US2652792A - Pressurized combustion and ash removal system for coal-fired gas turbine power plants - Google Patents

Description

Sept. 22, 1953 J. YELLOTT 2,552,792

PRESSURIZED COMBUSTION AND ASH REMOVAL SYSTEM FOR COAL-FIRED GAS TURBINE POWER PLANTS I Filed Nov. 23, 1951 3 Sheets-Sheet 1 m Q INVENTOR cfamvZYsuor-r N BY 3 g I ATTORNEY Sept. 22,, 1953 J. l. YELLOTT PRESSURIZED COMBUSTION AND ASH REMOVAL SYSTEM FOR COAL-FIREQ GAS TURBINE POWER PLANTS 3 sheets -sheet 2 Filed Nov. 23, 1951 INVENTOR Jamvjifi'uorr ATTORNEY Sept. 22, 1953 J. YELLOTT 2,652,

PRESSURIZED COMBUSTION AND ASH REMOVAL SYSTEM FOR COAL-FIRED GAS TURBINE POWER PLANTS I Filed Nov.- 23 1951 3 Sheets-Sheet 3 Patented Sept. 22, 1953 UNITED STATES PATENT OFFICE PRESSURIZED COMBUSTION AND ASH RE- MOVAL SYSTEM FOR COAL-FIRED GAS TURBINE POWER PLANTS John I. Yellott, New York, N. Y., assignor to Bitu minous Coal Research, Inc., Washington, D. 0., a corporation of Delaware Application November 23, 1951, Serial No. 257,701

This invention relates to ash removal systems for coal-fired pressurized combustors generating motive fluid for gas turbines and other prime movers. More particularly the invention relates to ash removal systems for stripping ash and uncombusted residues from the products of combustion of pulverized coal burnt under pressure in combustors of the so-called film-cooled type.

In the combustion of pulverized coal under pressure conditions considerable difficulty is experienced in handlingfthe solid residues of the combustion. Using a Pittsburgh #8 Seam containing 10% ash, the ash having a fusion point of 2700? with air heated to 1300 F., ash particles are found to range, by actual measurement, from 1 micron to agglomerates or large pieces of irregularly shaped masses up to 12 inches by 2 inches in size. These irregularly shaped masses arise from accumulations of ash on the walls of the combustor. With changes in combustor temperatures varying according to changes in turbine load, the ash accumulations on the combustor walls tend to crack off and are discharged in the motive fluid from the combustor.- The handling of these over-sized masses is of great importance as they must be removed promptly to prevent clogging of the apparatus and closing down of the power plant. All of this must be done without imposing too heavy a burden-on the ash removal equipment and cutting down the efiiciency of the system by withdrawing too much of the motive fluid for ash removal purposes.

According to the principles of the present invention a louver separator is interposed between the combustor andthe fine ash separator and the secondary flow-from the louver containing the concentrated heavier ash is discharged from the system in a very small blowdown flow, with return of cleaned gas to the primary flow from the louver. Thus, with 4000- lbs. per hour of ash from the secondary louver flow the ash can be concentrated in 200 lbs. of blowdown air per hour or 0.2% of the total gas flow. With dual units the blowdown will amount to about 0.4% of the total. The louver separator is particularly adapted for handling hot sticky ash residues including low melting residues, such as VazOs. This material and the like is found in an appreciable quantity in the ash from residual oils, whichash is characterized by a lower melting point" than coal ash. I The invention herein makes use of the fact that-the gas-pressure within the louver is sufiiciently above the gas pressure outside the louver 10 Claims. (Cl. 110-28) 2 to use the diiferential in pressure to cause a secondary stream to now through a suitable cyclone separator wherein the ash, which was conveyed from the louver by the secondary stream, is concentrated into a small blowdown stream. The major part of the secondary stream is then returned to the cleaned air side of the louver and the blowdown stream carries the separated ash through a blowdown nozzle into an atmospheric pressure collection system. The blowdown stream may be treated in an apparatus of the type shown in my allowed co-pending application, Ser. No. 148,594,. filed March 9, 1950, for Method and Apparatus for the Separation of Particulate Material From Entraining Gaseous Fluids, to chill the ash to atmospheric temperature as expeditiously as possible without cooling the primary hot gaseous fluid, which is separated from the ash and returned to the system.

It is, therefore, among the features of novelty and advantage of the present invention to provide a novel method and apparatus for cleaning louver blowdown streams of contained. ash and returning same to a cleaned gas stream.

It is also a feature of novelty and advantage of the present invention to provide a pressurized combustion system for pulverized solid fuels or other fuels having appreciable quantities of solid residues, wherein preliminary separation of residual masses from fine residues is effected, and the residual masses are concentrated and separated from a small blowdown stream, with the cleaned gas returned to the main system, and the separated ash discharged from the system at atmospheric pressure and temperature.

Other features of noveltyoand advantage include means for transferring the solids from the blowdown stream into a quenching stream and without substantial dissipation of heat from the original carrier stream;

Other features of novelty and. advantage include secondary separators for massive residues, for self-contained reducing means and cooling means for the removed solids.

The above and other desirable features of novelty and advantage of the present invention will be more clearly understood by reference to the specification and accompanying drawings in which certain preterred embodiments of the invention are illustrated, by way of exampleonly, it being understood that other modifications may be used without departing from the spirit and scope of the present invention.

In the drawings, like numeralsirefer to similar parts throughout theseve'ral views, of which:

Fig. 4 is a fragmentary view similar to Figs.

1-3, and showing coolant gas ash quenching means and separating means with separated as-h blowdown and return of cleaned hot gas to the system;

Fig. 5 is a vertical section through a novel secondary ash treating device;

Fig. 6 is a horizontalsection taken on line 6-6 of Fig. 5, and

Fig. '7 is a horizontal section taken on line 1-1 of Fig. 5.

The improvements of the present invention will be considered with a special reference to their incorporation in the motive fluid generator of the ash separating equipment of coal burning gas turbine power plants particularly designed for forming the primary power for generating electric locomotives.

A particular form of motive fluid generator which has been found specially suited for the pressurized combustion of combustive air-borne solids is illustrated, in part, in Fig. '1. In this system, tubular combustor casing 3|, of combustor 30, suitably lagged, mounts a conical film type combustion chamber or flame tube 32 in such a manner as to form a tapering annular air chamber 33 therearound. The inlet end of this combustor chamber is continuous with a duct supplying preheated air from a 'regenerator, not shown. The pulverized fuel stream '34, from a suitable supply, not shown, discharges through nozzle 35 into the film-cooled flame tube or combustion chamber 32. At the outlet end, the combined combustion products and cooling air discharge into and mix in the plenum chamber 36. This chamber, as shown, comprises .a tube section 3'! having flanges 38, severally secured to like members of combustor casing '31, and the louver separator housing '40. The louver separator housing 18 comprises a 'T-s'haped tubular housing having a top cross bar or tube '41 with flange 42 at the ends thereof, and a depending tubular leg 4'3 having flange 44. A conical louver separator 56 is mounted 'in the member m) with the base of the cone secured by and between flanges 33 and 42 and the apical discharge pipe 51 mounted in end plate 45 of the member fill, plate 45 being secured to the end flanges 42. The body portion 52 of the louver is of truncated conical shape, and is comprised of spaced elements of suitable construction, as will be described more in detail hereinafter. A second T pipe 60, having a vertically disposed tubular cross arm 61, and a horizontal stub leg 62, is provided with flanges 63 at the ends of each of the arms. This member has the bottom end of cross arm B l closed by plate 64 and the other end is secured to the louver separator casing 40, as shown. The fine ash-bearing motive fluid discharging across the elements 52 of louver 59 into the louver separator casing flow through T connector 60 into fore-chamber .11 .of fine ash separator 10. The ash separator comprises a cylindrical body ll having a truncated conical inlet end 12 terminating in flanged neck 13 which is secured to the discharge side of the T pipe or duct 50. The discharge end of cylinder ii is flanged, as indicated at 14, and is connected to a second conical chamber 15 through the usual flanges and to a central discharge duct 16 for cleaned motive gas. A battery of fly ash separators, designated generally by the numeral 80, is mounted in member ill in such a manner as to form a fore-chamber l1 and a cleaned gas plenum chamber 78. The individual fly ash separators in battery are mounted between wall members 8|, 82 and 83. The members Bi and 8.2 serve :to spacedly support the casings 84 of the individual units, while the wall or septum 83 supports the discharge tubes 85, and, with member 32, forms a collecting chamber into which the ash separated out from the several separator units is segregated. The units 84, as shown, severally have a casing open at both ends, with a cleaned air discharge tube extending 'well up into the body of the casing while the mouth. or inlet end is provided with spinners 81.. The solids-bearing gas from the fore-chamber 11 passes axially through the separator units 84 while undergoing an initial centrifugal action or spin imparted by the spinners 81. The solids in the gas streams are concentrated at the inside wall of the units and travel through the annular channel 88 formed between the central discharge duct and the casing 84 to discharge into the collecting chamber 86. The cleaned gas discharges through tubular sections 85 into the cleaned gas plenum chamber 18, and thence out through duct #6 to the turbine or other use, device.

The separated ash in collector chamber .85 is treated in a separate ash concentrator unit 84a, having a cleaned air discharge tube 85a, and an ash discharge line 89 provided with an ash blowdown nozzle 89', discharging to any suitable receiver. The cleaned air tube. 85a, as shown, discharges into the cleaned air plenum chamber '18, so that the ash discharged vfrom the system is entrained in a minimum amount or" motive fluid, and usually less than 1% of the total volume developed.

The separator system described immediately above, wherein the ash is removed from the separator system in two stages, and the primary battery of vortical whirl separators, which, as shown, may comprise a plurality of unitary separators, discharges cleaned air to the outlet, while the collected ash discharges of the said separators are reprocessed through a single unit to eiiect a final concentration of the separated ash, and its removal from the system, while retaining the heated, cleaned air separated therefrom, and returning it to the main cleaned gas stream. Thus, a maximum of ash separation is effected at the expense of a minimum amount of motive fluid which was used for the final blowdown.

Thus, it will be seen that fine ash separation and blowdown from a heated motive fluid can be eiiected without requiring extraneous equipment or operations and solely by the expenditure of a relatively small portion of the solids-bearing gas which is being cleaned.

As noted hereinabove, it is of paramount importance to segregate and remove oversize particles from the combustor, particularly when containing uncombusted carbonaceous material. Because of the accelerated combustion and fusion conditions obtaining in the flame tube of the combustor, as a-result of the pressures obtainingtherein, as well as of the quantity of combustible throughput, of the order of substantially,.on'e tonv per hour per combustor, appreciable quantities of slag, or siliceous aggregates are formed onthe walls of the combustor, and break off inthe course of the=combustion due;,to variations in temperature arising from variations in fuel feed, etc.

;The;desideratum in handling this material is ,to remove it as quickly as possible from the main motive fluid stream, and ahead of the main fly ash separator, -the coarse material being quenched or cooled as quickly as possible, and conveyed orblown down to atmospheric storage. As the ;efliciency of the coal-fired gas'turbine, on a; competitive basis, depends on the complete utilization of all available heat units, the invention,herein;comprehends the recovery of available heat from the removed ash and its-return to the motive fluid-cycle.

,Turningmore :particularly to Figs. 1' and 2, thereiis shown, schematically, a coarse ash separating and blowndown system with separator meansier returning cleaned. gas to the motive fluid plenum chamber.- 1 The motive fluid plenum chamber. is formed between the walls of member, 40, and the-outer conical surface of element-52 forming the body of the louver. The plenum chamberis designated by the numeral 53 for purposes of convenience, and discharges directly into, the motive fluid ofitake 60. The plenum chamber 53 may be provided with a cleaned, air inlet opening or return 54 formed in the end, plate 45. Desirably, and as shown more in detail in Figs. and 6, apical discharge pipe 5| has a terminal flange 55 to which the ash removal equipment is secured. 'As shown schematically in Figs. 1 and 2, the ash blowndown device comprises a cylindrical separator I00, havinga body portion*IOI, closed top I02, tapering bottom I03, and blowdown pipe I 04, discharging through blowdown nozzle I05. The body. portion IOI,is provided with a flanged intake I06 secured to flange. 55 .of' discharge line 5| in pressuretight relation: Azcleaned' air return line I0! depends axially from the top I02 into. the-body of the separator and below-the inlet line 'I-06.= The line I01 discharges through a bend -'I08- (F ig. 1) orla 'gooseneck-I08 (Fig. 2) and line I00 into plenum chamber 53, theline I09 being-herme't ically secured-in pressure-tight relation in the inlet54, described hereinabove.

I The line I00 may discharge radially into the separator I00,-as shown in Figs. 1 and 6, or tangentiallyi as indicated in Figs. 2 and 3. Where residual oils, gases, and coals containing minimum amounts'of'ash-forming constituents are used, the vorticaldischarges of Figs. 2 and 3 may beimade use of. However, where any considerable amount of residues, particularly of low melting ashiconstituents, are met with, the radial input andimpact plate of the device shown in Fig. -10, will be utilized.

'Inmy co-pending application, Ser. No. 148,594,..filediMarch 9, 1950, for Method and Apparatus for .the Separationof Particulate Material' From Entraining Gaseous Fluids, I have disclosed and :claimed' devices for-- transferring solids from heated exhaust gasesito a separate quenching air stream without substantialudiminution of the volumeof-the "heated. gases, while efi'ecting substantially instantaneous quenching and removal of the transferredsolids; "In the drawings. of Figs. :13 :and =4 eherein, II=have shown the incorporation of the ash exchanger features of my above-identified case to the ash blowdown system herein. In the form shown in Fig. 3 and corresponding generally to the structures shown in Figs. 5 and 6 of my said application, a cold air inlet tube I00 discharges tangentially into separator I 00 and immediately subjacent the tangentially disposed inlet I 06 from the combustor 30. As described and claimed in that application, the cold air discharges tangentially frompipe I00 and spirals downwardly to chamber I 00, scouring the inner walls thereof, and carrying the segregated ash particles, which are co-flowing in the same spiral from the upper inlet I 06. The heated carrying gas, originally introduced through inlet I 06, will be displaced toward the center of the separator by the cold gas introduced through subjacent line I00, with the simultaneous transfer of its originally contained ash to the sheath of cold air spiraling downwardly on the inner wall of the separator and out through discharge line I04, and a blowdown nozzle-not shown, to an atmospheric container. The cleaned heated gases will change direction and flow upwardly through cleaned air outlet I01 and connection I09, to return into the plenum chamber 53 of the, louver separator. Desirably, the volume of gas introduced through line I00 as the quenching fluid, will be equivalent in amount to that discharged as ash carrier fluid through blowdown line I 04, so that there is very little loss of heat units from the heated motive fluid originally blown down through louver outlet '5I. Because of the construction of the louver there will be a pressure diiferential across the elements 52, with the result that the pressure in the combustor plenum chamber 36 will be higher than that obtaining in the louver discharge chamber 53, so that a pressure head will be imposed on line I01, which, coupled with the positive pressure on the separa tor by inlet line I06, will insure continuous circulation of the gases from the louver through the separator and back to the louver plenum chamber.

Inthe modification shown in Fig. 4, herein, the ash transfer principle embodied in the structure detailed in Figs. 2 to 4 of my application, Serial No. 148,594, are made use of. As described inthe aforesaid application, this device includes an ash inlet I05 connected to louver discharge line 5I. A separator IIO includes a cylindrical body portion II2, tapered end III connected to inlet I06, and closed end II6, axially mounting discharge pipe II I. An annular ring member I I 3, having a closed end I I 4, defines an annular chamber II5 which i in fluid communication with the tangentially directed inlet line I 20. The tapered and III is in fluid communication with the interior of separator IIO, a spinner I I9 being mounted in the passage defined by the annulus I I3. The discharge line I I1 extends into the chamber I I0 beyond the mouth of the tangential ash discharge line I2I and forms an ash collecting-annular chamber II8 with the wall I12 and end wall II 6 of the separator. The discharge vline Ill is extended through the wall of pipe 60', downstream of the louver plenum chamber 53, to return cleaned heated air to the fly ash separator inlet stream.

' The system illustrated in Fig. 4 operates in the following manner. The mixture of combustion gases, diluting air, entrained ash, uncombusted particles, and slag residues, discharges from chamber 36 axially'into. the louver separator 50.

Owing to the conical structure of the louver sep arator, there is a concentration of solid particles in the gas stream discharging through a ical outlet I. Because of the inertia of the oversized particles in the gas stream they will be entrained in and by the axial discharge stream, while the fine ash contained in the motive fluid, will remain sus ended therein and be entrained thereby, as it objects a com lete change of direction, at right angles to its original flow, and flows out between the elements 52 of the louver body into the plenum chamber 53 and the fine ash scparator inlet 68. The oversized particles dis+ charged through outlet 5! will flow through eon nectar I65 and spinner H9 into separator cham= ber He, the particles of oversized ash and solids being whirled outwardly, in spiral flow, to engage the inner surface of wall H2 and be collected in chamber H 8 whence they are discharged through ash discharge outlet IZI. The axially streaming gas which has been cleaned of its contained solids will discharge through line In to the fly ash separator inlet line 693, wherein it mixes with the fine ash-carrying motive fluid from lenum chamber 53. 7 ing between the separator and the outlet line insures a positive flow of the ash-bearing motive fluid through separator HQ, with return of cleaned, heated motive fluid tothe fine ash sep water inlet stream. This stripping of oversized particles and the like, from the primary ash separator and quenching of the particles and returning the cleaned heated gas to the system, in a volume substantially equivalent to the original input, is effected, in the present instance, by in: trod'ucing a stream of quenching fluid, such as air, into separator IIB through tangential inlet line I10; The spiral flow of the incoming cooling gas causes it to hug the inner wall of the separator while simultaneously displacing the heated l motive fluid co-fiowing therewith. In this dis placement, the separated solids are not displaced, and, consequently, are entrained in and by the cooling sheath which is co-flowi-ng with the heated core gases and the separated particles are simultaneously quenched.- By making the outlet or ash blowdown line l2I of the same capacity as inlet line I20 the cooling gases willflow, as a separate stream, through the separator, in engagementwith the walls thereof, and out through discharge line I'2I, without any substantial admixture with the gases originally introduced through line 106. Thus, the coarse combustible: matter and: heavy ash particles, originally sepazratelythe louver, are removed from the system, with simultaneous quenching, and discharged. to atmospheric storage, in a fraction of. asecond without interfering with the main, hot motive gas stream and its flow from the cornbustor to-tl'le' turbine, and without requiring withdrawal of any substantial portion of the motivegas stream for blowd'own purposes. In fact, by properly correlating the inflow and outflow of the quenching gas the volume of the main gas stream can be maintained substantially constant while effecting simultaneous removal, quenching and blowdowzn of the separated solids.

In the. operation of power plants of the type herein referred to when incorporated in generating electric locomotives and the like, accelerated combustion conditions impose a distinct burden on the equipment due to the severe size limitations and the. heavy throughput volume.

Therelatively high temperatures: obtaining in the combustionzone of the pulverized coal combustor,

The pressure differential obtain wherein the coal is burned under pressure, as a o'o'mbu'stive airborne streaming entrainment of fluidized coal particles, may result in the slagging of the ash constituents and the development or generation of agglomerated, including uncenbusted combustible particles of appreciable size. These unconibusted masses and slagged ash constitiients tend to build up as layers on theinnei" surfaces of the flame tube elements; These masses agglomerate to an appreciable wall thickmess and then break on; as noted above, to form masses of relatively great site, running the gamut dwfl to microscopic particles.

Thespeed of the turbine is directly dependent upon the quantity or fuel burned in the combusted With variations in generator or train speed due to operative demands, there is a correspond n variation in the amount (if hlOt-iv gas l qiiiidbe generated in the combustor with as actors panying Variation in temperature Within the come buster flame tube depending upon the var ing combustible reed; These variations in temperature give rise to temperature difier'entials in the flame tube walls, with resulting shrinkage or an pansion thereof, and consequent breaking or: or the slag encrustations' therefrom, and their discharge and removal in the motive gas stream. For heavy duty Work, therefore, it is necessary to separately remove these bodies, as formed, to atmospheric storage, in a minimum or time, and without withdrawing appreciable quantities of heat units from the system. By the impreve ments in the present invention this is made passible with a minimum expenditure of motive fluid as the actual operating agent. Figs; 5 and" 6 there is illustrated a novel ash slowdown device which has given remarkably eflicient results in full scale operating tests.

Referring now to Figs. 5 and 6, the novel secondary ash separator and quenching device will be seen to comprise an outer casing, an inner collection tube, a cleaned gas return, and ash quenching and removing emiipm'ent; The sep= arator' is designated generally by the numeral and comprises an outer cylindrical casing l3! having a reinforced bottom I32 and a top collar or flange I33. A suitably gasketed head or coverplate 1341s secured flange I33,v in any suitable manner, as by stub bolts and nuts, desig= hated generally by the numeral I35. A radial inlet tube #36 is secured in the wall of the sap: ara tor about a-quarter of the casing height from the top. This tube is flanged,- as indicated at #31, and this flange is hermetically secured to flange 55 of louver separator outlet 5i, any suitable manner, well-known to those skilled in the art.

A suitably sealedclean-"out aperture, desig: nated generally by the numeral I38, .is-p'rovided at the bottom of the casing. A pulverizing air jet device: I39, is provided for the-purpose of fur ther reducing the oversize particles of ash. fine ash collecting tube MO- is axially moimted in the casing, and comprises; an" upper cylindrical body portion II t ain invertedconical bottom I42 terminating in' a discharge pipe 143. The latter maybe flanged, as indicated at I441 The discharge pipe I 13 is: axially mounted in the bottom 1:32 of easing 30 and is hermetically securedin' place; asby welding; An annular collar I45 is Welded' to the top end of tube Mt and has its upper surface I46= in varyingengagement with the under sideat cover plate in; The collar I 45 is slotted 'with a series of radial slots I41 pro viding access from the chamber IE8 formed be-:-

.and is desirably welded thereto.

tween the casing I30 and the collector tube I40 and-the interior of the collector tube. An outlet tube I50 is axially mounted in the cover plate The tube I 50 depends well into the body I4I of collector tube I40. The tube I50 is comprised generally of-a first depending tube section I5I, a central elbow section I52 and a downwardly slanting-outlet I 53 having a flanged end I54. The elbow section I52 may be provided with a flanged viewing and cleaning tube I55. A flanged inlet tube I is mounted in aperture 54 of end plate 45 and louver separator section 40 and is hermetically secured to flange I54 in any suitable manner.

' A collar I56 mounting spinner vanes I'I is secured in place on outlet tube section I5I by retaining ring I58, or by any other suitable means. The spinner vanes I5'I are ground to fit into the inner diameter of collector tube body MI, and are fitted on the carrying collar I 56 in such a manner as to disposethem below the plane of the bottom of the radial inlet slots I41 formed in collar I45.

' It will be seen that blowdown gas, entraining heavier aggregates, will discharge through louver outlet 5I and inlet I36 into separator I30, with the heavier particles falling to the bottom of the casing, where they are further reduced by the action of tangential air-jet I39. The lighter, gasborne particles are introduced into the collecting tube through the slots I4I of collar I45 and thence downwardly through spirmer vanes I5'I into the body of the collector tube I40. The air jet I39 causes the aggregates collected at the bottom of separator I30 to be driven, in a spinning action, around the inside of the separator wall with'a resultant abrasion and reduction of the particles. The resulting fine particles will be swept upwardly by the air stream from jet I39 and pass through theslots I4I into collector tube I40 together with the fine ash components of the original gas stream discharged through apical outlet of the combustor into the separator. The volume of air introduced through jet I39 will be relatively small and will serve to pick up heat units from the aggregates as they are being pulverized, thereby returning the heat units to the motive gas cycle. By reason of the-spin imparted to the gas stream the contained solids will be centrifuged or spun outwardly, engaging the inner wall of tube section I M in a descending spiral path, being collected in the conical bottom I42 .and blown down through outlet I43, and a blowdown nozzle, not shown, to ash quenching and storage means. The gas stream entering collector I40, after discharging its contained solid particles, is caused to undergo a complete reversal of direction, travelling upward to outlet tube I50 and discharging through inlet I 09' to be recycled to the plenum chamber 53 of the louver separator.

The separator described immediately above, along with the other separators, and embodying the principles of the present invention, markedly improve the overall efiiciency of pressurized combustion systems utilizing pulverized coal. However, and as noted above, under heavy duty, high pressure operating conditions, in equipment of severely restricted size, such as obtain in locomotive operations, appreciable quantities of massive residues are formed during combustion, and must be reduced and removed from the system as expeditiously as possible, to prevent clogging, and Without involving any appreciable loss of heat units from the motive gas system. This is accomplished' by incorporating a breaker plate I in the separator I30 directly in the path of the gas streaming inwardly through inlet pipe I36. With the tubes 5| and I36 of substantially 4 inches diameter, any length of aggregate can be handled, up to the inner diameter of the tubes, and will be projected against impact plate I60, and broken thereon and thereby. The plate I60 is mounted at an angle, as shown, and serves to deflect the incoming gas stream as well as to break up the contained solid masses, so that the solids-bearing gas stream is caused to travel spiral-1y within the upper portion of casing I30 before discharging through slots I 41 into the central collecting tube. During the spiral travel of the solids-bearing gases the heavier particles will be discharged into the bottom of casing I30, all as previously indicated.

A feature of prime importance regarding breaker plate I60 is its renewability. Under actual, full scale operating conditions, the coarse, solids-bearing gas streams have been found to have a highly abrasive efiect on any and all surfaces against which the solids impinge. As a practical matter, the use of special, abrasionresistant alloys is less economical, because of unduly high cost of installation and replacement, than the use of replaceable impact plates of relatively cheap metals, such as cast irons, or cast steels having the necessary temperature resistance characteristics.

The plate I60 will desirably be mounted with the center of impact in the axis of inlet tube I36. With tube I36 having a 4 inch diameter it is desirablethat impact plate I60 be half again as large in every dimension, that is about 6 inches on the side. This will take care of the spraying action of the gases issuing from the tube I36, so that the spray pattern will be effectually contained within the limits of the impact plate. The plate may be removably mounted as follows: A rectangular chamber I6I having top, bottom and side walls welded to each other, is welded in place on the outer surface of casing I30. A slot I62 is out in the casing to receive plate I 60 and its supporting arm I63. The supporting arm or plate I63 is detachably secured to plate I60 by any suitable means, such as screws or bolts, designated generally by numeral I64. The member I63 is. detachably secured to chamber I6I, the latter being desirably flanged, as indicated at I66. The joints between the flange I66 and the carrier plate I63 are suitably gasketed and the securing means may comprise stud bolts and nuts, or machine screws, all designated generally by the numeral I6'I.

It will now be appreciated that there have been provided novel pressurized combustion systems for the burning of residue-containing and forming fuels, both liquid and solid, with special ash blowdown, and quenching of the ash, while simultaneously recovering the major portion of heat units associated with the ash, and utilizing only a minor portion of the ash-bearing motive gas fluid as the entraining agent for blowdown of the separated residues.

I claim:

1. In a pressurized combustion system for the pressurized combustion of fluidized pulverized coal including a pressurized combustor and means to mix the products of combustion with a gaseous diluent and coolant to form an ash-bearing motive fluid, and ash separating means including a fly-ash separator receiving the ashbearing motive fluid and delivering ash-free motive fluid, the improvements comprising a conical louver separator in axial alignment with the said combustor and receiving the said ash-bearing motive fluid, said louver having an apical outlet, whereby the coarse, motive fluid-borne solids are concentrated by the conical louver and discharge in a blowdown stream through said apical outlet, the cleaned gas from the louver being. discharged to the fly ash separator; means for separating the ash from said blowdown stream to form a concentrated ash-carrying blowdown stream and a cleaned hot gas stream; means for returning the said cleaned hot gas stream to the motive fluid stream downstream of the louver separator, and separate means for removing the said concentrated ash blowdown stream from the said ash separating means.

2. A pressurized combustor system according to claim 1, characterized by the fact that the means used to separate the ash from the louver blowdown stream is a cyclone separator.

3. A pressurized combustor system according to claim 2, characterized by the fact that means are provided for introducing a stream of coolant gaseous fluid tangentially into' the separator whereby to form a spiral sheath of cooling gas about the core stream of heated motive gases, and the solids originally carried in the heated core stream are centrifugally transferred into and entrained in and quenched by the coolant stream.

4. A pressurized combustor system according to claim 3, characterized by the fact that the blowdown means serving to remove the separated ash offtake stream has a capacity substantially equivalent in volume to the capacity of the coolant input.

5. A pressurized combustor system according to claim 1, characterized by the fact that the means for separating the ash from the louver blowdown stream comprises, a closed cylindrical casing with a radial inlet for the solids-bearing gas, a central collection tube, a slotted annulus on said tube and establishing communication between the casing and the tube, a cleaned gas discharge pipe establishing fluid communication between the collection tube and the downstream side of the louver separator, an ash blowdown line at the bottom of the collecting tube, and an impact plate mounted in the path of the solidsbearing gases blown down from the louver separator.

A pressurized combustor system according to claim 1, characterized by the fact that the means for separating the ash from the louver blowdown stream comprises, a closed cylindrical casing with an inlet for the solids-bearing gas, a central collection tube, a slotted annulus on said tube and establishing communication between the casing and the tube, a cleaned gas discharge pipe establishing fluid communication between the collection tube and the downstream side of the louver separator, and an ash blowdown line at the bottom of the collecting tube.

7. A pressurized combustor system according to claim 1, characterized by the fact that the means for separating the ash from the louver blowdown stream comprises, a closed cylindrical casing with a radial inlet for the solids-bearing gas, a central collection tube, a slotted annulus on said tube and establishing communication between the casing and the tube, a cleaned gas discharge pipe establishing fluid communication between the collection tube and the downstream side of the louver separator, an ash blowdown 12 line at the bottom of thecollecting tube, an impact plate mounted in the path of the solidsbearing gases blow down from the louver separator, and air jet reducing and removal means for coarse agglomerates at the bottom of said cylindrical casing.

8. A pressurized combustor system according to claim 1, characterized by the fact that the means for separating the ash from the louver blowdown stream comprise a closed cylindrical casing with a radial inlet for the solids-bearing gas, a central collection tube, a slotted annulus at the top of said tube and establishing fluid communication between the casing and the tube, spinner means in the tube below the slotted an-. nulus, whereby spin is imparted to the solidsbearing gases introduced into the collector tube and the solids are projected out of the said gases. a cleaned gas discharge pipe mounted axially of the spinner means and establishing fluid communication, with a reversal of gas flow, between the collection tube and the downstream side of the louver separator, a restricted ash blowdown line at the bottom of the collecting tube, and an impact plate in the path of the solids-bearing gases from the louver separator.

9. A pressurized combustor system according to claim 1, characterized by the fact that the means for separating the ash from the louver blowdown stream comprises a closed cylindrical casing with an inlet for the solids-bearing gas, an impact plate mounted in the path of said solids-bearing gas, a central collection tube, a slotted annulus on said tube and establishing communication between the casing and the tube, spinner means in the tube below the said slotted annulus, whereby spin is imparted to the solids-bearing gaseous fluid introduced into the collection tube, a cleaned gas discharge pipe establishing fluid communication, with a reversal of flow of the gas stream, between the collection tube and the downstream side of the louver separator, an ash blowdown line at the bottom of the collecting tube, air jet reducing means for coarse agglomerates at the bottom of said cylindrical casing, whereby reduced solids are carried upwardly in the casing and introduced into the collection tube through the apertures of the slotted annulus, and separate solids removal means in the bottom of the wall of the casing.

10. A combination pressurized combustion and ash removal system for coal-fired gas turbine power plant, comprising, in combination, pulverized coal supply means; pressurized combustive air supply means; a combustor including a multiple segment cold wall combustion chamber mounted in a casing and defining an annular duct therewith; a burner in the combustion chamber in fluid communication with the pulverized coal supply means and pressurized combustive air supply means, whereby a streaming entrainment of combustive air-borne coal particle is delivered to the said burner; secondary air supply means in fluid communication with the combustor casing and the hot and cold wall surfaces of the combustion chamber segments, whereby the inner and outer walls of the combustion chamber are cooled by films of air; a coarse ash separator comprising a conical louver in the discharge line of the combustor; a cylindrical separator; a flne ash separator; fluid connection means delivering cleaned gas from the said cylindrical separator to the fine ash separator; separate cleaned gas and ash discharge means for the fine ash separator, said cylindrical separator having an inlet re- 13 ceiving coarse ash from the conical louver and discharging it to said cylindrical separator; and cold air inlet means in said cylindrical separator for establishing an ascending, spinning column of cold air, whereby coarse ash is quenched and ground, and removed in a stream of blow-down a1r.

JOHN I. YELLOTT.

References Cited in the file of this patent UNITED STATES PATENTS Number Number Number 10 469,339

Name Date Badenhausen Dec. 5, 1944 Noack May 7, 1946 Way Sept. '7, 1948 Kuhner Feb. 28, 1950 Yellott Jan. 29, 1952 FOREIGN PATENTS Country Date Great Britain July 23, 1937

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