Internal combustion engine exhaust gas cleaner including a vortex-type molecule separator.

The present invention relates to a scrubber for exhaust gases of internal combustion engines.

Scrubbers known for the indicated purpose usually act by filtration actions of oxidation, catalytic reaction and the like, to physically and chemically separate the exhaust gases which are to be introduced into the atmosphere, the solid residue and harmful substances contained therein. However, the efficiency of these scrubbers is restricted especially by the fact that the harmful substances are contained in the exhaust gases in percentages which, while being considerable from the point of view of pollution, are very small in absolute terms, so that any transaction affecting the state is hampered by the high diluition in which are these substances. Another impediment to treatment operations comes from the relatively high temperature shown by the exhaust gas; the catalytic effects and chemical reactions of oxidation and other are favored by higher temperatures to those shown by the exhaust gases of internal combustion engines. For this reason, in some scrubbing apparatus is introduced from heat sources, which on the other hand complicates the construction and relates to a power consumption to be supplied from the outside. Finally, many cleaners known oppose the flow of exhaust gas relatively high resistance, which results in a reduction of the internal combustion engine performance, or must be overcome by using fan means. The latter, on the other hand, complicates the construction and can lead to an energy consumption supplied from the outside.

In consideration of these problems, the object of the present invention is to provide a purifying device which must reach a clearly higher efficiency than known cleaners, particularly by making use of means capable of increasing the temperature and the local-concentration harmful substances in areas where such substances actions are applied to modify them, without introducing significant impediments to the flow of gas and without requiring excessively complicated construction nor any introduction of energy from outside. The principle on which the invention is based is to exploit this purpose the singular properties of a coach molecules vortex.

The coach of molecules vortex, more commonly known as the "hot-cold tube", is based on scientific principles already set forth in part by Maxwell and other scientists; he found fulfillment, although only experimentally, through Hilsch and others, and became suitable for industrial applications thanks to the improvements introduced by the author of the present invention, described in Italian Patent No. 975,810. This device is constituted substantially by a vortex chamber having a tangential inlet fitting containing a spiraloid surface which begins approximately tangential to said inlet fitting and extends in the centripetal direction terminating in a point nearest the axis of the chamber said inlet fitting, and provided with one side of a central outlet opening of reduced diameter and the opposite side of a large-diameter opening communicating with an interior chamber that has a slight back pressure . If a gas stream is sent in a suitable pressure to said inlet connection of the vortex chamber, because of its tangential inlet in the room, and in consequence of the presence of spiraloid surface, forms a vortex flow intense, and it is noted that through the central outlet opening of reduced diameter is debited a fairly cooled gas stream and highly purified, while a sufficiently heated gas stream and containing almost all the impurities is routed through the large-diameter opening towards the inner chamber communicating. This is due to the effect of the strong centrifugal force field that occurs in the vortex, and the thermodynamic effects, the other not yet fully clarified, that result. For his behavior, this device has been some applications, limited in practice to the air conditioning.

In consideration of the foregoing, the object of this invention is achieved by means of a scrubber for exhaust gas of internal combustion engines, characterized in that it comprises a circuit for the gas, closed on itself, having a entry for the exhaust gases to be purified, and comprising a breeder molecules vortex, whose outlet opening is connected to an exhaust pipe to the atmosphere outside, while the inner chamber communicating with the vortex chamber contains gas purification means and an output connected with the region of the circuit where is located said inlet.

With this arrangement, the gases supplied to the scrubber enter the vortex chamber, some of them well refined by selecting molecules and cool enough, is discharged to the atmosphere outside, while the remaining gas , yet having impurities and sufficiently heated, it is conveyed to the inner chamber communicating with the vortex chamber, wherein there are purification means. They act in more favorable conditions than usual, a side due to temperature increase supported by the gas, and the other side due to the greater concentration of impurities in the gas. Finally the thus purified gases back to the circuit input region and, mixing with new gas introduced, are routed back to the vortex chamber.

This way the impure gas roam the circuit several times, each time returning to its entry, and each time receiving the action of purification means, until they have reached a sufficient degree of purification to be discharged to the atmosphere out through the central outlet opening of the vortex chamber. Of course, in the operating condition the gas discharged outside the same temperature of the gas from the engine, except for the heat exchange between the purifier and the apparatus outside ambient, but the gas running through the circuit scrubber, instead, have a considerably higher temperature, which, as we have already said, is favorable for the action of purification means. In addition, the gas passing from the vortex chamber toward the inner chamber communicating have an intense rotational movement, which can be exploited for effective centrifugal separation of solid and liquid residues carried by the exhaust gas, without using to filtering operations that would include strong resistance to flow.

Preferably, in said inner chamber communicating with the vortex chamber and forming part of the circuit for the gas is mounted a coil body made of a material having a catalytic effect, while at the periphery of said inner chamber is provided a crossing communication to a receiving space for solid and liquid residues separated from the gas.

In this way, the coil body is licked by the gas flow and it exerts on his effective catalytic action, while the solid and liquid impurities, relatively heavy, are moved to the periphery of the inner chamber and discharged into the space receiving means provided for this purpose.

Preferably a turbine wheel, crazy, is mounted between the end of said inner chamber communicating with the vortex chamber, opposite the vortex chamber itself, and the area of ​​the circuit which leads to the gas inlet to purify.

Under this provision can be avoided effectively any possibility of reflux of gas entering into the inner chamber communicating with the vortex chamber, and ensures an orderly development of gas fluxes.

These and other features, and advantages of the subject of the invention will become more apparent from the following description of an embodiment, given by way of nonlimiting example and illustrated in the accompanying drawings, in which:<ul><li>Fig. 1 is an elevational side view of a purifying device, in a reduced scale;</li><li>Fig. 2 shows a section approximately horizontal made substantially along the broken line II-II of Figure 1;</li><li>Fig. 3 shows a cross section taken along line III-III of Figure 1;</li><li>Fig. 4 shows an end view of the arrow IV of Figure 1;</li><li>Fig. 5 shows a cross section taken along the line VV in Figure 1; and</li><li>Fig. 6 shows a cross section taken along line VI-VI of Figure 1.</li></ul>

The numeral 1 indicates an input connection to the scrubber, which is intended to be connected a pipe 0 exhaust of an internal combustion engine. The number 2 indicates a connection to a distribution pipe 3 forming part of the circuit for gas. The connector 1 may advantageously have a circular section, while the connector 2 and the delivery pipe 3 preferably have a rectangular section. Said distribution pipe 3, curved, tapered, is directed to an input pin 4 of a vortex chamber defined by a peripheral wall 5 and by a transverse wall 6, which is recessed a central outlet opening 7 connected to an exhaust pipe 8 open towards the outside ambient. The side opposite the transverse wall 6, the vortex chamber communicates widely with an inner chamber defined by a substantially frustoconical wall 9 which finishes with a portion of rectangular section 10 confluent with the inlet connector 1, said connector 2 the dispensing line 3. a portion of the inner surface of the wall 9 is provided with a layer 11 having a catalytic effect, preferably nickel. From the point of view of construction, the parts 1, 2, 9, 10, and others described below, are part, preferably from two shells, a lower shell and an upper shell, sealingly connected in a region average 12. The two shells may be made preferably of stainless steel, for example sintered. The distribution pipe 3 can, for example, be of stainless steel sheet.

In the end portion, opposite to the region 10, of the frustoconical wall 9 is inserted a body constituting the vortex chamber body that includes said peripheral wall 5 and the transverse wall 6 and a wall 13 constituting a surface spiraloid should take beginning the inlet connector 4, is directed centripetally and ends with a radius substantially corresponding to the radius of the outlet opening 7, as shown in Figure 6. This body may be made, e.g. , by a worked brass melting, preferably covered with nickel or other suitable metal, at least in the part 13 constituting the spiraloid surface. This surface, preferably exponential growth.

In the inlet connector 4 of the vortex chamber is arranged a control valve consists of a flap 14 pivoted on an axis 15. The axis 15 passes through the transverse wall 6 and, outside of this wall carries a lever 16 biased by a spring 17. the tension of the spring 15 may possibly be adjustable by means of a screw 18. the spring 17 resiliently pushes the flap valve 14 to a position shown by a solid line in Figure 6, wherein this valve partially constricting the passage in the connector 4, while allowing an elastic displacement of the valve towards a position, indicated in the same figure by broken lines, wherein the left free flow section is larger.

In the extreme portion 10 of the inner chamber defined by the walls 9, 10 is idly mounted a turbine wheel 19, pivoted on a pin 20 which, preferably, has reported ceramic ends, and is journalled in the ball holders 21 .

The frustoconical wall 9 has a longitudinal slot 22 communicating with a receiving space defined by a wall 23 provided in the lower part of a plug 24 of discharge. From the top of the internal accommodation space in the wall 23 takes beginning a pipe 25, which passes through the wall of the distribution pipe 3 and ends at the inside of the pipe with one end 26 forming an ejector.

In the inner chamber 9 is mounted a helical body 27 of a material having catalytic effect, for example a granular sintered copper, or a coated mesh tantalum, iridium or indium.

Operation of the device described is as follows. The exhaust gas from the exhaust pipe 0 of an internal combustion engine arrive at the inlet connector 1, the connector 2 and the delivery pipe 3 which conveys them to the inlet connector 4 of the chamber vortex. On entering the vortex chamber, the gas encountered the valve flap 14, which directs the flow in a direction tangential to the surface 13 spiraloid; the valve 14 moves elastically and automatically under the pressure of incoming gas, varying the flow area available depending on the flow of the gas flow directed to the spiraloid surface. Under these conditions, the flow of product gas in the interior of the spiraloid surface an intense vortex; a portion of the incoming stream is charged through the outlet opening 7 and discharged into the atmosphere outside, while the rest of the incoming flow is transferred into the inner chamber defined by the frustoconical wall 9. The arrangement described is a coach molecules vortex and, in consideration of the peculiarities of this device and its own inertia effects and thermodynamic, the portion of flow which is directed to the exterior is sufficiently cooled and cleaned effectively, while the portion of the stream that is channeled towards the inner room is quite reheated and contains almost all the impurities originally contained in the incoming flow of gas; therefore these impurities have a concentration considerably increased compared to the original.

The flow and routed to the tapered chamber 9, as it comes from a vortex, is run by a hard spin, which moves outwardly solid and liquid particles carried by the stream, up against the wall 9, of so that in encountering the slot 22 these particles escape to the space defined by the wall 23 and collected there. A light gas stream is established through the slot 22 due to the suction exerted by the pipe 25 that ends as an ejector in the distribution pipe 3 through which the gas, and this current promotes said separation of solid particles and liquid, and prevents the formation of a back pressure in the receiving space 23. the materials that accumulate in the space 23 can be discharged from time to time, through the plug 24.

Moreover, in room 9 the flow licks the helical body 27 and under body conformation 27, which substantially corresponds to the shape of the lines of flow of the gas, it suffers no appreciable resistance to its advancement. The helical body 27 exercises its catalytic effect on the gas, and this catalytic effect is particularly effective because it is applied to the gas in which the temperature and concentration of the materials to be modified are considerably increased compared to the original ones. In consideration of the relatively high temperature, becomes significant as the catalytic effect in the licking walls 9 and 10 of stainless steel, and particularly wall portions which are provided with the layer 11 of nickel.

The gases thus treated arrive at the chamber 10, they pass through the turbine wheel 19 by rotating and entering port 2 to be recycled. The presence of the turbine wheel 19 ensures that the gas entering the inlet 1 can not flow back into the chamber 10 instead of penetrating into the fitting 2. In the port 2, the gas from the inlet 1 and those recycled from the chamber 10 are mixed, and they are routed together with the distribution pipe 3 to input 4 of the vortex chamber.

The polluted gases are continually recycled, passing back and forth through the vortex chamber and the inner processing chamber 9, until they have reached a sufficient level of treatment and are discharged through the opening Release 7 of the vortex chamber. Thus we get a much more intense purifying effect of the effect we might have to carry out a gas passage just as it appears in the known scrubbers devices.

Of course, various modifications may be brought to the described parts. For example, the inlet valve 14 of the vortex chamber may be shaped differently, or it may be omitted in applications where the incoming gas has a substantially constant rate. The slit 22 may be replaced by a section of perforated or mesh walls. The turbine wheel 19 may be shaped differently, or may be replaced by a valve or device, especially in the substantially constant flow rate applications by an ejector device. The dimensions and proportions of parts must be commisurées the gas flow to be cleaned that are expected. The walls of the device, especially the wall 9, can optionally be isolated in order to increase the temperature of the gas being processed.