JP3221183U - Pulverizer, solid fuel pulverizer equipped with the same, and boiler system - Google Patents

Abstract

The present invention provides a crusher capable of easily cleaning the upstream side of the feed duct even when the crushed solid fuel is accumulated on the upstream side of the feed duct, and a solid fuel crusher and a boiler system provided with the same. A solid fuel pulverizing apparatus includes a housing and a supply duct in which a flow path for guiding a carrier gas to the housing is formed, the downstream end of the supply duct being connected to the outer wall of the housing and the housing Toward the upper end of the inclined duct, has a predetermined width dimension in the width direction, and has a longitudinal direction in the horizontal direction along the axis. An opening is provided on the ceiling of the horizontal duct 340 which extends and is provided at the ceiling of the horizontal duct 340 and whose central portion is offset from the axis of the horizontal duct 340 in the width direction to communicate the inside and the outside of the horizontal duct 340 It has a portion 420 and a lid 440 which can close the opening 420. [Selected figure] Figure 3

Description

  The present invention relates to a crusher, a solid fuel crusher including the crusher, and a boiler system.

  Conventionally, a carbon-containing solid fuel such as coal or biomass fuel is pulverized into a fine powder smaller than a predetermined particle size by a pulverizer (mill) and supplied to a combustion apparatus. The mill crushes solid fuel such as coal or biomass fuel, etc., which has been introduced into the rotary table between the rotary table and the roller by crushing it, and crushes it by the carrier gas supplied from the outer periphery of the rotary table through the duct. The pulverized fuel is sorted by the classifier into one having a small particle size, conveyed to the boiler, and burned by the combustion device. In a thermal power plant, steam is generated by heat exchange with a combustion gas generated by combustion in a boiler, and power generation is performed by driving a turbine using the steam.

  In the above-mentioned equipment, when the operation of the crusher is stopped due to the influence of the crusher or other equipment, crushed solid fuel will remain inside the crusher housing. However, since the remaining solid fuel may be heated and ignited by natural oxidation, it is desirable to discharge the remaining solid fuel as quickly as possible from the inside of the housing to the outside.

  As a means for discharging the solid fuel from the inside of the housing to the outside, the rotating table is rotated while the transfer gas is stopped, and the solid fuel on the rotating table is scraped up by the roller and dropped to the lower part of the housing There is a method of scraping solid combustion deposited on the lower part of the housing by a scraper co-rotating with a rotary table and conveying it to a spray chute.

  At this time, when stopping the operation of the crusher, the solid fuel (crushed solid fuel) deposited on the lower part of the housing is thrown up by the scraper that rotates with the rotary table, and the carrier gas is introduced inside the housing There is a possibility that solid fuel may flow backward toward the duct of In particular, when the solid fuel is a lightweight solid fuel such as a biomass fuel such as a wood-based fuel, there is a possibility that the solid fuel pulverized in the deep part of the duct flows back and accumulates inside the duct.

  If the crusher is restarted with solid fuel accumulated inside the duct, the solid fuel accumulated inside the duct may be ignited by being heated and heated by the carrier gas flowing inside the duct. There is. In particular, when the solid fuel is biomass fuel, there is a risk that the solid fuel may ignite even if the carrier gas has a temperature (for example, about 150 ° C.) lower than the carrier gas used when the solid fuel is coal. is there. If the solid fuel that has become a fire species by being ignited inside the duct is transported into the housing by the carrier gas, the solid fuel inside the housing may be ignited. For this reason, it is desirable to remove the solid fuel accumulated in the duct before restarting.

  Patent Document 1 discloses an apparatus for removing accumulated pulverized coal from the inside of a duct by injecting an assist gas into the inside of an inclined duct connected to a housing.

JP 2018-51524

  Among carbon-containing solid fuels, biomass fuels such as wood-based fuels have the property of being difficult to finely grind and capable of being suitably burned even if they have high combustibility and relatively large particle diameter. Therefore, when using a biomass fuel as a solid fuel, it is usual to supply from the mill to a combustion apparatus provided in a boiler in a state of a particle size about 5 to 10 times larger than that of coal.

  Thus, since coal and biomass fuel have different particle sizes after crushing, the pulverizers for pulverizing and classifying solid fuel have different designs for biomass fuel pulverizing application and coal pulverizing application (for example, housing shape, rotation) In principle, it is preferable to individually design the rotational speed of the table, the rotational speed of the classifier, and the like.

  However, from the viewpoint of equipment cost, installation space, etc., it is possible to cope with both solid fuel of biomass fuel and coal in the same mill, and use a crusher that can share the coal and biomass fuel It is desirable that biomass fuel can be used.

  As described above, when biomass fuel is crushed by a crusher capable of sharing coal and biomass fuel, biomass fuel has a smaller specific gravity than coal, so it is easy for backflow to the upstream side of the duct for guiding the carrier gas In the case of the device disclosed in Patent Document 1, there is a possibility that the biomass fuel may flow back to a position beyond the inclined duct. Then, there is a possibility that the assist gas injected toward the inclined duct can not properly remove the solid fuel accumulated inside the duct.

  The present invention has been made in view of such circumstances, and a crusher capable of easily cleaning the upstream side of the supply duct even if the pulverized solid fuel is deposited on the upstream side of the supply duct. An object of the present invention is to provide a solid fuel pulverizer and a boiler system provided with the same.

MEANS FOR SOLVING THE PROBLEMS In order to solve the above problems, the crusher of the present invention, the solid fuel crusher including the same, and the boiler system employ the following means.
That is, a crusher according to one aspect of the present invention comprises a housing for accommodating a rotary table and a roller for crushing solid fuel, and a carrier gas for conveying the pulverized solid fuel to the outside of the housing; And a supply duct formed with a flow passage leading from the outside to the inside, the supply duct being inclined so that the downstream end is connected to the outer wall of the housing and descends vertically downward toward the housing A horizontal duct which is connected to the upstream end of the slant duct and which has a predetermined width dimension in the width direction and whose horizontal direction extends in the longitudinal direction along the axis; It is provided on the ceiling of the duct and has a central portion offset from the axis of the horizontal duct in the width direction, and the inside and the outside of the horizontal duct are An opening for threaded, and a closable lid for opening.

According to the crusher according to the present aspect, the supply duct in which the flow path for guiding the carrier gas is formed has the downstream end connected to the outer wall of the housing and descends vertically downward toward the housing An inclined duct extending in an inclined manner, a horizontal duct connected to the upstream end of the inclined duct and having a predetermined width dimension in the width direction and a horizontal direction in which the longitudinal direction extends along the axis; It is provided on the ceiling of the duct and has a central part offset from the axis of the horizontal duct in the width direction, and has an opening for communicating the inside and the outside of the horizontal duct, and a lid capable of closing the opening. doing.
Thus, when cleaning the inside of the supply duct, the operator can easily enter the inside of the supply duct from the opening with the lid opened.
At this time, the opening is provided in the horizontal duct. For this reason, for example, workers can easily enter the inside of the horizontal duct located upstream of the supply duct where the lightweight pulverized solid fuel may be deposited. Therefore, even when biomass fuel is used as the solid fuel, and even when the possibility of further reduction of the lightweight biomass fuel accumulated inside the horizontal duct due to the small specific gravity, the worker Can easily clean the inside of the horizontal duct. Further, even when coal is used as the solid fuel and coal (pulverized coal) which has been crushed is deposited inside the horizontal duct, the worker can easily clean the inside of the horizontal duct.
In addition, the opening is provided on the ceiling of the horizontal duct. For this reason, even if there is a steel aggregate (iron aggregate accompanying the support of the pulverizer or the solid fuel pulverizer) in the vicinity of the side surface of the supply duct, an opening through which the operator can easily enter without interfering with them. A part can be provided. Furthermore, the opening is provided at a position offset in the width direction from the axis of the horizontal duct. For this reason, even when the signal wiring, power supply wiring, piping, and the like of the measuring device are installed on the outer upper surface and the side surface of the horizontal duct, the opening can be provided without interference with them. The term "measuring device" as used herein refers to, for example, a device for measuring the state of the carrier gas flowing through the inside of the supply duct, and is, for example, an oximeter, a thermometer, a flow meter or the like.

  In the crusher according to one aspect of the present invention, the lid portion is provided such that the lower surface is recessed in the same plane with respect to the inner upper surface of the horizontal duct, or in the direction of retracting from the inner upper surface of the horizontal duct. It is done.

According to the crusher of the aspect, the lower surface of the lid portion is provided so as to be recessed in the same plane with respect to the inner upper surface of the horizontal duct or in the direction of retracting from the inner upper surface of the horizontal duct.
Thus, the pressure loss can be suppressed because the lid (the lower surface side of the lid) does not obstruct the flow of the carrier gas flowing in the horizontal duct. If the lid (lower surface side of the lid) protrudes from the inner upper surface of the horizontal duct (that is, the ceiling surface inside the horizontal duct) to the flow path side, the flow of the carrier gas is blocked or disturbed by the protruding portion As a result, pressure loss may occur, resulting in a reduction in the flow rate of the carrier gas.

  In the crusher according to one aspect of the present invention, when the width dimension of the flow passage in the width direction is D, the horizontal distance from the downstream end of the inclined duct is 3D. It is provided at a position of 10D or less.

According to the crusher according to this aspect, the opening is from the downstream end of the inclined duct (that is, the connection between the outer wall of the housing and the supply duct), where the width dimension in the width direction of the flow path is D. The distance along the horizontal direction is provided at a position of 3D or more and 10D or less.
On the upstream side of the horizontal duct of the supply duct, a duct for supplying low temperature air to the supply duct and a duct for supplying high temperature air are connected. The low temperature air and the high temperature air are supplied to the supply duct through the respective ducts after the flow rates are respectively adjusted. At this time, the low temperature air and the high temperature air are mixed in the process of flowing through the supply duct to become the transport gas for the appropriate temperature, but in order to sufficiently mix, the supply duct having a predetermined flow path length is required. become.
By setting the distance along the horizontal direction from the downstream end of the inclined duct to the upstream end of the horizontal duct to be at least 5 D or more, it is possible to ensure a sufficient distance for the low temperature air and the high temperature air to be mixed. Further, by setting the distance along the horizontal direction from the downstream end of the inclined duct to the upstream end of the horizontal duct to 10 D or less, the increase in the installation space of the supply duct can be suppressed. Also, by setting the horizontal length of the inclined duct to 3D or less, it is possible to suppress an increase in the installation space of the inclined duct while suppressing backflow of the solid fuel crushed toward the upstream side of the supply duct. The appropriate inclination can be set in the inclined duct.
For this reason, the opening provided in the horizontal duct can be provided in the horizontal duct with certainty by being provided at a position at a distance of 3D or more and 10D or less along the horizontal direction from the downstream end of the inclined duct. It is.

  In the crusher according to one aspect of the present invention, when the width dimension of the flow passage in the width direction is D, a distance along the horizontal direction from the downstream end of the inclined duct is 5D. It is provided in the position of 7 D or less.

According to the crusher according to this aspect, the opening is from the downstream end of the inclined duct (that is, the connection between the outer wall of the housing and the supply duct), where the width dimension in the width direction of the flow path is D. The distance along the horizontal direction is provided at a position of 5D or more and 7D or less.
By providing the opening upstream of the downstream end of the horizontal duct, the deposited solid fuel can be easily moved from the upstream side to the downstream side. Therefore, the cleaning operation can be easily performed. On the other hand, on the upstream side of the horizontal duct, there may be a routing area of the supply duct after connection of the duct for supplying the low temperature air to the supply duct and the duct for supplying the high temperature air. For this reason, the upstream end of the horizontal duct may be positioned at 7D or less along the horizontal direction from the downstream end of the inclined duct.
Therefore, by providing the opening provided in the horizontal duct at a position at a distance of 5 D or more and 7 D or less along the horizontal direction from the downstream end of the inclined duct, the opening can be provided more reliably and appropriately in the horizontal duct It becomes possible.

  The crusher according to one aspect of the present invention is accessible from the outside of the horizontal duct through the opening, and is installed inside the horizontal duct, and deposited on the floor surface inside the horizontal duct. The conveying device is provided to move the crushed solid fuel to the inclined duct side.

According to the crusher according to the present aspect, the crushed solid which is accessible from the outside of the horizontal duct through the opening and is installed inside the horizontal duct and deposited on the floor surface inside the horizontal duct A transport device is provided to move the fuel to the inclined duct side. Thus, even when the conveying device for conveying the pulverized solid fuel is installed inside the horizontal duct, the conveying device can be easily accessed from the opening. Therefore, cleaning and maintenance of the transfer device can be facilitated.
As a conveying apparatus, there are, for example, a scraper or a brush which can scrape out solid fuel deposited on a floor surface by driving, a belt conveyor which can convey, and the like.

  In the crusher according to one aspect of the present invention, the solid fuel is a biomass fuel.

  According to the crusher of this aspect, pulverized biomass fuel, which has a specific gravity lower than that of coal and tends to flow backward to the upstream side of the supply duct, is deposited on the floor surface inside the horizontal duct beyond the inclined duct. Even if it does, it can easily enter from the opening to clean the inside of the horizontal duct.

  Moreover, in the crusher according to one aspect of the present invention, the solid fuel is coal.

  According to the crusher according to this aspect, even if coal (pulverized coal) that has been crushed temporarily deposits on the floor surface inside the horizontal duct beyond the inclined duct, the inside of the horizontal duct is cleaned. It can easily enter from the opening.

  Moreover, the solid fuel crushing apparatus which concerns on 1 aspect of this invention is equipped with the above-mentioned crushing machine.

  Moreover, the boiler system which concerns on 1 aspect of this invention is equipped with the above-mentioned solid fuel crushing apparatus.

  According to the pulverizer of the present invention, the solid fuel pulverizing apparatus having the same, and the boiler system, the upstream side of the supply duct can be easily disposed even when the pulverized solid fuel is accumulated on the upstream side of the supply duct. It can be cleaned.

It is a schematic block diagram of a solid fuel grinding device provided with a grinder concerning one embodiment of the present invention. It is a side view showing composition near a supply duct. It is a top view in the X section shown in FIG. It is a longitudinal cross-sectional view in cutting line II-II shown in FIG. It is the side view showing the modification of the crusher concerning one embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First, a solid fuel pulverizing apparatus 100 provided with a mill (pulverizer) 10 according to the present embodiment will be described.

  The solid fuel pulverizing apparatus 100 is an apparatus for pulverizing solid fuel such as coal and biomass fuel as an example, generating pulverized fuel, and supplying the pulverized fuel to a burner unit (combustion apparatus) 220 of the boiler 200.

  The boiler system 1 including the solid fuel pulverizing apparatus 100 and the boiler 200 shown in FIG. 1 includes one solid fuel pulverizing apparatus 100, but corresponds to each of the plurality of burner sections 220 of one boiler 200. It is good also as a system provided with a plurality of solid fuel grinding devices 100 which carry out.

The solid fuel pulverizing apparatus 100 of the present embodiment includes a mill 10, a coal feeder (fuel supply machine) 20, a blower unit 30, a state detection unit 40, and a control unit (determination unit) 50.
In the present embodiment, the upper side indicates the direction of the vertically upper side, and the “upper” such as the upper side or the upper surface indicates the vertically upper portion. Similarly, "lower" indicates a vertically lower portion.

  The mill 10 for pulverizing solid fuel such as coal and biomass fuel supplied to the boiler 200 into pulverized fuel which is pulverized solid fuel may be of a type of pulverizing only coal or pulverizing only biomass fuel It may be in the form or may be in the form of crushing biomass fuel with coal.

  Here, biomass fuel is an organic resource derived from renewable organisms, and for example, thinned wood, waste wood, driftwood, grasses, waste, sludge, tires, and recycled fuels (pellets or the like) Chips, etc., and is not limited to those presented here. Since the biomass fuel is carbon neutral which does not emit carbon dioxide, which is a global warming gas, because it takes in carbon dioxide in the process of growing biomass, its use has been variously studied.

  The mill 10 includes a housing 11, a rotary table 12, a roller 13, a drive unit 14, a classification unit 16, a fuel supply unit 17, and a motor 18 that rotationally drives the classification unit 16.

  The housing 11 is formed in a cylindrical shape extending in the vertical direction, and is a housing that accommodates the rotary table 12, the roller 13, the classification unit 16, and the fuel supply unit 17.

  A fuel supply unit 17 is attached to a central portion of the ceiling portion 42 of the housing 11. The fuel supply unit 17 supplies the solid fuel introduced from the bunker 21 into the housing 11 and is disposed at the center position of the housing 11 along the vertical direction, and the lower end portion is extended to the inside of the housing 11 ing.

  A drive unit 14 is installed near the bottom surface 41 of the housing 11, and a rotary table 12 that is rotated by the driving force transmitted from the drive unit 14 is rotatably disposed.

  The rotary table 12 is a circular member in plan view, and is disposed such that the lower end portion of the fuel supply unit 17 faces each other. The upper surface of the rotary table 12 may have, for example, an inclined shape in which the central portion is low and heights outward, and the outer peripheral portion may be bent upward. The fuel supply unit 17 supplies 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 crushes the supplied solid fuel with the roller 13. It is also called a grinding table.

  When solid fuel is introduced from the fuel supply unit 17 toward the center of the rotary table 12, the solid fuel is guided to the outer peripheral side of the rotary table 12 by the centrifugal force due to the rotation of the rotary table 12. It is pinched and crushed. The pulverized solid fuel is transferred from the carrier gas channel 100a (hereinafter referred to as "primary air channel 100a") formed in the supply duct 300 (hereinafter referred to as "primary air channel 100a"). And is led to the classification section 16.

  At a plurality of locations on the outer peripheral side of the rotary table 12, outlet ports (not shown) are provided which allow the primary air flowing from the primary air flow path 100 a to flow out to the space above the rotary table 12 in the housing 11. A vane (not shown) is installed above the air outlet to apply a swirling force to the primary air blown from the air outlet.

  The primary air to which a swirling force is applied by the vanes becomes an air flow having a swirling velocity component, and guides the solid fuel pulverized on the rotary table 12 to the classification portion 16 above the housing 11. Among the pulverized solid fuel mixed in the primary air, one having a particle diameter larger than a predetermined particle diameter is classified by the classification unit 16 or dropped without reaching the classification unit 16 and returned to the rotary table 12 Be crushed again.

  The roller (crushing roller) 13 is a rotating body that crushes the solid fuel supplied from the fuel supply unit 17 to the rotary table 12. The roller 13 is pressed against the upper surface of the rotary table 12 and cooperates with the rotary table 12 to break up the solid fuel.

  Although only one roller 13 is representatively shown in FIG. 1, the plurality of rollers 13 are disposed at regular intervals in the circumferential direction so as to press the upper surface of the rotary table 12. For example, three rollers 13 are arranged at equal intervals in the circumferential direction at an angular interval of 120 ° on the outer peripheral portion. In this case, in the portions (portions in which the three rollers 13 are in contact with the upper surface of the turntable 12), the distances from the rotation axis of the turntable 12 are equal.

  The roller 13 is rockable up and down by a journal head 45 and is supported so as to be close to and separated 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 with it. When solid fuel is supplied from the fuel supply unit 17, the solid fuel is pressed between the roller 13 and the rotary table 12 and pulverized to be pulverized fuel.

  The support arm 47 of the journal head 45 is supported by the side surface portion of the housing 11 so as to be able to pivot in the vertical direction of the roller about the support shaft 48 by a support shaft 48 whose middle portion extends in the horizontal direction. A pressing device 49 is provided at the upper end portion of the support arm 47 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 and the like so as to press the roller 13 against the rotary table 12.

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

  The classification portion 16 is provided in the upper part of the housing 11 and has a hollow substantially inverted conical shape, and a plurality of classification blades extending vertically in the circumferential side are provided at predetermined intervals (uniform intervals) around the central axis. ing. In addition, the classification unit 16 is a solid fuel pulverized by the roller 13 that has a particle size larger than a predetermined particle size (for example, 70 to 100 μm for coal) (hereinafter referred to as “coarsely pulverized fuel”) And a particle having a particle diameter equal to or less than a predetermined particle diameter (hereinafter, a pulverized solid fuel having a particle diameter equal to or less than the predetermined particle diameter is referred to as “fine powder fuel”).

  The classifying portion 16 has, for example, an inverted truncated conical outer shape, is attached to the upper side in the housing 11 along the cylindrical axis of the substantially cylindrical housing 11, and includes a plurality of classifying vanes on the outer peripheral side. In the classification unit 16, a rotary type classifier that performs classification by rotation is also referred to as a rotary separator, and is provided with a driving force by a motor 18 to center fuel around a cylindrical shaft (not shown) extending in the vertical direction of the housing 11. It rotates around the supply unit 17.

  The pulverized solid fuel that has reached the classification section 16 is crushed by the classification blade due to the relative balance between the centrifugal force generated by the rotation of the classification blade and the centripetal force of the primary air flow. And returned to the rotary table 12 and crushed again, and the pulverized fuel is led to the outlet 19 at the ceiling 42 of the housing 11.

  The pulverized fuel classified by the classification unit 16 is discharged from the outlet 19 to the supply flow passage 100b, and is transported to the post-process along with the primary air. The pulverized fuel that has flowed out to the supply flow passage 100 b is supplied to the burner unit 220 of the boiler 200.

  The lower end portion of the fuel supply portion 17 extends in the vertical direction so as to penetrate the upper end of the housing 11 so as to extend to the inside of the housing 11. Supply. The fuel supply unit 17 is supplied with solid fuel from the coal feeder 20.

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

Usually, primary air for conveying pulverized fuel which is a pulverized solid fuel is supplied to the inside of the mill 10, and the pressure is increased. The fuel is held in a stacked state inside the downspout portion 24 which is a vertically extending pipe directly below the bunker 21, and the solid fuel layer stacked in the downspout portion 24 makes the mill 10 side. The sealability is ensured so that the primary air and the pulverized fuel do not reversely flow.
The supply amount of solid fuel supplied to the mill 10 may be adjusted by the belt speed of the belt conveyor of the conveyance unit 22.

  On the other hand, the chips and pellets of biomass fuel before pulverization have a constant particle size as compared to coal fuel (ie, the particle size of coal before pulverization is, for example, about 2 to 50 mm) (pellet size) For example, the diameter is about 6 to 8 mm, and the length is about 40 mm or less), and is lightweight. For this reason, when biomass fuel is stored in the downspout part 24, compared with the case of coal fuel, the gap formed between each biomass fuel becomes large.

Therefore, since there is a gap between the chips and pellets of biomass fuel in the downspout portion 24, the primary air blown up from inside the mill 10 and the pulverized fuel pass through the gap formed between the biomass fuels, Internal pressure may decrease. In addition, if the primary air blows into the reservoir of the bunker 21, the transportation of the biomass fuel may deteriorate, dust generation, ignition of the downspout, or the pressure inside the mill 10 may decrease the amount of pulverized fuel transported. Various problems may occur in the operation of the mill 10 such as lowering.
For this reason, a rotary valve (not shown) may be provided midway from the coal feeder 20 to the fuel supply unit 17 so as to suppress the backflow due to the blowing up of the primary air and the pulverized fuel.

  The blower unit 30 is a device for drying the solid fuel pulverized by the roller 13 and blowing the primary air to be supplied to the classification unit 16 to the inside of 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 in order to adjust the primary air blown to the housing 11 to an appropriate temperature.

The hot gas blower 30 a is a fan that blows heated primary air supplied from a heat exchanger (heater) such as an air preheater via the hot gas duct 32.
On the downstream side of the heat gas blower 30a, a heat gas damper 30c (first air blower) provided in the heat gas duct 32 is provided. The opening degree of the thermal gas damper 30 c is controlled by the control unit 50. The flow rate of the primary air blown by the heat gas blower 30a is determined by the opening degree of the heat gas damper 30c.

The cold gas blower 30 b is a blower that blows primary air, which is ambient air at normal temperature, through the cold gas duct 34.
On the downstream side of the cold gas blower 30b, a cold gas damper (second blower) 30d provided in the cold gas duct 34 is provided. The opening degree of the cold gas damper 30 d is controlled by the control unit 50. The flow rate of primary air that the cold gas blower 30b blows is determined by the opening degree of the cold gas damper 30d.

  The flow rate of the primary air is the sum of the flow rate of the primary air 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 It is determined by the mixing ratio of the primary air which the cold gas blower 30b blows, and is controlled by the control unit 50.

  In addition, a portion of the combustion gas discharged from the boiler 200 that has passed through the environmental device such as the electric precipitator through the gas recirculation ventilator is guided to the primary air that the hot gas blower 30a blows, and is made into a mixture. You may adjust the oxygen concentration of the primary air which flows in from the primary air flow path 100a.

In the present embodiment, the measured or detected data is transmitted to the control unit 50 by the state detection unit 40 of the housing 11. The state detection unit 40 is, for example, a differential pressure measurement unit, and a portion where primary air flows into the mill 10 from the primary air flow passage 100a and an outlet from which the primary air and pulverized fuel are discharged from the mill 10 into the supply flow passage 100b. The differential pressure with 19 is measured as the differential pressure in the mill 10. For example, due to the classification performance of the classification unit 16, the increase and decrease in the amount of circulation of pulverized solid fuel circulating between the vicinity of the classification unit 16 and the vicinity of the rotary table 12 inside the mill 10 and the corresponding rise in differential pressure in the mill 10 are reduced. Changes.
That is, with respect to the solid fuel supplied to the inside of the mill 10, the pulverized fuel to be discharged from the outlet 19 can be adjusted and managed, so that the particle size of the pulverized fuel does not affect the combustibility of the burner 220 part. A large amount of pulverized fuel can be supplied to the burner unit 220 provided in the boiler 200.

In addition, the state detection unit 40 of the present embodiment is, for example, a temperature measurement unit, and an air blowing unit that blows the primary air for supplying the solid fuel pulverized by the roller 13 to the classification unit 16 into the inside of the housing 11 The temperature in the housing 11 of the primary air whose temperature is adjusted by 30 is detected, and the blower unit 30 is controlled so as not to exceed the upper limit temperature.
In addition, since primary air is cooled by conveying a pulverized material in the housing 11 while drying it, the temperature of the upper space of the housing 11 is, for example, about 60 to 80 degrees.

The control unit 50 is a device that controls each part of the solid fuel grinding device 100. The control unit 50 can control, for example, the rotation of the rotary table 12 with respect to the operation of the mill 10 by transmitting a drive instruction to the drive unit 14. For example, the control unit 50 transmits the drive instruction to the motor 18 of the classification unit 16 to control the number of rotations, thereby adjusting the classification performance, thereby optimizing the differential pressure in the mill 10 and supplying the pulverized fuel. It can be stabilized.
In addition, the control unit 50 adjusts the supply amount of solid fuel which the transport unit 22 transports solid fuel and supplies to the fuel supply unit 17 by transmitting a drive instruction to the motor 23 of the feeder 20, for example. Can. Further, the control unit 50 can control the flow rate and temperature of the primary air by controlling the opening degree of the heat gas damper 30c and the cold gas damper 30d by transmitting the opening degree instruction to the blowing unit 30.

  The control unit 50 includes, for example, a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), and a computer-readable storage medium. Then, a series of processes for realizing various functions are stored in the form of a program, for example, in a storage medium or the like in the form of a program, and the CPU reads this program into a RAM or the like to execute information processing and arithmetic processing. Thus, various functions are realized. The program may be installed in advance in a ROM or other storage medium, may be provided as stored in a computer-readable storage medium, or may be distributed via wired or wireless communication means 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 which performs combustion using the pulverized fuel supplied from the solid fuel pulverizing apparatus 100 to generate steam will be described.

  The boiler 200 includes a furnace 210 and a burner unit 220.

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

  The combustion gas discharged from the boiler 200 is subjected to predetermined processing by an environmental device (not shown by a NOx removal device, an electrostatic precipitator etc.) and heat exchange with the outside air by a heat exchanger (not shown) such as an air preheater. It is conducted and guided to a chimney (not shown) via an induction ventilator (not shown) and released to the atmosphere. Outside air heated by heat exchange with the combustion gas in the heat exchanger is sent to the above-described hot gas blower 30a.

  The feed water to each heat exchanger of the boiler 200 is heated in an economizer (not shown) and then further heated by an evaporator (not shown) and a superheater (not shown) to generate high-temperature and high-pressure steam. It is sent to a turbine (not shown) and a generator (not shown) is rotationally driven to generate power.

Next, the details of the mill 10 will be described.
As shown in FIG. 2, a supply duct 300 having a primary air flow passage 100 a formed therein is connected to the mill 10. The supply duct 300 includes an inclined duct 320 and a horizontal duct 340.

The inclined duct 320 is a duct whose downstream end is connected to the outer wall of the housing 11 of the mill 10 and inclined so as to descend obliquely downward toward the housing 11 side.
In addition, "downstream" said here means the downstream (front end side of the arrow) in the flow direction (direction which goes to the left from the right in the figure) of the primary air which distribute | circulates the primary air flow path 100a. Similarly, “upstream” described later means upstream (proximal end of arrow) in the flow direction of primary air flowing in the primary air flow path 100 a (direction from right to left in the same drawing).

A vane 460 is provided near the downstream end of the inclined duct 320 and the connection portion of the housing 11. The vanes 460 deflect and rectify primary air supplied from the inclined duct 320 toward the inside of the housing 11.
In addition, since the vane 460 is provided, the worker can not enter the inside of the inclined duct 320 from the inside of the housing 11. For this reason, in order for the worker to access the inside of the supply duct 300, it is preferable to provide an opening 420 described later.

  The horizontal duct 340 has a downstream end connected to the upstream end of the inclined duct 320 and is a horizontally extending duct. Specifically, as shown in FIG. 3, the horizontal duct 340 extends along the axis A with a predetermined width dimension. In addition, although the cross section of the horizontal duct 340 is made into the rectangle, it is not limited to this, A circle, an ellipse, a polygon etc. may be sufficient.

As shown in FIG. 2, a plurality of measuring devices 580 are installed downstream of the horizontal duct 340. The measuring device 580 may be installed in the inclined duct 320.
The “measuring device” referred to here is a device for measuring the state of primary air flowing in the inside of the supply duct 300, and is, for example, an oximeter, a thermometer, a flow meter or the like.

  For example, the downstream end of another inclined duct 520 may be connected to the upstream end of the horizontal duct 340. At this time, like the inclined duct 320, the inclined duct 520 is inclined so as to descend obliquely downward toward the housing 11 side. Further, another horizontal duct 540 is connected to the upstream end of the inclined duct 520. Further, there may be a case where the inclined duct 520 is not provided, or a case where a routing area of the supply duct 300 in connecting the supply duct 300 with the upstream duct is provided.

  Below the horizontal duct 540, a space S2 is provided, and for example, a passage that a worker uses for maintenance is installed. Therefore, the horizontal duct 540 is set higher in position than the horizontal duct 340.

  Further, the heat duct 32 and the cold gas duct 34 described above are connected to the upper part of the horizontal duct 540.

  That is, the high temperature primary air blown from the heat gas duct 32 after being heated by the heat exchanger (not shown) and the normal temperature primary air blown from the cold gas duct 34 are horizontal duct 540, inclined duct 520, horizontal duct 340, inclined The air flows through the duct 320 and is supplied to the inside of the housing 11. At this time, the high temperature primary air and the normal temperature primary air are mixed while flowing through the ducts. At this time, the temperature is adjusted so that the temperature of the primary air after mixing becomes a predetermined temperature (for example, 150 ° C. or more and 300 ° C. or less).

  As shown in FIG. 2, FIG. 3 and FIG. 4, the horizontal duct 340 includes an opening 420 and a lid 440.

  As shown in FIGS. 3 and 4, the opening 420 is an opening provided in the upper portion (ceiling) of the horizontal duct 340, and communicates the inside (primary air flow path 100 a) of the horizontal duct 340 with the outside. I am doing it.

  When viewed from above as shown in FIG. 3, the opening 420 is provided such that the center C thereof is offset from the axis A by a predetermined distance d1 in the width direction of the horizontal duct 340 (vertical direction in the same drawing). It is done.

  Further, on the upper surface of the horizontal duct 340 secured by the offset of the opening 420 and on the space S1 closer to the side, signal wiring, power supply wiring, piping and the like of the measuring device 580 are installed.

  As shown in FIGS. 3 and 4, a lid 440 capable of closing the opening 420 is installed in the opening 420 described above. At this time, a gap is provided between the inner circumferential surface of the opening 420 and the side circumferential surface of the lid 440 so that the opening operation and closing operation of the opening 420 can be easily performed. The gap is, for example, about 5 mm or more and 10 mm or less.

  For example, a handle 444 is attached to the upper surface of the lid 440, and the operator can easily open and close the lid 440.

  In order to improve the heat insulation between the primary air flowing inside the supply duct 300 and the air outside the supply duct 300, the inside of the cover 440 may be filled with a heat insulating material.

  As shown in FIG. 4, the cover 440 has a lower surface 442 flush with the inner upper surface (ceiling surface 342) of the horizontal duct 340, or the lower surface 442 is an inner upper surface (ceiling surface 342) of the horizontal duct 340. It is preferable to be provided so as to be recessed in the direction of retracting upward from. In the case of the same figure, it is evacuated and provided only distance d2. At this time, the distance d2 is 0 mm in the case of the same surface, and is, for example, 20 mm or more and 30 mm or less when recessed in the upward direction.

As shown in FIG. 3, the width dimension of the primary air flow passage 100 a formed by the horizontal duct 340 is D. The width dimension D is, for example, 0.5 m or more and 1.5 m or less.
At this time, as shown in FIG. 2, the lid 440 (and the opening 420 where the lid 440 is installed) is 3D or more 10D along the horizontal direction from the outer wall of the housing 11 (the downstream end of the inclined duct 320). It is preferable to be provided at the following positions.
In addition, the lid 440 (and the opening 420 in which the lid 440 is installed) may be provided at a position of 5D to 7D in the horizontal direction from the outer wall of the housing 11 (the downstream end of the inclined duct 320). And more preferred.

  Preferably, the downstream end of the horizontal duct 340 is provided in a position from 3D to 7D along the horizontal direction from the outer wall of the housing 11.

The above-mentioned lid 440 is used as follows.
That is, when solid fuel pulverized is accumulated on the inner lower surface (floor surface 344) of the horizontal duct 340 when restarting the mill 10, the worker confirms the safety of the atmosphere inside the horizontal duct 340. After that, the lid 440 is opened from the outside of the horizontal duct 340.

Then, the worker enters the primary air flow passage 100a from the opening 420 and removes the solid fuel deposited on the floor surface 344.
In addition, the cleaning operation is performed while moving the solid fuel deposited on the floor surface 344 of the horizontal duct 340 from the opening 420 to the downstream from the opening 420, and the housing 11 is used for the final remaining crushed solid fuel. The cleaning operation may be performed by moving it inward.

  Thereafter, the worker withdraws from the opening 420 to the outside of the horizontal duct 340 and closes the opening 420 by the lid 440.

According to the present embodiment, the following effects can be obtained.
When cleaning the inside of the supply duct 300, the operator can easily enter the inside of the supply duct 300 from the opening 420 opened by opening the lid 440.

  At this time, the opening 420 is provided in the horizontal duct 340. For this reason, for example, a worker can easily enter the inside of the horizontal duct 340 located on the upstream side of the supply duct 300 where the lightweight pulverized solid fuel may be deposited. Therefore, even when biomass fuel is used as the solid fuel, and even when the possibility of further reduction of the lightweight biomass fuel accumulated inside the horizontal duct due to the small specific gravity, the worker Can easily clean the inside of the horizontal duct 340. Further, even when coal is used as the solid fuel and coal (pulverized coal) that has been crushed is accumulated inside the horizontal duct 340, the worker can easily clean the inside of the horizontal duct 340. it can.

  Also, the opening 420 is provided on the ceiling of the horizontal duct 340. For this reason, even if there is a steel aggregate (iron aggregate accompanying the support of the mill 10 or the solid fuel pulverizing apparatus 100) in the vicinity of the side surface of the supply duct 300, the operator can easily enter without interfering with them. An opening 420 can be provided. Furthermore, the opening 420 is provided at a position where the central portion C is offset in the width direction from the axis A of the horizontal duct 340. Therefore, even if the signal wiring, power supply wiring, piping, and the like of the measuring device 580 are installed on the outer upper surface and side surface of the horizontal duct 340, the opening 420 is provided without interfering with them. Can.

In addition, the lid portion 440 is provided so that the lower surface 442 is recessed in the same plane with respect to the ceiling surface 342 of the horizontal duct 340 or in the direction of retracting from the ceiling surface 342 of the horizontal duct 340. As a result, pressure loss can be suppressed because the lower surface 442 of the lid 440 does not obstruct or disturb the flow of primary air flowing inside the horizontal duct 340.
If the lower surface 442 of the lid 440 projects from the ceiling surface 342 of the horizontal duct 340 toward the primary air flow passage 100a, the flow of the primary air is blocked by the projecting portion, causing a pressure loss, and as a result, the primary The flow rate of air may decrease.

Further, the opening 420 provided in the horizontal duct 340 is provided at a position where the distance along the horizontal direction from the downstream end of the inclined duct 320 is 3D or more and 10D or less, more preferably 5D or more and 7D or less . By setting the distance along the horizontal direction from the downstream end of the inclined duct 320 to the upstream end of the horizontal duct 340 to be at least 5 D or more, a sufficient distance between hot primary air and normal temperature primary air is ensured. it can. Further, by setting the distance along the horizontal direction from the downstream end of the inclined duct 320 to the upstream end of the horizontal duct 340 to 10 D or less, an increase in the installation space of the supply duct 300 can be suppressed. Further, by setting the horizontal length of the inclined duct 320 to 3D or less, the installation space of the inclined duct 320 can be increased while suppressing backflow of the solid fuel crushed toward the upstream side of the supply duct 300. The sloped duct 320 can be set to an appropriate slope for control. On the other hand, on the upstream side of the horizontal duct 340, there is a routing area of the supply duct 300 after connection of the cold gas duct 34 for supplying the primary air at normal temperature to the supply duct 300 and the hot gas duct 32 for supplying the primary air at high temperature. There is a case. Therefore, the upstream end of the horizontal duct 340 may be positioned at 7D or less along the horizontal direction from the downstream end of the inclined duct 320.
Therefore, by providing the opening 420 provided in the horizontal duct 340 at a position where the distance along the horizontal direction from the downstream end of the inclined duct 320 is 5D or more and 7D or less, the opening 420 can be more reliably and appropriately. It can be provided in the horizontal duct 340.

[Modification]
As shown in FIG. 5, a transfer device 600 may be installed to transfer the solid fuel deposited on the floor surface 344 to the inclined duct 320 side.

  The conveying device 600 includes, for example, a motor 614, a conveyor 610 driven by the motor 614, and a plurality of scrapers 612 attached at equal intervals in the circumferential direction of the conveyor.

  The scraper 612 located on the lower surface of the conveyor 610 moves along with the rotation of the conveyor 610, thereby scraping the crushed solid fuel deposited on the floor surface 344 toward the inclined duct 320. Thus, the pulverized solid fuel can be moved to the inside of the housing 11 by moving the pulverized solid fuel deposited on the floor surface 344 to the inclined duct 320 side. The scraper 612 may be replaced with a brush.

  The transfer device 600 is installed inside a horizontal duct 340 which is accessible from the outside of the horizontal duct 340 via the opening 420. Thus, the transport device 600 can be easily accessed from the opening 420. Therefore, cleaning and maintenance of the transfer device 600 can be facilitated.

1 Boiler system 10 mill (crusher)
Reference Signs List 11 housing 12 rotary table 13 roller 14 drive unit 16 classification unit 17 fuel supply unit 18 motor 19 outlet 20 feeder (fuel supply machine)
21 bunker 22 transport unit (feeder)
23 Motor (feeder)
24 down spout unit 30 air blower 30 a heat gas blower 30 b cold gas blower 30 c heat gas damper (first air blower)
30d cold gas damper (second air blower)
32 hot gas duct 34 cold gas duct 40 state detection unit (temperature detection means, differential pressure detection means)
41 bottom surface 42 ceiling 45 journal head 47 support arm 48 support shaft 49 pressing device 50 control unit (determination unit)
100 Solid Fuel Pulverization Device 100a Primary Air Channel (Gas Channel for Transfer)
100b supply flow path 200 boiler 210 furnace 220 burner unit (combustion device)
300 supply duct 320 inclined duct 340 horizontal duct 342 ceiling surface 344 floor surface 420 opening 440 lid 442 lower surface 444 handle 460 vane 580 measuring device 600 transport device 610 conveyor 612 scraper 614 motor A axis

Claims (9)

A rotary table for grinding solid fuel and a housing for containing the rollers;
A supply duct formed with a flow path for guiding a carrier gas for carrying the pulverized solid fuel to the outside of the housing from the outside of the housing to the inside;
Equipped with
The supply duct is
An inclined duct having a downstream end connected to the outer wall of the housing and extending obliquely downward toward the housing;
A horizontal duct connected to the upstream end of the inclined duct and having a predetermined width in the width direction and having the longitudinal direction extending horizontally along the axis;
An opening which is provided on a ceiling of the horizontal duct and which has a central portion offset from the axis of the horizontal duct in the width direction, and which communicates the inside and the outside of the horizontal duct;
A lid capable of closing the opening;
The crusher has.   The crusher according to claim 1, wherein the lid portion is provided such that the lower surface is recessed in the same plane with respect to the inner upper surface of the horizontal duct or in a direction in which the lower surface retracts from the inner upper surface of the horizontal duct.   When the width dimension of the flow passage in the width direction is D, the opening portion is provided at a position where the distance along the horizontal direction from the downstream end of the inclined duct is 3D or more and 10D or less. Or the grinder according to 2.   When the width dimension of the flow passage in the width direction is D, the opening portion is provided at a position at which the distance along the horizontal direction from the downstream end of the inclined duct is 5D or more and 7D or less. Or the grinder according to 2.   The inclined duct is accessible from the outside of the horizontal duct through the opening, and is disposed inside the horizontal duct, and the crushed solid fuel accumulated on a floor surface inside the horizontal duct is the inclined duct The crusher according to any one of claims 1 to 4, further comprising a transport device for moving to the side.   The crusher according to any one of claims 1 to 5, wherein the solid fuel is a biomass fuel.   The crusher according to any one of claims 1 to 5, wherein the solid fuel is coal.   A solid fuel pulverizing apparatus comprising the pulverizer according to any one of claims 1 to 7.   The boiler system provided with the solid fuel crushing apparatus in any one of Claims 1-8.

Images