CA1230783A - Pulverized fuel burner nozzle tip and splitter plate therefor - Google Patents
Pulverized fuel burner nozzle tip and splitter plate thereforInfo
- Publication number
- CA1230783A CA1230783A CA000449335A CA449335A CA1230783A CA 1230783 A CA1230783 A CA 1230783A CA 000449335 A CA000449335 A CA 000449335A CA 449335 A CA449335 A CA 449335A CA 1230783 A CA1230783 A CA 1230783A
- Authority
- CA
- Canada
- Prior art keywords
- inner shell
- nozzle tip
- furnace
- coal
- trailing edge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN A CARRIER GAS OR AIR
- F23C5/00—Disposition of burners with respect to the combustion chamber or to one another; Mounting of burners in combustion apparatus
- F23C5/02—Structural details of mounting
- F23C5/06—Provision for adjustment of burner position during operation
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D1/00—Burners for combustion of pulverulent fuel
- F23D1/02—Vortex burners, e.g. for cyclone-type combustion apparatus
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN A CARRIER GAS OR AIR
- F23C7/00—Combustion apparatus characterised by arrangements for air supply
- F23C7/02—Disposition of air supply not passing through burner
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D1/00—Burners for combustion of pulverulent fuel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D2201/00—Burners adapted for particulate solid or pulverulent fuels
- F23D2201/10—Nozzle tips
- F23D2201/101—Nozzle tips tiltable
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Combustion Of Fluid Fuel (AREA)
- Pre-Mixing And Non-Premixing Gas Burner (AREA)
Abstract
PULVERIZED FUEL BURNER NOZZLE TIP
AND SPLITTER PLATE THEREFOR
Abstract of the Invention An improved nozzle tip (30) which provides enhanced ignition and stabilization of pulverized fuel flames in furnaces operating at low load. The nozzle tip (30) comprises open-ended inner and outer shells (32,34) mounted to the fuel delivery pipe (12) and defining a flow passageway within the inner shell through which the pulverized fuel is directed into the furnace and an annular flow passageway (50) between the inner and outer shells through which additional air is directed into the furnace. A pair of diverging splitter plates (41,42) are disposed within the inner shell (32) so as to divide the flow passageway therethrough into two separate, diverging subpassages (52,54) so that the pulverized fuel stream discharging from the fuel delivery pipe is split into first and second streams (60,70) which pass from the nozzle tip (30) into the furnace in a diverging manner thereby establishing an ignition stabilizing pocket in the low pressure zone (80) created between the diverging fuel streams.
AND SPLITTER PLATE THEREFOR
Abstract of the Invention An improved nozzle tip (30) which provides enhanced ignition and stabilization of pulverized fuel flames in furnaces operating at low load. The nozzle tip (30) comprises open-ended inner and outer shells (32,34) mounted to the fuel delivery pipe (12) and defining a flow passageway within the inner shell through which the pulverized fuel is directed into the furnace and an annular flow passageway (50) between the inner and outer shells through which additional air is directed into the furnace. A pair of diverging splitter plates (41,42) are disposed within the inner shell (32) so as to divide the flow passageway therethrough into two separate, diverging subpassages (52,54) so that the pulverized fuel stream discharging from the fuel delivery pipe is split into first and second streams (60,70) which pass from the nozzle tip (30) into the furnace in a diverging manner thereby establishing an ignition stabilizing pocket in the low pressure zone (80) created between the diverging fuel streams.
Description
~23~
PULVERIZED FUEL BURNER NOZZLE TIP
AND SPLITTER PLATE THEREFOR
Background of the Invention The present invention relates to improving the low load operation of fuel burners for use in pulverized coal-fired furnaces and, more particularly, to improv~ng low load operat~on of fuel-air admission assemblies for directing a pulverized fuel-air mixture into the furnace by what is known as the tangential method of firing.
In view of today's fluctuating electricity demand, typified by peak demand occurring dur1ng weekday daytime hours and minimum demand occurring at night and on the weekends, electric utilities have chosen to cycle many of their conventional coal-fired steam generator boilers by operating them at full load dur~ng peak demand hours and reducing them to low loads during per~ods of minimum demand.
As a consequence of th;s mode of operation, the electric ut~lities have used large quantitites of natural gas or oil to furnish add~tional ign~tion energy dur~ng low load operation because the current generat~on from coal f~red steam generator furnaces requ1re stabllizatlon of the coal flames when operating at low loads. The required amount of auxiliary fuel fired for stabilization purposes is s~gn~f~cant and, for example, to maintain a 500 megawatt coal-f~red steam generator at 10 to 15 percent load during min~mum demand per~ods could require the use of 11,000 gallons of oil per day.
PULVERIZED FUEL BURNER NOZZLE TIP
AND SPLITTER PLATE THEREFOR
Background of the Invention The present invention relates to improving the low load operation of fuel burners for use in pulverized coal-fired furnaces and, more particularly, to improv~ng low load operat~on of fuel-air admission assemblies for directing a pulverized fuel-air mixture into the furnace by what is known as the tangential method of firing.
In view of today's fluctuating electricity demand, typified by peak demand occurring dur1ng weekday daytime hours and minimum demand occurring at night and on the weekends, electric utilities have chosen to cycle many of their conventional coal-fired steam generator boilers by operating them at full load dur~ng peak demand hours and reducing them to low loads during per~ods of minimum demand.
As a consequence of th;s mode of operation, the electric ut~lities have used large quantitites of natural gas or oil to furnish add~tional ign~tion energy dur~ng low load operation because the current generat~on from coal f~red steam generator furnaces requ1re stabllizatlon of the coal flames when operating at low loads. The required amount of auxiliary fuel fired for stabilization purposes is s~gn~f~cant and, for example, to maintain a 500 megawatt coal-f~red steam generator at 10 to 15 percent load during min~mum demand per~ods could require the use of 11,000 gallons of oil per day.
-2~ 3~3~3~3 One common method of firing a pulverized fuel such as coal in a conven~ional steam generator furnace is known as tangential firing. In this method, pulverized coal ~s introduced to the furnace in a primary air stream through burners, termed fuel-a;r admission assemblies, located in the corners of the furnace. The fuel-air streams discharged from these assemblies are aimed tan~entially to an ima~inary circle in the middle of the furnace. This creates a fireball which serves as a continuous source of ignition for the incoming coal. Each fuel-air admission assembly is comprised of a fuel delivery pipe through which pulverized fuel entrained in air passes to the furnace, a secondary air conduit surrounding the fuel delivery pipe through which additional air is introduced into the furnace, and a nozzle tip which is pivotally mounted to the outlet end of the fuel delivery pipe.
A typical nozzle tip comprises inner and outer shells disposed coaxially in spaced relationship thereby defining a first flow passageway within the inner shell through which the pulverized fuel and air mixture discharging from the fuel del~very pipe passes into the furnace and a second flow passageway in the annular space between the inner and outer shells through which the secondary air discharging from the secondary air conduit passes into the furnace. Typically, one or more splitter plates are disposed wlthin the inner shell parallel to the axis of the nozzle tip to divide the flow passageway within the inner shell into multiple subpassages.
The nozzle tip may be tilted upward or downward ln order to direct the fuel-alr m~xture, discharging into the furnace from the fuel del~very p~pe upwardly or downwardly as a means controll1ng the tempera~ure of the superheated steam produced ~n heat exchange surface typ~cally d~sposed at the outlet of the surface ~n the manner taught by U.S. Patent 2,363,875.
Dur~ng normal operation of a tangentially fired furnace, a flame is establ~shed at one corner which in turn suppl~es the requ~red lgnition energy to stabilize the flame emanating from the corner downstream of and laterally ad~acent
A typical nozzle tip comprises inner and outer shells disposed coaxially in spaced relationship thereby defining a first flow passageway within the inner shell through which the pulverized fuel and air mixture discharging from the fuel del~very pipe passes into the furnace and a second flow passageway in the annular space between the inner and outer shells through which the secondary air discharging from the secondary air conduit passes into the furnace. Typically, one or more splitter plates are disposed wlthin the inner shell parallel to the axis of the nozzle tip to divide the flow passageway within the inner shell into multiple subpassages.
The nozzle tip may be tilted upward or downward ln order to direct the fuel-alr m~xture, discharging into the furnace from the fuel del~very p~pe upwardly or downwardly as a means controll1ng the tempera~ure of the superheated steam produced ~n heat exchange surface typ~cally d~sposed at the outlet of the surface ~n the manner taught by U.S. Patent 2,363,875.
Dur~ng normal operation of a tangentially fired furnace, a flame is establ~shed at one corner which in turn suppl~es the requ~red lgnition energy to stabilize the flame emanating from the corner downstream of and laterally ad~acent
3 ~Z30~8~.~
to it. When load is reduced, the flames emanating from each corner become shorter and, as a consequence, a reduction in the amount of ignition energy available to the downstream corner occurs. As a result, auxiliary fuel such as oil or natural gas must be introduced in each corner adjacent to the pulverized coal-air stream to provide additional ignition energy thereby insuring that a flameout and resultant unit trip will not occur.
Another problem associated with operating a coal-fired burner at low loads results in the fact that the pulverizing mills typically operate with a relatively constant air flow over all load ranges. When furnace load is reduced, the amount of coal pulverized in the mills decreases proportionally while the amount sf primary air used to convey the pulverized coal from the mills through the admission assemblies into the furnace remains fairly constant, thereby causing the fuel-air ratio to decrease. When the load on the furnace is reduced to the low levels desired during minimum demand periods, the fuel-air ratio has decreased to the point where the pulverized coal-primary alr mixture has become too fuel lean for ignition to stabillze w~thout significant supplemental ignition energy being made available.
One way in which the need for auxiliary fuel firing during low load operation on coal-fired boilers can be reduced is presented in U.S. Patent 4,252,069. Thls patent discloses an improved fuel-alr admission assembly incorporating a split coal bucket which permits a pulverized coal-~ired furnace to be operated at low loads without use of auxiliary fuel to provide stabllizatlon. As dlsclosed thereln, the spllt coal bucket comprlses lndependent upper and lower coal nozzles plvotally mounted to the coal dellvery plpe, the upper and lower coal nozzles be~ng independently tiltable. When the furnace is operating at low loads such as durlng the minlmum demand per~ods, the primary alr and pulverlzed coal stream dlschar~ing from the coal dellvery pipe ~s split into an upper and a lower coal-air stream and independently directed into the furnace by tllt~ng the upper coal nozzle upward and the lower coal nozzle downward. In doing so, an ignition stabilizing pocket is ~%3~ 83 established in the locally low pressure zone created in the void between the spread apart coal-air streams. Hot combustion products are drawn, i.e., recirculated into this low pressure zone, thus providing enough additional ignition energy to the incoming fuel to stabilize the ,lame.
An additional nozzle tip designed to improve ignition stability, albeit directed to the ignition of low volatile coal rather than ignition at low load operation, is presented in U.S. Patent 2,608,168. Disclosed therein is a coal bucket p~votally mounted to the coal delivery pipe with the flow passageway defined within the inner shell bifurcated into two parallel but spaced apart flow subpassages. Secondary air is discharged into the furnace from the secondary air conduit surrounding the coal delivery pipe through the flow passageway between the inner and outer shells and through the central channel formed between the parallel but spaced apart subpassages formed within the inner shell. Ignition is said to be improved by increasing the contact area between the coal-air mixture discharged from the spaced flow passages of the inner shell and the bounding secondary air streams.
Despite the aforementioned nozzle tip designs, there stfll ex~sts a need for a nozzle tip of a relatively simple design which inherently provides improved ignition stability at low load operation. There also ex~sts a need for such a nozzle tip which is readlly manufactured by fabrication and/or casting.
Summary of the Invention The present ~nvention provides a novel tip for a burner on a pulverized fuel fire~ furnace whlch ~s partlcularly adapted to provlde Improved Ignttlon stab111ty durlng low load operat.lon of the furnace. The nozzle tip of the present Invention comprises an open-ended inner shell definlng a flow passageway through which a mixture of pulverized fuel and transport air passes from the burner into the furnace, an open-ended outer shell spaced from and surround~ng the inner shell thereby definin~ an annular flow passage therebetween through which additional air for combustion passes from the burner into the furnace, and plate means disposed within the inner shell _5 123~7~33 for dividing the flow passageway therethrough into first and second flow passages which extend from the inlet of the inner shell to the outlet of the inner shell in a diverging manner with a void region established therebetween through wh~ch flow is precluded. The coal-air mixture discharging from the burner is split by the plate means into a first stream which is directed into the furnace through the first flow passageway through the inner shell and a second stream which is directed into the furnace through the second flow passageway of the inner shell. Thus, the coal-air mixture is directed into the furnace in two diverging streams. In doing so, an ignition stabilizing pocket is established in the locally low pressure zone created between the spread-apart and diverging coal-air streams in the furnace just downstream of the void region established between the diverging first and second flow passageways through the inner shell of the noz le tip. Coal is concentrated in this pocket and hot combustion products are drawn back into the pocket from the flame to provide additional ignition energy to the incoming fuel to stabllize the flame.
Preferably, the plate means comprises first and second splitter plates disposed within the inner shell with their leading edge portion disposed transversely across the flow passageway of the inner shell at the inlet thereof and their trailing edge portion extending transversely across the flow passageway of the inner shell at the outlet end thereof. The first and second splitter plates converge along a line at the inlet end of the inner shell and extend outwardly therefrom in a diverging manner toward the outlet end of the lnner shell.
In this manner, the first and second spl~tter plates divlde the 3n flow passageway through the ~nner shell into a first flow passage bounded by the first splitter plate and the inner shell and a second flow passage bounded by the second splitter plate and the inner shell. The first and second flow passages diverge ~n the direction of flow through the nozzle tip and are separated by a void region established between the first and second divergent splitter plates through which flow is precluded. Accordingly, a low pressure recirculation zone will -6~ 3~'783 be established in the furnace just downstream of the void region of the nozzle tip between the diverging fuel-air streams as they discharge into the furnace from the divergent first and second flow passages through the inner shell.
Further in accordance with the present invention, ignition stabi1ity may be further enhanced by providing splitter plates having their trailing edge portion scalloped.
The trailing edge portion of a splitter plate is preferably scalloped by forming the trailing edge portion of the I0 splitter plate of a plurality of longitudinally elongated strips which extend longitudinally outward from the leading edge portion of the splitter plate in side-by-side relationship transversely across the flow passageway through the inner shell. A first portion of the trailing edge strips, ~isposed lS alternately between a second portion of the trailing edge strips, is bent radially away from the leading edge of the splitter plate in one direction while the second portion of the tra~llng edge strips is bent radlally away from the leading edge portion of the splitter plate in a direction opposite to that in wh~ch the first portion of the trailing edge strips are bent away from the leading edge portion of the splitter plate.
In this manner, a scalloped edge is provided along the trailing edge portion of the splitter plates which serves to generate turbulence along the boundries between the fuel-air streams discharging from the divergent flow passages and the void region establlshed therebetween whereby the mixing of pulverized fuel and hot combust~on products drawn into the low pressure recirculatlon zone formed in the furnace ,iust downstream of the void region of the nozzle ~ip thereby further stabiliz~ng ignition.
Brief Descript~on of the Drawings Figure 1 is a diagrammatic plan view of a furnace employing the tangential firing method;
Figure 2 is a elevational cross-sectional view, taken along line 2-2 of Figure 1, showing a set of three coal-air admission assemblies, the upper coal-air admission assemblies having a nozzle tip designed in accordance with the present 7 123~7~3 invention and the lower two coal-air admission assemblies equipped with a nozzle tip typical of the prior art;
Figure 3 is a elevational cross-sectional view of a single coal-air admission asse~bly equipped with a nozzle tip designed in accordance with the present invention;
Figure 4 shows an elevational cross-sectional view of a nozzle tip of the present invention, Figure 5 shows an elevational end view taken along line 5-5 of Figure 4 of the nozzle tip of the present invention; and Figure 6 is an eleva~ional end view of an alternate embodiment of the nozzle tip of the present invention.
Description of the Preferred Embodiment While the present invention may be applied, in spirit and in scope, to a number of different burner designs employed in the various firing methods commonly used in conventional pulverized fuel-fired steam yenerator boiler furnaces, it may be best described when em~odied on a pulverized coal-air admission assembly of the type employed in pulver~zed coal fired furnaces utllizing the tangential firing method illustrated in Figure 1. In the tangential firing method, pulverized coal and air are introduced into the furnace through coal-air admission assemblies 10 mounted in the four corners of the furnace 1. The coal-air admission assemblies 10 are oriented so as to dellver the pulverized coal and alr streams tangentially to an imaginary circle 3 in the center of the furnace 1 so as to form therein a rotating vortex-like flame termed a fire ball.
As shown in Figure 2, a plurallty of coal-air admlsslon assemblles 10 are arran~ed ln the corners of the furnace ln a vertlcal column separated by auxlllary alr compartments 20 and 20'. One or more of thes auxiliary air compartments, such as compartment 20', ~s adapted to accommodate an oll or gas burner 22, which ls used when starting and warmlng up the bo~ler and which, ln the prior art, is used when necessary to prov~de addit~onal ignition ener~y to stabllize the coal flame when operating the furnace at low loads.
-8- iL~3~ 3 Each coal-air admission assembly 10 comprises a coal delivery pipe 12 extending therethrough and opening into the furnace, and a secondary air conduit 14 which surrounds coal delivery pipe 12 and opens into an air supply plenum 18, termed S a windbox. Pulverized co~l entrained in transport air is discharged into the furnace through the coal delivery pipes 12 from a supply source such as a pulverizer wherein the coal is dried and comminuted. Secondary air is passed into the furnace through the secondary air conduits 14 as a stream surrounding the pulverized coal and transport air stream discharged from each coal-delivery pipe 12. Additional combustion air is passed into the furnace from windbox 18 through the auxiliary air compartments 20.
Each coal delivery pipe 12 is provided with a nozzle tip, often referred to as a coal bucket, which is pivotally mounted to the coal delivery pipe 12 so that the nozzle tip may be tllted about an axis 16 transverse to the longitudinal axis of the coal dellvery pipe 12 in order to direct the pulverized coal and alr mixture into the furnace at either an upward angle or a downward angle as a means of controlling the position of the fire ball within the furnace whereby the temperature of the superheat steam leaving the steam generator, not shown, Is controlled in the manner taught by U.S. Patent 2,363,875 issued November 2~, 1944 to Krelsinger et al for "Combustlon Zone Control". Nozzle tips 28, shown in Figure 2, are typical of the standard prior art nozzle tip commonly mounted to the coal delivery pipe 12.
The typ~cal pr~or art nozzle t~p 28 ls comprlsed of a open-ended ~nner shell def~nlng therethrough a flow passageway 3n through wh~ch the mixture of pulverlzed coal and transport air passes from the coal delivery pipe 12 into the furnace surrounded by an open-ended outer shell spaced therefrom so as to deflne an annular flow passage therebetween through which secondary air passes from the secondary air conduit 14 into the furnace. The inner and outer shell are adapted to be mounted to the outlet end of the coal delivery pipe 12 by means of a pivot pin so as to be tiltable about axis 16. Typically, one -9- 12;~0~7l33 or more baffle plates 26 are disposed within the inner shell of the prior art nozzle tip 28 along an axis parallel to the nozzle tip and the coal delivery pipe 12 so as to form two or more parallel flow passages within the inner shell through which the pulverized coal and air passes from the coal delivery pipe 12 into the furnace as a single strea~ subdivided into one or more parallel and contiguous substreams. As indicated earlier, when a furnace equipped with the prior art nozzle tips 28 was operated at low load, ignition became unstable and supplemental fuel, such a natural gas or oil, had to be fired in order to provide sufficient additional ignition energy to stabilize the ignition of the single coal-air streams discharging from nozzle tips 28.
In accordance with the present invention, stable ignition at low loads is insured by providing a nozzle tip 30 which inherently provides improved ignition stability during low load operation. Nozzle tip 30 comprises an open-ended inner she11 32, an open-ended outer shell 34 spaced from and surrounding the inner shell 32, and plate means 40 disposed within the inner shell for dividing the interior of the inner shell into first and second flow passageway. The inner shell 32 has an outlet end 36 opening into the furnace and an inlet end 38 adapted to be mounted about the outlet end of the coal delivery pipe 12 so as to receive the pulverized coai and a1r d~scharging therefrom. An annular flow passageway 50 is defined between the 1nner shell 32 and the outer shell 34 through which additional combustion air passes from the secondary air condu~t 14 into the furnace. In accordance wlth the present invention, plate means 4n 1s d1sposed wlthin the inner shell 32 for dlvld~ng the flow passage therethrough Into f1rst and second flow passages 52 and 54, respectively, extend~ng from the inlet end 3~ of the inner shell 32 to the outlet end 36 thereof In a diverging manner with a void region 56 established therebe~ween through which flow is precluded.
The nozzle tip accomplishes the deslred objective of improving ignition stabllity at low load operation by providing two separate and distinct diverging flow passages 52 and 54 through 1~ 12~ 83 the inner shell 32 which are spaced to lie above and below a central void 56 through which flow is precluded. As is evident from the drawingg the stream of pulverized fuel and transport air discharging from the coal delivery pipe 12 into the nozzle tip 30 will be split into two portions. One portion would pass into the furnace through the first f~ow passa~e 52 of the nozzle tip 30 to be dlscharged upwardly into the furnace while the second portion of the pulverized coal and transport air stream would pass into the furnace through the second flow passage 54 of the nozzle tip 30 to discharge downwardly into the furnace as best seen in Figure 3. A low pressure zone 80, which serves as an lgnition stabilizing region, will he created in the furnace at the outle~ of the nozzle tip 30 downstream of the void region 56 between the diverging coal-air streams 60 and 70. Coal particles from the streams 60 and 70 will be drawn into the low pressure zone 80 from the diverging coal-air streams 60 and 70. Ignition will be stabilized because a portion of the hot combustion products formed during the ignltion process are recirculated within the low pressure lgnltion stabillzing zone 80, thereby providing sufficient ignition energy for igniting coal partlcles which are subsequently drawn into the zone 80 from the diverging coal-air streams 60 and 70.
In the preferred embodiment of the present invention, the plate means 40 comprises first and second splitter plates 41 and 42 disposed within the inner shell 32 so as to divide the ~nterlor of the inner shell 32 into a first flow passage 52 bounded by the f~rst spl1tter plate 41 and the lnner shell 32 and a second flow passage 54 bo~nded by the second splltter plate 42 and the lnner shell 32. Each of the splltter plates 41 and 42 has a lead~ng edge portlon 43 dlsposed transversely across the flow passage of the lnner shell 32 at the lnlet end 38 thereof and a trailing edge portlon 44 extending transversely across the flow passage o~ the inner shell 32 a~
the outlet end 36 thereof. The first and second split.ter plates 41 and 42 converge along the line at the lnlet end 38 of the inner shell 32 and extend outwardly therefrom in a 23~)783 diverging manner, preferably at an included angle of approximately 20, toward the outlet end 36 of the inner shell 32 and defined therebetween a void region 56 throu~h which flow is precluded.
Achievement of the obJective of improving ignition stability may be further enhanced by providing that the trailing edge portion 44 of the first and second splitter plates 41 and 42 is scalloped as best, seen in Figures 4, 5 and 6. To scallop the trailing edge portion 44 of each of the first and second splitter plates 41 and 42, the t~railing edge portion 44 thereof comprises a plurality of longitudinally elongated strips ext,ending longitudinally outward from the leading edge portion 43 of the splitter plates in side-by-side relationship transversely across the flow passageway of the inner shell 32. A first portion 45 of the trailing edge strips extend~ng longitudinally outward from the leadin~ edge portion of the first and second splitter plates is disposed alternately across the inner shell 32 between a second portion 47 of the trailing ed~e strips and are bent radially away from the second portion 47 of the trailing edge strips thereby form7ng the desired scalloped trailing edge on the splitter plates 41 and 42. Preferably, the first portion 45 of the trailing edge strips are bent radially away from the leading edge portion 43 of each splitter plate in one direct~on while the second portion 47 of the trailing edge strips is bent, radially away from the leading edge portion 43 of each of the splitter plates ~n the direction opposite ~,o that in which the f~rst portion 45 are bent.
By providing a scalloped tra~ling edge port~on on 0ach of the splitter plates 41 and ~2, a turbulent zone ls established along the ~nterface between each of the coal-air streams 60 and 70 in the low pressure rec~rculation zone 80 formed therebetween. Such a turbulent interface insures that coal and alr will be drawn out of the coal-air streams and mlxed thoroughly w~th hot ignition products in the low pressure recirculation zone 80 t~hereby further enhancing ignition stability.
-12- ~23~7~33 It is also preferable to provide filler plates 4~ which extend transversely between adjacent first and second portions
to it. When load is reduced, the flames emanating from each corner become shorter and, as a consequence, a reduction in the amount of ignition energy available to the downstream corner occurs. As a result, auxiliary fuel such as oil or natural gas must be introduced in each corner adjacent to the pulverized coal-air stream to provide additional ignition energy thereby insuring that a flameout and resultant unit trip will not occur.
Another problem associated with operating a coal-fired burner at low loads results in the fact that the pulverizing mills typically operate with a relatively constant air flow over all load ranges. When furnace load is reduced, the amount of coal pulverized in the mills decreases proportionally while the amount sf primary air used to convey the pulverized coal from the mills through the admission assemblies into the furnace remains fairly constant, thereby causing the fuel-air ratio to decrease. When the load on the furnace is reduced to the low levels desired during minimum demand periods, the fuel-air ratio has decreased to the point where the pulverized coal-primary alr mixture has become too fuel lean for ignition to stabillze w~thout significant supplemental ignition energy being made available.
One way in which the need for auxiliary fuel firing during low load operation on coal-fired boilers can be reduced is presented in U.S. Patent 4,252,069. Thls patent discloses an improved fuel-alr admission assembly incorporating a split coal bucket which permits a pulverized coal-~ired furnace to be operated at low loads without use of auxiliary fuel to provide stabllizatlon. As dlsclosed thereln, the spllt coal bucket comprlses lndependent upper and lower coal nozzles plvotally mounted to the coal dellvery plpe, the upper and lower coal nozzles be~ng independently tiltable. When the furnace is operating at low loads such as durlng the minlmum demand per~ods, the primary alr and pulverlzed coal stream dlschar~ing from the coal dellvery pipe ~s split into an upper and a lower coal-air stream and independently directed into the furnace by tllt~ng the upper coal nozzle upward and the lower coal nozzle downward. In doing so, an ignition stabilizing pocket is ~%3~ 83 established in the locally low pressure zone created in the void between the spread apart coal-air streams. Hot combustion products are drawn, i.e., recirculated into this low pressure zone, thus providing enough additional ignition energy to the incoming fuel to stabilize the ,lame.
An additional nozzle tip designed to improve ignition stability, albeit directed to the ignition of low volatile coal rather than ignition at low load operation, is presented in U.S. Patent 2,608,168. Disclosed therein is a coal bucket p~votally mounted to the coal delivery pipe with the flow passageway defined within the inner shell bifurcated into two parallel but spaced apart flow subpassages. Secondary air is discharged into the furnace from the secondary air conduit surrounding the coal delivery pipe through the flow passageway between the inner and outer shells and through the central channel formed between the parallel but spaced apart subpassages formed within the inner shell. Ignition is said to be improved by increasing the contact area between the coal-air mixture discharged from the spaced flow passages of the inner shell and the bounding secondary air streams.
Despite the aforementioned nozzle tip designs, there stfll ex~sts a need for a nozzle tip of a relatively simple design which inherently provides improved ignition stability at low load operation. There also ex~sts a need for such a nozzle tip which is readlly manufactured by fabrication and/or casting.
Summary of the Invention The present ~nvention provides a novel tip for a burner on a pulverized fuel fire~ furnace whlch ~s partlcularly adapted to provlde Improved Ignttlon stab111ty durlng low load operat.lon of the furnace. The nozzle tip of the present Invention comprises an open-ended inner shell definlng a flow passageway through which a mixture of pulverized fuel and transport air passes from the burner into the furnace, an open-ended outer shell spaced from and surround~ng the inner shell thereby definin~ an annular flow passage therebetween through which additional air for combustion passes from the burner into the furnace, and plate means disposed within the inner shell _5 123~7~33 for dividing the flow passageway therethrough into first and second flow passages which extend from the inlet of the inner shell to the outlet of the inner shell in a diverging manner with a void region established therebetween through wh~ch flow is precluded. The coal-air mixture discharging from the burner is split by the plate means into a first stream which is directed into the furnace through the first flow passageway through the inner shell and a second stream which is directed into the furnace through the second flow passageway of the inner shell. Thus, the coal-air mixture is directed into the furnace in two diverging streams. In doing so, an ignition stabilizing pocket is established in the locally low pressure zone created between the spread-apart and diverging coal-air streams in the furnace just downstream of the void region established between the diverging first and second flow passageways through the inner shell of the noz le tip. Coal is concentrated in this pocket and hot combustion products are drawn back into the pocket from the flame to provide additional ignition energy to the incoming fuel to stabllize the flame.
Preferably, the plate means comprises first and second splitter plates disposed within the inner shell with their leading edge portion disposed transversely across the flow passageway of the inner shell at the inlet thereof and their trailing edge portion extending transversely across the flow passageway of the inner shell at the outlet end thereof. The first and second splitter plates converge along a line at the inlet end of the inner shell and extend outwardly therefrom in a diverging manner toward the outlet end of the lnner shell.
In this manner, the first and second spl~tter plates divlde the 3n flow passageway through the ~nner shell into a first flow passage bounded by the first splitter plate and the inner shell and a second flow passage bounded by the second splitter plate and the inner shell. The first and second flow passages diverge ~n the direction of flow through the nozzle tip and are separated by a void region established between the first and second divergent splitter plates through which flow is precluded. Accordingly, a low pressure recirculation zone will -6~ 3~'783 be established in the furnace just downstream of the void region of the nozzle tip between the diverging fuel-air streams as they discharge into the furnace from the divergent first and second flow passages through the inner shell.
Further in accordance with the present invention, ignition stabi1ity may be further enhanced by providing splitter plates having their trailing edge portion scalloped.
The trailing edge portion of a splitter plate is preferably scalloped by forming the trailing edge portion of the I0 splitter plate of a plurality of longitudinally elongated strips which extend longitudinally outward from the leading edge portion of the splitter plate in side-by-side relationship transversely across the flow passageway through the inner shell. A first portion of the trailing edge strips, ~isposed lS alternately between a second portion of the trailing edge strips, is bent radially away from the leading edge of the splitter plate in one direction while the second portion of the tra~llng edge strips is bent radlally away from the leading edge portion of the splitter plate in a direction opposite to that in wh~ch the first portion of the trailing edge strips are bent away from the leading edge portion of the splitter plate.
In this manner, a scalloped edge is provided along the trailing edge portion of the splitter plates which serves to generate turbulence along the boundries between the fuel-air streams discharging from the divergent flow passages and the void region establlshed therebetween whereby the mixing of pulverized fuel and hot combust~on products drawn into the low pressure recirculatlon zone formed in the furnace ,iust downstream of the void region of the nozzle ~ip thereby further stabiliz~ng ignition.
Brief Descript~on of the Drawings Figure 1 is a diagrammatic plan view of a furnace employing the tangential firing method;
Figure 2 is a elevational cross-sectional view, taken along line 2-2 of Figure 1, showing a set of three coal-air admission assemblies, the upper coal-air admission assemblies having a nozzle tip designed in accordance with the present 7 123~7~3 invention and the lower two coal-air admission assemblies equipped with a nozzle tip typical of the prior art;
Figure 3 is a elevational cross-sectional view of a single coal-air admission asse~bly equipped with a nozzle tip designed in accordance with the present invention;
Figure 4 shows an elevational cross-sectional view of a nozzle tip of the present invention, Figure 5 shows an elevational end view taken along line 5-5 of Figure 4 of the nozzle tip of the present invention; and Figure 6 is an eleva~ional end view of an alternate embodiment of the nozzle tip of the present invention.
Description of the Preferred Embodiment While the present invention may be applied, in spirit and in scope, to a number of different burner designs employed in the various firing methods commonly used in conventional pulverized fuel-fired steam yenerator boiler furnaces, it may be best described when em~odied on a pulverized coal-air admission assembly of the type employed in pulver~zed coal fired furnaces utllizing the tangential firing method illustrated in Figure 1. In the tangential firing method, pulverized coal and air are introduced into the furnace through coal-air admission assemblies 10 mounted in the four corners of the furnace 1. The coal-air admission assemblies 10 are oriented so as to dellver the pulverized coal and alr streams tangentially to an imaginary circle 3 in the center of the furnace 1 so as to form therein a rotating vortex-like flame termed a fire ball.
As shown in Figure 2, a plurallty of coal-air admlsslon assemblles 10 are arran~ed ln the corners of the furnace ln a vertlcal column separated by auxlllary alr compartments 20 and 20'. One or more of thes auxiliary air compartments, such as compartment 20', ~s adapted to accommodate an oll or gas burner 22, which ls used when starting and warmlng up the bo~ler and which, ln the prior art, is used when necessary to prov~de addit~onal ignition ener~y to stabllize the coal flame when operating the furnace at low loads.
-8- iL~3~ 3 Each coal-air admission assembly 10 comprises a coal delivery pipe 12 extending therethrough and opening into the furnace, and a secondary air conduit 14 which surrounds coal delivery pipe 12 and opens into an air supply plenum 18, termed S a windbox. Pulverized co~l entrained in transport air is discharged into the furnace through the coal delivery pipes 12 from a supply source such as a pulverizer wherein the coal is dried and comminuted. Secondary air is passed into the furnace through the secondary air conduits 14 as a stream surrounding the pulverized coal and transport air stream discharged from each coal-delivery pipe 12. Additional combustion air is passed into the furnace from windbox 18 through the auxiliary air compartments 20.
Each coal delivery pipe 12 is provided with a nozzle tip, often referred to as a coal bucket, which is pivotally mounted to the coal delivery pipe 12 so that the nozzle tip may be tllted about an axis 16 transverse to the longitudinal axis of the coal dellvery pipe 12 in order to direct the pulverized coal and alr mixture into the furnace at either an upward angle or a downward angle as a means of controlling the position of the fire ball within the furnace whereby the temperature of the superheat steam leaving the steam generator, not shown, Is controlled in the manner taught by U.S. Patent 2,363,875 issued November 2~, 1944 to Krelsinger et al for "Combustlon Zone Control". Nozzle tips 28, shown in Figure 2, are typical of the standard prior art nozzle tip commonly mounted to the coal delivery pipe 12.
The typ~cal pr~or art nozzle t~p 28 ls comprlsed of a open-ended ~nner shell def~nlng therethrough a flow passageway 3n through wh~ch the mixture of pulverlzed coal and transport air passes from the coal delivery pipe 12 into the furnace surrounded by an open-ended outer shell spaced therefrom so as to deflne an annular flow passage therebetween through which secondary air passes from the secondary air conduit 14 into the furnace. The inner and outer shell are adapted to be mounted to the outlet end of the coal delivery pipe 12 by means of a pivot pin so as to be tiltable about axis 16. Typically, one -9- 12;~0~7l33 or more baffle plates 26 are disposed within the inner shell of the prior art nozzle tip 28 along an axis parallel to the nozzle tip and the coal delivery pipe 12 so as to form two or more parallel flow passages within the inner shell through which the pulverized coal and air passes from the coal delivery pipe 12 into the furnace as a single strea~ subdivided into one or more parallel and contiguous substreams. As indicated earlier, when a furnace equipped with the prior art nozzle tips 28 was operated at low load, ignition became unstable and supplemental fuel, such a natural gas or oil, had to be fired in order to provide sufficient additional ignition energy to stabilize the ignition of the single coal-air streams discharging from nozzle tips 28.
In accordance with the present invention, stable ignition at low loads is insured by providing a nozzle tip 30 which inherently provides improved ignition stability during low load operation. Nozzle tip 30 comprises an open-ended inner she11 32, an open-ended outer shell 34 spaced from and surrounding the inner shell 32, and plate means 40 disposed within the inner shell for dividing the interior of the inner shell into first and second flow passageway. The inner shell 32 has an outlet end 36 opening into the furnace and an inlet end 38 adapted to be mounted about the outlet end of the coal delivery pipe 12 so as to receive the pulverized coai and a1r d~scharging therefrom. An annular flow passageway 50 is defined between the 1nner shell 32 and the outer shell 34 through which additional combustion air passes from the secondary air condu~t 14 into the furnace. In accordance wlth the present invention, plate means 4n 1s d1sposed wlthin the inner shell 32 for dlvld~ng the flow passage therethrough Into f1rst and second flow passages 52 and 54, respectively, extend~ng from the inlet end 3~ of the inner shell 32 to the outlet end 36 thereof In a diverging manner with a void region 56 established therebe~ween through which flow is precluded.
The nozzle tip accomplishes the deslred objective of improving ignition stabllity at low load operation by providing two separate and distinct diverging flow passages 52 and 54 through 1~ 12~ 83 the inner shell 32 which are spaced to lie above and below a central void 56 through which flow is precluded. As is evident from the drawingg the stream of pulverized fuel and transport air discharging from the coal delivery pipe 12 into the nozzle tip 30 will be split into two portions. One portion would pass into the furnace through the first f~ow passa~e 52 of the nozzle tip 30 to be dlscharged upwardly into the furnace while the second portion of the pulverized coal and transport air stream would pass into the furnace through the second flow passage 54 of the nozzle tip 30 to discharge downwardly into the furnace as best seen in Figure 3. A low pressure zone 80, which serves as an lgnition stabilizing region, will he created in the furnace at the outle~ of the nozzle tip 30 downstream of the void region 56 between the diverging coal-air streams 60 and 70. Coal particles from the streams 60 and 70 will be drawn into the low pressure zone 80 from the diverging coal-air streams 60 and 70. Ignition will be stabilized because a portion of the hot combustion products formed during the ignltion process are recirculated within the low pressure lgnltion stabillzing zone 80, thereby providing sufficient ignition energy for igniting coal partlcles which are subsequently drawn into the zone 80 from the diverging coal-air streams 60 and 70.
In the preferred embodiment of the present invention, the plate means 40 comprises first and second splitter plates 41 and 42 disposed within the inner shell 32 so as to divide the ~nterlor of the inner shell 32 into a first flow passage 52 bounded by the f~rst spl1tter plate 41 and the lnner shell 32 and a second flow passage 54 bo~nded by the second splltter plate 42 and the lnner shell 32. Each of the splltter plates 41 and 42 has a lead~ng edge portlon 43 dlsposed transversely across the flow passage of the lnner shell 32 at the lnlet end 38 thereof and a trailing edge portlon 44 extending transversely across the flow passage o~ the inner shell 32 a~
the outlet end 36 thereof. The first and second split.ter plates 41 and 42 converge along the line at the lnlet end 38 of the inner shell 32 and extend outwardly therefrom in a 23~)783 diverging manner, preferably at an included angle of approximately 20, toward the outlet end 36 of the inner shell 32 and defined therebetween a void region 56 throu~h which flow is precluded.
Achievement of the obJective of improving ignition stability may be further enhanced by providing that the trailing edge portion 44 of the first and second splitter plates 41 and 42 is scalloped as best, seen in Figures 4, 5 and 6. To scallop the trailing edge portion 44 of each of the first and second splitter plates 41 and 42, the t~railing edge portion 44 thereof comprises a plurality of longitudinally elongated strips ext,ending longitudinally outward from the leading edge portion 43 of the splitter plates in side-by-side relationship transversely across the flow passageway of the inner shell 32. A first portion 45 of the trailing edge strips extend~ng longitudinally outward from the leadin~ edge portion of the first and second splitter plates is disposed alternately across the inner shell 32 between a second portion 47 of the trailing ed~e strips and are bent radially away from the second portion 47 of the trailing edge strips thereby form7ng the desired scalloped trailing edge on the splitter plates 41 and 42. Preferably, the first portion 45 of the trailing edge strips are bent radially away from the leading edge portion 43 of each splitter plate in one direct~on while the second portion 47 of the trailing edge strips is bent, radially away from the leading edge portion 43 of each of the splitter plates ~n the direction opposite ~,o that in which the f~rst portion 45 are bent.
By providing a scalloped tra~ling edge port~on on 0ach of the splitter plates 41 and ~2, a turbulent zone ls established along the ~nterface between each of the coal-air streams 60 and 70 in the low pressure rec~rculation zone 80 formed therebetween. Such a turbulent interface insures that coal and alr will be drawn out of the coal-air streams and mlxed thoroughly w~th hot ignition products in the low pressure recirculation zone 80 t~hereby further enhancing ignition stability.
-12- ~23~7~33 It is also preferable to provide filler plates 4~ which extend transversely between adjacent first and second portions
4~ and 47 of the trailing ed~e strips along the interface between the trailing edge strips, as best seen in Figures 5 and 6, to preclude the flow of pulverized fuel and transport air across the interface formed between adjacent diverging leading edge strips 45 ann 47. If a significant amount of pulverized fuel and transport air were allowed to pass into the void region 56 through the divergent trailing ed~e strips 45 and 47, the establishment of a low pressure recirculation zone between the diverging coal-air streams 60 and 70 could be adversely affected. Additionally, the splitter plates 41 and 42 may be arranged within the inner shell 32 of the nozzle tip 30 so that the scalloped trailing edge portions thereof are disposed in an in-line arrangement as shown in Fi~ure 5 or a sta~gered arrangement as shown in Figure 6.
Although the splitter plates 41 and 42 are shown in the drawing as being fabricated of various p~eces of plate metal welded together, it is to be understood that the splitter plates 41 and 42 may also be readily manufactured by well-known casting processes. Additionally, it is to be a'ppreciated that the lifetime of the splitter plates with~n the coal flow passage through the inner shell 32 may be enhanced in accordance with the teachings of U.S. Patent 4,356,975 issued November 2, 1982 to Chadshay for "Nozzle Tip for Pulverized Coal Burner" by manufacturing the splitter plates 41 and 42 with their leading edge portion 43 formed of a relatlvely abrasion reslstant material such as sllicon carblde or Ni-hard, and their tralllng edge portion ~ formed of a materlal relatively resistant to high temperatures such as certain well-known stainless steels.
While the preferred embodiment of the present invention has been ~llustrated and described when Incorporated into a coal-air admission assembly of the type typically employed on a tangent~ally-fired furnace, it is to be understood that the invention should not be limited thereto. The nozzle tip of the present invention could be readily modified by those skilled in -13- ~ ,~3~783 the art to be applied within the spirit and scope of the present invention to any number of burner configurations wherein pulverized coal or other abrasive pulverized solids are to be combusted.
Although the splitter plates 41 and 42 are shown in the drawing as being fabricated of various p~eces of plate metal welded together, it is to be understood that the splitter plates 41 and 42 may also be readily manufactured by well-known casting processes. Additionally, it is to be a'ppreciated that the lifetime of the splitter plates with~n the coal flow passage through the inner shell 32 may be enhanced in accordance with the teachings of U.S. Patent 4,356,975 issued November 2, 1982 to Chadshay for "Nozzle Tip for Pulverized Coal Burner" by manufacturing the splitter plates 41 and 42 with their leading edge portion 43 formed of a relatlvely abrasion reslstant material such as sllicon carblde or Ni-hard, and their tralllng edge portion ~ formed of a materlal relatively resistant to high temperatures such as certain well-known stainless steels.
While the preferred embodiment of the present invention has been ~llustrated and described when Incorporated into a coal-air admission assembly of the type typically employed on a tangent~ally-fired furnace, it is to be understood that the invention should not be limited thereto. The nozzle tip of the present invention could be readily modified by those skilled in -13- ~ ,~3~783 the art to be applied within the spirit and scope of the present invention to any number of burner configurations wherein pulverized coal or other abrasive pulverized solids are to be combusted.
Claims (4)
1. A nozzle tip for a burner on a pulverized fuel fired furnace comprising:
a. an open-ended inner shell having an inlet end and an outlet end and defining therebetween a flow passageway through which a mixture of pulverized fuel and transport air passes from the burner into the furnace;
b. an open-ended outer shell spaced from and surrounding said inner shell thereby defining an annular flow passageway therebetween through which additional air passes from the burner into the furnace; and c. first and second splitter plates disposed within said inner shell, each having a leading edge portion disposed transversely across the flow passageway of said inner shell at the inlet end thereof and a trailing edge portion extending transversely across the flow passageway of said inner shell at the outlet end thereof, said first and second splitter plates converging at the inlet end of said inner shell and extending outwardly therefrom in a diverging manner toward the outlet end of said inner shell, said first and second splitter plates thereby dividing the flow passageway through said inner shell into a first flow passage bounded by the first splitter plate and said inner shell and a second flow passage bounded by the second splitter plate and said inner shell, said first and second flow passages diverging in the direction of flow through the nozzle tip and being spaced apart at the outlet end of the nozzle tip so as to establish a void region therebetween through which flow directly from the nozzle tip is precluded, the trailing edge portion of each of said first and second splitter plates being formed of a plurality of longitudinally elongated strips extending longitudinally outward from the leading edge portion of each of said first and second splitter plates in a side-by-side relationship transversely across the flow passageway of said inner shell, a first portion of said trailing edge strips disposed alternately between a second portion of said trailing edge strips and bent radially away from the leading edge portion of each of said first and second splitter plates thereby forming a scalloped trailing edge portion of each of said first and second splitter plates.
a. an open-ended inner shell having an inlet end and an outlet end and defining therebetween a flow passageway through which a mixture of pulverized fuel and transport air passes from the burner into the furnace;
b. an open-ended outer shell spaced from and surrounding said inner shell thereby defining an annular flow passageway therebetween through which additional air passes from the burner into the furnace; and c. first and second splitter plates disposed within said inner shell, each having a leading edge portion disposed transversely across the flow passageway of said inner shell at the inlet end thereof and a trailing edge portion extending transversely across the flow passageway of said inner shell at the outlet end thereof, said first and second splitter plates converging at the inlet end of said inner shell and extending outwardly therefrom in a diverging manner toward the outlet end of said inner shell, said first and second splitter plates thereby dividing the flow passageway through said inner shell into a first flow passage bounded by the first splitter plate and said inner shell and a second flow passage bounded by the second splitter plate and said inner shell, said first and second flow passages diverging in the direction of flow through the nozzle tip and being spaced apart at the outlet end of the nozzle tip so as to establish a void region therebetween through which flow directly from the nozzle tip is precluded, the trailing edge portion of each of said first and second splitter plates being formed of a plurality of longitudinally elongated strips extending longitudinally outward from the leading edge portion of each of said first and second splitter plates in a side-by-side relationship transversely across the flow passageway of said inner shell, a first portion of said trailing edge strips disposed alternately between a second portion of said trailing edge strips and bent radially away from the leading edge portion of each of said first and second splitter plates thereby forming a scalloped trailing edge portion of each of said first and second splitter plates.
2. A nozzle tip as recited in Claim 1 wherein the second portion of said trailing edge strips is bent radially away from the leading edge portion of each of said first and second splitter plates in the direction opposite to that in which the first portion of said trailing edge strips are bent radially away from the leading edge portion of each of said first and second splitter plates.
3. A nozzle tip as recited in Claim 1 further comprising a plurality of filler plates disposed transversely between adjacent first and second portions of said trailing edge strips along the interface therebetween thereby precluding the flow of pulverized fuel and transport air across the interface formed between adjacent diverging first and second portions of said trailing edge strips.
4. A nozzle tip as recited in Claim 1 wherein the leading edge portions of said first and second splitter plates diverge at an included angle of approximately twenty degrees.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US48755283A | 1983-04-22 | 1983-04-22 | |
| US487,552 | 1983-04-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1230783A true CA1230783A (en) | 1987-12-29 |
Family
ID=23936209
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000449335A Expired CA1230783A (en) | 1983-04-22 | 1984-03-09 | Pulverized fuel burner nozzle tip and splitter plate therefor |
Country Status (10)
| Country | Link |
|---|---|
| EP (1) | EP0129001B1 (en) |
| JP (1) | JPS59205510A (en) |
| KR (1) | KR890000326B1 (en) |
| AU (1) | AU567340B2 (en) |
| CA (1) | CA1230783A (en) |
| DE (1) | DE3472154D1 (en) |
| ES (1) | ES8503424A1 (en) |
| IN (1) | IN161339B (en) |
| MX (1) | MX158316A (en) |
| ZA (1) | ZA841738B (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2791029B2 (en) * | 1988-02-23 | 1998-08-27 | バブコツク日立株式会社 | Pulverized coal burner |
| FR2689211B1 (en) * | 1992-03-30 | 1994-05-06 | Stein Industrie | ADJUSTABLE NOZZLE OF REFRACTORY MATERIAL FOR INJECTION OF AIR AND FUEL IN THE BURNERS OF BOILERS OF THERMAL POWER PLANTS. |
| US5315939A (en) * | 1993-05-13 | 1994-05-31 | Combustion Engineering, Inc. | Integrated low NOx tangential firing system |
| GB9322016D0 (en) * | 1993-10-26 | 1993-12-15 | Rolls Royce Power Eng | Improvements in or relating to solid fuel burners |
| CA2167341C (en) * | 1995-01-17 | 2000-03-21 | Joel Vatsky | Tiltable split stream burner assembly with gasket seal |
| KR100325948B1 (en) * | 1999-04-22 | 2002-02-27 | 김병두 | nozzle tip assembly of boiler for suppling of pulverized coal |
| JP5271680B2 (en) * | 2008-12-05 | 2013-08-21 | 三菱重工業株式会社 | Swirl combustion boiler |
| JP5344897B2 (en) * | 2008-12-12 | 2013-11-20 | 三菱重工業株式会社 | Swirl combustion boiler |
| JP5344898B2 (en) * | 2008-12-12 | 2013-11-20 | 三菱重工業株式会社 | Swirl combustion boiler |
| JP2010139182A (en) * | 2008-12-12 | 2010-06-24 | Mitsubishi Heavy Ind Ltd | Turning combustion boiler |
| JP2011127836A (en) * | 2009-12-17 | 2011-06-30 | Mitsubishi Heavy Ind Ltd | Solid fuel burning burner and solid fuel burning boiler |
| JP5374404B2 (en) | 2009-12-22 | 2013-12-25 | 三菱重工業株式会社 | Combustion burner and boiler equipped with this combustion burner |
| CN101718431B (en) * | 2009-12-28 | 2011-03-23 | 上海交通大学 | Spout structure of direct current burner of coal burning boiler of power station |
| RU2664749C1 (en) | 2015-03-31 | 2018-08-22 | Мицубиси Хитачи Пауэр Системз, Лтд. | Burner for burning and boiler |
| MX2017009771A (en) | 2015-03-31 | 2018-03-28 | Mitsubishi Hitachi Power Sys | Combustion burner and boiler provided therewith. |
| JP6642912B2 (en) | 2015-09-11 | 2020-02-12 | 三菱日立パワーシステムズ株式会社 | Combustion burner and boiler provided with the same |
| JP6632841B2 (en) * | 2015-09-11 | 2020-01-22 | 三菱日立パワーシステムズ株式会社 | Combustion burner and boiler provided with the same |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE504814C (en) * | 1927-04-12 | 1930-08-08 | Adolf Steinbrueckner | Coal dust burner with additional air supply and with an inner distributor for the fuel-air mixture |
| US2608168A (en) * | 1949-10-21 | 1952-08-26 | Comb Eng Superheater Inc | Dual nozzle burner for pulverized fuel |
| DE913092C (en) * | 1951-04-06 | 1954-06-08 | Kohlenscheidungs Ges Mit Besch | Burner for coal dust or the like finely divided fuel |
| DD127792A1 (en) * | 1976-08-20 | 1977-10-12 | Gerd Boche | CARBON BURNERS, ESPECIALLY FOR STEAM GENERATORS |
| US4252069A (en) * | 1979-04-13 | 1981-02-24 | Combustion Engineering, Inc. | Low load coal bucket |
| JPS5735366A (en) * | 1980-07-03 | 1982-02-25 | Nec Corp | Semiconductor integrated circuit device |
-
1984
- 1984-02-25 EP EP84102001A patent/EP0129001B1/en not_active Expired
- 1984-02-25 IN IN139/CAL/84A patent/IN161339B/en unknown
- 1984-02-25 DE DE8484102001T patent/DE3472154D1/en not_active Expired
- 1984-03-08 ZA ZA841738A patent/ZA841738B/en unknown
- 1984-03-09 CA CA000449335A patent/CA1230783A/en not_active Expired
- 1984-03-15 MX MX200675A patent/MX158316A/en unknown
- 1984-04-18 ES ES531781A patent/ES8503424A1/en not_active Expired
- 1984-04-18 JP JP59076733A patent/JPS59205510A/en active Granted
- 1984-04-19 AU AU27115/84A patent/AU567340B2/en not_active Ceased
- 1984-04-21 KR KR1019840002119A patent/KR890000326B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| EP0129001A1 (en) | 1984-12-27 |
| DE3472154D1 (en) | 1988-07-21 |
| AU2711584A (en) | 1984-10-25 |
| JPS59205510A (en) | 1984-11-21 |
| ES531781A0 (en) | 1985-02-16 |
| EP0129001B1 (en) | 1988-06-15 |
| MX158316A (en) | 1989-01-23 |
| KR840008492A (en) | 1984-12-15 |
| AU567340B2 (en) | 1987-11-19 |
| JPH0225086B2 (en) | 1990-05-31 |
| ZA841738B (en) | 1984-10-31 |
| IN161339B (en) | 1987-11-14 |
| KR890000326B1 (en) | 1989-03-14 |
| ES8503424A1 (en) | 1985-02-16 |
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