CA1190046A

CA1190046A - Partial oxidation burner

Info

Publication number: CA1190046A
Application number: CA000429268A
Authority: CA
Inventors: Warren G. Schlinger
Original assignee: Texaco Development Corp
Current assignee: Texaco Development Corp
Priority date: 1982-06-29
Filing date: 1983-05-31
Publication date: 1985-07-09
Also published as: US4443228A; EP0098043A2; EP0098043A3; DE3364507D1; JPS5922991A; ZA833760B; AU1573883A; EP0098043B1; AU558256B2

Abstract

ABSTRACT

A high turndown de-slagging burner is provided for simultaneously introducing one or two mixed pairs of reactant feedstreams into a free-flow noncatalytic partial oxidation gas generator for the production of synthesis gas, fuel gas, or reducing gas by way of the central and/or annular sections of the burner, respectively. Each pair of feedstreams comprises a stream of free-oxygen containing gas with or without a temperature moderator and a pumpable liquid slurry stream of solid carbonaceous fuel, such as a coal-water slurry. Other hydrocarbonaceous fuels may be employed. The burner comprises four coaxial concentric conduits that are radially spaced to provide coaxial concentric annular passages. All of the conduits and annular passages are closed at the upstream ends and open at the downstream ends. Each pair of feedstreams is separately mixed together in a central or annular pre-mix chamber located upstream from the face of the burner. A
water-cooled flat face-plate is provided with separate passages for discharging air or soot-blowing or de-slagging media at the face of the burner.

-I-

Description

ACKGROITND OF TEE INVENTIO~
Field of the Invention This invent1on relates t:o the manufacture of gaseous mixtures comprisirlg H~ and C0 , e . g., synthesis gas , fuel gas, and reducing ga by the partial oxidation o:E pumpable slurries of solid carbonaceous fuels in a li~uid carrier or liquid or gaeous hydrocarbon fuel. In one o:E its more ~peci:Eic aspects, the present inventiorl relates to an improve~ burner for such gas manufacture.
Descri tion of the Prior Art 1 ~ .
Annulus-t~e burners have ~een employed for introducing liquid hydrocarbonaceous ~uels into a partial oxidation gas generator. For example, coassigned U. S .
Patent 3, 528, 930 s~ows a single annulus burner, and coassigrled U.S. Patents 3,758,037 and 3,847,5h4 show double a~ulus ~urners. However, in 5uch burners, only one pair of reactarlt feedstreams are mixed downstream from the burner face, and missiny are the high turndown, p.re-mix, and soot~blowing or de-slagging features of the subject burner .
To obtain proper mixing, atomization, and stability of operation, a buEner for the partial oxidation process is sized for a spPcific throughput. Wi th prior art burners, should the reguired outpuk of product gas change substantially, shut--down of t:he system is required in order to replace ~he burner with one of proper size. This prohlem is a~roided and costly shut-downs are avoided by ~e subject bur:nex which will operate at varying levels of output whil,e retaining efficiency~ stability, and axial s~nnmetry .

~..

The more complex process for preheating a gas genera-tor by means of a preheat burner, removing -the prehea-t burner from the gasifier, and inserting a separa-te production burner is describecl in coassigned United States Patent No.
4,113,445. In contrast, the subject burner may be used for both preheating and production without being removed from the gas generator.
SUMMARY OF THE INVENTION
The inventlon provides a burner Eor introducing firs-t and second reactant feedstreams in-to a partial oxidation gas generator comprising: a central conduit having a central longitudinal axis that is coaxial with the central longitudinal axis of the burner, closing means attached to the upstream end of said central conduit for closing off same; an unobstructed exit nozzle at the downstream end of the central condui-t which discharges through a circular exit orifice located upstream from the face of the burner to provide a central pre-mix chamber that discharges through an unobstructed circular exit orifice at the face of the burner, inlet means connected to the upstream end of the central conduit for introducing a first reactant feedstream; a second conduit coaxial and concentric with said central conduit along i-ts length, an unobstructed exit nozzle at the downstream end of the second conduit which discharges through the circular orifice of said central pre-mix chamber at the face of the burner, spacing means between said central and second conduits for maintaining a spaced relationship and forming therebetween an unobstructed first annular passage with an unobstructed downstream annular exit orifice that discharges into the central pre-mix chamber, clos-ing means attached to said second conduit and first annularpassage at -their upstream ends for closing off same, said central conduit passing through the upstream closed end of said

- 2 -second condui-t and making a gastight seal therewith, and inlet means connected -to the ups-tream end of the second condui-t for introducing a second reactant feedstream; a third condui-t coaxial and concentric wi-th said second conduit along i-ts leng-th, spacing means for between said second and third conduits for maintaining a spaced relationship and forming therebetween an unobstructed second annular passage wi-th an unobstructed downstream annular exit orifice located upstream from the face of the burner to provide a portion of an annular pre-mix cham-ber that discharges through an unobstruc-ted annular exit orifice at the face of the burner, closing means at-tached to -the second annular passage and third conduit at their upstream ends for closing off same, said second conduit passing through the up-stream closed end of the third conduit and making a gastight seal therewith, and inlet means connected to the upstream end of the third conduit for introducing a third reactant feed-stream; an outer conduit coaxial and concentric with said -third conduit along its length, an unobstructed exit noz21e at the downstream end of the outer conduit which discharges through said annular exit orifice at the face of the burner, spacing means between said third and outer conduits for maintaining a spaced relationship and forming therebetween an unobstructed third annular passage with an unobstructed downs-tream annular exit orifice located upstream from the face of the burner that discharges into the remaining portion of said annular pre-mix chamber, closing means attached to the third annular passage and outer condui-t at their upstream ends for closing off same, said third conduit passing through the upstream closed end of the outer conduit and making a gastight seal -therewith, and inlet means connected to the upstream end of the outer conduit for introducing a fourth reactant feedstream; an outer annular water-cooled flat face-plate encircling the downs-tream end of - 2a --the burner, saicl face-plate being cored -to provide an annular passage for circulating water and an annular header for dls-tri-buting a gaseous material, passage means extending longitudinal-ly in the wall of said ou-ter conduit and in communication with said distribution header, inlet rneans in communication with -the ups-tream end of said longitudinal passage means for introducing said gaseous material, and downstream passage means in communi--cation with said distribution header Eor discharging said gaseous material at the face of the burner.
Each pair of reactant feeds-treams may comprise a carbonaceous or hydrocarbonaceous fuel stream, such as a pump-able liquid slurry of coal in water or a liquid or gaseous hydrocarbon fuel, and a stream of free-oxygen containing gas.
A wide range of gasifier throughputs are obtained by simultane-ously passing through the burner one or both of the mixed pairs ; of feedstreams. The burner includes separate central and annular sections so that each pair of feedstreams is kept separate as it passes through the burner.
The burner has pre-mix and high turn-down capabilities and includes four concentric cylindrical shaped conduits which are coaxial with the central longitudinal axis of -the burner.
The four coaxial concentric condui-ts are radiall.y spaced to provide three coaxial concentric annular passages. All of the conduits and annular passages are - 2b -clo~ed at the upstream ends and open at the downstream ends. The four concentric coaxial conduits are each substankially cylindically shaped with a downstream end ~hat gradually develops into a converging long radius frusto-conical shaped nozzle at the downstream end of the burner. Central and annular pre-mix zones are provided by retracting the downstream tips of the central and third conduits upstream from the face of the burner. The downstream ends of the second and outer conduits terminate at ~he face of the burner. Aiternate pairs of feedstreams of free-oxygen containing gas and carbonaceous fuel ~lurries or hydrocarbonaceous fuel are introduced respectively into the upstream ends of the four conduits.
A pair of feedstreams is mixed together in the central or annular pre~mi~ chamber. Alternatively, simultaneously each of two pairs of feedstreams ar~ separately mixed - one pair in each separate pr~-mix chamber. A water-cooled flat face-plate is provided with separate passages for introducing air or soot blowing or de-slagging media at the face of the burner.
Advantageously by means of the subject burner, the velocity of the reaction components at the exit of the burner may be maintained at near optimum value over a much wider range of gasifier throughput. Throughput may be varied ~ up or down - over a wide range. F~rther, axial symmetry fo:r the reactant 1OW pattern is achieved, and buildup of 'soot or ~lag on the ~ace of the burner is prevented.

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In one embodiment, the b~lrner may be used as a combination pre-heat-production burner by passing fuel gas ~hrough the central pas~age and air through all of the other passages.
BRIEF DESCRIPTION ()F THE DRAWING
In order ~o illustrate the invention in greater detail, reference is made to severa~ embodiments involving burner con~truction~ as shown in the figures of the drawing wherein Fig. 1 as a diagramatic vertical.longitudinal schematic represe~tation showing one embodiment or the burner;
Fig. 2 is a transverse longitudinal cross-section through the upstream and down~tre~m ends of the burner shown in Figure 1.
~'~L~
The present invention pertains to a novel burner for use in the non-catalytic partial oxidation process for the manufacture of ~nthesi~ gas, uel gas, or reducing gas.
The bu~ner is preferably used with a reactant fuel stream comprising a pumpable slurry of ~olid carbonaceous fuel in a liquid carrier. Other suitable hydrocarbonaceous reactant fuel streams include liquid or gaseous hydrocarbon fuel, and mixtures thereof wi~h or without admixture with a temperature moderator. Within the burner, a reactant feedstream of free-o~ygen contai~ing gas with or without admixture w;ith a temperature moderator is mixed with the reactant fuel stream. The mixture of reactants i~ ~hen discharged into the reaction zone of a conventional parti~l oxidation gas generator.
A hot raw gas s l:ream is produced in the reac tion zone of the noncatalytlc, refractory-lined, free-flow partial oxidation gas generator at a temperature in the range of about 1700 to 3500F. and a ~pressure in the range of about 1 to 300 atmospheres, such as abou-t 5 to 250 atmospheres, say about 10 t~ 100 atmospheres. A typical partial oxidation gas generator is describ~d in coassi~ned U. S . Patent No . 2, 809 ,104 . The effluerlt raw gas stream from the gas generator comprises EI2 ~ C0, C02 and at least one material selected from the group consisting of H20, N2 A, CH~, }I2S and COS. Dependiny on the fuel and operating conditions, particulate carbon, îly-ash, or slag m~y be produced along wi1:h the raw gas stream.
~ uring operation of ~he par1:ial oxidation gas generator, it may be necessary to rapidly turndown the produc:tion of the ef~luent gas to less than the plant-design output, without replacing the burner.
20 Changing the burner reguires a costly shut-down period with resultant delay. Thus, in combined cycle operation fox power generation a durable burner is required with offers minimum pressure drop and with which throughput lev~ls may be rap.idly changed - up and down - without sacrificing stable operation and efficiency~ Further, the burner should operate with a variety of liguid, solid, and gaseous fuels, and mixtures thereof. These requirements have been fulfilled with ~he subject burner. Combustion instability and poor e:Eficiency can be encountered when prior art burners are used for the ga~ ication of li~uid phase slurries of solid carbonaceous fuels. Further, feedstreams may be poorly mixed and solid fuel particles may pass thxough the gasifier without contacting significant amou~ts of oxygen. Unreacted o~yg~n :in the reaction zone may then react with the product gas. ]~urther, soot and slag build-up on the flat surfaces surrounding the discharge orifices at the face of the prior art bur~ers would interfere with the velocity and ~low pattern of the reaction compone~ts at the exit of the burner. These problems and others are avoided by the subject burner.
The velocity of the reactant stream through the central conduit and annular passages of the subject burner is in the range of about 1-50, say about 2-20 f~et per second when said reactant stream is a liquid hydrocarbon fuel wi~h or without admixture with a temperature moderator or liquid sl-lrry of solid carbonaceous fuel, and in the xange of about 100 feet per second to sonic velocity, say 150-500 feet per seco~d when said reactant stream is a gaseous hydrocarbon fuel or a free-oxygen containing gas with or without admixture with a temperature moderator.
Alignment pins, fins, centering vanes, spacers and other conventional means are used to symmetrically space the conduit~ wi~h respect to each other and to hold same in stable ali~Iment without obstructing the free-flow of the feedskreams..
The do~nstream ends of the central and third coaxial concentric conduits are retracted upstream from the burner face to provide central and annular pre-mix chambers, respectively. Intimate mixing of the reactants takes place -- lj .

i~ the pre~mix chambers prior to discharge. There may also be some volatilization of the slurry medium without burnin~
in ~he pre-mix chambers. For example, from about O to 100 volume %, such as 2 to 80 vol.%, of the li~uid carrier may be volatilized without burning, the rati~ of the volumes of the central/annular pre-mix chambers may be in the range of about 0.5 to l.S, ~uch as 1Ø The downstream ends of the second and outer condults terminate at the face of the ~urner. The downstream ends of the central and third conduits are retracted upstream from the face of the burner a distance in the range of about ~.5 to 12 times, such as preferably greater than 2 to 10 times ~he minimum diameter of the central pre-mix chamber exit orifice at the face of the burner for better mixing. Preferably, th~ ends of the central and third conduits are retracted upstream from the face of the ~urner about the same distance.
Each o~ ~he four concentric coaxial conduits are subst~ntially cylindrically shaped with a downstream end that gradually develops into a converging long xadius frusto-conical shaped nozzle at the downstream end of the burner. The term "long radius" is well known and i~ the shape of an American Society of Mechanical Engineer's tA~S-M-E.? standard long radiu~ nozzle. A further description of the term may be found in "Thermodynamics Fluid Flow and ~eat Transmission" by Huber 0. Croft, page 155, Fixst Edition, 1938 McGraw-Hill Book Company.
The length of the si~gle central pre-mi~ chamber is detex~lined by the distance that the tip of the central conduit is retracted upstream from the face of the burner.

The inside walls of the central pre-mix ehamber are bounded by a portion of the inside surfaces of the second conduit that gxadually develops into a converging long radius frustoconical shaped nozzle. The length of the single annular pre mix chamber is de~texmined by the distance that the tip of the third conduit is retracted upstream from the face o ~he burner. The insi.de walls of the a~nular pre~mix chamber comprise a portion of the outside surface of the second conduit and a portion of the inside surace of the outer conduit that gradually develop into converging long radius frustoconical shaped nozzles at the downstream end of the burner.
The outlet portion at the face of the burner of said pre-mix cha~bers may be provided with frustoconical shaped inserts made from a ~hermal and wear resistant material, such as from tung~ten carbide or silicon carbide.
In the operation of the burner, flow control means may be uæed to start, ætop and regulate ~he flow of the four feedstrea~s to ~he passages in ~he burner. The feedstreams entering the burner and.simultaneously and concurrently pa~sing through at different velocities impinge and mix with each other the pre-mix chambers. The impingement o one reactant stream, such as the liquid slurry of solid carbonaceous fuel in a liquid medium optionally in admixture with a temperature moderator, wi-th ano~her reactant stream, such as a gaseous stream of free-o~ygen containing gas ; optionally in admixture wi~h a temperature moderator at a higher velocity, causes the liquid slurry to break up into a fine spra,y. A multiphase mixture is produced~ As the mixture passes freely through the su~ject unobstructed burner its velocity chan~es. For example, at various points in the burnex the velocity of the mixture may range from about 20 to 600 ft. per sec. As the mixture flows through the burner, the velocity changes are mainly the result of changes in the diameter o~ the flow path and the guantity and temperature of the mixture. This promotes a thorough mixing of ~he component~. By operating in the region of turbulent flow, mixing may be maximized.
Further, direct heat exchange between the matexials takes place withi~ the burner. From 0-100 vol.%, say about 5 80 vol.~ of the liguids in the feedstreams may be vaporlzed without bur~ing before the feedstreams leave the ~urner.
By means of converging exit orifices, the feedstreams may be accelerated directly into the reaction zone of the partial oxidation gasifier.
Burning of the combustible materials while passing through the pre mix chambers of ~he burner may be prevented by discharging the multiphase mixtures at the central and annular exit orifices at the tip of the burner with a discharge velocity which is greater than the flame propagation velocity. Flame speeds are a function of such factors as composition of the mixture, temperature and pressure. They may be calculated by conventional methods or determined experimentally. The ratio of the discharge velocity for the multiphase mixture being discharged through the central e~it orifice to the multiphase mixture being discharged through the annular exit orifice may be in ~he range of abvut 0.5 to 1.5, such as 1.OO Depending on such factors as the temperature, ~elocity, dwell time and composition of the feedstreams; the desired amount of ~ g ~

vaporization of liquid carrier; the temperature and amount of recycle gases in the ~enerator; and the desired life of the burner; cooling coils may or may not encircle the outside barrel of the burne:r along its length.
The multiphase mixtuxes simultaneously depaxting rom the cerltral orifice arld/or ar:~ular orifice at the downstream tip of the burner mix together downstream from the face of the burner. Adv2ntageously, by means of the subject burner, the exothermic partial oxidation reactions take place a sufficient distance downstream from the burner face so as to protect the burner from thermal damage.
Pumpable slurries of solid carbonaceous fuels having a dry solids content in the range of about 30 to 75 wt.%, say about ~0 to 70 wt.% and/or liquid hydrocarbon fuels may be passed ~hrough the inlet passages of the subject burner.
The inlet temperature o ~he liguid hydrocarbon fuel or the slur~y is in ~he range of about ambient to 500F., but preferably below the vaporization temperature of the liquid hydrocarbon or the carrier for the solid carbonaceous ~uel at ~he given inlet pressure in the range of about 1 to 300 atmospheres, such as 5 to 250 atmosphexes, say about 10 to 100 atmosphexes.
The term solid carhonaceous fuels, as used herein to d~scribed suitable solid carbonaceous feedstocks, is intended to i~clude various materials and mixtures thereof from the group consisting of coal, coke from coal, char from coal, coal liquefaction residues, petroleum coke, particulate carbon soot, and solids derived from oil shale, tar sands, and pitch. All types of coal may be used including anthracite, bituminous, sub-bituminous, and lignite. The particulate carbon may be that which is obtai~ed a5 a byproduct of the subject partial oxidation proces~, or that which is obtained by burning fossil fuels.
The term sQlid carbonaceous filel also includes by definition bits of ~arbage, dewatered ~anitary sewage, and semi-solid organic materials ~,uch as asphalt, rubber and rubbér-like materials includillg rubber automobile tires which may be ground or pulverized to the aforesaid particle size. Any suiteible gri~ding ystem may be used to convert the solid carbo~aceous fuels ox mixtures thereof to ~he proper size.
The solid carbonaceous fuels are preferably gxound to a particle size so ~hat 100% of the material passes through an AS~M E 11-70 Sieve Designation Standard ~.4 mm ~Alternative No. 14) emd ?t least 80% passes ~hrough an ASTM E 11~70 Sieve Desi~nation Standard 0.~25mm (Alternative No. 40). The moisture content of the solid carbonaceous fuel particles is in the range of ~bout 0 to 40 wt.%, such as 2 to 20 wt.%.
The term free-oxygen containing gas, as used herein is intended to include air, oxygen-enrlched aix, i.e., greater tha~ 21 mole% oxysen, and substantially pure oxygen, i.e., greater than 95 mole % oxygen, ~the remainder comprising ~2 and rare gas;~s~.
Simultcmeousiy with the fuel stream, a stree~m of free-oxygen containing gas ic supplied to the reaction zo~e of the gas generator by way of a free passage in the burner at a temperature i~ ~he ra~ge of e~bOut e~mbient to 1500F., and preferably in the range of about a~bient to 300F., for oxygen-enriched air, a~d about 500 to 1200F., for air.
The pressure is in the range of about 1 to 300 a~mosphere, such as 5 to 250 atmosphere, say 10 to 100 a~mospheres.
The atoms of free-oxygen plus atoms of organically combi~ed oxygen in the solid carbonaceous fuel per atom of carbon in ~he solid carbonaceous fuel (0/C atomic ratio) may be in ~he xange of O.S to 1.95. With free;~oxygen containing ga~
in the reaction zone the broad range of said 0/C atomic ratio may be about 0.5 to i.7, such as about 0.7 to 1.4.
More specifically, with air feed to the reaction 20ne, said O/C atomic ratio may be about 0.7 to 1.6, such as about 0.9 to 1.4.
The term temperature moderator as employed herein includes water, steam, C02, N2~ and a recycle portion of the pro~uct gas stream. The temperature moderator may by in a~mixture with the fuel stream and~or the oxidant stream.
For example in one embodiment, the feedstream compri es a slurry of liquid hydrocarbonaceous material and ~olid carbonaceous fuel. E20 in liquid phase may be mixed with the li~uid hydrocarbonaceous carrier, for example as an emulsion. A portion of the H20 i.e., about 0 to 25 weight % of the total ~mount of H20 present may be introduced as steam in admixture with the free-oxygen containing gas. The weight ratio of H20/fuel may be in the range of about C to 5, say .about 0.1 to 3.
The term liguid carriex, as used herein as the suspending medium to produce pumpable slurries of solid carbonaceous fuels .is intended to include various matexials from the group consisting of water, liquid hydrocarbonaceous materials,.and mixtures thereof. However, water is the pxeferred c~rrier for the particles of solid carbonaceous fuel.
In one embodiment, the li~uid carrier is liquid carbon dioxide.
In such case, ~he liquid slurry may comprise 40~70 wt.% o~
solid carbonaceous fuel and the remainder is liguid C02.
The C02~solid uel slurry may be introduced into the burner at a temperature in the range of about -67F to 100 F
depending on the pressure.
The term liguid hydrocarbonaceous material as used herein ~o describe suitable liguid carriers is intended to include various materials, such as liguified petroleum gas, petroleum distillates and residues, gasoline, naph~ha, kerosine, ~rude petroleum, asphalt, gas oil, residual oil, tar sand oil and shale oil, coal derived oil, aromatic hydrocarbon (such as be~zene, toluene, ~ylene fractions), coal tar, cycle gas oil fxom fluid~catalytic crackin~
operation, furfural extract of coker gas oil, methanol, ethanol and o~her alcohols and by product oxygen containing liquid hydrocarbons from oxo or OXyl syn~hesis, and mixtures thereof.
The term sootblowing or de~-slagging gaseous media as employed herei~ includ~s steam, N2, C02, recycled product gas, and m:ixtures ~hereof.
The Sl~j ect-burners as shown in Figures 1 and 2 may be .operated w:ith ~he feedstreams pa~sing through alternate passages in the burner. Typical modes of operation are summari2ed in T~bles I and II below.

Table I lists the materials being introduce~ into the gasifier by way of the buxner and their corr~sponding symbol. The solid carbon~ceolis fuel (B), water ~C), and liguid hydrocarbonaceous material (E) may bs mixed together in various combinatlons upstream from the hurner inlet to produce a pumpable slurry which may be introduced into the burner and then passed through one the sevexal free-flow passsage~ of the bur~er as shown in Table II. Fox example, ~he first entry in Table II shows ~hat a pumpable slurry stream comp~ising solid carbonaceous fuel (B) in admixture with water (C) may be passed through the first annular passage and/or the third annular passage in ~he burner, i.e. Fig. 1 and ~. In ordinary operation, whenever a fuel stream is introduced into a passage in one section of the bur~er, a corresponding stream of free-oxygen containing gas optionally in admixture with steam is simultaneously passed through the free passage in the same section of the ~urner.
TABLE I
Mat S~mbol 20 Free-oxygen Containing Gas A
Solid Carbonaceous Fuel Water or Carbon ~ioxide C
Steam D
Liguid ~ydrocarbonaceous Material E
TeMperature Moderating Gas F
Gaseous Hydrocarbon Fuel G

TABLE Il First Second Third Central ~nnular Annular Annular 30 Conduit Passa~ Passaqe Passa~e A B ~ C A B + C
B + C A B + C A
A + D B ~ E A ~ D B + E
B + E A + D B + E A + D
B ~ C A E A
E A E
A E A E
E A B t C A
A G A B + C
A G A ~ D E
A E ~ F A E + F

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Other modes of operation of the subject invention are possible in addition to those shown in Table II.
When one o the fuel streams is a liquid hydrocarbon 'or the liquid carrier for the slu~ry of solid carbonaceous fuel is a liquid hydrocarbonaceous material premature combustion within the burner may be avoided by one or more of the following:

(1) employlng less retraction of the ends of the central and third conduits from the face of the burner.
(2) keeping the fuel below its autoignition temperature, t3) discharging the multiphase mixture at the central and annular exit ori~ices at the tip of the burner with discharge velocities that exceed the flame propagation velocity.
(4) including watex in the solid fuel slurry, (5) mi~ing steam with ~ie air, (6) using air or air enriched with oxygen i.e. up to about 40 vol-% 2 The subject burner assembly is ins~rted downward through a top i~let port of a compact unpacked free-flow noncatalytic refractory lined syn~hesis gas generator, for example as show~ in coassigned U.S. Pate~t No. 3,544,291.
The burner extends along the central longitudinal a~is of the gas generator with the down~tream end di~charging directly into the reaction zona. The relative proportions of the reactant feedstreams and optionally temperature moderator that are intxoduced into the gas yenerator are carefully regulated to convert a substantial portion of the carbon in ~he fuel e.g., up to about 90% or more by weight, to carbon oxides; and to maintain an autogenous reaction zone temperature in the range of about 1700 to 3500F., preferably :in the range o 2000 to 2800F.

The dwell time in the reaction zone is in the ran~e of about 1 to 10 seconds, and preferably in the range of about 2 to 8. Wi~h substantially pure oxygen feed to the gas generator, the composition oi. the ~ffluent gas from the gas generator in mole % dry basis, may be as ollows:
H~ 10 to 60, C0 20 to 60, C02 5 to 40, CH4 Q.01 to 5, H~S +
COS nil to S, N2 nil to 5, and A nil to 1.5. With air feed to the gas generator, the composition of the generator effluent gas in mole % dry basls may be about as follows:
H2 2 to 30, C0 5 to 35, C02 5 to 25, CH4 nil to 2, H2S +
COS nil to 3, N2 gS to 80, and ~ 0.5 to 1.5. Uncoverted carbon and ash are contained in the effIuent gas stream.
Advantageously, in ano~her embodiment of the subject invention the subject burner may be used as ~he preheat burner during start up of the y~sifier, as well as for the production burner. Start-up procedures ar~ ~lereby simplified~ Previously, time was lost when the gas preheat burner was replaced by the production burner, and the gasifier cooled down. Now the gasifier may be brought up ~0 to operati~g temperature and held there by simultaneously passing fuel ga~ through the central conduit and air through all of ~he o~her passages in the burner for feedstreams including the passages leading from the gaseous media distribution header located in the face~plate.
The fuel gas and air are mixed together to produce a well-di~tributed blend. Burning of the mixture by substantially complete combustion then takes place in the reaction zone of the gas generator at an ~bsolute pres~ure in the range of about 0.56 to 300 atmospheres, and

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preerab1y at 1 atmosphere. The p~oducts of ~he complete combustion are removed from reaction zone. For example, they may be vented to ~he a~nosphere. By this means, the reactio~ zone is heated to ~le temperature required for ignition of the autothermal partial oxidation reaction of the principal fuel selected from the group consisting of a pumpable slurry of solid carbonaceous fuel, liquid or yaseous hydrocarbon fuel~ and mixtures thereof with a free-oxygen containing gas and with or without a temperature moderator. FOI e~ampl~, the autoignition temperatuxe may be in the range of about 2000 to 2700F.
At this point, the fuel gas and air are cut off, and the principal fuel a~d free-oxygen containi~g gas, with or wi~hcut admixture with a temperature moderator are passed through the respective passages in ~he ce~tral and/or annular sections of the burn~r.
The stream of principal fuel and free-o~yyen containing gas are mixed together to produce a well~distributed blend. The mixture igllites by ZO autoignition and burns by partial oxidation downstream in the reaction zone of ~he ~ree-1Ow noncatalytic gas generator.
DESCRIPT~N OF T~WING
A more complete understanding of the invention may be had by reference to the accompanying schematic drawing which show the subject invention in detail. Although the drawing illustrate preferred e~bodiments of the invention, it is ~ot intended to limit the subject inventi.on to ~he particular apparatus or materials described. Corresponding ~ 17 -parts in ~he several igures have khe same reference numbers.
Referrlng to Fig. 1, a high turndown, de-slaggi~g burner assembly is depicted. Burner 1 i5 inskalled with downstre~m face 2 passing downwardly through a port in ~he top of a free flow partial oxdia~ion synthesis gas generator. The longitudinal central axis of burner 1 is preferably ali~ned along the ce~tral axis of the s~nthesis gas generator by means of mount~ng flange 3. Burner 1 comprises central, second, third and outer concentric cylindrically shaped conduits 4, S, 6 and 7 respectively.
~n annular coaxial water-çooled face plate 8 i5 located at the downstre~n end of the burner. External cooling coils 9 may encircle the downstream end of burner 1. Inlet pipes 15 - 18 for the reactant feedstreams are connected to central conduit 4, and concentric cylind~ical conduits 5 to 7, respectively. X~l~t pipe 19 for air or soot blowing or de~slagging gaseou~ media is connected to outer conduit 17.
Burner 1 comprises two principal sections, i.e.
central and annular sections. The burner may be used with ei~her one or both sections operating simultaneously.
Thus, a pair of reactant feedstreams may be introduced into either one or both sections.
The central section of the burner comprises central co~duit 4,.second cylindrlcal coaxial conduit 5, and the a~nular pass~ge therebetween. The annular section of ~he burner comprises the thiFd cylindrical coaxial conduit 6, the outer cylindrical coaxial conduit 7, and two aDnular passages. A pair of reactant feedstreams may be introduced into ~he central section of the burner, or example, by passing th~ stream of free-oxygen co~taining gas in line 26 into central conduit 4 by way of line ~6, flow control means 27, lin~ 28, and inlet pipe 15. Simultaneously, a portion o the feedstream of coal-water slurry in line 31 may be passed into the ~econd cylindrical conduit by way of line 31, flow control means 32, line 33 and inlet pipe 16.
In a similar manner, a pair of reacta~t feedstxeams may be introduced into the annular section of the buxner, for example, by pa3sing a portion of the free-oxy~n containln~
gas in line 35 into the third cylindrical conduit by way of line 35, flow con~rol m~ans 36, line 37, and pipe 17.
Simultaneously, a portion of the feedstream of coal-water slurry in line 38 may ~e passed into outer cylindrical conduit 7 by way of line 38, flow control means 39, line 40, and pipe 18.
In another embodiment, the eedstreams ar~
interchanged so that coal-water slurry is in lines 26 and a portion of which may be i~troduced into central conduit 4 ~0 and/or ~hird conduit 6. Simultaneously, the free-oxygen - containing gas is in lines 31 and 38, and a portio~ of which may-be introduced into second conduit 5 and/or outer conduit 7.
~ dvantageously, a gaseous material such as air or a soot blowing or de-slagging madia in line 45 is supplied to a p~ssage extending longitudinally within the wall of outer conduit 7 (1:o be further de~cribed3 by way o line 45, flow control means 46, line 47, and pipe 19.

Referring to Fig. 2, t~ere is depicted a longitudinal cross~section of the upstream and downstream ends of the burner shown in Fig. 1.
With respect to ~he upstream end of burner 1, disc plate 50 is attached to, for example by welding, and closes off central conduit 4 at the upstream end. The ~eedstream in line 15 passes down unobstructed central passage 51.
Central conduit 4 and second conduit 5 are spaced apart by a plurality of spacers 52 to provide concentxic first annular p~ssage 53. The feedstream in line 16 passes down unobstructed annular passage 53. Disc plate 54 is attached to and closes off the upstream end of second conduit 5 and annular passage ~3. CentrAl conduit 4 passes vertically ~hrough plate 54 and makes a gastight seal ~herewith.
Second conduit 5 and third conduit 6 are spaced apart by a pluxality of spacers ~5 to provide a concentric second an~ular passage 5~. The feedstream in line 17 passes down unobstru~t~d annular passage 56. Disc plate 57 is ~ttached to and closes off the upstream ends of third conduit 6 and annular passage 56. Second conduit 5 passes vertically through plate 57 and makes a gastight seal therewi th.
Third conduit 6 and outer conduit 7 are spaced apart by a plurality of spacers 58 to provide a concentric third annular passage 59. The feedstream in line 18 passes down unobstructed annular passage 59. Disc plate 60 is attached - to and closes off the upstream end of outer cond~it 7 and annular passage 59. Xnlet pipe 19 is shown in communication with the uE1stxeam encl of longitudinal passage )ne~ns 61.
Passas~e mearls 6ï is shown in Fig. 2 as a concentric right cylindrical shaped ar~ular passage that is coaxial with ~ 20 --.

~he central longitudinal axis of the burner. In another embodiment, said longitudinal passage means 61 may comprise a plurality of cylindrical shaped passages whose central lungitudinal axes extend parallel to the central longitu~inal axis of the burner. Such cy].indrical shaped passage6 may be egually spaced in a concenkri.c ring and pa~s longitudinally through the wall of outer conduit 7. Further, pas~age means 61 may be fed at its upstream end with air or other gaseous media from a plurality of inlet pipes 18 equally spaced around the circumference of the burner. The air or sootblowi~g or de-slagging gaseous media in line 19 passes down unobstructed passage 61.
With respect to the downstream end of burner 1, longitudi~al pas~age 61 at its downstream end is in communication with concentric annular air or gaseous media distribution header 65 in an~ular flat face-plate 8. A
plurality o right cylindrical ~haped passage means 66 are in commu~ication with distribution header 65 for passage of a plurality of high velocity jet streams of said gaseous 29 media at the face of burner 1. The plurality of passage means 66 are egually spaced in a concentric ring and fonm a right cylindrical or frusto-concial shaped pattern with a converging angle with ~he central longitudinal axis of the burner in the range of about O to 45, such as about 10 to 35. Alternatively, passage means 66 may be a single concentric .right cylindrical or frusto~conical shaped annular passage with a converging angle in ~he range of ~bout O to 45, and with or without distribution header 65.
Centra:l pre-mix chamber 67 is a single chamber whose length is determined by the distance that tip 68 of central - 21 ~

~3~

conduit 4 i9 retracted upstream from face 2 of burner 1.
Central pre~mix chamber 67 is bounded on all sid~s by ~he inside ~all of converging long radiu~ frusto-conical shaped noz21e 59 of second conduit 5. Starting upstream from the face of the burner a distance~ of about 2.5 times the ~inimum ~iameter of the central pre mix chamber exit orifice, in the embodiment shown conduits 4 7 may be substantially cylindrical. ~ frustoconically shaped insert 70 of thermal and wear resistant material i.e., ~ungsten or ~ilicon carbide is optionally i~serked in the downstream tip of nozzle 69.
~ nnular pre-mix chamber 71 is a single chamber whose length is determined by ~he dista~ce that tip 72 of the third conduit 6 is retracted upstream fxom face 2 of burner 1. ~nnular pre-mix chamber 71 comprises a coaxial generated co~erging long radius frustoconical ~haped annular passage. Annular pre-mix chamber 71 is bounded on ; all sides by ~he outside wall of con~erging long radius frustoconical 6haped nozzle 69 of seco~d conduit 5 and ~he inside wall of conv~r~ing long radius frustoconical shaped noxzle 73 of outer conduit 7. A frustoconically shaped ~ insert 74 of thermal and wear resistant material i.e., : tungsten or silicon carbide is optionally inserted in the downstream tip of nozzle 73.
~ ace plate 8 is pro~ided with a concentric "L" shaped annular passage 75 for cixculating cooling water. Cooling coils 9 are connected to the inlet and outlet of passage 75.

Although modificatio~s and variations of the invention may be made without departing from the spirit and scope ~hereo~, only such limitations should be imposed as are indicated in the appended claims.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows;

1. A burner for introducing first and second reactant feedstreams into a partial oxidation gas generator comprising: a central conduit; having a central longitudinal axis that is coaxial with the central longitudinal axis of the burner, closing means attached to the upstream end of said central conduit for closing off same; an unobstructed exit nozzle at the downstream and of the central conduit which discharges through a circular exit orifice located upstream from the face of the burner to provide a central pre-mix chamber that discharges through an unobstructed circular exit orifice at the face of the burner, inlet means connected to the upstream end of the central conduit fox introducing a first reactant feedstream; a second conduit coaxial and concentric with said central conduit along its length, an unobstructed exit nozzle at the downstream end of the second conduit which discharges through the circular orifice of said central pre-mix chamber at the face of the burner, spacing means between said central and second conduits for maintaining a spaced relationship and forming therebetween an unobstructed first annular passage with an unobstructed downstream annular exit orifice that discharges into the central pre-mix chamber, closing means attached to said second conduit and first annular passage at their upstream ends for closing off same, said central conduit passing through the upstream closed end of said second conduit and making a gastight seal therewith, and inlet means connected to the upstream end of the second conduit for introducing a second reactant feedstream; a third conduit coaxial and concentric with said second conduit along its length, spacing means for between said second and third conduits for main-taining a spaced relationship and forming therebetween an unobstructed second annular passage with an unobstructed downstream annular exit orifice located upstream from the face of the burner to provide a portion of an annular pre-mix chamber that discharges through an unobstructed annular exit orifice at the face of the burner, closing means attached to the second annular passage and third conduit at their upstream ends for closing off same, said second conduit passing through the upstream closed end of the third conduit and making a gastight seal therewith, and inlet means connected to the upstream end of the third conduit for introducing a third reactant feedstream; an outer conduit coaxial and concentric with said third conduit along its length, an unobstructed exit nozzle at the downstream end of the outer conduit which discharges through said annular exit orifice at the face of the burner, spacing means between said third and outer conduits for maintaining a spaced relationship and forming therebetween an unobstructed third annular passage with an unobstructed downstream annular exit orifice located upstream from the face of the burner that discharges into the remaining portion of said annular pre-mix chamber, closing means attached to the third annular passage and outer conduit at their upstream ends for closing off same, said third conduit passing through the upstream closed end of the outer conduit and making a gastight seal therewith, and inlet means connected to the upstream end of the outer conduit for introducing a fourth reactant feedstream; an outer annular water-cooled flat face-plate encircling the downstream end of the burner, said face-plate being cored to provide an annular passage for circulating water and an annular header for distributing a gaseous material, passage means extending longitudinally in the wall of said outer conduit and in communication with said distribution header, inlet means in communication with the upstream end of said longitudinal passage means for introducing said gaseous material, and downstream passage means in communication with said distribution header for discharging said gaseous material at the face of the burner.

2. The burner as described in Claim 1 provided with cooling coils encircling the outside circumference of the burner at the downstream end.

3. The burner of Claim 1 wherein the downstream tips of the exit nozzles of the central and third coaxial conduits are retracted upstream from the face of the burner a distance in the range of about 0.5 to 12 times the minimum diameter of the central pre-mix chamber exit orifice at the face of the burner.

4. The burner of Claim 1 wherein the downstream tips of the central and third coaxial conduits are retracted upstream from the face of the burner a distance of greater than two times the minimum diameter of the central pre-mix chamber exit orifice at the face of the burner.

5. The burner of Claim 1 wherein each of said four.
concentric coaxial conduits are substantially cylindrical shaped with a downstream end that gradually develops into a converging long radius frustoconical shaped nozzle at the downstream end of the burner.

6. The burner of Claim 1 wherein the passage means connected to said distribution header is directed inwardly toward the central longitudinal burner axis for soot-blowing or de-slagging the burner with a gaseous material selected from the group consisting of steam, N2, C02, recycled cooled product gas, and mixtures thereof.

7. The burner of Claim 1 wherein said longitudinal passage means in the wall of the outer conduit and the inlet means in communication thereof comprises a coaxial concentric annular shaped passage with a plurality of pipes in communication thereof.

8. The burner of Claim 1 wherein said longitudinal passage means in the wall of the outer conduit comprises a plurality of cylindrically shaped passages.

9. The burner of Claim 1 wherein said downstream passage means in communication with said distribution header comprises a coaxial concentric right cylindrical or frustoconical shaped passage with a converging angle in the range of about 0 to 45°.

10. The burner of Claim 1 wherein said downstream passage means in communication with said distribution header comprises a plurality of cylindrical shaped passages in a coaxial ring with the longitudianl central axis of said passages forming a right cylindrical or frusto-conical shaped pattern with a converging angle in the range of about 0 to 45°.

11. The burner of Claim 1 wherein said first and third reactant feedstreams, and said second and fourth reactant feedstreams, comprise streams of free-oxygen containing gas and hydrocarbonaceous or slurry of solid carbonaceous fuel, respectively.

12. The burner as described in Claim 3 provided with cooling coils encircling the outside circumference of the burner at the downstream end.

13. The burner as described in Claim 1 wherein said annular coolant passage in the face-plate is an "L" shaped passage for circulating cooling water.

14. The burner as described in Claim 1 wherein the downstream ends of the exit nozzles for said second and outer conduits are provided with frusto-conical shaped inserts made from a thermal and wear resistant material.

15. The burner as described in Claim 14 wherein said material is tungsten carbide or silicon carbide.

16. The burner as described in Claim 1 wherein said second and fourth reactant feedstreams or first and third reactant feedstreams comprise streams of a pumpable slurry of solid carbonaceous fuel selected from the group consisting of coal, lignite, coke from coal, char from coal, coal liquefaction residues, petroleum coke, particulate carbon soot, and solids derived from oil shale, tar sands, pitch, bits of garbage, dewatered sanitary sewage, and semi solid organic materials such as asphalt, rubber and rubber-like materials including rubber automobile tires and a liquid carrier selected from the group consisting of water, liquid hydrocarbonaceous materials, and mixtures thereof; and respectively said first and third or second and fourth feedstreams comprise a free-oxygen containing gas selected from the group consisting of air, oxygen-enriched air, and substantially pure oxygen optionally in admixture with steam.

17. In a continuous process for the manufacture of gas mixtures comprising H2, CO, CO2 and at least one material from the group H2O, N2, A, CH4, H2S and COS by the partial oxidation of a feedstream comprising a pumpable slurry of solid carbonaceous fuel in a liquid carrier and a feedstream of free-oxygen containing gas optionally in admixture with a temperature moderator, said partial oxidation occuring in the reaction zone of a free-flow gas generator at an autogenous temperature in the range of about 1700° to 3500°F, and a pressure in the range of about 5 to 250 atmospheres, the improvement which comprises: (1) passing a first stream of a first reactant feedstream comprising a slurry of solid carbonaceous fuel in a liquid carrier in liquid phase at a temperature in the range of about ambient to 500°F., a pressure in the range of about 5 to 250 atmospheres, and a velocity in the range of about 1 to 50 ft. per second through either the central or first annular passage of a burner and into a central pre-mix chamber in said burner, wherein said burner comprises a central conduit having a central longitudinal axis that is coaxial with the central longitudinal axis of the burner, closing means attached to the upstream end of said central conduit for closing off same; an unobstructed exit nozzle at the downstream end of the central conduit which discharges through circular exit orifice located upstream from the face of the burner to provide a central pre-mix chamber that discharges through an unobstructed circular exit orifice at the face of the burner, inlet means connected to the upstream end of the central conduit for introducing a reactant feedstream; a second conduit coaxial and concentric with said central conduit along its length, an unobstructed exit nozzle at the downstream end of the second conduit which discharges through the circular orifice of said central pre-mix chamber at the face of the burner, spacing means between said central and second conduits for maintaining a spaced relationship and forming therebetween an urlobstructed first annular passage with an unobstructed downstream annular exit orifice that discharges into the central pre-mix chamber, closing means attached to said second conduit and first annular passage at their upstream ends for closing off same, said central conduit passing through the upstream closed end of said second conduit and making a gastight seal therewith, and inlet means connected to the upstream end of the second conduit for introducing a reactant feedstream; a third conduit coaxial and concentric with said second conduit along its length, spacing means between said second and third conduits fox maintaining a spaced relationship and forming therebetween an unobstructed second annular passage with an unobstructed downstream annular exit orifice located upstream from the face of the burner to provide a portion of an annular pre-mix chamber that discharges through an unobstructed annular exit orifice at the face of the burner, closing means attached to the second annular passage and third conduit at their upstream ends for closing off same, said second conduit passing through the upstream closed end of the third conduit and making a gastight seal therewith, and inlet means connected to the upstream end of the third conduit for introducing a reactant feedstream; an outer conduit coaxial and concentric with said third conduit along its length, an unobstructed exit nozzle at the downstream end of the outer conduit which discharges through said annular exit orifice at the face of the burner, spacing means between said third and outer conduits for maintaining a spaced relationship and forming therebetween an unobstructed third annular passage with an unobstructed downstream annular exit orifice located upstream from the face of the burner that discharges into the remaining portion of said annular pre-mix chamber, closing means attached to the third annular passage and outer conduit at their upstream ends for closing off same, said third conduit passing through the upstream closed end of the outer conduit and making a gastight seal therewith, and inlet means connected to the upstream end of the outer conduit for introducing a reactant feedstream; an annular water-cooled flat face-plate encircling the downstream end of the burner, said face-plate being cored to provide an annular passage for circulating water and an annular header for distributing a gaseous material, passage means extending longitudinally in the wall of said outer conduit and in communication with said distribution header, inlet means in communication with the upstream end of said longitudinal passage means for introducing said gaseous material, and downstream passage means in communication with said distribution header for discharging said gaseous material at the face of the burner; (2) simultaneously and concurrently passing a second reactant feedstream comprising a free-oxygen containing gas optionally in admixture with steam through either the central conduit or the first annular passage whichever is free at a temperature in the range of about ambient to 1500°F., a pressure in the range of about 5 to 250 atmosphere, and a velocity in the range of about 100 feet per second to sonic velocity; (3) mixing together said first and second reactant feedstreams from (1) and (2) in said central pre-mix chamber and vaporizing about 0 to 100 volume % of said liquid carrier to produce a multiphase mixture at a temperature below its autoignition temperature and in which the ratio of the atoms of free-oxygen plus atoms of organically combined oxygen in the solid carbonaceous fuel per atom of carbon in the solid carbonaceous fuel (O/C
atomic ratio) is in the range of 0.5 to 1.95; and the H2O/fuel weight ratio of lbs. of H2O per lb. of solid carbonaceous fuel plus liquid hydrocarbonaceous material, if any, is in the range of about 0.1 to 3.0; (4) simultaneously and concurrently passing a second stream of said first reactant feedstream at substantially the same temperature, pressure, and velocity as specified in (1), through either the second or third annular passage of the burner and into the annular pre-mix chamber in the burner;
(5) simultaneously and concurrently passing a second stream of said second reactant feedstream at substantially the same temperature, pressure and velocity as specified in (2) through either the second or third annular passage of the burner whichever is free and into said annular pre-mix chamber; (6) mixing together said first and second reactant feedstreams from (4) and (5) in said annular pre-mix chamber and vaporizing about 0 to 100 volume % of said liquid carrier to produce a multiphase mixture at a temperature below its autoignition temperature and having substantailly the same O/C atomic ratio and H2O/fuel weight ratio as specified in (3); (7) discharging the multiphase mixtures produced in the pre-mix chambers in (3) and (6) from the burner; and (8) mixing together and reacting by partial oxidation the multiphase mixtures from (7) in the reaction zone of the gas generator.

18. The process as described in Claim 17 provided with the step of simultaneously and concurrently with (7), discharging at least one high velocity jet stream(s) of sootblowing or de-slagging gaseous media through said longitudinal passage means in the water-cooled face-plate.

19. The process of Claim 18 wherein said sootblowing or de-slagging gaseous material is selected from the group consisting of steam, CO2, N2, a recycle portion of the product gas, and mixtures thereof.

20. The process as described in Claim 17 wherein the liquid carrier for said solid carbonaceous fuel is water and said pumpable slurry has a solids content in the range of about 30 to 75 weight percent; and wherein the tips of said central and third conduits are retracted upstream from the face of the burner a distance of 0.5 to 12 times the minimum diameter of said central pre-mix chamber exit orifice at the face of the burner to provide said central and annular pre-mix-chambers

21. The process as described in Claim 17 wherein the tips of said central and third conduits are retracted upstream from the downstream face of the burner a distance in the range of greater than 2 to 10 times the minimum diameter of said central pre-mix chamber exit orifice at the face of the burner.

22. The process as described in Claim 17 wherein said pumpable slurry of solid carbonaceous fuel in a liquid carrier said solid carbonaceous fuel is selected from the group consisting of coal, lignite, coke from coal, char from coal, coal liquefaction residues, petroleum coke, particulate carbon soot, and solids derived from oil shale, tar sands, pitch, bits of garbage, dewatered sanitary sewage, and semisolid organic materials such as asphalt, rubber and rubber-like materials including rubber automobile tires; and said liquid carrier is selected from the group consisting of water, liquid hydrocarbonaceous materials, and mixtures thereof;
and said free-oxygen containing gas is selected from the group consisting of air, oxygen-enriched air, and substantially pure oxygen.