VANE-TYPE SEPARATOR

Abstract: A vane-type separator for separating liquid from liquid­ laden gases, comprising a plurality of hollow vanes (10a, 10b, 10c) mounted generally upright and spaced apart to define zig-zag paths between for the passage of gas from a bottom entry level to an upper exist level, the zig-zag paths (14) between the vanes causing the upward flowing gas to change in direction and velocity at each angle of the zig-zag so that entrained liquid is separated from the gas and is instant of the exterior surfaces of the vane walls, the vane walls having downwardly facing apertures (16) through which the surface water is impelled by the upward gas flow, whereby the liquid runs in the interiors of the vanes to be collected at the bottom thereof.

Description: This invention relates to a vane-type separator for separating liquid from liquid-carrying gases, ie, gases in which liquid particles, especially water particles, are entrained. A known vane-type separator passes the gases in a generally horizontal direction. A series of generally parallel, solid vanes extend generally horizontally and define between them paths for the flow of gas along which the gas is forced to change direction several times, with some degree of centrifugal action occurring as the change in direction occurs. The heavier liquid droplets are then thrown against the walls of the solid vanes, coalescing to flow as a sheet across the vanes, ie, in a direction perpendicular to the flow of gas. The liquid is collected by side troughs provided on the vanes. Furthermore, in US-A-3938972 there is disclosed a vane-type separator for separating liquid from liquid-laden gas, of a kind comprising a plurality of hollow vanes mounted generally upright and spaced apart to define paths between for passage of gas from a bottom entry level to a top exit level, the walls of the hollow vanes being shaped so that in following said paths liquid laden gas is made to undergo such variations in direction and velocity that the entrained liquid is separated from the gas and is caused to be incident on the exterior surface of the vane walls, said vane walls having apertures through which the surface water thereon tends to be impelled into the interiors of the hollow vanes by the upward gas flow, whereby the liquid collects at the bottom of the interiors of the vanes whilst gases with liquid removed therefrom exit at the top between the vanes. Whilst such known vane-type separators operate satisfactorily, it is an object of this invention to provide an alternative vane-type separator having a higher degree of efficiency in separating the entrained liquid from the gases. According to the present inventin a vane-type separator of a kind as hereinabove defined is characterised in that adjacent to the apertures the vane walls are provided with deflectors which extend into the hollow vanes in such a manner that each hollow vane has a continuous substantially unobstructed interior passage extending between the entry and exit levels for a free downward flow of separated liquid to the bottom of the interior of the vane to allow drainage therefrom. The improved separator in accordance with the invention is believed to becapable of removing approximately 98% of entrained liquid particles fro the gas flow. The change in path direction at each angle of the zig-zag is typically of the order of 100°. Each zig-zag path preferably has at least four positions between the top and bottom thereof at which a liquid-separating change in direction is produced. In a preferred arrangement, the vanes have apertures on parts of the walls thereof which face downwardly; whereby liquid running on the exterior of the walls is impelled upwardly through said apertures by the upwardly directed gas flow. In one convenient arrangement, the vane wals have horizontal lines of horizontally elongated apertures. The separator may comprise a cylindrical chamber having a substantial plurality of vanes mounted therein to extend across the chamber in parallel, with lengths varying so that the vanes fully span the chamber except at two opposite side regions thereof, where the chamber is closed to upward passage of gases. In this way, all the gases flowing upwardly from the bottom of the chamber are caused to enter the tortuous paths between the hollow vanes. The vanes may communicate at the bottom with a liquid drainage channel. In a preferred arrangement, this drainage channel is formed around the periphery of the chamber, the bottom of the interiors of the vanes communicating with the channel at the lateral ends of said vanes. Brief description of the drawings The invention is now exemplified with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a vane-type liquid/gas separating chamber in accordance with the invention; Figure 2 is a perspective view of the chamber from above; Figure 3 is an enlarged view showing three parallel hollow vanes in transverse cross-section at right-angles to their lengths; and Figure 4 is a perspective view of a single hollow vane. Description of embodiment Referring first to Figures 1 and 2, a series of parallel upright vanes 10 extend from side to side across the interior of a cylindrical chamber 12. In practice, the chamber is mounted at the top of a gas liquid treatment apparatus (not shown). Within said apparatus, the gases in which water or other liquid is entrained pass upwardly at high velocity into the bottom of the chamber. The gases emerge from the top of the chamber with substantially all entrained liquid removed therefrom. This is achieved by an arrangement of hollow vanes 10 substantially as shown in Figures 3 and 4 of the drawings. Referring first to Figure 3, the left-hand vane 10a is the last vane, ie, is shortest, on one side of the chamber. The vane referenced 10c is the last vane, ie, the shortest, on the opposite side of the chamber. The vane referenced 10b is one of a substantial plurality of vanes which span the chamber between the aforementioned vanes 10a and 10c. The various vanes 10b are of differing lengths so as fully to span the chamber. Thus, the whole area of the chamber is filled by the vanes except for two small regions at opposite sides thereof. As indicated at 12a in Figure 2, the top of the chamber is closed off at these opposite side regions to prevent the flow of gas. Thus, all gas entering the base of the chamber passes upwards between the vanes. Each vane 10 is hollow and the parallel walls thereof define zig-zag paths 14 for upward passage of the gas between said vanes. Each zig-zag path is similar, and has five positions between the bottom and the top at which the path changes in direction by an angle of nearly 90°. In use, at each of these positions, the upwardly flowing gas is caused to change direction and velocity, with the result that the liquid particles entrained therein are caused to be incident on the exterior surfaces of the walls of the vanes, there to coalesce and flow on said exterior surfaces. In order to define the said zig-zag paths 14, the walls of the hollow vanes 10 have inclined parts which alternately face downwardly and upwardly. The downwardly facing parts are provided with apertures 16. When the liquid flowing on the exterior surfaces of the walls reaches these apertures, the liquid is impelled into the interior of the vane 10 by the upwardly directed gas flow in the passages 14. Deflectors 18 within the hollow vanes act to arrest the inwardly impelled liquid and assist in ensuring flow of said liquid to the bottom of the interior of the vanes, where it is collected in a drainage channel 20 (see Figure 1) provided around the periphery of the cylindrical chamber 12. Figure 4 shows one of the vanes 10 in perspective. From this Figure it can be seen that the apertures 16 take the form of a horizontal line of horizontally elongated slots extending across the vane from one lateral end thereof to the other. It will be noted that, in the vertical direction, the slots 16 in successive rows are in slightly staggered relationship to one another. Referring again to Figure 3, it will also be noted that the hollow vanes 10a and 10c, which are the last vanes in the assembly on opposite sides thereof, do not include apertures 16 and associated internal deflectors 18 on the walls thereof which face outwardly. As abovementioned, gas flow is prevented from taking place between the wall of the chamber and these outside walls of the edge vanes 10a and 10c.

Claims: A vane-type separator for separating liquid from liquid-laden gases, comprising a plurality of hollow vanes (10) mounted generally upright and spaced apart to define paths (14) between for passage of gas from a bottom entry level to a top exit level, the walls of the hollow vanes being shaped so that in following said paths liquid laden gas is made to undergo such variations in direction and velocity that tile entrained liquid is separated from the gas and is caused to be incident on the exterior surface of the vane walls, said vane walls having apertures (16) through which the surface water thereon tends to be impelled into the interiors of the hollow vanes by the upward gas flow, whereby the liquid collects at the bottom of the interiors of the vanes whilst gases with liquid removed therefrom exit at the top between the vanes, characterised in that adjacent to the apertures (16) the vane walls are provided with deflectors (18) which extend into the hollow vanes (10) in such a manner that each hollow vane has a continuous substantially unobstructed interior passage extending between the entry and exit levels for a free downward flow of separated liquid to the bottom of the interior of the vane to allow drainage therefrom. A separator according to claim 1, characterised in that the vanes (10) define similar and parallel zig-zag paths between them. A separator according to claim 2, characterised in that the change in path direction at each angle of a zig-zag is of the order of 100°. A separator according to claim 2 or claim 3, characterised in that each zig-zag path (14) has at least four positions between the top and the bottom thereof at which a liquid-separating change in direction is produced. A separator according to any one of claims 1 to 4, characterised in that the vanes (10) have apertures on parts of the walls thereof which face downwardly whereby liquid running on the exterior of the walls is impelled upwardly through said apertures by the upwardly directed gas flow. A separator according to any one of claims 1 to 5, characterised in that the vane walls have horizontal lines of horizontally elongated apertures. A separator according to any one of the preceding claims characterised by a cylindrical chamber (12) having a substantial plurality of vanes mounted therein to extend across the chamber in parallel, with lengths varying so that the vanes fully span the chamber except at two opposite side regions (12A) thereof, where the chamber is closed to upward passage of gases. A separator according to claim 7, characterised in that the vanes communicate at the bottom with a liquid drainage channel (20). A separator according to claim 8, characterised in that the drainage channel (20) is formed around the periphery of the chamber (12) and the bottom of the interiors of the vanes (10) communicate with the channel at the lateral ends of the vanes. A separator according to any one of the claims 6 to 9 characterised in that each horizontally elongated aperture (16) is staggered in a vertical direction relative to the adjacent aperture in the respective vane wall.

Inventors: ARETZ, HANS JURGEN, DIEKMANN, RAINER, KOENE, FRITS
Applicants: BURGESS-MANNING LIMITED
Application year: 1987
Main classification: B01D45
IPC codes: B01D45