Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INV:ENTION
The present invention relates to improved means
for supportin~ equipment which is subjected to relatively
high temperature differentials which cause both vertical and
horizontal expansions. More particularly, the invention re-
lates to such improved support means when used in connection
with e~uipment such as cyclone separator stage, which forms
part of a ~urner vessel employed in fluid coking.
A conventional way of supporting cyclones is to sup-
port them from the vessel head by rods and from the plenum
cham~er by the outlet ducts. The plenum chamber comprises a
cylindrical skirt welded to the vessel head and is enclosed at
the bottom ~y a dished floor mem~er welded to the lower edge
of the sk~rt. According to this arrangement, some of the cy-
clones are'supported from the vessel head and some from the
plenum cham~er floor. The problem with such arrangements is
that the`support system is subjected to different temperatures
whi`ch`causes thermal expansion problems. Other known designs
support all of the cyclones from the plenum chamber by means
of rods and cyclone outlet ducts and this type support system
av~ids the problem of differential thermal expansion. In
thes`e conventional' c'yclone systems, the plenum chamber floors
are generally fairly thick, for example, on the order of one
inch`or more, and are constructed to carry the weight and
differential pressure loads of the cylones during operation
of the vesseI. The`need for this heavy construction is due to
the load imposed on the floor by the cyclones which introduce
compound stresses, i.e. primary ~ending and tensile stresses
in the`plenum floox and cylindrical support skirt.
Other prior art arrangements for supporting cyclone
separators are shown in U.S. Patents No. 3,951,629 wherein a
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support beam secured to the vessel head by support bars actual-
ly supports for the cyclone separators. This patent also
discloses the expedient providing a thinner floor (see Column
4, lines 50-53); however, the support rods or bars do not
directly support the operator stages and there is no floor
supported by the rods. U.S. Patent No. 3,982,902 discloses a
support for cyclone separators which employs a horizontal bar
that is privotally mounted to the vessel wall. U.S. Patent No.
2,873,175 discloses a cyclone supported from the vessel head
(see Column 7, lines 31-35); however, there is no plenum
chamber`disclosed in the patent. Still yet another support
scheme for cyclones is disclosed in U.S. Patent No. 2,~39,850
wherein the cyclones are attached to each other such that they
move as a unit.
None of the prior art, however, is considered to
afford the advantages of a cyclone support system wherein the
plenum chamber is constructed and arranyed to accommodate
the~mal expansion and wherein the plenum chamber serves to
separate and contain the relatively clean gas generated from
the dilute phases produced in the vessel and does not support
the cyclones; but instead the cyclones are supported by in-
dividual support means connected directly to the head of the
vessel and the plenum chamber floor in turn is supported by
the c~clones.
SUMMAR~ OF THE ~NVENT~ON
According to the ~resent invention there is provided
a relatively thin flat steel floor which forms part of the
plenum chamber in a vessel such as may be found in a fluid
coker burner, which affords fle~ing of the floor that may be
caused by differential thermal movement of the cyclones in
the vessel. The floor is supported by an attachment to each
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k~
of the cyclone stages which themselves are independently
harnessed or supported from the vessel head by means of sup-
port rods or straps. The rods which support each of the cy-
clone~ are basically in tension and because of the relatively
large number of cyclone stages, a simple flat plate on the
order of 3/16" 5/~" thick can be employed since the unsup-
ported spans of the floor between the cyclones are small which
reduces and/or eliminates the need for horizontal supports
bet~een the`cyclones themselves.
This cyclone system support/plenum chamber design
differs from conventional systems in that the cyclones are
individually supported by rods from the vessel head. The plen-
um head itself serves no support function except to separate
and contain thè reIatively clean gas from the dilute gas phase
which has passed through the cyclone system. Most cyclone
systems consistof ~ p'rimary a~d secondary cyclone,;i.e., two
stages and these are'generally arranged so that a number of
primary cyclones can be located below the cylindrical skirt
joining the``vessel head and the plenum chamber floor. It is,
the`refore, possi~le t4 support these primary cyclones by rods
from thè sk~rt.~ Since the'plenum chamber floor does not sup-
port the'`cyclones, the floor can be made thinner. By welding
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the`plenum floor to tRe'cyclones themselves, the floor is sup-
pQrted by the cyclones for the differential pressure which acts
Qn thè floor. The cyclones themselves then support the plenum
chamber floor, while in a conventional cyclone system, the
plenum floor and plenum skirt support the cyclone. Since the
individual supports of the cyclones vary in length, there will
be ~ome'small differential thermal expansion in the support
3Q rods. hes'e expansion differences can be absorbed by the
-reIat~veIy thin and flexible plenum chamber floor which is
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welded to each of the cyclones. with a conventional arrange-
ment, the floor is heavy, often one inch or more in thickness,
which allows little or no flexing to make up for differential
thermal expansion.
Other objects and advantages of the present invention
~ill become apparent from the following description when taken
in connection with the accompanying drawings which illustrate
various em~odiments of the present invention.
BRIEF DESCRrPTION OF THE DRAWINGS
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Fig. 1 is a partial elevational view of a vessel
having cyclone separator stages mounted independently and sup-
porting a plenum chamber floor in accordance with the present
invention.
Fig~ 2iIl-ustra-tes a cross-sectional view taken sub-
stantially on the line 2-2 of Fig. 1 illustrating the indepen-
dently supported cyclones.
Fig. 3 illustrates an enlargement of the support
for the primary cyclone stage of Fig. 1.
Fig. 4 illustrates a cross-sectional view taken sub-
stantially on the line 4-4 of Fig. 3.
Fig. 5 illustrates an enlarged partial cross-section-
al vie~ illustrating the support in detail for mounting the
primary cyclone stages relative to the floor.
Fig. 6 illustates a cross-sectional view of a secon-
dary cyclone.
DESCR~PT~ON OF THE PREFERRED EMBODIMENTS
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Having reference to the drawings wherein like parts
are design~ated by the same reference numerals throughout the
several views, there is shown in Flg. 1 a typical fluid coker
vessel 10 having a plenum chamber 12 which comprises a thin
plate flat floor 14 preferably of steel and a cylindrical
support skirt 16 which is welded as shown at 18 to the vessel
head portion 20 and at the other or opposite end is welded
to the floor 14 as shown in 22. The plenum chamber 12 func-
tions as a collection header for the gas which is discharged
from a plurality of primary and secondary cyclone stages 24,
26 respectively, which are in the vessel. It is recognized
tha~t while the invention is disclosed in its preferred embodi-
ment in a fluid coker ~urner vessel other vessels such as 1uid
catalytic cracking, fluidized iron ore, or other fluid solids
processes also are'within the contemplation of this invention,
which relates to the support system for the cyclone stages and
the plenum chamber floor. The present support system has
utility in any vessel so long as it employs the basic compo-
nents of a plenum cham~er. The plenum chamber is designed to
facilitate'thermal expansion through flexure in response to
the` temperature differentials which will occur during opera-
tion of the unit. ~t serves to separate and contain the clean
gas wh~ch`is exhausted from`-the-cyclone outlet 28 that pene-
trates the plenum cham~er floor 14.
2a Each of the cylone stages (only a relatively small
number are shown for purposes of illustrating the present
in~entionl are'individually supported by means generally des-
ignated 30 whi`ch include hanger straps 32. Each cyclone has
t~o support means 30`wherein the straps 32 which are connect-
ed ~ith straps 36 are welded on either side of the cyclone
~ody. The support means extend through the plenum floor up-
ward to the vessel' head 20 where they are welded directly to
mounting ~rackets or lugs 34 extending downward therefrom or
to support sklrt 16 as shown in Fig. 1 fo~r the outer one of
the stages 24. The plenum chamber floor 14 is welded to the
cyclones as shown àt 35 (see Figs. 4, 5 and 6) for purposes
of supporting the floor in contrast to conventional schemes
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which utilize a heavy floor capable of supporting the cyclones.
The flexure of the floor will occur based on the pressure
differential which occurs between the inlet into the primary
cyclones and the outlet from the secondary cyclones. Because
the cyclones are many in number and are relatively closely
and uniformly spaced in a conventional manner, this affords
the opportunity to employ the relatively thin flat floor which
accept a small amount of distortion resulting from the differ-
ential vertical thermal movement between the different cyclone
stages,
The supporting system is normally stretched (i.e.
in tension~ because of the load imposed thereon by the support-
ed cyclones. However, the support system could be in compres-
sion because of the differential pressure acting on the plenum
floor. The upward pressure force therefrom would exceed the
~eight load of the cyclones. As mentioned heretofore, the
straps 32 are secured, e.g. by welding, to opposed sides of
tHe cyclone and in thè case of the secondary and some primary
c~clones extend upward for a predetermined distance through
and aBQve the plenum cham~er floor. At this point, the portion
of the strap 32 which extends above the floor 14 is connected
(e.`g. by ~elding~ to a further support member or strap 36
oriented at right` angle relative thereto. The strap 36 ex-
tends upward and is secured to the downward protruding brack-
ets 34 from the vessel head 20, or directly to skirt 16 in
the case of the outer stage as shown in Fig. 1. The hanger
straps 32 of SQme of the primary cyclones 24 terminate at
thè~r upper end beIow the plenum floor 14. ~ metal shroud
40 is placed about the portion of the support within the
plenum cham~er for thermal protection of the support member
a~ a means of reducing the metal temperature of the support
so as to reduce the verticaldiferential thermal expansion
between the cyclones and the plenum skirt.
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