Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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SPIRAL COIL COOL W~LL CONSTRUCTION
FOR HIGH TE~IPER~TURE CYLINDRICAL
FURNACES, VESSELS, CYCLONES, ETC.
BACKGP~OU~D OF THE INVENT.ION
This invention relates to high temperature process
vessels such as furnaces, reactors, containment vessels,
cyclones, etc. which are subjected to relatlvely high
temperatures and, more particularly, to such type of vessels
in which water cooled spiral coils are provided to reduce
the temperature of the vessel.
Certain types of process vessels, such as cylindrical
furnaces, cyclone separators or the like, operate at extremely
high temperatures, such as 3000F, and therefore must be
designed to continuously withstand the temperature without
failing. For example, cyclone separators used in coal
gasification, incineration, fuel combustion, calcining,
etc., include a gas discharge tube, or vortex finder, located
centrally within the cyclone separator and extending into
the housing below the .op of the separator. Since both the
exterior and the interior walls of the discharge tube are
exposed to extremely high tem?erature conditions these walls
must be fabricated from materials including a co~mercially
available ceramic or refractory material. However, it is
difficult, if not im~ossible, to construct a gas discharge
tube of the above type entirely of such material without
encountcring structural limitations and support ?rob1ems.
" ~ .
For e~ample, it has been suggested to construct the dischar~e
tube from metallic materials and insulate same on bo-th sides
with ceramic or refractory materials. However, this is
unsatisfactory since both sides of the tube are exposed to
the high temperature and the metal is trapped within the
insulation materials and is subjected to the high temperature
on both sides. Thus, the metal can reach its molten tempera-
ture and fail structurally. Other attempts to copa with
this problem include designs having water cooled tangent
tubes in front of tne refractory or internal vessel heads,
fluidization grids, cyclone throats, etc. However, each of
these designs gives rise to other problems, such as inadequate
sealing, poor support and short life spans.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to
provide a vessel and a discharge tube associated with the
vessel for withstanding relatively high temperatures and
which i~ relatively free of any structural or support problems.
It is a furtner object of the present invention -to
provide a vessel of the above type which contains a water-
cooled spiral coil forming a portion of the wall or discharge
tube of the vessel.
It is a furtl-er object of the present invention to
provide a vessel of the above ty?e in which the vessel wall
and/or discharye tube is formed by a water-cooled spiral
coil insulated by refractory material in a manner to struc-
turally stabilize the assembly.
It is a further ob~ect of the instant invention to provide
a vessel of the above type in which the s?iral coil forms the
major structural support and that by selection of cooling -luids
and control of their temperatures, the spiral coil can be Xept
at a temperature above the dewpoints of corrosive specie in
in the contained gases such as H2CO3, ~12SO3, 1-12SO~, etc. in
the vessel.
It is a still further objec-t of the present inven-tion -to
provide a vessel oE the above type in which the adjacent tube
portions forming the spiral coil are welded together.
Toward the fulflllment of these and other objects, the
present invention contemplates a vessel for separating entrained
particles from a gas which comprises a metallic shell having
a vertically extending axis, a circular cross section, and first
and second openings in its upper end and its lower end, respect-
ively. A refractory lining extends around the shell, a first
tube formed into a first spiral co~l extends between the shell
and the lining, a means is available for introducing a cooling
fluid into the first tube, and an inlet is in communication with
the interior of -the shell and is disposed in tangen-tial relation
to the shell so that the gas and entrained particles are dis-
charged tangentially into the interior of the shell for separating
-the gases from the entrained particles by centrifugal forces.
That inlet is located in the upper portion of the shell so tha-t
the separated particles fall by gravity into the lower portion
of the shell and discharge through the second opening. A second
tube formed into a second spiral coil extends through the first
opening for providing an outlet for the separated gas which
rises into the upper portion by convection with a layer of
insulation material surrounding the second spiral coil, a means
is available for introducing cooling fluid into the second
spiral coil, and a firs-t and second continuous fin extends
from the first and second tubes, respectively, for the lengths
of the tubes and are welded to adjacent sections of ~he tubes
to render the first and second spiral coils airtight.
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BRIEF DESCRIPTION OF T~IE DR~WINCS
The above brief description, as well as further objec-ts,
features and advantages oE the present invention will be
more fully appreciated by reference to the following detailed
description of a presently preferred but none-theless illus-
trative embodiment in accordance with the present invention,
when taken in conjunction with the accompanying drawings
wherein:
Fig. 1 is a vertical cross-sectional view of the vessel
of the present invention;
Fig. 2 is a horizontal cross-sectional view taken along
the lines 2-2 of Fig. l;
Fig. 3 is an enlarged partial view within the area denoted
by the reference numeral 3 in Fig. l;
Figs. 4 and 6 are views similar to Fig. 1, but depicting
-3a-
alternate embodiments of the present invention; and
Fig. 5 is an enlarged partial ~iew within the area
denoted by reference numeral S in Fig. 4.
DESCRIPTION QF THE PREFERRED EMBODIMENTS
_. _ _ _
- An exemplary ~mbodiment of ~he Yessel of the present -,.,
invention is shown in Figs. 1-3 in the form of a cyclone:
sPparator consisting of a metallic outer cylindrical shell
l~~having an open upper end portion lOa and a conically.: .
shaped lower end portion lOb. A refractory lining 12 extends
immediately within the shell 10 and has an upper top por~ion
~, 12a having a central opening formed therein for reasons that
will be described in detail later, and a lower conical
i2b '' ' ' ' ' ''
portion/complementing the,en~ por~on lOb of.the shell 10.
... . . . ....... . . ... .. .. . . .. ... ~ . . . . . . . .
An inlet pipe 14.extends substantially horizontally at
the upper portion of the shell 10 and'extends through a -. -
suitable opening formed in.the.wall of the shell and in a
tangential relation to the interior o the sheli as bet~er
.. . ... . ..
shown in Fig. 2. Thus, hot gases containing entrained
.. . .
{ particulate material entering the inlet pipe 14 are discharged
into the intexior of the shell in a substantially tangential
relationship to the interior wall thereof which promotes
separation of the particulate material from the gases,
in a conventional manner. An outlet opening 16 is formed
through the lower end portions of the shell 10 and the
lining 12 to permlt discharge of the particulate material to
external processing apparatus (not shown).
.
A water-cooled outlet tube assembly, shown in general
by the reference numeral 18, is provided through the afore-
mentioned central opening formed in the top portion 12a of
the lining l~. The assembly 18 oonsis~s of a tube 20 formed
in a spiral coil configuration ex~ending from the interior
of the vessel upwardly through the opening and projecting
from the latter opening. The diameter of the spiral coil
portion of the tube 20 is less than tha' of the interior
wall portion of the lining 12 to form an annular chamber 21.
One end portion 20a of the tube 20 extends through
~ppropriate openings formed through the side wall o~ the
shell 10 and the corresponding port~on of the lining 12; and
across the shell and upwardly to the spiral portion, as
shown. The other end portion 20b of the tube 20 extends
.: . -._ . , - :,
outwardly from the piane of the spiral poxtion projecting
from the upper end portion of the sheii 10, f~r con~e~tion
to external equipment (not shown). As better shown in Fig.
3, a continuous fin 22 is attached to the spiral coil porkion
of the tube 20 for lts entire length and is connected between
adjacent sections of the spiral portions of the tube 20 by
weldments, or the like, to render the spiral portion air-
tight. . .
The tube assembly 18 also includes two tubular portions
24 and 26 of refractory insulation material extending to
either side of the spiral portion of the tube 20. The
; tubular portions 24 and 26 are secured to the spiral portion
of the tube 20 by a plurality of anchors 28 extending from
the fin 22 and into the tubular portions as shown. An
insulating material, shown in general by the reference
numeral 29, also surrounds that portion of the tube 20
between its end ?ortion 20a and the spiral portion.
A cooling fluid, such as water, is circulated through
the tube 20 by a pump, or the like, ~not shown) connected
between the tube end portions 20a and 20b to reduce the
temperature of the tube 20.
In operation, ~ases from the inlet tube 14 are introduced
in.o the interior of the shell 10 and into the annular
chamber 21 and the centri~ugal forces thus created cause a
separation o the particulate material entrained in the gas.
The separated particulate material falls downwardly by
gravity and discharges from the shell through the outlet 16,
while the clean gases rise by convection upwardly through
the hollow portion of the tube assembly 18 and outwardly to
e~ternal apparatus for further processing.
The spiral coil tube 20 ~rovides a structural support
for the refractory portions 24 and 26 to render them struc-
turally stable. Also, the temperatures surrounding the
tube can be kept below a value that will cause potential
damage Further, in situations in which corrosive specie, such as
H2CO3, H2SO3, H2SO4, etc., are present in the gases introduced
into the chamber 21, the temperature of the spiral tube 20 can
be kept at a temperature above the dewpoint of these specie to
eliminate any corrosion.
The embodiment of ~ig. 4 is similar to that of Figs. 1-
3, and identical components will be given the same reference
nu~bers.
According to the em~odiment of ~is. 4, an additional
spiral coil tube, shown in general by the reference numerai
30 is sandwicned between the liner 12 and the metallic shell
10, and has a continuous fin 32 attached thereto and extend-
ing for the length of the tu~e.
--6--
.
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As shown in Pig. 5, a plurality of anchors 34 extend
from the interior side of the fin 32 into the refractory
material of the liner 12 to anchor the latter in place.
The spiral coil portion of the tube 30 is shaped to
conform to the shape of the shell 10 and includes a conically
shapëd lower end portion. The uppe~ portion of the ~piral
coil extends horizontally as sllown in Fig. 4, with the
adjacent sections of the coil being connected by'the fin 32.
The lower and upper end portions 30a and 30b of the
tube 30 extend externally of the shell io as shown and are
adapted to be connected to a pump or the like, for circulating
a cooling fluid through the tube as in the previous embodi-
ment. Since the tube assembly 18 of the shell of Fig. 4 is
formed,and cooled in a manner identical to that of the
previous embodiment, the entire vessel may be utilized in a
very high temperature environment.
It is understood that the shell o the present invention
is not limited to cyclone separators as,discussed, in connec-
tion with the above two exemplary embodiments. For example,
and referring to Fig. 6, the vessel can be a process vessel
having an outer metallic shell 40, an inner refractory
lining 42 and spiral coil tube 44 sand,wiched therebetween.
The shell 40, ~he lining 42 and the tube 44 each have a
necked-down portion in the upper and lower portions of the
shell to define an open inlet 46 at the lower end portion of
the shell and an outlet 48 at the upper end portion o~ the
shell, and a conical portion 50 extending between the lower
t
necked-down portion and the cylindrical wall portion.
The tube 44 extends in a spiral coil configuration from
the lower inlet end portion to the upper outlet end ~ortion
of the shell 40 and has two end portions 44a and 44b extending
out of tne plane of the shell and functioning as an inlet
and outlet, respectively for a cooling fluid as in the
previous embodiment.
A continuous fin 52 is connected to the tube ~4 ~nd
extends between adjacent tube sections for the entire length
of the shell to render the shell gas-tight.
Though not clear from the drawing, it is understood
that anclors similar to those disclosed in the previous
embodiments can be utilized to anchor the refxactory lining
.
42 relative to the spiral coil tube 44. -- ~
A cooling fluid, upon being introduced into the inlet
portion 44a of the tube 44 travels the entire distance of
the shell before discharging through the outlet end tube
~ - - , . . .: .i
portion 44b to maintain the vessel at a lower temperature
( than otilerwise would be possi.ble.
The material to be processed, whether in a solld,
liquid or gaseous form, is introduced into the shell inlet
46 ~here it passes upwardly into the shell where the desired
reaction is completed, with the reacted material then dis-
. .
; charging from the outlet 48.
It is understood that in each of the previ~us embodiments,
; the particular location of the inlet and outlet of the water
. .. __ .. _ . ... __, .. ._ . _~ __ .. . . ., . . .. ,.. .. . . .. . . _ . _ . .
. . ~,~' . .
tubes can be varied within the scope of the invention. For
example, both the inlet and outlet end portions of the water
tube can be located at the upper portion of the shell as
shown by the reference numerals 44c and 44d, respectively,
in Fig. 6. In this conflguration the water would flow down- j
wardly through alternating sections of the spiral coil tube
and then upwardly through other alternating sections before
discharging from the outlet end portion 44d. It is understood
that this circuit can also be incorporated in any of the
2revious embodiments.
In each of the embodiments of the present invention, a
shell is provided with or without a discharge tube, that
is stable from a structural standpoint, yet is immune to corro-
sion and can withstand relative high temperatures.
A latitude of modification, change and substitution is
intended in the foregoing disclosure and in some instances
some features of the invention will be employed without a
corresponding use of other features. Accordingly, it is
appropriate that the appended claims be construed broadly
and in a manner consistent with the spirit and scope of the
invention therein.
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