U.S. patent application number 13/525431 was filed with the patent office on 2012-10-04 for polymer melt distributor header design.
This patent application is currently assigned to FINA TECHNOLOGY, INC.. Invention is credited to Roy Kennedy, Jose M. Sosa, John Tomlinson.
Application Number | 20120247687 13/525431 |
Document ID | / |
Family ID | 39201156 |
Filed Date | 2012-10-04 |
United States Patent
Application |
20120247687 |
Kind Code |
A1 |
Tomlinson; John ; et
al. |
October 4, 2012 |
Polymer Melt Distributor Header Design
Abstract
A vessel header comprising a plurality of lateral flow tubes
arranged in a parallel configuration and entering the vessel header
through alternating header penetrations with a single header
penetration per lateral flow tube. A method of increasing the
throughput of a polymerization reaction comprising conducting the
polymerization reaction in a reaction vessel comprising a plurality
of lateral flow tubes arranged in a parallel configuration and
entering the vessel header through alternating header penetrations
with a single header penetration per lateral flow tube wherein the
polymerization reaction displays an increase in throughput of 10%
and a decrease in volatiles of from 5% to 10% when compared to a
polymerization reaction carried out in a reaction vessel lacking a
plurality of lateral flow tubes arranged in a parallel
configuration and entering the vessel header through alternating
header penetrations with a single header penetration per lateral
flow tube.
Inventors: |
Tomlinson; John;
(Prairieville, LA) ; Kennedy; Roy; (Prairieville,
LA) ; Sosa; Jose M.; (Deer Park, TX) |
Assignee: |
FINA TECHNOLOGY, INC.
Houston
TX
|
Family ID: |
39201156 |
Appl. No.: |
13/525431 |
Filed: |
June 18, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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|
11533983 |
Sep 21, 2006 |
8241459 |
|
|
13525431 |
|
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Current U.S.
Class: |
159/2.1 |
Current CPC
Class: |
B01D 1/08 20130101; B01J
4/002 20130101; C08F 6/001 20130101; B01J 4/001 20130101 |
Class at
Publication: |
159/2.1 |
International
Class: |
B01D 1/00 20060101
B01D001/00 |
Claims
1-21. (canceled)
22. A polymer melt distribution header comprising: a plurality of
lateral flow tubes arranged in a parallel configuration wherein the
lateral flow tubes enter the header through alternating header
penetrations with a single header penetration per lateral flow tube
and; an internal support structure for support of the lateral flow
tube within the header opposite the header penetration wherein the
internal support structure accommodates horizontal expansion or
contraction of the lateral flow tube, wherein the internal support
structure comprises a support cradle located opposite the header
penetration on which the flow tube rests, the support cradle is
interior to the header wall and wherein the support cradle is
welded to the header interior along one or more weld arcs
positioned inside the support cradle.
23. The header of claim 22 wherein the support cradle is welded to
the header interior along one or more weld arcs positioned inside
the support cradle such that the weld root spacing between the weld
arc and penetration welds is minimized.
24. The header of claim 22 wherein the lateral flow tubes comprise
devolatilizer nozzles having a perforated area for discharging
molten polymer in strands.
25. The header of claim 24 wherein the lateral flow tubes comprise
devolatilizer nozzles having a perforated area extending
substantially the entire length of the flow tubes from the header
penetrations to the internal support structure.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not applicable.
FIELD OF THE DISCLOSURE
[0004] This disclosure relates generally to fluid exchange vessels.
More particularly, it relates to devolatilizer nozzles and methods
of distributing fluid within fluid exchange vessels.
BACKGROUND OF THE DISCLOSURE
[0005] Polymer may be recovered from a polymerization reactor and
fed to a devolatilization vessel where undesirable components such
as unreacted monomer or solvent may be removed from the polymer.
For example, volatiles may be removed by vacuum distillation, flash
devolatilization, stripping, increasing polymer surface area, or
combinations thereof. The polymer may be passed through a
devolatilizer nozzle, which is an arrangement of one or more flow
tubes having a plurality of small perforations or holes directed
downward in a vessel for discharging molten polymer in strands. The
polymer strands provide increased surface area for devolatilization
of the polymer within the vessel. As the strands fall in the
devolatilization vessel, the unreacted monomer and solvent is
released while the polymer strands collect at the bottom of the
vessel. The devolatilized polymer may then be sent to subsequent
polymer processing steps. Given the commercial importance of
devolatilization, an ongoing need exists for improved
devolatilization processes and associated equipment such as solvent
exchange vessels incorporating devolatilizer nozzles.
SUMMARY OF THE DISCLOSURE
[0006] The foregoing has outlined rather broadly the features and
technical advantages of the present disclosure in order that the
detailed description of the disclosure that follows may be better
understood. Additional features and advantages of the disclosure
will be described hereinafter that form the subject of the claims
of the disclosure. It should be appreciated by those skilled in the
art that the conception and the specific embodiments disclosed may
be readily utilized as a basis for modifying or designing other
structures for carrying out the same purposes of the present
disclosure. It should also be realized by those skilled in the art
that such equivalent constructions do not depart from the spirit
and scope of the disclosure as set forth in the appended
claims.
[0007] Disclosed herein is a vessel header comprising a plurality
of lateral flow tubes arranged in a parallel configuration and
entering the vessel header through alternating header penetrations
with a single header penetration per lateral flow tube.
[0008] Also disclosed herein is a method of increasing the
throughput of a polymerization reaction comprising conducting the
polymerization reaction in a reaction vessel comprising a plurality
of lateral flow tubes arranged in a parallel configuration and
entering the vessel header through alternating header penetrations
with a single header penetration per lateral flow tube wherein the
polymerization reaction displays an increase in throughput of 10%
and a decrease in volatiles of from 5% to 10% when compared to a
polymerization reaction carried out in a reaction vessel lacking a
plurality of lateral flow tubes arranged in a parallel
configuration and entering the vessel header through alternating
header penetrations with a single header penetration per lateral
flow tube.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1A is a top plan view of a polymer melt distributor
vessel header design.
[0010] FIG. 1B is a partial side plan view of a polymer melt
distributor vessel design.
[0011] FIG. 2A is a partial cross-sectional view of an internal
support structure along the interior wall of the vessel header.
[0012] FIG. 2B is a partial cross-sectional view of an alternative
internal support structure along the interior wall of the vessel
header.
[0013] FIG. 3A is a cross-sectional side view of an internal
support structure.
[0014] FIG. 3B is a cross-sectional side view of an alternative
internal support structure.
[0015] FIG. 3C is a cross-sectional side view of an alternative
internal support structure.
[0016] FIG. 4 is a cross-sectional side view of a welded lateral
flow tube connection.
[0017] FIG. 5 is a cross-sectional side view of an externally
flanged lateral flow tube connection.
[0018] FIG. 6A is a cross-sectional view of an internally flanged
lateral flow tube connection.
[0019] FIG. 6B is a cross-sectional view of an alternative
internally flanged lateral flow tube connection.
[0020] FIG. 7 is a flow chart of a method of distributing a fluid
within a vessel.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0021] The present disclosure contemplates a vessel header design
that may comprise a plurality of lateral flow tubes ("flow tubes").
The spacing between the flow tubes may be minimized through the use
of alternating header penetrations. The lateral flow tubes may be
welded into the vessel header penetrations, may be externally
flanged to the vessel header penetrations, may be internally
flanged to the vessel header penetrations, or combinations thereof.
Additional features such as staggered external flanges and an
internal support structure are disclosed herein and may further
allow the spacing between the flow tubes to be minimized. The
decreased spacing may result in an increase in the usable flow tube
surface area within the vessel header and an associated vessel
body, which may cumulatively be known as a fluid distribution
system. As a result of the increase in the usable surface area, the
throughput capacity of the system may increase relative to
conventional designs.
[0022] As shown in FIGS. 1A and 1B, a fluid distribution system may
comprise a devolatilizer vessel 100 having a vessel header 101 and
a vessel body 128. A devolatilizer vessel 100 may be used to remove
the volatile components from a polymer prior to further polymer
manufacturing processes such as pelletizing and forming. In an
embodiment, a devolatilizer vessel 100 comprises a vessel header
101 disposed above a vessel body 128, a devolatilized polymer
outlet 120, a volatile vapor outlet 126, and a plurality of lateral
flow tubes 102 disposed within the vessel header 101 for
distribution of the polymer within the devolatilizer vessel 100. An
external manifold 107 may be used to supply the polymer to the flow
tubes 102. The vessel header 101 may be connected to the vessel
body 128 through the use of a flanged connection 133, a welded
connection, or any other connection method capable of substantially
sealing against unintended leakage between the vessel header 101
and the vessel body 128, as would be known to one skilled in the
arts. The devolatilized polymer outlet 120 may be connected at or
near the bottom of the devolatilizer vessel 100 and is used to
convey the devolatilized polymer to downstream processing units.
The devolatilized polymer outlet 120 may comprise one or more
pipes, connections, or pipes and connections to facilitate polymer
collection or to reduce the required pump size. The volatile vapor
outlet 126 may be connected at or near the top of the vessel body
128 and/or the vessel header 101 and is used to remove the
volatiles that exit the polymer within the devolatilizer vessel
100. The volatile vapor outlet 126 may comprise one or more pipes,
connections, or pipes and connections in order to balance vapor
flows. In an embodiment, the lateral flow tubes 102 comprise
devolatilizer nozzles. The devolatilizer nozzles may be disposed
within the vessel header 101 and are intended to convey the polymer
containing the volatiles from an upstream process to the
devolatilizer vessel 100 interior for devolatilization. FIG. 1A
indicates the direction of flow 108 through the lateral flow tubes
102 while Figure B indicates the direction of polymer flow 124 into
the devolitizer vessel 100. The arrangement of the lateral flow
tubes 102 in relation to the vessel header 101 will be more fully
described herein.
[0023] Referring to FIGS. 1A and 1B, the vessel header of the
present disclosure offers several advantages and benefits as
compared to conventional designs. The use of flanged connections
111 (FIG. 1A), removable parts such as the flow tube end cap 130
(FIG. 1B), and the internal support structure 103 (FIGS. 1A and 1B)
allow improved access to the respective components for inspection,
cleaning, and maintenance. In addition, the flanged connections 111
and designs disclosed herein allow for changing or replacing flow
tubes 102 individually, which allows for repair and modification
cost savings and optimization as compared to existing monolithic
type designs. The flanged connections 111 also provide a means to
blind individual flow tubes 102 to reduce vessel capacity, maintain
optimal flow rates and patterns in the vessel header 101, and
isolate individual flow tubes due to damage or plugging. The
flanged connections 111 also provide the option to introduce
orifice plates or restriction plates for polymer distribution
management within the vessel header 101 and vessel body 128.
[0024] As shown in FIGS. 1A and 1B, the vessel header 101 is
disposed adjacent and above the vessel body 128. A plurality of
lateral flow tubes 102 is disposed near the interface of the vessel
body 128 and vessel header 101 for distribution of a fluid within
the vessel body 128. The lateral flow tubes are arranged
substantially parallel to a plane of the interface between the
vessel header 101 and vessel body 128, and further are arranged
substantially perpendicular to the sidewalls of the vessel body
128. The plurality of lateral, substantially parallel flow tubes
may form an assembly, for example a devolatilizer nozzle assembly
as described in more detail herein. In various embodiments, the
flow tube assembly may be considered part of the vessel header 101,
part of the uppermost portion of the vessel body 128, part of both
the vessel header 101 and the uppermost portion of the vessel body
128, or a component that is separate from both the vessel header
101 and the uppermost portion of the vessel body 128. For
convenience, the disclosure herein will describe the flow tubes 102
in relationship to the vessel header 101, with the understanding
that such description may apply equally to the vessel body 128.
[0025] In an embodiment, each individual flow tube 102 may enter
the vessel header 101 through a vessel header penetration 109 and
be supported within the vessel header 101 by an internal support
structure 103. As used herein, the vessel header penetration 109
comprises any opening created in the vessel header 101 for the
purpose of passing a flow tube 102 through to the interior of the
vessel header 101, and the internal support structure 103 comprises
a device for providing mechanical support to the end of the flow
tube 102 opposite the vessel header penetration 109 within the
vessel header 101. The vessel header penetrations 109 of nearby
flow tubes 102 may be on opposite sides of the vessel header 101
such that vessel header penetrations 109 form an alternating
pattern, as more fully described herein. The internal support
structure 103 may also form an alternating pattern along the
interior of the vessel header 101. The flow tubes 102 may be
connected to the vessel header 101 using any method capable of
substantially sealing the flow tubes 102 in the vessel header
penetration 109 including, for example, welding and flanging. The
flow tubes 102 may comprise external flanges 111 in order to
sealingly connection to an external distribution manifold 107 in
order to convey fluid to the interior of the vessel header 101.
[0026] As shown in FIGS. 1A and 1B, the vessel header 101 and
vessel body 128 are used to provide a substantially sealed
environment for the processing of a fluid. In an embodiment, the
vessel header 101 and the vessel body 128 are circular in shape. In
an embodiment, the vessel body 128 is substantially cylindrical,
conical, or truncated conical in shape and the vessel header is
substantially dome-like in shape. Alternatively, the vessel header
101 and the vessel body 128 may have a non-circular shape depending
on the specific uses required for the fluid distribution system. In
an embodiment, the vessel header 101 and vessel body 128 are
composed of a material capable of withstanding a differential
pressure between a vessel interior and a vessel exterior as well as
an elevated operating temperature. Without intending to be
limiting, an example of a suitable material may be steel. The
vessel header 101 and vessel body 128 may optionally comprise
additional elements such as insulation or reinforcement plating
surrounding the vessel header 101 and the vessel body 128.
[0027] In an embodiment, the vessel header 101 and vessel body 128
may be components of a polymer devolatilization vessel 100, which
may also be known as a solvent exchange vessel. In this embodiment,
molten polymer is fed to the polymer devolatilization vessel 100
wherein the polymer is formed into strands 127 upon exiting the
flow tubes 102 and the volatiles exit the polymer strands. The
polymer strands extend downward in the vessel and form a molten
mass 122 of devolatilized polymer in the bottom of the vessel. The
devolatilized polymer exits the vessel header 101 via the
devolatilized polymer outlet 120, which transmits the devolatilized
polymer to a finishing operation such as a pelletizer. The vessel
header 101 and vessel body 128 may be sized according to various
criteria such as the polymer devolatilization throughput
requirements, production rate, material strength, pressure rating,
and other factors as known to one of ordinary skill in the art. In
an embodiment, the diameter of the vessel header and associated
vessel may be between 35 inches and 240 inches, alternatively
between 50 and 210 inches, alternatively between 70 inches and 195
inches.
[0028] In an embodiment shown in FIGS. 1A and 1B, the plurality of
flow tubes 102 are disposed within the vessel header 101 above the
vessel body 128. In an embodiment, the vessel header 101 may
comprise, in the alternative, a plurality of between 2 and 100, 2
and 90, 2 and 80, 2 and 70, 2 and 60, or 2 and 50 flow tubes 102.
The actual number of flow tubes 102 may be a function of vessel
size, flow tube size, flow tube shape, production rate, throughput
requirements, material strength, and pressure rating requirements.
The flow tubes 102 may comprise any type of pipe or conduit
intended to convey a fluid with a size capable of being
incorporated into a vessel header 101 and a design capable of
withstanding the fluid distribution system operating conditions.
The flow tube 102 may have a cross sectional shape suitable for its
intended use, including a non-circular cross section in some
embodiments. In order to facilitate removal and maintenance, the
flow tubes 102 may be approximately straight and may optionally
have an end cap 130 that may be removable. The end cap 130 may also
be used to provide a support for the flow tube 102 within the
vessel header 101 and may be shaped to take any internal curvature
of the vessel header 101 into account.
[0029] In an embodiment shown in FIG. 1B, the lateral flow tubes
102 may be devolatilizer nozzles ("nozzles"), and the terms flow
tube and devolatilizer nozzle may be used interchangeably herein.
The nozzles 102 comprise a flow section 134 coupled with a
perforated section 132. The flow section 134 conducts molten
polymer from an external polymer source to the perforated section
132 within the vessel header 101. The perforated section 132 may
comprise a plurality of perforations or holes from which molten
polymer may exit and form strands 127. Examples of devolatilizer
nozzles 102, their use and methods of production may be found in
U.S. Pat. Nos. 5,540,813, 4,294,652, 4,934,433, 5,118,388, and
5,874,525, U.S. Published Application 2005/0097748, and pending
U.S. patent application Ser. No. 11/345,439, which are incorporated
herein by reference.
[0030] As shown in FIGS. 1A and 1B, the flow tubes 102 disposed
within the vessel header 101 may be configured using a parallel and
alternating vessel header penetration 109 design in order to
increase the number of flow tubes 102 and useable flow tube surface
area (e.g., area suitable for perforations 132) within the vessel
header 101. In an embodiment, the nozzles 102 may be arranged
parallel to one another in order to decrease the nozzle spacing 112
and increase the number of nozzles 102 that may be placed within a
vessel header 101. The term flow tube spacing or nozzle spacing 112
as used herein is intended to refer to the closest distance between
the outer surfaces of adjacent flow tubes 102 inside the vessel
header 101 as measured perpendicular to the surface of the flow
tubes 102. The fluid distribution system capacity may be partly
determined by the number of perforations or holes 132 within the
nozzles 102 through which a polymer may be extruded. As a result,
an embodiment utilizing a parallel nozzle 102 arrangement with
alternating header penetrations 109 may increase the throughput
capacity of the fluid distribution system. In an embodiment, the
flow tube spacing 112 may be from 1 to 10 inches, alternatively
from 1 to 8 inches, alternatively from 1.5 to 6 inches.
[0031] As shown in FIG. 1A, the vessel header penetrations 109 may
alternate between sides of the vessel header 101. The internal
support structure 103 may be located along the vessel header 101
interior surface opposite the vessel header penetrations 109. An
alternating pattern comprising a vessel header penetration 109
located next to an internal support structure 103 such as for
example an internal cradle may be created and repeated along the
interior surface of the vessel header 101. The alternating pattern
of flow tubes may extend across substantially the entire cross
section of the vessel header 101, for example across the entire
diameter of FIG. 1A.
[0032] As shown in FIG. 2A, the flow tube spacing 112 may be
limited by a weld root spacing 201, where a weld root 204 refers to
the point or points at which the back of a weld intersects the base
metal surface or surfaces. In an embodiment, the base metal is the
vessel header 101 wall. Following industry best practices requires
a 1 inch minimum spacing between weld roots, based on the heat
affected zone from the weld. The 1 inch spacing avoids potential
weld problems due to the stresses present in the heat affected zone
of the weld. By avoiding the heat affected zone, stress relieving
may be avoided which may reduce fabrication costs and time. In an
embodiment, a typical flow tube spacing may be less than or equal
to 4 inches, alternatively less than or equal to 3 inches,
alternatively less than or equal to 2 inches. By alternating the
vessel header penetrations 109 and the internal support structure
103, the minimum weld spacing requirements may still be met and any
reinforcing vessel requirements may be more easily met. As used
herein, the reinforcing vessel requirements refer to engineering
requirements for the construction of vessels as described in ASME
section VIII division 1. As a result of the alternating
configuration, the flow tube spacing 112 may be decreased, which
may allow for more flow tubes 102 to be placed in the vessel header
101, and thereby increasing the perforated area 132.
[0033] An internal support structure 103 may be disposed along the
interior surface of the vessel header 101 and may be used to
support the end 104 of the flow tube 102 within the vessel header
101. The internal support structure 103 design may involve
consideration of its ability to alleviate mechanical stresses on
the flow tube 102 and allow for thermal expansion and contraction
of the vessel header 101 in relation to the flow tube 102. In an
embodiment, the internal support structure 103 design may depend on
the vessel size, vessel operating conditions, and number and type
of flow tubes 102.
[0034] In an embodiment shown in FIGS. 2B and 3B, the internal
support structure 103 may be a sliding cradle 300. As used herein,
the sliding cradle 300 comprises a support structure 209, for
example a support beam or rail, located above the flow tube 102
within the vessel header 101 wherein support is provided by a flow
tube hanger 207 ("hanger") connecting the support structure 209 and
the flow tube 102. In this embodiment, the hanger 207 may move
relative to the support structure 209, which may allow for movement
in response to thermal expansion or contraction forces. The
resulting movement reduces stress on the vessel header 101 wall and
the flow tube 102. In an embodiment, the sliding cradle may allow
movement of the flow tube 102 of less than or equal to 12 inches,
alternatively less than or equal to 3 inches, alternatively less
than or equal to 1 inch in order to account for thermal expansion
of the vessel header 101 during operation and allow removal of flow
tube 102 for maintenance or cleaning purposes. In an embodiment,
the support structure 209 may be a section of an I-beam welded to
the interior of the vessel header 101. In an alternative
embodiment, the support structure 209 may be a section of pipe or
conduit. In an embodiment, a typical support structure 209 may
extend from the vessel header 101 interior surface approximately
horizontally above the flow tube 102 a distance 310 of less than 12
inches, alternatively less than 6 inches, alternatively less than 2
inches.
[0035] As shown in FIG. 2B, the hanger 207 may comprise a beam
clamp or beam roller 208, a support rod 210, and a pipe clamp,
roller, or support 206. The beam clamp or beam roller 208 comprises
a device intended to connect to the support structure 209, which
may either clamp to the support structure 209 or connect to the
support structure 209 while allowing for movement. The pipe clamp,
roller, or hanger 206 comprises a device intended to support a flow
tube 102. In an embodiment in which the pipe clamp is used, the
support may be fixed relative to the flow tube 102, and the use of
a roller may allow movement relative to the flow tube 102. The
support rod 210 is intended to comprise a mechanical connection
between the beam clamp or roller 208 and the pipe clamp, roller or
hanger 206. An example of a connection method may be through the
use of a support rod 210 with a threaded end secured by a threaded
nut. In an alternative embodiment, the hanger 207 may comprise a
device in which the beam clamp 208 and support rod 210 comprise a
single device that may be directly connected to the flow tube 102,
for example, through a welded connection to the top of the flow
tube 102. In an embodiment, the flow tube 102 may be a
devolatilizer nozzle. In this embodiment, the hanger 207 may be
connected to the nozzle 102 at or near the nozzle end 104 or end
cap 130 using for example, a weld to the top of the nozzle 102 or a
threaded connection extending into the interior of the flow tube
102 that is accessible via the end cap 130. The resulting
configuration, which does not obstruct the bottom surface area of
the flow tube 102, may allow for an increase in the perforated
section 132 of the nozzle 102 within the vessel header 101 relative
to other internal cradle embodiments and may increase the fluid
distribution system capacity.
[0036] In an alternative embodiment as shown in FIGS. 2A and 3A,
the internal support structure 103 may be a support cradle 205 on
which the flow tube end 104 directly rests. Alternatively, the flow
tube end 104 may indirectly rest on the support cradle 205 as a
result of a moveable device, such as a sliding sleeve or bearing,
being placed between the support cradle 205 and the flow tube end
104 to allow for movement. As used herein, a support cradle 205
refers to any structure capable of supporting a flow tube end 104
including but not limited to a section of pipe of greater diameter
than the flow tube end 104 or a half section of pipe oriented such
that the flow tube end 104 will rest in a stable position when
placed inside. In addition, the support cradle 205 may be shaped as
necessary to support a flow tube end 104 based on considerations
including but not limited to a non-circular flow tube 102 shape and
any angles that may be produced due to a curvature in the interior
vessel header 101 surface. In an embodiment, a support cradle 205
may be welded to the interior surface of the vessel header 101 via
welds 105, as described in more detail herein. The flow tube end
104 may then be supported by being placed in the support cradle
205. The support cradle 205 may be of any length 310 sufficient to
support the flow tube end 104 during operation and maintenance.
Several factors may affect the length 310 of the support cradle 205
including but not limited to requirements for thermal expansion and
contraction, vessel size, flow tube length and diameter, and vessel
operating conditions including operating temperature. Any support
cradle 205 length beyond that necessary to support the flow tube
end 104 may reduce the surface area of the flow tube 102 for use
within the vessel header 101 by covering an area that could
otherwise be used for the perforation section 132. In an
embodiment, the support cradle 205 may extend the same length 310
from the interior of the vessel header 101 surface as the sliding
cradle 300.
[0037] In an alternative embodiment shown in FIG. 3C, the flow tube
end 104 opposite the vessel header penetration 109 may be supported
by the vessel header 101 using a design in which the vessel header
101 forms a support recess 304. In this embodiment, the vessel
header 101 is designed such that a small section of the vessel
header 101 is recessed outward from the interior of the vessel to
allow the flow tube end 104 to pass into the support recess 304 and
be supported. The flow tube end 104 may slide in the support recess
304 to allow for movement in response to thermal expansion forces.
The flow tube end 104 may rest directly in recess 304 or may rest
indirectly in recess 304 as a result of a moveable device, such as
a sliding sleeve or bearing, being placed between the upper surface
of recess 304 and the flow tube end 104 to allow for movement. The
support recess 304 may be sealingly connected to the vessel header
101 as a result of being formed at the same time as the vessel
header 101, being welded to the vessel header 101, or any other
method known to one skilled in the arts that is capable of forming
a substantially sealed connection to the vessel header 101. In an
embodiment, the support recess 304 in the vessel header 101 may
extend less than or equal to 12 inches, alternatively less than or
equal to 6 inches, alternatively less than or equal to 3 inches
beyond the outer surface of the vessel header 101. This embodiment
may allow the perforated section 132 to extend substantially the
entire length between the interior surfaces of the vessel header
101, and thereby maximize the surface area available for perforated
section 132.
[0038] The internal support structure 103 may be connected to the
interior of the vessel header 101. In an embodiment, the internal
support structure 103 is welded to the interior of the vessel
header 101. The resulting welds and weld roots may result in flow
tube spacing 112 requirements that may determine the minimum
allowable spacing between flow tubes 102.
[0039] In an embodiment shown in FIG. 2B, the sliding cradle 300
may be welded or otherwise connected to the interior of the vessel
header 101. The support structure welds 203 are not generally in
horizontal alignment with the nearby header penetration welds 106,
as welds 203 are shown above the horizontal plane of welds 106 in
FIG. 2B. The welds illustrated in FIG. 2B are shown as individual
dots for illustration purposes. In an embodiment, the welds may be
any type of weld, including but not limited to, spot welds, stitch
welds, or seal welds, as would be known to one skilled in the arts.
The resulting weld configuration may reduce or eliminate any
complications with meeting the ASME weld requirements, which may
reduce installation difficulty. In addition, this weld
configuration may reduce complications in maintaining the industry
best practice of a minimum 1-inch spacing between weld roots, and
may allow for a reduction in flow tube spacing 112 relative to
other cradle embodiments. In an embodiment, the flow tubes 102 may
be devolatilizer nozzles. In this embodiment, the use of a sliding
cradle 300 to decrease the flow tube spacing 112 may allow for an
increase in the number of nozzles 102 within a vessel header 101,
may increase the perforated nozzle area 132 within the vessel
header 101, and may increase the associated throughput capacity of
the fluid distribution system.
[0040] In an embodiment shown in FIG. 2A, a support cradle 205 may
be welded or otherwise connected to the interior surface of the
vessel header 101. In an embodiment in which a support cradle 205
is welded to the interior surface of the vessel header 101, the
support cradle weld 105 may be located along a portion or portions
of the support cradle 205 interior so as to form a weld arc 202
along the support cradle 205 bottom, top, or both. As used herein a
weld arc 202 refers to a section of a weld or group of welds that
extend in an arc along the inner perimeter of the support cradle
205 but does not continue around the entire support cradle 205
perimeter. In an embodiment, the use of a weld arc 202, and in
particular a weld arc interior to the support cradle 205, to
connect the support cradle 205 to the interior vessel header 101
surface may impact the weld root spacing 201 requirements including
the minimum 1-inch spacing between weld roots. The weld arc 202 may
be continued around the bottom, top, or the bottom and top of the
support cradle 205 to the extent that the weld arc 202 would not be
closer than the minimum weld spacing 201 to an adjacent header
penetration weld 106. In an embodiment in which the support cradle
205 comprises a section of pipe or conduit of greater diameter than
the flow tube 102, the support cradle 205 may be connected to the
interior vessel header 101 surface using a weld arc 202 placed
along the inner perimeter of the support cradle top, bottom, or
both. Placement of the weld arc 202 along the inner, rather than
the outer, support cradle 205 joint allows the weld arc 202 to be
extended further around the interior of the support cradle 205
without violating the 1-inch requirement. In an alternative
embodiment, the support cradle 205 may comprise a half section of
pipe. In this embodiment, the weld arc 202 may be placed along the
lower, inner perimeter of the support cradle to the extent that the
weld arc 202 is not located closer than the required minimum weld
root spacing 201 as determined by industry best practices, which
may avoid potential weld problems due to the stresses present in
the heat affected zone of the weld. By avoiding the heat affected
zone, no stress relieving is required which may reduce fabrication
costs and time.
[0041] The plurality of lateral flow tubes 102 disposed within the
vessel header 101 may enter the vessel header 101 through vessel
header penetrations 109. The vessel header penetrations 109 may be
substantially sealed against unintended leakage through the use of
a sealed connection between the flow tube 102 and the vessel header
101. Examples of suitable connections include welded and flanged
connections. In an embodiment in which the flow tube 102 is
sealingly connected to the vessel header 101 using a flanged
connection, the same flanged connection may be used to form a
sealing connection to the external distribution manifold 107, which
may be used to convey a fluid to the flow tubes 102.
[0042] In an embodiment shown in FIG. 4, welded flow tubes 400 may
be connected directly to the vessel header 101 through the use of
welded connections 106 at the vessel header penetrations 109. The
welded connections 106 are intended to structurally and sealingly
connect the welded flow tube 400 to the vessel header 101 while
maintaining the vessel header's structural integrity. Since the
welded flow tube 400 is welded to the vessel header 101 at the
vessel header penetration 109, it is fixed and cannot be removed.
The welded flow tube 400 may then be connected to an external
manifold 107 through the use of external manifold flange 405,
flanged connection 111 on flow tube 400, and a connection device
406. In an embodiment a connection device 406 may comprise a set of
bolts in addition to a sealing mechanism, which may be required to
prevent leakage into or out of the vessel header from the flange.
The sealing mechanism may be packing, welding, special washers, use
of a stud flange, or any other means or methods known to those
skilled in the arts. In an embodiment, the welded flow tube 400 may
comprise a devolatilizer nozzle. In this embodiment, the perforated
portion 132 of the nozzle 400 may be wholly contained within the
vessel header 101 while the flow section 134 continues from the
vessel header 101 interior through the vessel header 101 wall for
connection to the external manifold 107 via an external manifold
flange 405. While FIGS. 4-6 each show the end of the flow tube
supported via a support cradle 205, it should be understood that
other supports such as sliding cradle 300 or support recess 304 may
be used in combination with any of the flange embodiments described
herein.
[0043] In an alternative embodiment shown in FIG. 5, the flow tubes
500 may be externally flanged to the vessel header penetrations
109. An externally flanged flow tube 500 refers to a flow tube 500
that is sealingly connected to the vessel header 101 using a short
section of pipe or conduit 402 that is larger in diameter than the
flow tube 400. The section of conduit is welded via welds 407 or
otherwise connected to the exterior of the vessel header 101 and
extended a short distance from the vessel. In an embodiment, a
typical externally flanged flow tube 400 connection may extend a
distance 410 from the vessel header 101 outer surface ranging from
48 in to 1 in, alternatively from 18 in to 3 in, alternatively from
12 in to 6 in. In an embodiment, a typical externally flanged flow
tube 400 connection may have a diameter ranging from 2 inches to 36
inches, alternatively from 8 inches to 24 inches, alternatively
from 10 inches to 20 inches. The extended end of the pipe or
conduit 402 may have a flange 403 to receive the external flange
111 of flow tube 500 and a flanged connection 405 to an external
manifold 107. The smaller diameter externally flanged flow tube 500
passes through the section of conduit 402 into the vessel header
101. The external manifold flange 405 may be connected to the
external flow tube flange 111 and the conduit flange 403 with a
connection device 406 such as a set of bolts and a sealing
mechanism. Examples of sealing mechanisms include packing, washers,
welding, stud flanges, and the like. This embodiment may allow the
externally flanged flow tube 500 to be removed for cleaning or
maintenance by removing the flange connection device 406. In an
embodiment, the externally flanged flow tube 500 may comprise a
devolatilizer nozzle. In this embodiment, the flow section 134 of
the nozzle 500 may extend from the external flow tube flange 111 to
near the inside wall of the vessel header 101, and the perforated
section 132 may extend across the vessel 101 interior. This
embodiment combines a nearly wall to wall perforated section 132,
or a complete wall to wall perforated section when used in
combination with recess 304, with the ability to remove the nozzle
500 for cleaning and maintenance.
[0044] In an alternative embodiment as shown in FIG. 6A, an
internally flanged flow tube 600 may be internally flanged to a
vessel header penetration 109. The internally flanged flow tube 600
may refer to a connection in which the vessel header 101 has a
flanged connection in the vessel header wall 503, and the
internally flanged flow tube 600 has a flanged end 111 that is
coupled to the connection in the vessel header wall 503. Fluid is
supplied by an external manifold 107 that is flanged 405 to the
external surface of the vessel header wall 503. The external
manifold 107, the vessel header wall connection 503, and the flow
tube flange 111 are coupled together using a connection device 406,
such as a set of bolts and a sealing mechanism. In an embodiment,
the internally flanged flow tube 600 may be a devolatilizer nozzle.
In this embodiment, the perforated portion 132 of the nozzle 600
may be reduced relative to an externally flanged nozzle 400, 500
because the section of the nozzle 600 near the flow tube flange 111
on the inside of the vessel header 101 cannot be perforated. The
internally flanged nozzle 600 may be removed for cleaning by
removal of the flange connection device 406. The internally flanged
nozzle 600 design may result in a reduced fluid distribution system
throughput capacity relative to the externally flanged nozzle 400,
500 configuration due to the reduction in the perforated area 132
of the internally flanged nozzle 600.
[0045] In an alternative embodiment shown in FIG. 6B, the
internally flanged flow tube 600 may be flanged within the vessel
header 101. In this embodiment, the manifold flange 405 is welded
into the vessel header penetration 109 with header penetration
welds 106. The manifold flange 405 may extend into the vessel
header a distance 601 of 12 to 3 inches. The manifold flange 405 is
then flanged to the internally flanged flow tube 600 within the
vessel header 101. The manifold flange 405 and the internally
flanged flow tube flange 111 are coupled together using a
connection device 406, such as a set of bolts and a sealing
mechanism. In an embodiment, the internally flanged flow tube 600
may be a devolatilizer nozzle 600. In this embodiment, the
perforated portion 132 of the nozzle 600 may be reduced relative to
an externally flanged nozzle 400, 500 due to the extension of the
manifold flange 405 within the vessel header 101. This embodiment
allows the internally flanged nozzle 600 to be removed for cleaning
and maintenance by removal of the flange connection device 406.
[0046] Returning to FIG. 1A, the header penetration external
flanges 111 may optionally be staggered 110 in order to decrease
the flow tube spacing 112 and increase the number of flow tubes 102
within the vessel header 101. In an embodiment, the external
flanges 111 may comprise the flanged ends of flow tubes 400 that
are welded into the vessel header penetrations 109 or the flanged
connections 111 of externally flanged flow tubes 500. In some
embodiments, the diameter of the external flange 111 may be large
enough so that adjacent flanges would be in contact or overlap if
they were aligned. In an embodiment, the external flanges 111 may
be staggered 110 such that the external flanges 111 do not align,
or do not directly align, with adjacent external flanges 111. As
used herein, staggered alignment refers to the arrangement of
external flanges 111 outside the vessel header 101 in a direction
perpendicular to the external flange's longitudinal axis such that
adjacent flanges are not in an approximately horizontal plane. Such
staggered alignment, configuration, or pattern (as shown in FIGS. 4
and 5) may be achieved by varying the distance 410 from the vessel
header 101 to adjacent external flanges. The staggered
configuration 110 may result in a decrease in flow tube spacing 112
and an increase in the number of flow tubes 102 that can be placed
in a vessel header 101. The decrease in spacing 112 is limited by
the minimum weld root spacing 201 requirements. In an embodiment,
the flow tubes 102 may be devolatilizer nozzles with staggered 110
external flanges 111. This embodiment may allow a greater number of
nozzles 102 to be placed in a vessel header 101, which may increase
the perforated nozzle area 132 and the fluid distribution system
capacity.
[0047] An external manifold 107 may supply fluid to the flow tubes
102. The alternating vessel header penetration 109 design may
require that more than one external manifold 107 be used to supply
fluid to the vessel header 101 flow tubes 102. In an embodiment,
the flow tubes 102, which may be present in an even number, may be
supplied fluid by two external manifolds 107. This embodiment
results in the same number of flow tubes 102 being supplied by each
external manifold 107, which may simplify the external manifold 107
design and facilitate even fluid distribution. In an alternative
embodiment, the plurality of flow tubes 102 may comprise an odd
number of flow tubes 102.
[0048] A method 700 of distributing a fluid within a fluid
distribution system such as devolatilizer vessel 100 may comprise
the use of a vessel header 101 coupled to a vessel body 128 of the
disclosed design. The disclosed method 700 may comprise penetrating
702 a vessel header on alternating sides, distributing 704 flow
tubes 102 parallel to each other within the vessel header 101,
supporting 706 the flow tubes 102 opposite the vessel header
penetrations 109 within the vessel header 101, and supplying 708 a
fluid to the flow tubes 102. The steps of the disclosed method may
be carried out in any order that may achieve the desired results.
While more than one order may culminate in the distribution of a
fluid, the following discussion is presented to illustrate one
particular order that may be used.
[0049] Initially, a vessel header 101 may be penetrated 702 so that
flow tubes 102 may be inserted into the vessel header 101. The
vessel header penetrations 109 may be arranged so that the flow
tubes 102 within the vessel header 101 are inserted from
alternating sides of the vessel header 101. The vessel header
penetrations 109 in the vessel header 101 may be made using any
method sufficient to create a penetration in the vessel header 101
capable of receiving a flow tube 102 while maintaining the vessel
header 101 structural integrity. Methods of making such vessel
header penetrations 109 may be known to one skilled in the arts.
The vessel header penetrations 109 may be substantially sealed
against leakage using a welded or flanged connection at the vessel
header penetration 109. Examples of specific types of connections
available have been disclosed herein.
[0050] Following the creation of vessel header penetrations 109,
flow tubes 102 may be distributed 704 into the vessel header
penetrations 109 in a parallel configuration. A parallel
configuration refers to an alignment of the flow tubes 102 such
that the flow tube's primary axis, i.e. its longitudinal axis, is
in parallel alignment with an adjacent flow tube's primary axis. In
the disclosed method, the flow tubes 102 may be distributed such
that the flow tubes 102 enter the vessel header 101 through
alternating header penetrations 109. In this method, a flow tube
102 within a vessel header 101 will have entered the vessel header
101 through a vessel header penetration 109 on the opposite side
through which the adjacent flow tube entered the vessel header 101.
As previously discussed in this disclosure, the distribution of
flow tubes 102 through alternating vessel header penetrations 109
may allow the flow tube spacing 112 to be reduced, which may allow
for additional flow tubes 102 to be placed in the vessel header
101.
[0051] The distributed flow tubes 102 may then be supported 706
within the vessel header 101 through the use of the disclosed
internal support structure 103. The internal support structure 103
is intended to support a flow tube end 104 opposite the vessel
header penetration 109 through which the flow tube 102 entered.
Supporting the flow tube 102 within the vessel header 101 may
eliminate the need for two vessel header penetrations 109 per flow
tube 102, which may reduce thermal stresses on the vessel header
101. The reduction in vessel header penetrations 109 may also allow
the flow tube spacing 112 to be reduced due to the elimination of a
header penetration weld 106. Supporting the flow tubes 102 within
the vessel header 101 may therefore increase the number of flow
tubes 102 within a vessel header 101, and the fluid distribution
system throughput capacity.
[0052] Once the flow tubes 102 have been distributed 704 and
supported 706 within a vessel header 101, a fluid may be supplied
708 to the flow tubes 102. Any method capable of supplying a fluid
to a flow tube 102 may be used and may be known to one skilled in
the arts. In the disclosed method, a fluid may be supplied to the
flow tubes 102 through the use of an external manifold 107. As
discussed in this disclosure, the external manifold 107 may
comprise external manifold flanges 405 arranged in a staggered
configuration for connection to the external flange 111. In a
method in which the flow tubes 102 are devolatilizer nozzles, the
fluid may be a polymer and may be supplied to the nozzles 102 for
devolatilization within the fluid distribution system, which may be
a devolatilizer vessel in an embodiment. The use of the disclosed
method 700 may result in a fluid being distributed within the fluid
distribution system. The disclosed method 700 may allow the flow
tube spacing 112 to be reduced and an increased number of flow
tubes 102 to be included within the vessel header 101.
[0053] The devolatizer as disclosed herein may provide improvements
in polymer production when compared to a conventional devolatizer.
In an embodiment, the devolatizer disclosed herein may exhibit an
improved throughput rate, an increase in the amount of volatiles
removed from the polymeric material or both. In an embodiment, the
devolatizer disclosed herein results in a 5% increase in the amount
of volatiles removed from the polymer material, alternatively a 10%
increase in the amount of volatiles removed from the polymer
material, alternatively a 20% increase in the amount of volatiles
removed from the polymer material, alternatively a 30% increase in
the amount of volatiles removed from the polymer material,
alternatively a 40% increase in the amount of volatiles removed
from the polymer material, alternatively a 50% increase in the
amount of volatiles removed from the polymer material,
alternatively a 60% increase in the amount of volatiles removed
from the polymer material, alternatively a 70% increase in the
amount of volatiles removed from the polymer material,
alternatively a 80% increase in the amount of volatiles removed
from the polymer material, alternatively a 90% increase in the
amount of volatiles removed from the polymer material,
alternatively a 100% increase in the amount of volatiles removed
from the polymer material. In an embodiment, the devolatizer
disclosed herein exhibits a 10% increase in throughput,
alternatively a 15% increase in throughput, alternatively a 20%
increase in throughput, alternatively a 25% increase in throughput,
alternatively a 30% increase in throughput.
[0054] While embodiments of the disclosure have been shown and
described, modifications thereof can be made by one skilled in the
art without departing from the spirit and teachings of the
disclosure. The embodiments described herein are exemplary only,
and are not intended to be limiting. Many variations and
modifications of the disclosed design are possible and are within
the scope of the disclosure. Where numerical ranges or limitations
are expressly stated, such express ranges or limitations should be
understood to include iterative ranges or limitations of like
magnitude falling within the expressly stated ranges or limitations
(e.g., from 1 to 10 includes, 2, 3, 4, etc.; greater than 0.10
includes 0.11, 0.12, 0.13, etc.). Use of the term "optionally" with
respect to any element of a claim is intended to mean that the
subject element is required, or alternatively, is not required.
Both alternatives are intended to be within the scope of the claim.
Use of broader terms such as comprises, includes, having, etc.
should be understood to provide support for narrower terms such as
consisting of, consisting essentially of, comprised substantially
of, etc.
[0055] Accordingly, the scope of protection is not limited by the
description set out above but is only limited by the claims which
follow, that scope including all equivalents of the subject matter
of the claims. Each and every claim is incorporated into the
specification as an embodiment of the present disclosure. Thus, the
claims are a further description and are an addition to the
disclosed embodiments of the present disclosure. The discussion of
a reference herein is not an admission that it is prior art to the
present disclosure, especially any reference that may have a
publication date after the priority date of this application. The
disclosures of all patents, patent applications, and publications
cited herein are hereby incorporated by reference, to the extent
that they provide exemplary, procedural or other details
supplementary to those set forth herein.
* * * * *