Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
B~CKGl~OUN~ OF THE INVENTION
FIELD OF THE INVENTION
This invention concerns high temperature furnace
structure, in general. More specifically, it deals with an
improvement in the intexnal structure for a high temperature
furnace of the type which is used as -the generator in a coal
gasification procedure.
DESCRIPTION OF THE PRIOR ~RT
In a furnace of the type that is employed in con-
nection with coal gasification or the like, the internal
structur~ of the generator, i.e. furnace, includes an outer
steel shell and it has the interior buil~ up of walls of
refractory bricks. These walls are held in place with
insulating cement and by castable insulation. The yeometric
structure of the brick walls or columns includes a dome at
the top to accommodate the hemispherical shape of the vessel
itself. Such a generator is subjected to high wear condi-
tions since the internal temperatures of the gasification
process are ext:remely high and the generation of liquid slag
tends to erode the inner surfaces of the walls Such ero-
sion is particularly heavy down the side walls below the
dome configuration. Consequently, the operative life of
such a furnace is limited, necessitating repair and re-
building of the interior wall structure which is a time-
consuming and expensive operation.
While ~arious furnace wall interior structures
have been shown in earlier patentst such as those to Liptak,
No. 1,463t053; Dobie, No. 1~806,793; Beall, No. 2,114,960;
Pollen, No. 2,548,908; N~gaard, No~ 2,818,035; Potocnik et
al, No, 3j315,950; and Boggum et al, No 4,130,391; none of
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these has dealt with a principal concern of the applicant's
invention, i.e. that relating to the ability to replace an
inner wall of refractory bricks without disturbing the
remainder o~ the furnace wall structure. Such remainder
includes the dome that must be supported at the lower edges
thereo~.
Consequently, it is an object of this invention to
provide for high temperature furnace structure that includes
an inner hot ~ace wall or lining of refractory bricks that
can expand without raising the dome structure of the furnace
interior.
Another object of the invention is to provide a
high temperature ~urnace structure having a hot face wall or
column of interior lining which can be replaoed easily
without concern for the support o~ the dome section of the
furnace interiorO
Another object of the invention is to provide a
hot face brick wall or column that can withstand the high
temperatures in a gasifier generator type of furnace, with-
out requiring sufficient crushing strength to support the
dome portion of such a furnace.
SUMM~RY OF _IE INVENTION
Brie~ly, the invention is in combination with a
high temperature furnace having an outer shell and adapted
for being mounted in an upright position. The ~urnace in-
cludes a temperature resistant lin.ing with a dome at the
upper end thereo~. The said linin~ comprises at least one
layer of first insulating means inside o~ said shell and
supporting said dome. It also comprises second insulating
means inside of said first insulating means~ Said second
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insulating means is free standing inside the bottom o~ said
dome, whereb~ said second insulating means may expand with-
out applying any upward thrust to said dome~
Again bxiefly, the invention is in combination
with a high tempera~ure furnace having an outer shell and
adapted for being mounted in an upright position. It in~
cludes a temperature resis~ant lining which comprises a dome
constructed of refractory bricks and located at the upper
end o~ said lining, and a first layer of firebricks having
sufficient stxength to support said dome and having said
dome resting thereon. It also comprises a layer of in-
sulating cement inside of and adjacent to said shell, and a
plurality o~ layers of firebricks between said cement and
said first layer of firebricks. It also comprises a second
layer of ~ree standing refractory bricks located inside of
said first laye:r o~ firebricks for withstanding said high
temperature. The said second layer compxises replaceable
bricks and extends vertically above the bottom of said dome
to permit expansion without any upward thrust to said dome.
And, the temperature resistant lining comprises castable
insulation filling spaces between said layer of insulating
cement and said dome and said other layers of bricks.
Once more briefly, the invention concerns a high
temperature furnace for coal gasification and the like, and
it comprises a combustion chamber for carrying out said coal
gasification having an inlet at the top of said chamber and
an outlet at the bottom. It also comprises a dome surround-
ing said inlet and constructed of hot ~ace brick for ex-
posure to said coal gasification, and a first side wall for
supportin~ said dome and constructed o~ insulating brick
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having sufficient crushing strength at temperatures below
said coal gasification. It also comprises a second side
wall inside of said first side wall and constructed of hot
face brick for exposure to said coal gasification without
support for said dome.
BRIEF D~SCRIPTION OF THE DRAWINGS
~ . . . _
The foregoing and other objects and benefits of
the invention will be more fully set forth below in connec-
tion with the best mode contemplated by the inventor of
carrying out the invention~ and in connection with which
there are illustrations provided in the drawings, wherein:
Fîgure 1 is a schematic longitudinal cross section
illustrating a furnace according to the invention; and
Fi~ure 2 is an enlarged lateral fragmentary cross
section of one side wall of the furnace tha~ is illustrated
in Figure 1, taken along the lines 2-2 of Figure 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
. . . ~
In connection with coal gasification procedures
and the like, there is a necessity for constructing a
generator that is, in effect, a furnace where the gasifi-
cation procedure takes place. Such a generator structure
is, in fact, a furnace construction which includes a steel
shell that must be lined with refractory materials in order
to withstand the high temperatures oE the gasi~ication
combustion takiny place inside. Furthermore, the gasifi-
cation of solids involves the generation of a high temper
ature liquid slag that tends to run down the walls of the
furnace and is highly erosive in its e;Efect on the inside of
such wall. Consequently, the operative life of the interior
lining structure is quite short, and the replacement process
becomes ver~ expensive. This is especiall~ so since the
usual structure involves a dome at the top of the furnace,
which dome is formed of high temperature resistant refrac-
tory bricks and is supported by vertical side walls of
similar refractory bricks therebelow. However, the erosive
effects are much greater below the dome portion so that the
lower wall portion is what needs replacement while the dome
itself remains substantially in~act. But, prior to this
invention when the supporting walls needed replacement, the
dome also had to be removed since the supporting walls
beneath it were being removed for replacement thereof.
An internal structure of a furnace according to
this invention provides for the inner wall layer of the
furnace to be replaceable without concern for support of the
dome. And, an additional benefit is realized in that the
wall supporting the dome portion may be constructed of
stronger bricks since they will not be subjected to the high
temperatures or erosive conditions that the other interior
surfaces of the ~urnace will be. Also, by having an in
terior layer made o~ hot face bricks, it may expand sep-
arately from the supporting wall structure of the dome.
Thus, it is relieved of any support load or pressure caused
by expansion ef~ects.
It may be noted that in this disclosure the use of
the terms "refractory bric}cs" is intended to be particularly
concerned with extra high temperature bricks that can stand
the hot face location on the inner lining of a furnace
chamber. Also, the term "~irebrick" is intended to connote
a relatively high temperatuxe resistant brick that, however,
may be constructed to have better crushing strength than
bricks designated as "re~ractory bricks~"
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Referring to the drawings, it will be observed
that there is a generator for coal gasi~ication which is
schematically illustrated as the high temperature furnace
according to this invention. Thus, the furnace includes an
outer shell 11 which may be constructed of any feasible
material such as steel or the like. The shell 11 is adapted
for mounting in an upright position such as indicated in
Figure 1~ Consequently, there is a flanse 12 at the bottom
of the shell 11. Inside the ~urnace 11 there is a combus-
tion chamher 15 where the coal gasification reaction takes
place. And, there is an inlet 16 at the top and an outlet
17 at the bottom of the chamber 15.
Inside of the shell 11 there is a temperature
resistant lining that includes a dome 20 which is construc-
ted of refractory bricks and is, as indicated, located at
the upper end o~ the furnace lining. Also, there is a first
layer of fi.rebricks 21 that is made of suficient strength
to support the dome 20. The base of the dome 20 rests on
the top of the wall or columns of bricks 21. And, there is
a layer of insulating cement 24 which is located inside of
and adjacent to the shell 11. In addition~ there are a
plurality of layers 25 and 26 of firebricks that are located
between the cement layer 24 and the first layer of fire-
bricks 21.
There is a second layer of free standing refrac-
tory bricks 29 that is located inside of the first layer 21
and acts as so-called hot face bricks to withstand the high
temperature within the chamber 15~ This layer 29 is made up
of replaceable bricks ~nd it extends vertically above the
bottom o~ the dome 20 so as to pe~mit expansion of the wall
or columns of brick la~er 29 without any upward thrust or
suppor-t applied to the dome 20,
The remaining spaces wi-thin the shell 11 are
filled with castable insulation, i.e. insulation 30 near the
bottom of the furnace and insulations 31 and 32 near the
top. Also, it will be noted that the base of the layer of
firebricks 21 is supported on an angle 35 while the free-
standing layer of refractory bricks 29 is supported on
another angle 36. It will be appreciated that the outlet 17
may be lined with a layer of refractory bricks 39 that has a
frustoconical upper portion 40 which joins the base of the
layer 29.
As indicated above, it will be appreciated that a
primary benefit of the furnace structure according to this
invention incl~des the ability o~ the hot face inner column
29 of bricks to expand without raising the dome 20 or apply-
ing extra comp:ressive load to the columns of the layer 29.
In addition, the hot face bricks of columns 29 may be re-
placed easily without concern for the support of the dome 20
since the dome is maintained with vertical support from the
other columns of firebricks 21. Another benefit of the
construction is that of having the hot face bricks of col-
umns 29 constructed of materials that need not have extra
strength for supporting the dome 20, Consequently, these
bricks may be more effective for high temperature resistance
as well as more economical~
While a particular embodiment of the invention has
heen described above in considerable detail in accordance
with the applic~ble statutes~ this is not to be taken as in
any way limiting the invention but merely as being descrip-
tive thereo~.
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