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A mist eliminator for eliminating droplets from a gaseous flow, for instance in cooling towers, comprises parallel profile elements including flow passages with constrictions and deflecting sections for mist elimination therebetween. A droplet acceleration section is provided upstream of the first d

A mist eliminator for eliminating droplets from a gaseous flow, for instance in cooling towers, comprises parallel profile elements including flow passages with constrictions and deflecting sections for mist elimination therebetween. A droplet acceleration section is provided upstream of the first deflecting section in order to reduce pressure losses while keeping the eliminating efficiency constant or even improving the same.

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1. A method of eliminating droplets from a gaseous flow that is guided through flow passageways including constrictions and deflecting sections, in which the walls of the flow passageways are oriented so that the eliminated liquid may flow off along said walls towards the inlet portion of the flow p

1. A method of eliminating droplets from a gaseous flow that is guided through flow passageways including constrictions and deflecting sections, in which the walls of the flow passageways are oriented so that the eliminated liquid may flow off along said walls towards the inlet portion of the flow passageways under the action of gravity, characterized in that the flow in the flow passageways formed between adjacent profile elements upstream of the first deflecting sections is accelerated so that at the inlet to the deflecting section at least the small droplets achieve a velocity which is equal to or only comparatively slightly less than the velocity of the gaseous flow. 2. A mist eliminator for eliminating droplets from a gaseous flow, in which flow passageways including constrictions and deflecting sections are formed by means of profile elements on the walls of which the droplets are eliminated and which are oriented such that the eliminated liquid may flow along said walls towards the inlet portion of the flow passageways under the action of gravity, characterized in that a droplet acceleration section is provided between adjacent profile elements upstream of a first deflecting section effective to eliminate droplets, said droplet acceleration section being dimensioned so that at least small droplets are accelerated at the inlet to the first deflecting section to a velocity which differs only slightly from the gas flow velocity. 3. A mist eliminator as claimed in claim 2, characterized in that between two adjacent profile elements there is formed a gas acceleration section with rapid reduction of the flow passage cross-section, which is succeeded downstream thereof by the droplet acceleration section having a substantially constant flow cross-section. 4. A mist eliminator as claimed in claim 3, characterized in that the length of the gas acceleration section is approximately 0.2 to 1-times the length of the droplet acceleration section. 5. A mist eliminator as claimed in claim 4, characterized in that each profile element in the region of the droplet acceleration section, starting from a profile nose on the side of the approaching flow, increases to a profile thickness of about 0.2 to 0.6 times the centre distance (t) between two adjacent profile elements, and that the length (b) of the droplet acceleration section is about 0.5 times to twice the centre distance between two adjacent profile elements. 6. A mist eliminator as claimed in claim 5, characterized in that the predetermined maximum profile element thickness is substantially constant throughout the length of the droplet acceleration section. 7. A mist eliminator as claimed in claim 5, characterized in that each droplet acceleration section is inclined relative to the approach flow direction at an angle of not more than 30°, preferably between 5° and 20°, whereby the first deflection is increased. 8. A mist eliminator as claimed in claim 7, characterized in that the radius of curvature on the concave profile element side at the deflecting section is smaller than or equal to about 0.25 times the centre distance between two adjacent profile elements. 9. A mist eliminator as claimed in claim 7, characterized in that the radius of curvature on the convex profile element side at the deflecting section is larger than or equal to about 0.25 times the centre distance between two adjacent profile elements. 10. A mist eliminator as claimed in claim 9, characterized in that the radius of curvature on the concave profile element side at the deflecting section is smaller than or equal to about 0.25 times the centre distance between two adjacent profile elements. 11. A mist eliminator as claimed in claim 3, characterized in that each profile element in the region of the droplet acceleration section, starting from a profile nose on the side of the approaching flow, increases to a profile thickness of about 0.2 to 0.6 times the centre distance between two adjacent profile elements, and that the length of the droplet acceleration section is about 0.5 times to twice the centre distance between two adjacent profile elements. 12. A mist eliminator as claimed in claim 2, characterized in that the cross section of the profile elements is of unsymmetrical configuration. 13. A mist eliminator as claimed in claim 2, characterized in that the thickness of the profile elements towards the exit plane of the flow passageways, starting with the first deflecting section, is reduced to form diffusors having a flare angle of between 4° and 12°. 14. A mist eliminator as claimed in claim 2, characterized in that the profile elements are provided with drain-off flutes for the eliminated liquid, said drain-off flutes terminating towards the inlet plane. 15. A mist eliminator as claimed in claim 2, characterized in that each droplet acceleration section is inclined relative to the approach flow direction at an angle of not more than 30°, and, whereby the first deflection is increased. 16. A mist eliminator as claimed in claim 2, characterized in that one profile element side is convexly curved into the flow and the other profile element side is substantially planar in said droplet acceleration section. 17. A mist eliminator as claimed in claim 15, characterized in that the droplet acceleration section between the inlet, which is oriented in approach flow direction, and the exit at the first deflecting section is slightly curved. 18. A mist eliminator as claimed in claim 15, characterized in that one profile element side is convexly curved into the flow and the other profile element side is substantially planar in said droplet acceleration section. 19. A mist eliminator as claimed in claim 15, characterized in that the eliminating surface behind the first deflecting section is succeeded by a second deflecting section. 20. A mist eliminator as claimed in claim 19, characterized in that the flow passageway in the region behind the first deflecting section includes a constriction to thereby provide a further droplet acceleration section. 21. A mist eliminator as claimed in claim 19, characterized in that a further eliminating surface is located downstream from the second deflecting section. 22. A mist eliminator as claimed in claim 19, characterized in that the flow passageway in the region behind the second deflecting section includes a constriction to thereby provide a further droplet acceleration section. 23. A mist eliminator as claimed in claim 19, characterized in that the exit ends of the profile elements are enlarged. 24. A mist eliminator as claimed in claim 15, characterized in that the angle is between about 5° and about 20°. 25. A mist eliminator as claimed in claim 2, characterized in that the eliminating surface behind the first deflecting section is succeeded by a second deflecting section. 26. A mist eliminator as claimed in claim 25, characterized in that a further eliminating surface is located downstream from the second deflecting section. 27. A mist eliminator as claimed in claim 2, characterized in that the radius of curvature on the concave profile element side at the each deflecting section is smaller than or equal to about 0.25 times the centre distance between two adjacent profile elements. 28. A mist eliminator as claimed in claim 25, characterized in that the flow passageway in the region behind the first deflecting section includes a constriction to thereby provide a further droplet acceleration section. 29. A mist eliminator as claimed in claim 2, characterized in that the exit ends of the profile elements are enlarged. 30. A mist eliminator as claimed in claim 2, characterized in that between two adjacent profile elements there is formed a gas acceleration section with rapid reduction of the flow passage cross-section, which is succeeded downstream thereof by the droplet acceleration section having a substantially progressively decreasing flow cross-section. 31. A mist eliminator as claimed in claim 2, characterized in that the radius of curvature on the convex profile element side at the deflecting section is larger than or equal to about 0.25 times the center distance between two adjacent profile elements. 32. A mist eliminator as claimed in claim 31, characterized in that the radius of curvature on the concave profile element side at the deflecting section is smaller than or equal to about 0.25 times the centre distance between two adjacent profile elements. 33. A mist eliminator for eliminating droplets from a gaseous flow, in which flow passageways including constrictions and deflecting sections are formed by means of profile elements on the walls of which the droplets are eliminated and which are oriented such that the eliminated liquid may flow off along said walls substantially transversely to the main flow direction under the action of gravity, a droplet acceleration section being provided between adjacent profile elements in the region preceding a deflecting section and collecting flutes being formed on an eliminating surface following the deflecting section, characterized in that the maximum thicknesses of each profile element is about 0.2 to about 0.6 times the centre distance between two adjacent profile elements, that the length of the droplet acceleration section is about 0.5 times to about twice the centre distance, and that the collecting flutes are disposed on the eliminating surfaces in such a way that their tips, as viewed in the direction of flow, are spaced from the preceding deflecting section by between about 1/4 and about 2/3 the length of the eliminating surface following said deflecting section.