Coal gasification apparatus

Coal gasification apparatus wherein a combustible mixture is formed and burned, comprising a combustion supporting gas such as oxygen, and a coal slurry. The hot products of combustion which issue from the burner, are directed into the reaction chamber of a synthesis gas generator. To avoid deposition of slag and ash particles along the hot, exposed face of the burner, a dynamic fluid blanket or barrier is directed transversely of the burner face. The reaction chamber includes an elongated port in which the burner is registered. To shield the burner, a manifold depends from the reaction chamber wall adjacent to the burner face and projects a stream of coolant fluid transversely of the face.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to an apparatus for generating a synthetic gas by 
introducing a combustible mixture comprising hydrocarbon fuel, free 
oxygen-containing gas, and optionally a temperature moderator (liquid or 
vapor) into a free-flow partial oxidation synthesis gas generator. 
2. Description of the Prior Art 
In the partial combustion of a hydrocarbon with oxygen, or air enriched 
with oxygen, in the presence of steam and/or carbon dioxide, temperatures 
between 1,100.degree. and 1,500.degree. C. are often reached. Special 
requirements are therefore placed on the design and the material from 
which the burner is constructed to avoid damage to the latter. 
An essential requirement in burner construction of the type contemplated is 
that they be cooled or otherwise protected from the high temperature 
environment. This is most often and most readily achieved by circulating 
water or a similar coolant through the burner unit. Thus, by constructing 
the burner both internally and externally with coolant passages, a 
sufficient amount of heat transfer to the circulating cooling fluid can be 
achieved to minimize and stabilize the temperature which the burner itself 
reaches. 
Normally, the oxidizing flame which combusts the mixture, introduces the 
hot flame as well as the products of combustion into the reaction chamber 
of a synthetic gas generator. The latter is lined with a suitable 
refractory material to avoid damage as a result of the high temperatures 
that will be reached and sustained. 
A relatively vulnerable part of the apparatus however is that section of 
the burner which is continuously exposed for extended periods of time to 
the high reactor temperatures. Although means have been provided for 
cooling internal segments of the burner, the problems which result from 
the high temperature still persist. 
For example, external walls of the burner are generally surrounded with a 
cooling coil or the like. The latter includes means to circulate a liquid 
such as water to effectuate a cooling action. Further, the lower or flame 
end of the burner is provided with passages which permit coolant to be 
internally circulated to maintain a desired temperature range. 
In either instance, the forward most vulnerable face of the burner, can 
reach certain temperatures, or range of temperatures within which 
accumulations of particular slag or ash will tend to cling to the exposed 
burner face. Such a slag build-up will cause a reduction in burner 
efficiency and eventually impairment of operation and eventual unit 
shutdown. 
These accumulations are prompted generally by back mixing of the 
combustible particles or ash, as the particles enter the reactor. Here 
they are caught up into the violently turbulent flows of the gas 
associated with the high velocity flame. 
More specifically it is found that if the temperature on the exposed burner 
face is in excess of 750.degree. to 900.degree. F., ash particles will be 
prone to stick thereto. If, on the other hand, the temperature is kept 
lower than 750.degree. to 900.degree. F. on the face of the burner, the 
ash sticking possibility will be substantially avoided. 
In burners that function as required, it is found that a particle build-up 
along the burner face will generally commence at the lip of the discharge 
opening or nozzle. Thereafter, the build-up will progress radially outward 
from the nozzle and gradually cover a substantial segment of the exposed 
face. Slag will also build upon itself due to progressive insulation from 
the cooling coil/channel. 
One way for precluding or at least limiting this slag build-up along the 
burner face is to inject steam directly into the combustible mixture 
within the burner itself. This step will facilitate the avoidance of 
undesired accumulations at the discharge lip. It will not, however, 
completely preclude the accumulations as herein mentioned. 
For example, the back mixing and flow of the particulated matter as a 
result of the turbulence immediately inside the reactor, will continue to 
cause or prompt a certain degree of build-up at the burner face. 
Toward overcoming the above stated problems, the present invention is 
addressed to means for providing within the generator reactor chamber a 
fluid, dynamic shield which protects the entire burner face. The shield 
takes the configuration of one or more jets of a fluid such as steam, 
which are projected transversely of the face from a point at the burner 
periphery. 
A number of fluids such as steam, CO.sub.2 or even water could serve as the 
protective dynamic shield. For the present disclosure, however, the fluid 
will be considered to be steam. 
Physically, one or more high velocity steam jets are caused to sweep the 
burner face. The jets first of all form a barrier which precludes the hot 
particles from getting to, or contacting the face. Secondly, the fluid jet 
is so aligned that it will flow parallel to the face, or will impinge 
against the face preferably adjacent to the discharge lip. This creates a 
thermal radiation/convection shield to keep the burner face below 
750.degree. to 900.degree. F. Thirdly, the flow will clear the face of any 
accumulation that might be initiated. 
It is therefore an object of the invention to provide in combination, a 
synthetic gas generator and a burner which is adapted for use in 
combusting a coal-oxygen mixture to achieve a partial oxidation of the 
gaseous product. A further object is to provide a gas generator adapted to 
register a burner of the type contemplated, that is capable of 
withstanding undesired particulate depositions along the burner exposed 
face. A still further object is to provide a gas generator coolant 
manifold burner wherein one or more high velocity fluid jets are directed 
to sweep across the face of a burner to maintain it free of accumulated 
particulate matter, and to concurrently protect the face by establishing a 
fluidized radiation/convection shield thereacross.

DESCRIPTION OF THE APATUS 
One embodiment of a partial oxidation apparatus of the type generally 
contemplated is shown in FIG. 1 and comprises primarily a burner 10. The 
latter is normally connected to a source of oxygen 11 as well as to a 
source 12 of particulated hydrocarbon such as a coal slurry or the like. 
Thus, the two elements when introduced to the burner, will form a 
combustible mixture which, as it burns, forms products of combustion. The 
latter are discharged into the reaction chamber 13 of generator 14. 
It will be appreciated that a synthetic gas generator of this type is 
subjected to sustained high internal temperatures and is formed basically 
of a steel shell 16. The shell's inner walls and openings therefore, are 
so constructed and lined with a refractory material 17 that they will 
withstand the harsh environment. 
The discharge end 18 of burner 10 is positioned to introduce the resulting 
flame, as well as the products of combustion into refractory lined 
reaction chamber 13. In the latter, the hot products of the partial 
combustion are collected. 
Generator 14 reaction chamber 13 as noted, is provided with a refractory 
liner as well as with a refractory lined access opening 19, within which 
burner 10 is registered. Said opening 19 as shown, can include an 
elongated neck 21 which surrounds the burner to provide a degree of 
protection thereto. 
The upper end of burner 10 is provided with a flange 22 which corresponds 
with a support flange 23. The latter projects outwardly from reactor neck 
21 to hold the burner in place through bolts, and yet permit its ready 
removal for replacement or repair. 
Burner 10 comprises primarily an elongated body 26 having a longitudinal 
passage which extends the body length. The lower end of said passage 
terminates at a cylindrical opening 27 which is defined by a peripheral 
lip 28 at the burner face 29. A progressively narrowing wall 31 connects 
the body elongated passage with lip 28, to define a mixing compartment 32. 
The elongated passage through body 26 is provided with a conduit 33 
disposed preferably coaxially thereof. Discharge port 34 terminates at 
mixing compartment 32 between said conduit 33 and said discharge port. 
Proper positioning of conduit 33 defines an elongated annular passage 36 
between the conduit walls, and the adjacent walls of the body 26. Annular 
passage 36 is communicated with source 12 of coal slurry and/or steam, by 
way of a valved conductor 37 to permit the introduction of the 
subsequently formed combustible mixture, into the mixing compartment 32. 
For the present description, oxygen will be referred to as the combustion 
supporting medium which is introduced through central conduit 33 by way of 
valved conduit 38. 
In a similar manner, annular passage 36 is communicated with conductor 
passage 37, which is controlled through valve 39. Said valve is operable 
to regulate the volume of particulated or finely ground coal mixture which 
is introduced from source 12 for combining with oxygen, to establish the 
desired combustible mixture in mixing compartment 32. 
Lower face 29 of burner body 26 as herein noted is exposed to the maximum 
temperature and the turbulent environment experienced within reaction 
chamber 13. Said lower face 29 is normally formed of a heat resistant 
material such as inconel or the like which will be capable of functioning 
in spite of the high temperatures to which it is constantly exposed. 
However, although capable of withstanding the elevated temperatures, face 
29 is nonetheless susceptible to the herein noted particulate 
accumulations. 
To achieve the desired degree of cooling and thermal protection for burner 
10, the latter is provided with one or more internal, strategically 
positioned channels such as 41. The latter are arranged to circulate a 
coolant, preferably water. The cooling water channels are so arranged 
within burner body 26 to assure adequate heat removing capability thereby 
to stabilize the temperature within burner mixing compartment 32, and to 
protect the entire unit from excessive heating. 
Further cooling of the burner is achieved on body 26 by an externally 
positioned cooling coil 42. The latter is formed as shown of a thermally 
conductive material to withstand the extreme temperatures, and yet remain 
capable of conducting a flow of water through conduits 51 and 52 at a 
sufficient rate to maintain a desired temperature gradient. 
To avoid the herein mentioned undesired solid deposit of ash, slag and 
other particulate matter along burner face 29, an annular manifold 43 is 
provided. The manifold is disposed within reaction chamber 13 in a manner 
to cooperate with burner 10, and is communicated with a pressurized source 
44 of fluid by way of pipe 46 and control valve 47. 
In the embodiment shown, the torus-shaped, annular manifold 43 depends 
downwardly from generator shell 16 at the lower end of neck 21. 
Preferably, it extends inwardly to engage the burner face 29. 
Manifold 43 comprises in essence a substantially closed annular chamber 48 
which is formed of a series of welded plates or communicated compartments. 
The manifold can engage the lower end of burner 10, or it can be 
positioned sufficiently close thereto as to permit direction of the fluid 
flow which is projected transversely of the burner face 29. 
As shown in FIG. 2, in one embodiment manifold 43 is provided with a single 
constricted opening 49 which communicates with fluid chamber 48 to direct 
a pressurized jet of fluid across the burner face 29. To function most 
effectively, the fluid, such as steam, preferably traverses burner face 29 
in a substantially uninterrupted pattern. 
The steam will thus achieve at least two functions. Firstly, it will define 
a dynamic curtain or barrier across burner face 29. This will 
substantially preclude slag or ash particles from physically contacting 
the face. Secondly, the velocity of the steam jet or jets will be such as 
to dislodge any solid accumulation which might be initiated at lip 28. 
Thirdly, the disposition of the jet will be such as to afford a thermal 
radiation shield between face 29 and reaction chamber 13. 
The volume of steam which leaves constricted opening 49 will be regulated 
to avoid adversely affecting production of the partially oxidized product 
in reaction chamber 13. 
Manifold 43 is suspended within the reaction chamber 13 in a manner that it 
will cooperate with the removable burner 10, and yet itself be removable 
from generator 14. Thus, manifold 43 is removably fastened to a series of 
elongated support brackets 53. The latter are fastened to the adjacent 
walls of neck 21, preferably behind the refractory brick layer which forms 
the inner wall of the neck. Said brackets 53 are so shaped as to not only 
position burner 10 but also to maintain contact with the latter in spite 
of thermal expansion and contraction while operating. The brackets thus 
embody a transverse segment 56 that will permit burner to expand 
downwardly against manifold 43 when the burner becomes heated. 
The fluid connection 54 which conducts steam into manifold 43 includes at 
least one member. The latter, to be afforded a degree of protection, can 
also be disposed behind the refractory brick layer within the neck 21. 
Operationally, manifold 43 extends inwardly toward the discharge end of 
burner 10. To facilitate cooperation with the burner face 29, the manifold 
upper side can be contoured or shaped that it slidably or abuttingly 
receives the lower edge of the burner 10. To this end, manifold support 
members 53 can be conformed with neck 21 in a manner to permit the 
manifold to be displaced downwardly, and remain in contact with burner 10 
when the latter is bolted into place at flange 23.