A ROTOR FOR SPRAYING LIQUIDS, AND AN EXHAUST-GAS WASHER

Abstract: A liquid-spraying rotor (1) is described, the purpose of which is to receive liquids and to fractionate this liquid into as small as possible particles and to generate a flow of gases in a direction. Especially, a rotor of the type suggested by the present invention has application in exhaust-gas washers, for instance, in garbage-burning installations. The invention proposes a rotor that avoids or minimizes the accumulation of residues on the side walls of a gas washer, while maintaining the effect of generating rising streams, besides providing a fractionation of a liquid into minute particles, so as to increase the area of contact among the fractionated particles of the washing liquid and the particles in suspension in a gas. The proposed rotor (1) comprises: a first group of flaps (5, 6) suitable for, in rotation, spraying a liquid that falls onto them and providing a flow of gases and sprayed liquid in axial direction; a second group of flaps (9) located radially more outward than the flaps of the first group (5, 6) and suitable for, in rotation, providing a flow of gases and sprayed liquid radially inwards. A gas washer (2) is equally proposed, which contains said rotor.

Description: Title: "A ROTOR FOR SPRAYING LIQUIDS, AND AN EXHAUST-GAS WASHER" The present invention refers to a iiquid-spraying rotor, the purpose of which is to receive liquids such as pure water or a liquid solution containing water, and to fraction this liquid into as fine as possible particles and generate a gas flow in a direction. Especially, a rotor of the type suggested by the present invention has application in exhaust-gas washers, for instance, in garbage-burning installations. The present invention equally refers to an exhaust-gas washer containing such a rotor. Description of the Prior Art Patent application PI 9404414-7 of November 10, 1994, belonging to the same owner, describes an installation for treating organic material, in order to convert it into a mineral state, especially for treating urban garbage. The installation proposed in that application includes a number of rotary propellers inside an exhaust-gas washer. The propellers have the double purpose of producing a rising stream of the gases and dividing a liquid washing solution into small particles, so as to increase the efficiency of washing exhaust gases with this solution. Although the propellers function satisfactorily, they generate an unwanted secondary effect, which consists in accumulating residues on the walls of the washer, due to the centrifugal effect of the propellers on the medium that circulates inside the washer. Objectives of the invention One objective of the present invention is to provide a rotor that will avoid the above-mentioned drawback, namely accumulation of residues on the side walls, while maintaining the effect of generating rising streams. Another objective of the invention is to provide a rotor that will produce a frac- tionation of a liquid into even smaller particles than that technique of the prior art, so as to increase the area of contact between the fractionated particles of the washing liquid and the particles in suspension in a gas. Brief Description of the Invention According to the invention, a rotor is proposed which comprises: - a first group of flaps suitable for, in rotation, spraying a liquid that falls onto them and produce a flow of gases and sprayed liquid in an axial direction; and - a second group of flaps located radially more outwards than the first group and suitable for, in rotation, providing a flow of gases and sprayed liquid radially inwards. Preferably, the second group of flaps is located on a ring that surrounds the first group of flaps. The combination of generation of axial and radial flows inwards, achieved by means of the rotor proposed eliminates the unwanted effect of centrifuging particles, thus avoiding the accumulation of residues on walls of a washer in which the rotor is operating. Brief Description of the Drawings The present invention will now be described in greater detail with reference to an embodiment represented in the drawings, in which: Figure 1 is a schematic side view, partly in cross-section, of rotors according to the present invention, provided inside an exhaust-gas washer; Figure 2 is a top view of a rotor according to figure 1. Detailed Description of the Figures As can be seen from figure 1 , a series of four rotors 1 is provided inside an exhaust-gas washer 2. The rotors 1 are fixed on an axle 3, which in turn rests on bearings and is turned by a non-illustrated motor. Each rotor 1 comprises a disc-shaped base 4, formed integrally with a set of four first flaps 5 extending radially towards the axle 3. On the disc-shaped base 4 there is a further set of four second flaps 6 inclined with respect to the axle 3. Of course, the number of flaps may vary, so as to adjust the capacity of fractionating and propelling the washing liquid. Also integral with the base 4, a conical or truncated-conical side wall 7 is provided, which in turn is connected to a cylindrical wall 8 provided with flaps 9. The third flaps 9 may be produced by stamping and folding windows outwards from the cylindrical wall 8. Alternatively, one can make openings in the cylindrical wall 9, and weld plates that will form the third flaps 9. As an alternative to the embodiment illustrated, the third flaps 9 may be arranged immediately on the edge of larger diameter of the conical or truncated-conical wall. In the described embodiment, a first group of flaps is formed by the first flaps 5 and second flaps 6. The function of the first group of flaps 5, 6 is to fractionate into as small as possible particles a liquid that is poured onto the rotor 1 and to impart a vertical propul- sion to them. A second group of flaps, formed by the third flaps 9, has the purpose of providing a radial gas/liquid flow from the outside inwards, so as to eliminate the centrifugal effect of the action of the first group of flaps 5, 6, and to provide a rising flow virtually without radial components. Therefore, the third flaps are arranged at an angle α (figure 2), where 0° < α < 90° with respect to the displacement direction of the rotor 1. The illustrated gas washer 2 further comprises tubes 10 to produce a pure liquid or an aqueous solution for each rotor 1. Each tube discharge close to the first group of flaps 5, 6. The gas washer 2 has an inlet 11 for exhaust gases to be washed, an out let 12 for washed exhaust gases and an out let 13 for the liquid washing medium, which precipitates into the washer. The illustrated assembly functions as follows: - exhaust gases originated, for instance, from a garbage-burning furnace are admitted through the inlet 11 for exhaust gases to be washed; - water or a washing liquid solution is admitted through the tubes 10 into each rotor 1 ; - at high rotations the rotors 1 bring about a fractionation of the water of liquid solution by means of the first flaps 5, this fractionation being intensified by the vacuum that forms in the center of the rotor 1 due to the displacement of air provided by the first flaps 5 from the center to the periphery; - the inclined second flaps 6 aid in producing a rising flow of the mist that forms from the finely fractionated water or liquid solution; - the third flaps 9 produce a radial gas/liquid flow from outside inwards, thus reducing or eliminating the radial outwardly component of the displacement caused by the first and second flaps 5, 6, and confining the flow of gas/washing liquid to a rising axial direction; - the washed exhaust gases leave the washer 2 through the outlet 12 for washed exhaust gases, while the liquid washing medium precipitates into the washer 2 and drains through the outlet 13. Tests carried out with an assembly similar to that illustrated and described show that the embodiment proposed for a rotor enables a quite intense fractionation of the washing liquid, forming a fine mist inside the washer, which increases the area of contact with the particles in suspension in the exhaust gas and, consequently, increases the efficiency of washing the gases. Parallelly, the predominance of the axial component in the flow of mist formed from the washing liquid avoid, to a great extent, the accumulation of residues on the side walls of the washer. A further preferred embodiment consists in conducting the pure liquid or aqueous solution to the rotors directly through a hollow and perforated axle 3 and/or with nozzles discharging into the rotors. In this embodiment, the tubes 10 are dispensed with. An example of embodiment having been described and illustrated, it should be understood that the invention can be carried out in numberless other ways, being limited only by the contents of the accompanying claims, which include the equivalents. For instance, an effect of annulling radial components can be achieved with the propellers of case PI 9404414-7, by providing an outer ring, connected to the free ends of the propellers, containing flaps that generate a radial flow of gases inwards.

Claims: Claims 1. A rotor for spraying liquids, characterized by comprising: - a first group of flaps (5, 6,) suitable for, in rotation, spraying a liquid that falls onto them and producing a flow of gases and sprayed liquid in axial direction; e - a second group of flaps (9) located radially more outward than the flaps of the first group (5, 6) and suitable for, in rotation, providing a flow of gases and sprayed liquid radially inwards. 2. A rotor according to claim 1 , characterized in that the second group of flaps (9) is located on a ring (8) that surrounds the first group of flaps (5, 6). 3. A rotor according to claim 2, characterized in that said ring is formed by a cylindrical wall (8) provided with openings from which the flaps forming the second groups of flaps (9) are folded outwards. 4. A rotor according to claim 2, characterized in that said ring is formed by a cy- lindrical wall (8) provided with openings, close to which the flaps forming the second group of flaps (9) are soldered. 5. A rotor according to any one of claims 1 - 4, characterized in that the first group of flaps comprise flaps (5) having radial orientation. 6. A rotor according to any one of claims 1 - 5, characterized in that the first group of flaps comprise flaps (6) inclined with respect to axis of rotation of the rotor (1). 7. A rotor according to claim 6, characterized in that the first group of flaps simultaneously comprises said flaps (5) with radial orientation and said inclined flaps (6), all these flaps being integral with a disc-shaped base (4) provided with a passage for the axle (3). 8. A rotor according to any one of claims 1 - 7, characterized by comprising a conical or truncated-conical side-wall section (7) located on a plane other than that of the flaps of the second group of flaps (9), the flaps of the first group of flaps (5, 6) being surrounded by this conical or truncated-conical side wall. (7). 9. An exhaust-gas washer comprising a washing compartment having at least one inlet (11 ) for exhaust gases to be washed, at least one inlet (10) for a gas-washing liq- uid, at least one outlet for washed gases and at lest one outlet for washing liquid; having at least one rotary propelling and fractionating means inside it, for producing a flow of gases and fractionating the washing liquid, characterized in that said propelling and fractionating means is a rotor (1) according to any one of claims 1 - 8. 10. A washer according to claim 9, characterized in that a tube (10) for admission of washing liquid is associated to each rotor (1), said tube discharging close to the first group of flaps (5, 6) of the rotor (1). 11. A washer according to claim 9, characterized in that the axle of the rotor (s) (3) is hollow and suitable for conducting the washing liquid to each rotor (1), the axle (3) being provided with perforations and/or nozzles discharging inside each rotor (1).

Inventors: GOMES PINTO ANTONIO GERMANO, GOMES PINTO, ANTONIO, GERMANO
Applicants: GOMES PINTO ANTONIO GERMANO, GOMES PINTO, ANTONIO, GERMANO
Application year: 1999
Main classification: B01D47
IPC codes: B01D47, B05B3