Abstract:
A scrubbing muffler for internal combustion engines comprises coaxial counter-rotating disk pairs stacked in a cascade. Acoustic pulses are attenuated by doing work and dissipated by the circuitous path through the dynamic cascade. A motor and/or Venturi effect from slipstream over a vehicle assists exhaust and reduces backpressure for greater fuel economy. Exhaust gas fed at the axis is sheared between the disks of the first stage of the cascade as it passes radially outward into a shrouding tank disposed about the cascade. Vortex rebound at the tank wall advects flow radially inward back through the workspace between the first stage disks to axial extraction as feed for the second stage of the cascade. N2 and H2O, along with CO and NO, can pass radially inward to successive stages. Soot and CO 2  stay in the tank. NO and CO are reduced at a Faraday disk cathode.

Description:
APPLICATION HISTORY 
       [0001]    The applicants claim priority based on U.S. Provisional Application 61/438,596 filed Feb. 1, 2011. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to mufflers and means for diminishing the noise and emissions of internal combustion engines such as catalytic converters and soot collectors. It also relates to electrolytic reduction of nitric oxide (NO) and to collection of soot and carbon dioxide from internal combustion engines. 
         [0004]    2. Prior Art 
         [0005]    Internal combustion engines produce exhaust streams which contain pollution and noise. Mufflers have been used to reduce the noise out of the exhaust pipe, but the mufflers do not capture the pollution in the exhaust stream, and reduce fuel efficiency by causing backpressure. 
         [0006]    Noise from internal combustion engines results from acoustic pulses of the engine exhaust stream. These acoustic exhaust pulses conventionally are dissipated by a muffler, which conventionally is a static device which forces the exhaust gas to flow through a tortuous path among baffles. The acoustic pulses of hot and dirty exhaust from the engine, which otherwise would produce a loud sound out of the exhaust pipe, are broken up and their linear momentum becomes diffused in isotropic turbulence. Backpressure due to this isotropic turbulence in the tortuous flow path means that the engine must work harder to push the exhaust through to discharge, raising the fuel requirements and increasing the heat and wear on the engine. A need exists for a way to reduce backpressure without increasing noise out of the exhaust pipe. 
         [0007]    The faster an exhaust pulse moves, the better it can suck out the spent gases during valve overlap, called exhaust pulse scavenging. Because conventional muffler design obstructs flow, exhaust gas pulses cannot move fast enough to create low pressure wakes to evacuate the cylinders and accomplish exhaust pulse scavenging. 
         [0008]    Reetz, U.S. Pat. No. 1,109,702 (1914) and Jackson, U.S. Pat. No. 2,479,165 (1949) teach a rotatable baffle comprising helical blades and having an axis of rotation along the path of flow into and out of the muffler (axial exhaust flow). Chang, U.S. Pat. No. 6,343,673 (2002) teaches a multibladed turbine having its axis of rotation along the axial exhaust flow path through the turbine blades. 
         [0009]    Corless, U.S. Pat. No. 2,003,500 (1935) and U.S. Pat. No. 2,518,869 (1950), teaches a rotatable baffle actuated by exhaust flow radially inward to its axis of rotation. Chimento, U.S. Pat. No. 2,958,506 (1960) also teaches a radial flow turbine. These radial flow turbine references teach an impulse turbine fed at the rotor periphery by engine exhaust. Wall, U.S. Pat. No. 7,331,422 (2008) teaches a vortex muffler having a stationary fan disposed along an axial flow path for imparting swirl to an exhaust gas stream and thereby assisting discharge into the atmosphere 
         [0010]    Cumins, U.S. Pat. No. 5,772,235 teaches deflectors for lowering the pressure in the exhaust stream. Yates et al., U.S. Pat. No. 4,970,859 teaches a deflection shield which has the effect of lowering the pressure in the exhaust system and directing the exhaust soot away from a truck cab. 
         [0011]    Soot, CO 2 , and NOx (mainly nitric oxide, NO) as well as metals and volatile organic compounds (VOCs), such as polycyclic aromatic hydrocarbons, BTEX and formaldehyde, are pollutants in the exhaust gas stream from gasoline or diesel internal combustion engines. Natural gas internal combustion engines also have CO 2  and NOx pollution. 
         [0012]    Nitric oxide is thermodynamically unstable, so its reduction to form harmless N 2  and O 2  only takes a little energy input. Conventionally nitric oxide is reduced to N 2  and O 2  by catalytic converters comprising platinum, an expensive metal. Urea is another way, but it entails a chemical process which adds weight and occupies space. A need exists for an alternative to precious metal catalytic converters for reducing nitric oxide in vehicle exhaust. 
         [0013]    Soot includes diesel particulate emissions. Particulate emissions cannot be filtered from vehicle exhaust streams economically because of the large pressure drop through any dead-end filter. Dead-end filtration adds yet another flow impedance with consequent backpressure and loss of fuel efficiency, and filters tend to clog, requiring frequent replacement. A need exists for a way to capture and concentrate soot from exhaust in a continuous process. 
         [0014]    Carbon dioxide in the exhaust streams of cars and trucks is a major contributor to the accumulation of carbon dioxide in the atmosphere, which has implications for global climate. Amine scrubbing and cryogenic distillation are unsuitable for carbon dioxide capture in vehicles, and membrane filters are not feasible due to the soot and water in the exhaust gas. Again, dead-end filters such as membranes entail a large backpressure which reduces fuel efficiency. 
         [0015]    Most of exhaust gas is harmless N 2  and water vapor (collectively referred to as “nitrogen ballast”) so stripping the nitrogen ballast would concentrate the pollutants and thus aid collection and treatment of the noxious constituents, such as soot, CO 2  and nitric oxide. Nitrogen gas (N 2 ) has a molecular weight of only 28 g/mol, and H 2 O is lighter still, at 18 g/mol, while CO 2  is 44 g/mol, NO 2  is 46 g/mol, and soot is much denser than these gases. VOCs are also relatively heavy gases. This task is aided by the difference in molecular weight of the constituents of exhaust gas, which allows for centrifugal gas separation in the open von Karman geometry. See McCutchen, U.S. Pat. No. 7,901,487 (2011). 
       SUMMARY 
       [0016]    In an embodiment, exhaust gas from an internal combustion engine is fed through an axial feed port and radially expanded through a radial workspace between opposed coaxial counter-rotating disks. Vanes on the turbines define channels through which the feed flows radially outward, diffusing its momentum into the turbines. Counter-rotation of the turbines creates a shear layer between them, and in this shear layer a sink flow is radially inward toward the turbines&#39; common axis of rotation. A shrouding wall disposed about the periphery of the turbines rebounds nitrogen ballast radially inward through the shear layer to axial extraction into a succession of stages in a cascade. 
         [0017]    Heavier constituents, such as soot, CO 2 , and NO 2 , are collected from the periphery of the disks. N 2  and H 2 O, because of their lesser molecular weight, flow through the shear layer radially inward and are extracted through an axial extraction port. Nitric oxide (NO) flows with the nitrogen ballast radially inward and up through the cascade because its molecular weight (30 g/mol) is approximately the same as N 2  (28 g/mol). The NO, having been separated from the CO 2  and other pollutants, is then reduced by electrolysis. 
         [0018]    For electrolysis, rotation of at least one disk through an axial magnetic field turns an annular portion of the disk downstream in the cascade into an electrode (cathode) for reduction of NO. Because most of the CO 2  has been previously separated out and collected in the shrouding tank, this cathode will is less likely to produce carbon monoxide in the final output stream. 
         [0019]    Feed of exhaust gas from an internal combustion engine is continuous through an axial feed port in one turbine/impeller disk, and the extraction of the nitrogen ballast (and NO) is through an axial extraction port in the other disk. A baffle separates the axial feed port from the axial extraction port. A cascade of such devices, each stage in the cascade fed by the axial extraction port of an upstream device, provides means for absorbing the momentum of the exhaust gas and performing complete gas and particulate separation. Acoustic pulses are converted to motive force for the counter-rotation of the turbines of the cascade, so the noise from the engine is dissipated not in the isotropic turbulence of a conventional muffler but in the anisotropic turbulence of this dynamic cleaning muffler. 
         [0020]    A long residence time in the workspace effectively separates pollutants from the nitrogen ballast. Centrifugal separation occurs in vortices forced in the shear layer between the turbines, and multi-scale coherent structures in the shear layer integrate the tiny separation effects of these vortices and allow for the continuous extraction of nitrogen and water vapor from the exhaust gas, thus concentrating the soot, CO 2 , NO 2  and VOCs, which collect in the periphery of the disks. 
         [0021]    The soot is concentrated, while the carbon dioxide can go into a separate peripheral gas vent. Electrostatic charge attracts soot to a screen over a hopper which is charged as an anode, as in a conventional electrostatic precipitator. The soot concentrates at the periphery of the turbines and at the wall of the shrouding tank, eventually migrating down through the charged screen and into a hopper. The captured carbon dioxide is clean and concentrated enough to be compressed for later disposal. 
         [0022]    A motor assists exhaust flow through the cascade, and under some circumstances the motor becomes a generator, for example in long-haul trucks, harvesting power to run cooling equipment or compressors for CO 2 . 
         [0023]    Counter-rotating disks such as this can be turned by a motor, by vanes driven by the passing wind outside a vehicle, or by the energy contained in the exhaust stream. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1  shows a cross section of the left half of a single pair of counter-rotating radial turbines. 
           [0025]      FIG. 2  shows a cross section of a cascade of counter-rotating radial turbines, with a drive motor, and a charged impeller for the cathodic reduction of NO. 
           [0026]      FIG. 3  shows a cross section of the left half of a single pair of counter-rotating radial turbines in an alternate design, with separate soot and carbon dioxide capture conduits. 
           [0027]      FIG. 4  shows this cross section with indications of the locations of the four lateral cross section planes shown in composite in  FIG. 5 . 
           [0028]      FIG. 5  shows a composite of the four cross sectional planes indicated in  FIG. 4 , starting in the lower left and going clockwise, with the view looking downward in each case. 
           [0029]      FIG. 6  shows a cross section of a cascade of disks, and an example of the path that the exhaust gas, and the sound vibrations that it contains, travels through them. 
           [0030]      FIG. 7  shows an alternate design with a cross section of a cascade of disks featuring a combined peripheral capture of soot and CO 2  within an enclosing shrouding tank, and where the disks are turned by the pressure of the exhaust stream on vanes on the disks. 
           [0031]      FIG. 8  shows a top view of the vanes from both upper and lower disks superimposed. 
           [0032]      FIG. 9  shows a schematic view of radial counterflow in the workspace between the disks. 
           [0033]      FIG. 10  shows a cross section of a cascade of disks where an early release of the exhaust stream into the environment can be made if the stream has been sufficiently cleaned or quieted. 
       
    
    
     DRAWING REFERENCE NUMERALS 
       [0000]    
       
           1  Exhaust gas input stream from engine 
           2  Axial feed port 
           3  Baffle 
           4  Workspace 
           5  Lower radial turbine 
           6  Vane 
           6   a  Impeller vane 
           7  Upper radial turbine 
           8  Axial extraction port 
           9  Shrouding wall 
           10  Input conduit 
           11  First rotation direction 
           12  Second opposite rotation direction 
           13  Central drive spindle 
           14  Motor 
           15  Soot hopper 
           16  Conductive disk 
           17  Magnet 
           18  Cathode 
           19  Outlet of shrouding tank 
           20  Atmospheric outlet stream 
           21  Exhaust gas input stream 
           22  Intake vent 
           23  Baffle 
           24  Workspace 
           25  Lower disk 
           26  Axial intake port 
           27  Upper disk 
           28  Axial outlet port 
           29  Axial outlet vent 
           30  Axial outlet stream 
           31  Motion of upper disk 
           32  Motion of lower disk 
           33  Inlet screw pump 
           34  Outlet screw pump 
           35  Lighter constituents 
           36  Heavier constituents 
           37  Axis of rotation 
           38  Periphery 
           39  Angled annular deflector wall 
           40  Embedded vanes in deflector wall 
           41  Heavy particulates 
           42  Outlet in disk for soot 
           43  Annular soot collection pipe 
           44  Soot collection vertical pipe 
           45  Gases on periphery 
           46  Heavier gaseous elements 
           47  Opening for peripheral gases 
           48  Static annular gas collection pipe 
           49  Gas collection vertical pipe 
           50  Pad for triboelectric charging 
           51  Outer casing 
           51   a  Rotation linkage 
           52  Open scoop vane 
           53  Closed shield vane 
           54  Inter-disk gear 
           55  Gear tooth rack on the baffle 
           56  Vane between baffle and lower disk 
           57  Rigid shaft for gear 
           58  Central support shaft 
           59  Thrust bearings and centering support structure for lower disk 
           60  Thrust bearings and centering support structure for upper disk 
           61  Cross section plane A below the lower disk 
           62  Cross section plane B above the lower disk 
           63  Cross section plane C below the upper disk 
           64  Cross section plane D above the upper disk 
           65  Slipstream from the motion of a vehicle 
           66  Induced motion of the vanes 
           67  Windshield 
           68  Outer gear 
           69  Outer gear track 
           70  Outer gear shaft 
           71  Path of exhaust 
           72  Vane casing connection to top impeller 
           73  Soot compression chamber 
           74  Soot chunks 
           75  Soot compression motor 
           76  Main soot collection pipe 
           78  Gas pump 
           79  Main gas collection pipe 
           80  Gas storage tank 
           81  Driving vane underneath baffle 
           82  Vane on lower disk 
           83  Vane on upper disk 
           84  Vortex 
           85  Peripheral gap 
           86  Peripheral shield 
           87  Enclosing Tank 
           88  Interior of tank 
           89  Boundary layer 
           90  Shear Layer 
           91  Vortex axis 
           92  Rotating drum 
           93  Planetary gears 
           94  Escape valve 
           95  Anode 
           96  Cathode 
       
     
       DETAILED DESCRIPTION 
       [0131]      FIG. 1  shows a cross section of the left half of a single pair of counter-rotating radial turbines in the first stage of a cascade. An exhaust gas input stream  1  from an internal combustion engine enters through an axial feed port  2  which is at the center of a lower radial turbine  5 . The input stream is partially blocked by a baffle  3 , disposed between the axial feed port  2  at the center of the lower radial turbine  5  and an axial extraction port  8  at the center of the upper radial turbine  7 . The vanes  6  on the disks can be radial turbine vanes that are actuated by a radially outward flow from the axis of rotation a-a through the workspace  4  between the radial turbines, or they may advect the outward flow when the disk is turned by suitable means, such as a motor. The term radial turbine herein refers to the combination of the disk and one or more vanes, whether the turbine advects or is advected by the flow through the workspace  4 . 
         [0132]    Each of the disks  5 ,  7  comprises an array of vanes  6  extending into the radial workspace  4 , and in this case the vane  6  attaches the baffle and the lower disk  5  together so they will rotate together. The exhaust gas expands through a radial workspace  4  between the lower disk  5  and an upper disk  7 . The opposite curvature of the radial vanes on the turbines causes counter-rotation of the disks  5 ,  7  in opposite directions  17  and  19  about a common axis of rotation a-a as the exhaust gas expands between them and pushes against the vanes. By doing work turning the disks  5 ,  7  the exhaust gas loses enthalpy and its acoustic pulses are dissipated so engine noise is abated. 
         [0133]    Due to counter-rotation of the coaxial disks  5 ,  7  a shear layer forms between them in the workspace  4 . The shear layer comprises a vortex network for separation of the lighter and heavier constituents of the feed by enhanced centrifugal force in radial counterflow. The heavier constituents including soot, CO 2 , NO 2  and VOCs pass out of the periphery of the disks and into a shrouding tank from which they may be separately extracted. The lighter constituents including the nitrogen ballast, oxygen, water vapor and NO form a sink flow radially inward toward the axis a-a and out of the workspace and through the axial extraction port  8 . 
         [0134]    The heavy constituents impinge a shrouding tank wall  9  disposed about the periphery of the disks. Backpressure from vortex impingement on the shrouding wall assists the inward sink flow through the shear layer. In contrast to prior art mufflers, backpressure does not go back into the axial feed port but instead it goes over the baffle into the axial extraction port  8 . So the backpressure problem of the conventional static muffler is avoided by the open von Karman geometry, and noise is abated. The exhaust gas is expanded and made to do work, so it loses enthalpy and the acoustic pulses are dissipated. 
         [0135]      FIG. 2  shows a cascade of several disks, plus other elements. An exhaust gas input stream  1  enters through an axial feed port  2  in a rotatable axial feed conduit  10  which forms a lower disk  5 . All of the disks above this lower disk it are linked together by vanes  6  so all of the disks of the cascade are co-rotatable in the direction shown by the arrow  11 . That includes the upper disk for this stage and for the successive stages. A baffle  3  disposed between the upper and lower disks of each stage is attached to a drive spindle  13  and not to either of the disks. The drive spindle is connected to a motor  14 . The baffle of each stage separates its axial feed port  2  and the axial extraction port  8 . The baffle rotation direction  12  is opposite to the direction  11  of the rotation of the disks. 
         [0136]    The motor  14  also rotates the vanes on a blower which assists exhaust of nitrogen ballast out of the shrouding tank at  19 . The motor may be an electric motor, a device connected to the engine, or a device actuated by slip stream over a vehicle. Assisted exhaust reduces backpressure and increases fuel efficiency of the internal combustion engine. 
         [0137]    The advection caused by the motor-driven baffles and their vanes  6   a  extending into the workspace  4  of each of the stages drives the disks in counter-rotation by means of peripheral vanes  6  connecting the disks of the stages. 
         [0138]    The heavier products that accumulate at the periphery of the counter-rotating baffles and disks are stored in a receptacle such as the soot hopper  15  and the CO 2  outlet in the shrouding tank which leads to tanks and compressors suitable for storing gases. 
         [0139]    After the exhaust stream has been stripped of its heavier constituents, the remaining NO and other gases such as CO and CO2 can be cracked by electrolysis at a stage in the cascade. In this stage, a conductive disk  16 , here also attached to the drive shaft  13 , is rotated through the transverse magnetic field of at least one magnet  17  to form create a Faraday disk, or disk dynamo, having opposite radial currents making the edge of the disk a cathode  18  and the center of the disk an anode. As the NO, CO, and residual CO 2  passes over this cathode, both above and below the spinning disk, the molecules dissociate. Harmless N 2  and O 2  flow out at  19  while elemental carbon deposits on the cathode. 
         [0140]    Any residual soot then accumulates at the central anode end of the disk. The anode charge may be used to attract soot to the inlet screen of the soot hopper  15  as in conventional electrostatic precipitators. and this charge can also be used to charge the inlet screen of the soot hopper  15  as an anode. 
         [0141]    The light fractions, including the nitrogen ballast, then pass though the central outlet port  19  of the shrouding tank. Slipstream over a muffler mounted on a moving vehicle will also maintain low pressure by the Venturi effect in the outlet of the shrouding tank  19 . The result is a safe atmospheric outlet stream  20  of N 2 ,O 2  and water vapor that is released to the atmosphere, without noise. 
         [0142]    Under certain conditions, such as long-haul trucking, the slipstream may assist exhaust so much that mass flow through the muffler is sufficient to allow the motor to be used as a generator. In that case, the baffles will be driven by instead of driving the mass flow through the muffler, such that the drive shaft turns a generator. Suitable means for switching the motor  14  to generator mode are available for that possibility. 
         [0143]      FIG. 3  shows a cross section of the left half of a single pair of counter-rotating disks featuring more detailed capture of the heavier constituents. The exhaust gas input stream  21  enters through an intake vent  22 . The intake flow is partially blocked by a baffle  23  and passes through vanes  56 . These vanes either act as turbines to extract mechanical energy from the flow to use for increased disk rotation, or act as impellers, to increase the flow, if the disk rotation is driven by a motor The intake flow then passes into a workspace  24  located between the lower disk  25 , which contains an opening  26  for the intake vent  22 , and the upper disk  27  which contains an opening  28  for an axial outlet vent  29  for the axial outlet stream  30 . The two disks turn in opposite directions, as indicated by  31  for the motion of the top disk and  32  for the motion of the lower disk. 
         [0144]    An net positive pressure in the input stream  21  can be the result of the positive pressure created by the engine, and it can be enhanced by an input pump, such as the inlet screw pump  33  incorporated into the intake vent  22 , and which turns from the motion  32  of the spinning lower disk  25 . Similarly, a net negative pressure in the axial outlet stream  30  can be created by an axial outlet pump, such as the outlet screw pump  34  incorporated into the axial outlet vent  29 , which turns from the motion  31  of the spinning upper disk  27 . The inlet screw pump  33  and the outlet screw pump  34  serve to assist flow of exhaust out of the engine for improved fuel efficiency. Because the disks are turning in opposite directions, the slope or “handedness” of the screws must be opposite as well, in order to maintain the same upward flow. 
         [0145]    In the workspace  24  between the counter-rotating disks  25  and  27 , radial counterflow turbulence with a branching network of fine vortices in the shear layer separating the lighter constituents  35 , such as oxygen, nitrogen, and water vapor, from the heavier constituents  36  in the exhaust stream, such as soot, NOx, VOCs and carbon dioxide. The lighter constituents  35  such as nitrogen and water vapor are drawn inward through the vortex cores into the axial outlet stream  30  near the axis of rotation  37 , and the heavier fractions  36  churn in the workspace  24  until they eventually migrate outward to the periphery  38  of the disks. 
         [0146]    For particulates such as soot, an angled annular deflector wall  39  built into the lower disk  25  could direct the stream downward, while at the same time inducing cross-turbulence with embedded vanes in the deflector wall  40 . The heavier particulates such as soot, because of their weight and inertia, are left behind and fall downward through an opening in the disk  44  into a static annular soot collection pipe  43  which connects to a descending vertical soot collection pipe  44 . At the same time, the heavier gaseous components  46  continue onward and drift upward to a gas opening  47 , and beyond that to a static annular gas collection pipe  48  which connects to a descending vertical gas collection pipe  49 . 
         [0147]    The collection of the soot is preferably enhanced by an electrostatic charge applied to the soot outlet pipe  42 . This electrostatic charge can be generated by triboelectric charging means. For example, the static annular soot outlet pipe  42  can be made of polyvinyl chloride (PVC), and a charging element, such as a leather or rabbit fur pad  50  attached to the moving disk rubs against the annular soot outlet pipe  42  to charge it. This charge is regulated by a periodic connection to ground. 
         [0148]    The disks can be turned by the action of the flow against turbine vanes, by a motor such as one connected to the central shaft  58 , or by an air stream. Here vanes attached to the outer casing  51  and to the upper disk  25  rotate the disk using the air stream passing by a moving vehicle. One example of a turbine for capturing the wind is this design based on a Pelton wheel. The forward-facing open scoop-type vane is at  52 . Both the forward-facing open scoop vane  52  and the backward-facing closed vane  53  are shown in  FIG. 6  as coupled by a link  51   a  to the upper disk  27  in order to turn it. The counter-rotation of the lower disk  27  is caused here by inter-disk gears  54  between the disks, engaging a gear tooth track in the upper disk  25  and a gear tooth rack  55  on the baffle  23  with its vanes  56  underneath which couple the baffle to the lower disk. The gears have bearings coupled to a rigid shaft  57  coupled to the central support shaft  58 . This central shaft supports the rigid cylindrical support structures containing the central axial intake port  22  for the lower disk and the central exhaust port  29  for the upper disk, as well as the low-friction thrust and roller bearings and centering support structures for the lower disk at  59  and for the upper disk at  60 , which allow the disks to rotate freely. The baffle also has a bearing and is centered on this central shaft, and the baffle is linked by the vane  56  to the lower disk so they rotate together. 
         [0149]      FIG. 4  shows another cross section of the left half of a single pair of counter-rotating disks shown in  FIG. 3 , with indications of the locations of the four horizontal cross section planes shown in composite in  FIG. 5 . The cross section plane A below the lower disk is at  61 , the cross section plane B above the lower disk is at  62 , the cross section plane C below the upper disk is at  63 , and the cross section plane D above the upper disk is at  64 . 
         [0150]      FIG. 5  shows a composite of the four cross sectional planes indicated in  FIG. 4 , starting in the lower left and going clockwise, with the view looking downward in each case. The cross section plane A below the lower disk shows the annular soot collection pipe  43  which connects to a descending vertical soot collection pipe  44 . The outer casing  51  is coupled to multiple vanes which in their open scoop position  52  can capture the energy of a passing airstream from the motion of a vehicle  65  to induce a rotary motion in the casing and to any disks coupled to it. 
         [0151]    The cross section plane B above the lower disk  25  shows the axial intake port  26  and the lower disk  25 , with its rotary motion  32 , its periphery  38 , the soot collection slot  42 , and the vanes connecting the lower disk  23  to the baffle  23 . Both the slots in the upper and lower disks are not continuous, but have periodic interruptions to maintain the structural integrity of the disk. 
         [0152]    The cross section plane C below the upper disk, again looking down, shows the upper surface of the lower disk  25  and its rotary motion  32 , and its periphery  38 . The baffle  23  has a gear tooth track  55  for at least one inter-disk gear  54 , which has a shaft coupled to the rigid central support shaft  58 . Outside of the periphery are the alternating vertical pipes for the collection of soot  44  and of heavy gases  49 . The counterflow turbulence between the disks features vortices separating the components, where the lighter constituents  35  go inward and the heavier constituents  36  go outward. 
         [0153]    The cross section plane D above the upper disk  27  shows its rotary motion  31 , which is the opposite of the rotary motion of the lower disk  32 . The heavier gases collection slot  47  is shown underneath the static annular peripheral gases collection pipe  48  which leads to the vertical gas collection pipe  49 . The closed shield orientation of the vanes in the outer casing is shown at  53 , along with the induced motion of the vanes  66  caused by the passing airstream from the motion of a vehicle  65 ; the effect of the airstream on the vanes can be increased with a windshield  67  which favors the engagement with the vanes in their open scoop position  52 . For a stack of disks such as that shown in  FIG. 6  and  FIG. 7 , other gears between the upper and lower disks would transmit the motion of one disk in counter-rotation to the next. This is shown here with an outer gear  68  which engages an outer gear track  69  on the upper surface of the upper disk, and has a corresponding gear track on the underside of the lower disk. This outer gear  68  is attached by a shaft  70  to the static centering support structure for the upper disk at  60 . 
         [0154]      FIG. 6  shows a cross section of a cascade of disks, and an example of the path  71  that the exhaust gas, and the sound vibrations that it contains, travels through them. As the pressure waves of various frequencies caused by the engine travel through repeated regions of extreme turbulence, they lose their coherence and strength, and thus the exhaust stream becomes quieter. 
         [0155]    The stack of counter-rotation disks can be driven by a motor, or be passively driven by the passing wind motion in turbine vanes. Here a large scoop vane  52  is shown along with its corresponding shield vane  53  in a rotated position. Both are coupled to a rotating casing  51 . Through the casing, the scoop vane&#39;s energy is coupled through a connection  72  between the casing and the topmost disk  27 . From there, the energy is transmitted in turn downward through successive disks in the stack through inter-disk gears such as at  54 , and outer gears such as at  68 , engaging gear racks inside  55  and outside  69  of the workspace  24 . The energy from the pressure of the exhaust stream is also translated into rotary motion through the passage of the stream through the screw pumps such as  34 , which also act as turbines to turn the disks. Thus, the speed of rotation of the disks can be determined by how fast the engine is running or how quickly the vehicle is moving. 
         [0156]    The soot collected toward the periphery  38  of each of the stacks of disks is channeled into a descending network of pipes. It first goes into an annular static soot collection pipe  43  and outward in a radial soot collection pipe to a vertical soot collection pipe  44 , collected into a main pipe leading to a soot compression chamber  73  where it can be compacted for storage into small brick-like soot chunks  74 . This compaction can be aided by a motor  75  driving a screw conveyor  76 . Because of the combustible carbon, which may include nanotubes, and the unburned fuel in the compressed soot, these compressed soot chunks can have commercial value, which justifies the business activity of collecting them at gas stations. 
         [0157]    Similarly, the peripheral gases, including carbon dioxide, are collected by a network of pipes, beginning with a static annular collection pipe  48  leading to descending collection pipe  49 . The final collection can be aided by a gas pump  78  between the main collection pipe  79  and the storage tank  80 . 
         [0158]    The cascade of successive processing shown here will progressively clean the outlet gas stream through stage after stage, until what is released at the top is significantly less polluted than the original gas stream. 
         [0159]      FIG. 7  shows an alternate design with a cross section of a cascade of disks featuring a combined peripheral capture of soot and CO 2  within an enclosing shrouding tank, and where the disks are turned by the pressure of the exhaust stream on vanes on the disks, optionally assisted by a motor  14  attached to a central shaft. The path of the exhaust stream is shown at  71 . The main driving vanes  81  are underneath the baffle  23  and connect it to the lower disk, and other shallow vanes are in the surfaces of the disks, and on the top surface of the baffle. The vane on the lower disk is at  82 , and the vane on the upper disk is at  83 . The vanes also extend out toward the periphery  38 . The pattern of the vanes is shown in  FIG. 8 . An example vortex in the workspace is shown at  84 . More detail about the radial counterflow in the workspace is shown in  FIG. 9 . The internal exhaust gas pressure with optional assistance from the motor turns the disks in counter-rotation, thereby also evening out the pulses and leading to exhaust pulse scavenging. The motion from the vanes is also transferred in counter-rotation through outer gears  68  engaging outer gear tracks on the outer surfaces of the disks, with the gear shaft  70  anchored to the axial static support and bearing  60 . The rotation of this gear transmits the motion of an upper disk  27  to cause the counter-rotating motion of the lower disk  25  in the opposite direction. These opposite directions are shown at  31  and  32 . The disks have a peripheral gap  85  which allows for the escape of soot and CO 2  which is contained in the interior  88  of an enclosing tank  87 . The bottom of the tank can contain the soot hopper  15  and the outlets for captured gases. A peripheral shield  86  prevents the soot from clogging the gear  68 , and the small gap at the periphery can be kept clear of accumulated soot by an intermittent element such as a piece of nylon attached to the edges of one disks sweeping the gap clear. 
         [0160]      FIG. 8  shows a top view of the scissoring vanes from both upper and lower disks superimposed. The disks  25 ,  27  are shown in superposition, with the heavier lines such as at  83  representing the vanes on the lower disk, whose motion is shown at  32 , and the lighter lines such as at  84  representing the vanes on the opposing upper disk, whose motion is shown at  31 . Each disk comprises an array of radial vanes curving away from its direction of rotation, such that rotation advects the exhaust gas stream and heavier components radially outward by both disks simultaneously. In superposition, the radial vanes  83 ,  84  on the disks intersect at shearing points which are in close opposition but not in contact with each other. These shearing points move out along radial lines (indicated by the dashed lines) as the disks counter-rotate. These lines of high shear sustain the sink flow of the lighter product stream by refreshing the radial vortices, and the periodic shear pulses cause peristaltic pumping of sink flow through the vortex cores. The vortex-wall interaction as swirl collapses where the disks pinch together at the periphery  38  converts the radial vortices generated by the shearing disks into axial jets driving a recirculation flow radially inward toward the axis of rotation. See Shtern and Hussain, “Collapse, Symmetry Breaking, and Hysteresis in Swirling Flows,”  Ann. Rev. Fluid Mech.  31:537-66 (1999), particularly  FIG. 1  thereof. 
         [0161]      FIG. 9  shows a schematic view of radial counterflow in the workspace  24  between the disks. Laminar boundary layers, where the momentum diffusion from the disks  25 ,  27  into the exhaust stream occurs, set up against the disks. Radially outward flow of the exhaust stream and the heavier product is forced by momentum diffusion in the boundary layers. A shear layer sets up between the counter-rotating laminar boundary layers. The shear layer comprises radial vortices which act as a sink flow network, into which the lighter gas product stream concentrates and proceeds in sink flow to the axial extraction port  28  which provides a path for the scrubbed exhaust stream out of the workspace, leaving soot, CO 2 , and NOx behind in a collection tank. 
         [0162]    Area-preserving fractal flow networks, such as the root system of trees, are Nature&#39;s way of organizing flow with a minimum of pressure drop, in a multi-scale path of least resistance. The open von Karman geometry of the present disclosure allows a fractal flow network in the shear layer. One radial vortex axis is shown as a dashed line  91 . Low density fractions in the workspace  24 , such as oxygen, nitrogen, and water vapor, concentrate in the shear layer, and soot and CO2 are expelled by centrifugation out of the shear layer and into the boundary layers. The arrows show the magnitude and direction of radial flows at various distances from the disks, with respect to the axis  91  in the workspace  24 . 
         [0163]      FIG. 10  shows a cross section of a cascade of disks where an early release of the exhaust stream into the environment can be made if the stream has been sufficiently cleaned or reduced in noise. If the successive stages have produced an acceptable outlet after only a part of the stages have been used, a valve can be thrown and the outlet from the acceptable stage immediately released into the environment. 
         [0164]    The vanes have been omitted from the representation for clarity. The central stack of disks are linked to a central shaft, and are turned together by a motor or other motive force. All of these components turning in the same direction have a hatched fill. The interspersed disks are linked together at their periphery in a rotating drum  92  with holes to allow for the escape of the heavy constituents. Planetary gears  93  drive the two assemblies in counter-rotation. Alternatively, only the central stack could move, and the others would be static. 
         [0165]    The processing can be considered as being divided into four zones, rising from bottom to top. Escape valves  94  allow for the gases to exit the processor early, if they have been sufficiently cleaned. 
         [0166]    The materials used for the stack of disks will likely vary according to their height in the stack. For instance, in the lowermost disks, where hot and corrosive gases are coming from the engine, resistant materials such as ceramics or specially coated metal can be used. For the disks in the highest parts of the stack, the temperature and corrosiveness of the gases is much lower, and sound muffling is more important, so flexible disks or disks made of energy-absorbing materials can be used to absorb vibrations, or mesh disks with soft coatings that are periodically replaced as part of oil change services. Particulates such as metals may adhere to the coatings. 
         [0167]      FIG. 11  shows an example of the charging of the disks for cracking the component gases. In this case, the inner disks linked to a central shaft are all charged as anodes  95 , and the interspersed disks are charged as cathodes  96 . The electrical potential transferred into the workspace would be used to crack gases and molecules into their constituents. 
         [0168]    This design can be used to treat many kinds of exhaust gas streams, including those from static engines, ships, and trains. Therefore, the scope of this disclosure should not be considered to be limited to the exemplary description herein.