WO2015024096A1

WO2015024096A1 - Seperator for a gas stream

Info

Publication number: WO2015024096A1
Application number: PCT/CA2013/050650
Authority: WO
Inventors: Robert Mckenzie
Original assignee: Rng Holdings International Limited
Priority date: 2013-08-22
Filing date: 2013-08-22
Publication date: 2015-02-26

Abstract

A separator for a wet gas stream has an upper conduit having an inlet, an outlet and an outer peripheral wall. A helical baffle is positioned within the upper conduit defining a helical flow path. The helical flow path generates a vortex in gas flowing through the upper conduit, such that liquids in the gas stream move toward the outer peripheral wall. A lower conduit has an input in axial alignment with the outlet of the upper conduit and an outlet. The input of the lower conduit and the output of the upper conduit are separated by a gap, such that liquids are ejected from the upper conduit without entering the lower conduit, and such that the gas stream within the upper conduit is transferred to the lower conduit.

Description

TITLE

[0001 ] S eparator for a gas stream

FIELD

[0002] A separator for removing liquid from a gas stream using a vortex. BACKGROUND

[0003] Traditionally, gas streams are dried using chemicals, such as glycol, or using separators that remove moisture using filtering or mechanical separation. An example of a filtering separator can be found in Canadian patent application no. 2,270,152 (McKenzie et al.) entitled "Apparatus and method for removing entrained liquid from gas or air".

SUMMARY

[0004] There is provided a separator for a wet gas stream, comprising an upper conduit having an inlet, an outlet and an outer peripheral wall. A helical baffle is positioned within the upper conduit defining a helical flow path. The helical flow path generates a vortex in gas flowing through the upper conduit, such that liquids in the gas stream move toward the outer peripheral wall. A lower conduit has an input in axial alignment with the outlet of the upper conduit and an outlet. The input of the lower conduit and the output of the upper conduit are separated by a gap, such that liquids are ejected from the upper conduit without entering the lower conduit, and such that the gas stream within the upper conduit is transferred to the lower conduit.

[0005] According to an aspect, the helical flow path comprises two rotations.

[0006] According to an aspect, the gap is between 1/20 and 1/8 inches, or between 1/20 and 1/5 inches.

[0007] According to an aspect, one of an inner surface of the outlet of the upper conduit and an outer surface of the inlet of the lower conduit is bevelled. The angle of one or both bevels may be between 10 and 20 degrees.

[0008] According to an aspect, the upper conduit and the lower conduit are positioned within a tank, the tank having a liquid collection area.

[0009] According to an aspect, there is provided a separator for a wet gas stream, comprising an upper section having an inlet for receiving the gas stream, a liquid collection area and a gas outlet. An upper conduit is positioned within the tank, the upper conduit having an input connected to the input of the tank and an outlet. A helical baffle is positioned within the upper conduit defining a helical flow path. A lower conduit is positioned within the tank, the lower conduit having an input in axial alignment with the outlet of the upper conduit and an outlet connected to the gas outlet of the tank. The input of the lower conduit and the output of the upper conduit are separated by a gap. The output of the upper conduit has a bevelled inner surface such that liquids collected on an inner surface of the upper conduit are ejected from the upper conduit into the liquid collection area of the tank via the bevelled inner surface, and such that the gas within the upper conduit is substantially transferred to the lower conduit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:

FIG. 1 is an exploded side elevation view of an internal pipe of a separator for a gas stream.

FIG. 2 is a side elevation view in section of the internal pipe of the separator shown in FIG. 1.

FIG. 3 is a detailed side elevation view of section 'A' of FIG. 2.

FIG. 4 is a top plan view of a hub found in the separator.

FIG. 5 is a side plan view of the hub found in the separator.

FIG. 6 is a perspective side view of a three phase separator that works in combination with the separator for a gas stream shown in FIG. 1.

FIG. 7 is a perspective side view of a particulate separator that works in combination with the separator for a gas stream shown in FIG. 1.

FIG. 8 is a perspective side view of a separator that works in combination with the separator for a gas stream shown in FIG. 1.

FIG. 9 is a perspective view of the separator for a gas stream using a vortex shown in FIG. 1.

FIG. 10 is a schematic view of a three phase separator.

FIG. 11 is a schematic view of a particle bed separator.

FIG. 12 is a side elevation view, in section, of an alternative separator for a gas stream.

FIG. 13 is a top plan view, in section, of the separator shown in FIG. 12. FIG. 14 is a side elevation view of the cons-shaped baffle found in the separator shown in FIG. 12.

FIG. 15 is a top plan view, in section, of the separator shown in FIG. 12.

DETAILED DESCRIPTION

[0011] A separator for a gas stream using a vortex generally identified by reference numeral 10 will now be described with reference to FIG. 1 through FIG. 5 and 9.

Structure and Relationship of Parts:

[0012] Referring to FIG. 9, separator 210 is preferably positioned within a tank 212, which has an input 214 for receiving a gas/liquid mixture, a liquid collection area 216 within tank 212 and a gas outlet 218. Referring to FIG. 1, separator 210 has an upper conduit 220 with an inlet 222 and an outlet 224. Upper conduit 220 is preferably installed within tank 212 such that inlet 222 is connected to the input 214 of the tank 212 shown in FIG. 9. Referring to FIG. 1, upper conduit 220 is positioned above a lower conduit 232, which has an inlet 234 in axial alignment with outlet 224 of upper conduit 220 and an outlet 236 connected to gas outlet 218 of the tank 212. Lower conduit 232 is preferably installed within tank 212 such that outlet 236 is connected to gas outlet 218 shown in FIG. 9 and such that inlet 234 is in axial alignment with outlet 224. Preferably, referring to FIG. 3, the inner surface 226 of the outlet 224 of the upper conduit 220 is bevelled, and the outer surface 227 of the inlet of the lower conduit 232 is bevelled to assist in the extraction of water collected on an inner surface of upper conduit 220. Preferably, the angle of the bevel is between 10 and 20 degrees. A helical baffle 228 is positioned within the upper conduit 220 and defines a helical flow path in a fixed manner. Helical baffle 228 preferably causes the flow path to make two full rotations to induce a vortex, which causes liquids in the gas to move toward the inner surface of upper conduit 220. [0013] Referring to FIG. 3, the inlet 234 of the lower conduit 232 and the output 224 of the upper conduit 220 are separated by a gap 240, such that liquids collected on an inner surface 242 of the upper conduit 220 are ejected from the upper conduit 220. The gap is preferably between 1/20 and 1/8 inches, but may be as high as 1/5 inches. Referring to FIG. 2, ejected liquids are ejected out of upper conduit 220 via the gap 240 and into the liquid collection area 216 of the tank 212 while the gas within the upper conduit 220 is substantially transferred to the lower conduit 232. Preferably, as shown in FIG. 2, a mist pad 231 is position outside gap 240 to collect he liquid as it is ejected. As liquid is connected on mist pad 231, it will fall to the bottom of tank 212. The position of upper conduit 220 relative to lower conduit 232 is fixed by using gussets 235 that are spaced about conduits 220 and 232.

[0014] FIG. 4 and 5 show a hub assembly 233 that is positioned within lower conduit 232.

Operation:

[0015] An example of how separator 210 may be used will now be described, with reference to FIG. 1 through 15. Referring to FIG. 9, separator 210 may be used in combination with other separators to dry gas without the use of chemicals. In this example, separator 210 is used on relatively dry gas as a "polishing" separator. However, it may also be used in other situations as well.

[0016] Referring to FIG. 6, a common three-phase separator 100 may be used as the first stage of the separation process. Referring to FIG. 10, a schematic of a generic three-phase separator is shown, where production fluid enters the phase separator 100 through an inlet 102 and exits from gas outlet 108. A baffle 107 retains the liquids, while the gas is free to be removed via gas outlet 108. Water and oil will form separate layers, allowing water to be removed via water outlet 109, and oil, which flows over baffle 107, is removed via oil outlet 111. The oil and water may be disposed of or treated as desired or required, and will not be discussed further. Three-phase separator 100 is intended to be an initial separator to separate the gas from the bulk of the liquids. However, the gas exiting separator 100 will still be

"wet".

[0017] Referring to FIG. 7, the gas stream flows from output 108 of tank 100 to inlet 12 in tank 11, which operates as will be described below. The gas exits through gas outlet 34.

[0018] Referring to FIG. 8, the gas stream flows from output 34 of tank 11 into another separator, such as a particulate bed separator 110, via an inlet 112. Referring to FIG. 11, a generic particulate bed separator 110 is shown, and includes a horizontal tank in which particulate is present. Separator 110 includes vertical baffles 115 and is at least partially filled with particulate. The vertical baffles (not shown) increase the flow path of the gas stream, come into contact with the gas stream, and redirect the gas stream to create turbulence, each of which reduces the amount of moisture in the gas stream. The baffles generally alternate between being open on the top or bottom of separator 110. Fluids are collected at the bottom of the tank and removed via a liquid outlet 117. The gas stream then exits via outlet 118. [0019] Referring to FIG. 9, separator 10 is positioned at the end of the separation process. Referring to FIG. 2, the gas is injected into separator 210 via the inlet 214. The gas flows through inlet 214 and into the upper conduit 220 of the tank 212. A helical baffle 228 in the upper conduit 220 creates a helical flow path 230 that forces the liquid to the inner surface 42 of the upper conduit 220. The flow path 230 comprises of two complete circuits of the tank 212. The liquids on the inner surface 242 are ejected through a gap 240 created by the connection between the output 224 of the upper conduit 220 and the inlet 234 of the lower conduit 232. The liquids are collected in a collection area 216 of the tank 212. The gas within the upper conduit 220 is transferred to the lower conduit 232 via the upper conduit outlet 224 and the lower conduit inlet 234. The gas flows through the lower conduit 232 and may be extracted from gas outlet 218. [0020] Referring to FIG. 7, the gas stream flows from output 108 to inlet 122 in separator 10, Referring to FIG. 12, separator 10 has a tank 11 with a peripheral sidewall 16, which encloses an upper, separation section 14 and a lower, collection section 18. Tank 11 has an inlet 12 through which the gas stream which is a gas/liquid mixture, enters and is connected to the separation area 14. Generally, the liquid in the gas stream that is being removed is preferably water, or mostly water. A perforated baffle 20, such as a grill or a perforated plate 24 as shown in FIG. 13, forms the bottom of upper section 14 and separates the upper section 14 from the lower section 18. Referring to FIG. 12, the baffle 20 surrounds a cone-shaped baffle 22 that extends into the separation area 14. As the teachings contained herein are understood, it will be understood that cone-shaped baffle 22 need not be a perfect geometric cone, and that a cone-like shape is sufficient, for example, with the radius of cone-shaped baffle 22 reducing as it extends away from perforated baffle 20. Furthermore, while cone- shaped baffle 22 is shown as being hollow in FIG. 14 with an opening from lower section 18, cone-shaped baffle 22 may be solid, or may be positioned on baffle 20 that may not have an opening. It will also be understood that perforated baffle 20 may be formed in different ways. For example, instead of perforating a solid plate, baffle 20 may be formed using a mesh.

[0021] The separation area 14 is covered by a top plate 21 that has an opening 23 connected to inlet 12. Referring to FIG. 12 and 15, a spiral baffle 25 is mounted on the cons- shaped baffle 22. Spiral baffle 25 begins at the top of cons-shaped baffle 22, and is angled outward. The bottom edge of spiral baffle 25 spirals outward as it travels down cons-shaped baffle 22, while the top edge of spiral baffle spirals outward along top plate 21. As depicted, spiral baffle 25 ends when the bottom edge reaches the bottom of cons-shaped baffle 22, and the top edge reaches peripheral sidewall 16, in about 1 ½ rums. It will be understood that the actual design of spiral baffle 25 may vary depending on the preferences of the user and the design requirements, while still allowing the purpose to be satisfied. Opening 23 is depicted as being aligned with the center of spiral baffle 25, such that it causes the inlet gas to flow in a vortex or vortex-like flow path as it flows downward and approaches perforated baffle 20. Referring to FIG. 12, spiral baffle 25 defines a vortex flow area 27 bounded on the top by spiral baffle 25, on the bottom by perforated baffle 20, and on the sides by outer peripheral sidewall 16 of tank 11. The movement of gas in this manner induces separation of any fluid in the gas stream, and also forces the gas/liquid mixture toward the peripheral sidewall 16.

[0022] Preferably, there is a liquid collection medium 29 positioned adjacent to outer wall 16 that leaves flow area 27 relatively unobstructed. Liquid collection medium is used to enhance collection of liquid from the gas stream. Liquid collection medium 29 is preferably a mist pad, such as a pad made from a mesh of stainless steel or other substances. Medium 29 may take other forms as well, such as particulate matter. Referring to FIG. 12 and 13, perforated baffle 20 preferably has liquid flow ports 31 below liquid collection medium 29, such that the collected liquid captured by liquid collection medium 29 is permitted to flow down through flow ports 31 into lower section 18, while the dried gas passes substantially through perforations 19 in perforated baffle 20. Referring to FIG. 12, a peripheral baffle 33 may be mounted in lower section 18 below perforated baffle 20 between flow ports 31 and perforations 19 to prevent contact between the separated gas and liquid. [0023] A cylindrical flange 24 extends downward from the baffle 20 to form a cavity 26. The cylindrical flange 24 is preferably an extension of the cons-shaped baffle 22 that receives a pipe 28 with a vertical section into an interior 30 of the cons-shaped baffle 22 in the upper separation section 14. Referring to FIG. 12, particulate matter 23 in the separation section 14 adsorbs liquid from the gas stream. Particulate matter 23 is preferably any material that is at least partially hydrophyllic. In one example, gravel may be used as a readily available, inexpensive material. Referring to FIG. 12, the particulate matter 23 is supported within the upper separation section 14 by the baffle 20 and the peripheral sidewall 16. The adsorbed liquid and gas stream flow through the baffle 20 into the lower collection section 18. A liquid outlet 32 toward the bottom of the lower section 18 is used to remove separated liquids from the tank and a gas outlet 34 toward the top of the lower section 18 is used to remove separated gases from the tank. Outlet 32 preferably includes a dump valve to remove the fluid once a certain level has been reached. The gas outlet 34 includes a pipe 28 that has an opening that extends into the cavity 26 formed by a cylindrical flange 24. [0024] In this patent document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements. [0025] The following claims are to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, and what can be obviously substituted. Those skilled in the art will appreciate that various adaptations and modifications of the described embodiments can be configured without departing from the scope of the claims. The illustrated embodiments have been set forth only as examples and should not be taken as limiting the invention. It is to be understood that, within the scope of the following claims, the invention may be practiced other than as specifically illustrated and described.

Claims

What is Claimed is:

1. A separator for a wet gas stream, comprising:

an upper conduit having an inlet, an outlet and an outer peripheral wall

a helical baffle positioned within the upper conduit defining a helical flow path, the helical flow path generating a vortex in gas flowing through the upper conduit, such that liquids in the gas stream move toward the outer peripheral wall;

a lower conduit having an input in axial alignment with the outlet of the upper conduit and an outlet, the input of the lower conduit and the output of the upper conduit being separated by a gap, such that liquids are ejected from the upper conduit without entering the lower conduit, and such that the gas stream within the upper conduit is transferred to the lower conduit.

2. The separator of claim 1, wherein the helical flow path comprises two rotations.

3. The separator of claim 1, wherein the gap is between 1/20 and 1/8 inches.

4. The separator of claim 1, wherein the gap is between 1/20 and 1/5 inches.

5. The separator of claim 1, wherein an inner surface of the outlet of the upper conduit is bevelled.

6. The separator of claim 5, wherein the angle of the bevel is between 10 and 20 degrees.

7. The separator of claim 1, wherein an outer surface of the inlet of the lower conduit is bevelled.

8. The separator of claim 7, wherein the angle of the bevel is between 10 and 20 degrees.

9. The separator of claim 1, wherein the upper conduit and the lower conduit are positioned within a tank, the tank having a liquid collection area.

10. A separator for a wet gas stream, comprising:

an upper section having an inlet for receiving the gas stream, a liquid collection area and a gas outlet;

an upper conduit positioned within the tank, the upper conduit having an input connected to the input of the tank and an outlet;

a helical baffle positioned within the upper conduit defining a helical flow path;

a lower conduit positioned within the tank, the lower conduit having an input in axial alignment with the outlet of the upper conduit and an outlet connected to the gas outlet of the tank, the input of the lower conduit and the output of the upper conduit being separated by a gap, the output of the upper conduit having a bevelled inner surface such that liquids collected on an inner surface of the upper conduit are ejected from the upper conduit into the liquid collection area of the tank via the bevelled inner surface, and such that the gas within the upper conduit is substantially transferred to the lower conduit.