorbing and adsorbing members 57 and 57 can be made uniform. Therefore, the conveying gas and the differential fuel can be uniformly supplied to the plurality of burners 9 via the plurality of differential fuel feed pipes 7, so that uniform burning to the burner 9 becomes possible, It is possible to improve the combustion efficiency in the combustion chamber.

When the driving force is not applied to the rotary separator 53 from the driving device 52 (separate driving mode), the load from the driving device 52 is not applied to the classifying portion 60, The particle distributor 60 rotates naturally by the flow of the carrier gas. As described above, since the classifying portion 60 is rotated only by the flow of the conveying gas, disruption of the flow of the conveying gas due to the rotation of the classifying portion 60 is suppressed as much as possible and the flow of the conveying gas is rectified It can be changed.

Further, in the separate operation mode, since the classifying portion 60 is rotated only by the flow of the transporting gas, the rotation of the classifying portion 60 causes the conveying gas and the differential fuel conveyed by the carrying gas to pass most easily Rotation. As a result, the pressure loss caused when the transporting gas and the non-fissile fuel pass through the classifying portion 60 can be suppressed as much as possible. Therefore, it is possible to discharge the pulverized fuel to the outside of the pulverizer 5 very suitably, and suppress the increase of the pressure difference in the pulverizer 5.

In addition, in the separate operation mode, it is possible to suppress the increase of the differential pressure in the crusher 5 only by setting the state in which no driving force is supplied to the classifying portion 60 from the drive device 52. [ Therefore, the cost can be reduced as compared with the case where the special control is continuously executed to suppress the rise of the differential pressure and the case where the apparatus is continuously operated.

Further, in the separate operation mode, the classifying portion 60 rotates in the reverse direction. Therefore, as in the case of reversely rotating the classifying portion 60, it is possible to suppress the rise of the differential pressure in the crusher 5.

Note that the present disclosure is not limited to the above-described embodiment, and can be appropriately modified within a range not departing from the gist of the present invention.

For example, in the above-described embodiment, an example has been described in which the control device 64 switches the operation modes, but the present disclosure is not limited to this. The operator may manually switch the operation mode. When the operator manually switches the operation mode, for example, a display means for indicating the differential pressure measured by the differential pressure sensor 65 is provided, and the operator switches the operation mode based on the differential pressure or the like displayed on the display means Maybe.

Further, in the above embodiment, the case where the control device 64 has three operation modes of the forward rotation operation mode, the reverse rotation operation mode and the separation operation mode has been described, but the present disclosure is not limited to this. The control device 64 may have only the normal rotation operation mode and the reverse rotation operation mode, or may have only the normal rotation operation mode and the separation operation mode.

1: Boiler equipment
3: Boiler body
5: Grinder
9: Burner
11: Hopper
41: Housing
43: fuel supply pipe
45: Grinding table (crushing part)
46: crushing roller
50: conveying gas supply pipe (conveying gas supply part)
52: Driving device (driving part)
53: Rotary separator (rotary classifier)
57: discharge hole (discharge portion)
59: Wings
60: Branch supply
61: inner space
62: outer space
64: Control device
65: differential pressure sensor (differential pressure measurement means)
66: Driving force measuring device (driving force measuring means)
69: Reverse gear (rotation direction changing means)

Claims (10)

A crushing section for crushing the supplied solid fuel,
A classifier having a plurality of vanes provided at predetermined intervals around a central axis thereof, the classifier comprising: a rotary classifier for classifying the pulverized pulverized fuel in the pulverizing section by rotating around the central axis;
A discharge portion provided inside the distributor for discharging the differential fuel classified by the distributor,
And rotational direction changing means for controlling a rotational direction around the center axis of the classifying portion,
The plurality of vanes are provided so as to be inclined with respect to a tangent to a rotation locus of a radially outer end portion when viewed in a plane
grinder. The method according to claim 1,
A conveying gas supply unit for supplying a conveying gas for conveying the pulverized fuel from the crushing unit to the discharge unit,
And a differential pressure measuring means for measuring a differential pressure between the transfer gas supply portion and the discharge portion,
Based on the differential pressure measured by the differential pressure measuring means, determines the rotating direction of the classifying portion
grinder. The method according to claim 1,
A driving unit for supplying a driving force to the classifying unit of the rotary classifier,
And driving force measuring means for measuring a driving force of the driving portion,
Based on the driving force measured by the driving force measuring means, determines the rotational direction of the classifying portion
grinder. The method according to claim 1,
And rotation speed control means for controlling the rotation speed of the classifying portion
grinder. The method according to claim 1,
A driving unit for supplying a driving force to the classifying unit of the rotary classifier,
And a separating means for bringing the rotary classifier into a state in which no driving force is supplied from the driving portion
grinder. A crushing section for crushing the supplied solid fuel,
A classifier having a plurality of vanes provided at predetermined intervals around a central axis thereof, the classifier comprising: a rotary classifier for classifying the pulverized pulverized fuel in the pulverizing section by rotating around the central axis;
A discharge portion provided inside the distributor for discharging the differential fuel classified by the distributor,
A driving unit for supplying a driving force to the classifying unit of the rotary classifier,
And a separating means for bringing the classifying portion into a state in which no driving force is supplied from the driving portion,
The plurality of vanes are provided so as to be inclined with respect to a tangent to a rotation locus of a radially outer end portion when viewed in a plane
grinder. The method according to claim 5 or 6,
A conveying gas supply unit for supplying a conveying gas for conveying the pulverized fuel from the crushing unit to the discharge unit,
And a differential pressure measuring means for measuring a differential pressure between the transfer gas supply portion and the discharge portion,
Based on the differential pressure measured by the differential pressure measuring means,
grinder. The method according to claim 5 or 6,
And driving force measuring means for measuring a driving force of the driving portion,
Based on the driving force measured by the driving force measuring means,
grinder. A crushing section for crushing the supplied solid fuel,
A classifier having a plurality of vanes provided at predetermined intervals around a central axis thereof, the classifier comprising: a rotary classifier for classifying the pulverized pulverized fuel in the pulverizing section by rotating around the central axis;
A discharge portion provided inside the distributor for discharging the differential fuel classified by the distributor,
And rotational direction changing means for controlling a rotational direction around the center axis of the classifying portion,
Wherein the plurality of blades are each provided so as to be inclined with respect to a tangent to a rotation locus of a radially outer end portion when viewed in a plan view,
And changing the rotating direction of the classifying portion by the rotating direction changing means
How to operate the crusher. A crushing section for crushing the supplied solid fuel,
A classifier having a plurality of vanes provided at predetermined intervals around a central axis thereof, the classifier comprising: a rotary classifier for classifying the pulverized pulverized fuel in the pulverizing section by rotating around the central axis;
A discharge portion provided inside the distributor for discharging the differential fuel classified by the distributor,
A driving unit for supplying a driving force to the classifying unit of the rotary classifier,
And a separating means for bringing the classifying portion into a state in which no driving force is supplied from the driving portion,
Wherein the plurality of blades are each provided so as to be inclined with respect to a tangent to a rotation locus of a radially outer end portion when viewed in a plan view,
And a step of bringing the classifying portion into a state in which the driving force is not supplied from the driving portion by the separating means
How to operate the crusher.

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