U.S. patent application number 10/500724 was filed with the patent office on 2005-03-31 for device for the transformation of gas/liquid flow to laminar or stratified flow.
Invention is credited to Gramme, Per.
Application Number | 20050066637 10/500724 |
Document ID | / |
Family ID | 19913302 |
Filed Date | 2005-03-31 |
United States Patent
Application |
20050066637 |
Kind Code |
A1 |
Gramme, Per |
March 31, 2005 |
Device for the transformation of gas/liquid flow to laminar or
stratified flow
Abstract
A device in connection with a pipe (1) for transformation of
dispersed gas/liquid flow into laminar stratified flow. The
solution involves a first set of stationary guide blades (6) being
arranged in the pipe (1) and being designed to rotate the
liquid/gas flow. The pipe (1) is, in turn, connected to a second
pipe (2) with the same or a different diameter and, in the
transition between the pipe (1) and the second pipe (2), there is a
second set of blades or a device (8) that is designed to stop the
rotation of the gas. The natural flow pattern of the gas/liquid in
the second pipe (2) then becomes stratified over a predefined
distance.
Inventors: |
Gramme, Per; (Porsgrunn,
NO) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
19913302 |
Appl. No.: |
10/500724 |
Filed: |
November 29, 2004 |
PCT Filed: |
January 31, 2003 |
PCT NO: |
PCT/NO03/00029 |
Current U.S.
Class: |
55/456 |
Current CPC
Class: |
B04C 3/00 20130101; B01D
45/16 20130101 |
Class at
Publication: |
055/456 |
International
Class: |
B01D 045/12 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 8, 2002 |
NO |
20020619 |
Claims
1-5. (Cancelled)
6. A device in connection with a pipe for transformation of
dispersed liquid/gas flow into stratified flow, wherein a first set
of stationary guide blades is arranged in the pipe and is designed
to rotate the liquid/gas flow, the pipe is connected to a second
pipe with the same or a different diameter and, in a transition
between the pipe and the second pipe, there is a second set of
blades or a device that is designed to stop the rotation of the gas
so that the natural flow pattern of the gas/liquid in the second
pipe becomes stratified over a predefined distance.
7. A device in accordance with claim 6, wherein the second pipe has
a larger diameter than the first pipe.
8. A device in accordance with claim 6, wherein a venturi is
arranged in the pipe, and the first set of guide blades is arranged
at the inlet of the venturi, while the second set of guide blades
is arranged at the outlet of the venturi.
9. A device in accordance with claim 6, wherein the second device
is a perforated plate.
10. A device in accordance with claim 9, wherein the perforated
plate is arranged at an angle in relation to the longitudinal
direction of the pipe.
11. A device in accordance with claim 7, wherein the second device
is a perforated plate.
12. A device in accordance with claim 8, wherein the second device
is a perforated plate.
Description
[0001] The present invention concerns a device in connection with
pipes for the transformation of dispersed liquid/gas flow into
laminar or stratified flow. More precisely, the present invention
concerns a device that is designed to break down drops of liquid in
a gas flow, in particular a gas flow in a pipe or a pipe
separator.
[0002] In many situations in connection with the flow of gas in a
pipe, there will also be drops of liquid dispersed in the gas flow.
In particular in connection with the production of oil and gas or
in installations for processing, for example the separation of oil
and gas, there will be flow conditions in which large quantities of
liquid exist as drops dispersed in the gas. For several reasons, it
is desirable to break down the drops of liquid in such gas flows in
order to achieve pure flows of gas/liquid.
[0003] The prior art contains the use of so-called drop traps for
the separation of drops of liquid from a gas flow, but such drop
traps consist of separate devices connected to the transport pipe
and have external dimensions that extend far beyond the diameter of
the transport pipe. Such a drop trap has a relatively expensive
design and cannot be used in contexts in which there is a lack of
space or where it is required that the diameter of the transport
pipe for the gas/liquid transported cannot be exceeded by much.
[0004] The applicant having filed the present patent application
has previously filed patent applications, including PCT/NO98/00085,
concerning the separation of fluids in pipes or wells, for example
sea bed and downhole separation of oil, water and gas. An essential
precondition for achieving separation in a pipe or well is that the
flow is stratified. In connection with the extraction of oil and
gas, there may be dispersed liquid/gas flow in many situations
where downhole pipe separators are used.
[0005] With the present invention, a device has been produced that
transforms dispersed liquid/gas flow into stratified flow in a
simple fashion over a very short distance. The solution is very
effective and inexpensive and can easily be adapted to pipe
separators as described in the above application.
[0006] The present invention is characterised in that a first set
of stationary guide blades is arranged in the transport pipe. The
guide blades are designed to rotate the liquid/gas flow. The
transport pipe is connected to a second pipe with the same or a
different diameter. A second set of blades or a device that is
designed to stop the rotation of the gas is arranged in the
transition between the transport pipe and the second pipe so that
the natural flow pattern of the gas/liquid becomes stratified over
a predefined distance, as defined in the attached claim 1.
[0007] The dependent claims 2-3 define advantageous features of the
present invention.
[0008] The present invention will be described in further detail in
the following by means of examples and with reference to the
attached figure, which shows a diagram of a transport pipe 1 with a
solution in accordance with the present invention.
[0009] The special feature of the solution is that a set of
stationary guide blades 6 is arranged in the pipe 1 for transport
of liquid and gas. The guide blades are designed to rotate the
dispersed liquid/gas flow. In turn, the transport pipe 1 is
connected to a pipe 2 with a larger diameter. A second set of guide
blades 8 or another suitable device that is designed to stop the
rotation of the gas flow is arranged in the transition between the
pipe 1 and the pipe 2 with a larger diameter.
[0010] The solution works as follows. Gas with a high gas/liquid
ratio flows in the pipe 1 towards the guide blades 6. The guide
blades cause the gas to rotate so that the drops are slung towards
the pipe wall on account of centrifugal force, partially at the end
of the blades 6 and in the area 7 of the pipe towards the second
set of blades 8. A film of liquid is thus produced on the pipe in
the area 7 with a flow direction towards the second set of blades
8. The gas is thus cleared of drops of liquid but will continue to
rotate until it meets the blades 8, which have the opposite guide
direction to the first set of blades 6. The rotation of the gas is
stopped here, after which the liquid will flow towards the lower
part of the pipe on account of gravitational force, while the gas
will flow into the upper part of the pipe, thus establishing a
stratified gas/liquid flow.
[0011] A decisive precondition for achieving stratified flow,
however, is that the diameter of the pipe 3 is large enough to
prevent redispersion being initiated and to ensure that the natural
flow pattern remains stratified.
[0012] Moreover, the ratio between the diameter of the transport
pipe 1 and the diameter of the pipe with a larger diameter 2, as
well as the length of the guide blades and their angle to the pipe,
will depend on the flow speed, the gas/liquid ratio, the viscosity
of the liquid and the density of the liquid.
[0013] It should be noted that the present invention, as it is
defined in the claims, is not limited to the embodiment shown in
the attached drawing and described above. Therefore, instead of the
second set of guide blades 8, it is possible to use another device
that stops the gas rotation after the guide blades 6. A vertical or
horizontal perforated plate arranged in the transition part between
the transport pipe 1 and the pipe with the larger diameter 2 may be
used. Moreover, the perforated plate may be arranged at an angle in
relation to the longitudinal direction of the pipe with a direction
that is the opposite of the guide direction of the blades 6.
[0014] Although the above description concerns a solution in which
the second pipe has a larger diameter, it is also possible, in
given flow situations, depending on the flow speed and drop
density, to use solutions in which the second pipe has a larger or
smaller diameter than the first pipe (the transport pipe). However,
this requires, as stated above, that the flow speed of the gas
after drop separation does not cause the liquid to be redispersed.
Otherwise it will be possible to use a constriction in the pipe in
the form of a venturi. The first set of guide blades 6 should then
be arranged at the inlet of the venturi so that they extend from a
place in front of the inlet of the venturi and a little way into
it.
[0015] The use of a venturi means that the speed is increased
(through the venturi) so that-a more intensive rotational field is
established. The second set of blades 8 that stops the rotation is
arranged at the outlet of the venturi, where the speed increases
again. This results in equivalent liquid separation and stratified
gas/liquid flow as in the example shown in the figure.
* * * * *