Abstract:
A thermal emission-conversion muffler for reducing the toxic emissions output from the muffler has an inlet pipe, an outlet pipe, and a body extending lengthwise between the inlet and outlet pipes. The muffler further has a plurality of plates disposed within the body, and the plates extend in a sideways direction substantially between the side walls of the body. The plates are of a predetermined length, and adjacent plates are at a predetermined distance from each other. In one plate configuration, the plates are arranged in a substantially stacked manner and are parallel as regards exhaust gas flow passing through the muffler.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to a thermal emission-conversion muffler, particularly to such a device which reduces emitted toxic pollutants passing through the device. 
       BACKGROUND TO THE INVENTION 
       [0002]    Noise and pollutants emitted from vehicles using internal combustion engines and devices such as exhaust stacks are an increasing issue. Engines, and other devices such as stacks, utilise mufflers and catalytic converters to reduce the sound and toxic emissions. 
         [0003]    A muffler consists of an inlet pipe and an outlet pipe with a chamber between the inlet and outlet pipes. This chamber is the part of the muffler that reduces the noise of the exhaust gases by being a resonating chamber, which is tuned to cause destructive interference of the sound waves generated by the gas travelling through the exhaust system. This reduces the amount of noise emitted because of the exhaust gases. 
         [0004]    Mufflers can also result in increased engine efficiency, performance, power output and assist in reducing the wear and tear on the engine components by providing reduced backpressure. 
         [0005]    A muffler is typically designed to reduce exhaust noise of vehicles. They are normally installed as part of the exhaust system along the exhaust pipe. The exhaust system usually consists of tubing which conveys the waste exhaust gases away from the engine where they are created. 
         [0006]    There has also been focus on the polluting effect of vehicular exhaust. Although the largest part of most combustion gases is relatively harmless nitrogen, water vapour and carbon dioxide, there are still undesirable noxious or toxic substances emitted such as carbon monoxide, hydrocarbons, nitrogen oxides, unburnt fuel and particulate matter. 
         [0007]    As such, catalytic converters can be used in engines or stacks and the like to reduce the toxicity of emissions. They are used most commonly in motor vehicle exhaust systems, but also in other devices with engines such as generator sets, forklifts, mining equipment, trucks, buses and trains. A catalytic converter provides an environment for a chemical reaction wherein toxic combustion by-products are converted to less toxic substances. 
         [0008]    Catalytic converters do have a number of drawbacks. They require a temperature above 400° C. to work effectively and therefore substantially increase toxic pollutants for about 15 minutes from a cold start. They are also damaged by misfire, rich fuel mixture, contaminated fuel, oil contamination, carbon contamination from short trip driving and various other factors that cause them to work ineffectively. 
         [0009]    It is an object of the present invention to provide an alternative or complementary device that reduces the environmental impact through reduced toxic emissions of internal combustion engines and other devices such as exhaust stacks. 
       SUMMARY OF THE INVENTION 
       [0010]    According to one aspect, the present invention provides a thermal emission-conversion muffler for reducing the toxic emissions output from the muffler, the muffler having an inlet pipe, an outlet pipe, and a body extending lengthwise between the inlet and outlet pipes, the muffler further having a plurality of plates disposed within the body, the plates extending in a sideways direction substantially between the side walls of the body and being of a predetermined length, and adjacent plates being at a predetermined distance from each other. 
         [0011]    Preferably, the plates are arranged in a substantially stacked manner and are parallel as regards exhaust gas flow passing through the muffler. The plate geometry may be selected from the following list: substantially flat, substantially corrugated, substantially curvilinear, substantially U-shaped, substantially flattened tubes. 
         [0012]    Preferably, the predetermined length of the plates is between 35 and 45 millimetres and the predetermined distance is between 2.0 and 4.0 millimetres. Even more preferably, the predetermined distance is between 2.5 and 3.5 millimetres. 
         [0013]    Alternatively, the predetermined length of the plates may be between 35 and 45 millimetres and the predetermined distance is between 5.0 and 7.0 millimetres. More preferably, the predetermined distance is between 5.5 and 6.5 millimetres. 
         [0014]    The thickness of the plates may be between 1 and 2 millimetres. 
         [0015]    The muffler may be used in conjunction with a catalytic converter. 
         [0016]    According to a second aspect, the present invention provides a thermal emission-conversion muffler for reducing the toxic emissions output from the muffler, the muffler having an inlet pipe, an outlet pipe, and a body extending lengthwise between the inlet and outlet pipes, the muffler further having a plurality of plates disposed within the body, the plates extending in a sideways direction substantially between the side walls of the body and being of a predetermined surface area and adjacent plates being at a predetermined distance from each other. 
         [0017]    According to a third aspect, the present invention provides a thermal emission-conversion muffler for reducing the toxic emissions output from the muffler, the muffler having an inlet pipe, an outlet pipe, and a body extending lengthwise between the inlet and outlet pipes, the muffler further having a series of sets of a plurality of plates disposed within the body, the plurality of plates being arranged in a stacked manner, the plates extending in a sideways direction substantially between the side walls of the body and being of a predetermined surface area and adjacent plates being at a predetermined distance from each other, the sets of plates being separated by a predetermined separation distance. 
         [0018]    According to a fourth aspect, the present invention provides a thermal emission-conversion muffler for reducing the toxic emissions output from the muffler, the muffler having an inlet pipe, an outlet pipe, and a body extending lengthwise between the inlet and outlet pipes, the muffler further having a series of sets of a plurality of plates disposed within the body, the plurality of plates being arranged in a stacked manner, the plates extending in a sideways direction substantially between the side walls of the body and being of a predetermined length and adjacent plates being at a predetermined distance from each other, the sets of plates being separated by a predetermined separation distance. 
         [0019]    Each set of stacked plates may have the same predetermined length, distance between the plates, and separation distance between the sets of plates. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    An illustrative embodiment of the present invention will be described by way of example only with reference to the accompanying figures, in which: 
           [0021]      FIG. 1  is a schematic of a top plan view of a thermal emission-conversion muffler with a rectangular body enclosed within a muffler housing according to an embodiment of this invention; 
           [0022]      FIG. 2  is a schematic of the end plan view of a thermal emission-conversion muffler with a rectangular body enclosed within a muffler housing according to an embodiment of this invention; 
           [0023]      FIG. 3  is a schematic of one example of the plate configuration within the body of the muffler; 
           [0024]      FIGS. 4-8  are schematics of alternative plate configurations for the body of the muffler of  FIGS. 1 and 2 ; 
           [0025]      FIG. 9  is a cross-sectional view of the plate configuration along the axial length of the muffler body shown in  FIG. 8 ; 
           [0026]      FIG. 10  is a schematic of three alternative plate configurations for placement within the body of the muffler of  FIGS. 1 and 2 ; 
           [0027]      FIG. 11  is a schematic of a top plan view of a thermal emission-conversion muffler with a cylindrical body enclosed within a muffler housing according to an embodiment of this invention; 
           [0028]      FIG. 12  is a schematic of the end plan view of a thermal emission-conversion muffler with a cylindrical body enclosed within a muffler housing according to an embodiment of this invention; 
           [0029]      FIGS. 13   a  and  b  shows schematics of two alternative plate configurations for the body of the muffler of  FIGS. 11 and 12 ; 
           [0030]      FIG. 14  is a schematic cross-sectional view of the plate configuration having separated regions along the axial length of a rectangular or circular body for the body of the muffler of  FIGS. 1 ,  2 ,  11  and  12 . 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
       [0031]    The present invention may be implemented in a variety of ways and the embodiments illustrated are to be considered only as illustrative constructions. 
         [0032]      FIGS. 1 and 2  show schematically the top and end plan views of a thermal emission-conversion muffler  10  enclosed within a muffler body  30 . The muffler  10  has an inlet pipe  20 , an outlet pipe  25  and a body  30  placed between these two pipes  20 , 25 . The body  30  is connected to the pipes  20 , 25  by tapered pipe sections  20   a , 25   a  extending between the body  30  and each of the inlet pipe  20  and outlet pipes  25 . These tapered pipe sections  20   a , 25   a  may transition into the body  30  with a predetermined radii of curvature. This measure will contribute to a more even gas flow through the muffler  10 . The body  30  is surrounded by a heat shield  15  with an air gap between the body and heat shield as is known in the art. 
         [0033]    As shown in  FIG. 3  in a schematic of the inside of the body from a end view, the body  30  can be made in two parts and seam welded together 35. The body  30  and heat shield  15  of the rectangular mufflers  10  are constructed from two symmetrical halves. Internal to the body is a plurality of plates  45  held firmly within a holding device  40 . The plates  45  extend substantially the full sideways width of the body  30 . 
         [0034]    The plates shown in  FIG. 3  are flattened tubes of a predetermined length and have a predetermined separation d between adjacent plates. The plates shown in  FIG. 3  are rectangular with bull-nosed sides. The holding device  40  is configured to hold such a shape firmly in place to avoid any movement of the plates  45 . 
         [0035]      FIGS. 4-8  are end view schematics of alternative plate  40  configurations for the body  30  of the muffler  10 :
         FIG. 4  shows the plates  45  as a serpentine shape made from one piece of metal and held in place by a holding device  40  similar to the holding device in  FIG. 3 .   The plates  45  of  FIG. 5  are elongated U-shapes which self-lock within the holding device  40 . The bent ends of the U-shaped plates  45  can be shortened or lengthened to achieve the required predetermined distance d between the plates  45 .   Flat plates  45  in  FIGS. 6 and 7  are held in place by crimping edges of the holding device  40 .     FIG. 8  shows the pre-formed holding device  40 , that locks the stacked plates  45  together as one unit, before it is compressed to the reduced length shown in  FIGS. 6 and 7 . The pre-formed holding device  40  may have numerous small raised humps  40   a  along the length of the surface and between the holding device and plates to hold the plates  45  more firmly and prevent the plates from separating from the holding device  40 .
 
The rectangular and round mufflers may be constructed with one or more long narrow slots  51  in opposing sides of the muffler body  30  to allow the plates  45  to be welded to the body  30 . Also, the ends of the plates  45  of all the plate configurations used in the rectangular and round mufflers are radiused  52 .
         
         [0040]      FIG. 9  is a cross-sectional view along its axial length of the plate configuration shown in  FIG. 8 , before the pre-formed holding device  40  is compressed to the reduced length shown in  FIGS. 6 and 7 . As stated above, the plates are separated by a predetermined distance d. 
         [0041]      FIG. 10  is a schematic of three alternative configurations of plates  45  for placement within the body  30  of the muffler  10 . The shapes shown at  FIGS. 10   a  and  b  are corrugated versions of the plates  45  shown in  FIGS. 3 and 4  respectively. The shapes shown in  FIGS. 10   a,b,c  can be placed in a body  30  with flat surfaces and no corrugations. 
         [0042]    The rectangular muffler bodies  30  can be constructed using flat plates with corrugated holding devices  40  on each side of the flat plates. The ends of the flat plates are inserted into the valleys of the corrugated holding devices  40  which are compressed to lock the plates  45  into position. The flat plates  45  can be inserted into each valley or every second valley depending on the predetermined distance d required between the plates  45 . Corrugated holding devices  40  of about 1.5 mm thickness can support the plates  45  being positioned at a distance of 3 mm to 6 mm apart. Alternatively, 3 mm thick corrugated holding devices  45  can be used to position the plates the desired thickness apart (eg 6 mm). The body  30  of the rectangular muffler  10  with the corrugated holding device  40  has a rectangular section on opposing sides to lock the plates  45  and corrugated holding device  40  into position. 
         [0043]    The mufflers  10  can also include a heat shield  15  that follows the shape of the rectangular or round muffler, as shown in  FIGS. 11 and 12 . The heat shield  15  is open at each end to allow a flow of air between the muffler body  30  and the heat shield  15 . The heat shield as shown on the round muffler in  FIGS. 11 and 12  has a plurality of retaining portions  53  at the ends of the heat shield which are V-shape bends that bend inwards towards the tapered pipe sections  20   a , 25   a  of the muffler body  30 . The retaining portions  53  can be welded at the tip  54  of the retaining portions to the tapered pipe sections  20   a , 25   a  of the muffler. Apart from the shape of the body  30 , the muffler  10  is the same as that shown in  FIG. 1 . 
         [0044]      FIGS. 13   a  and  b  shows two alternative plate configurations for the body  30  of the cylindrical muffler  10  which are equivalent to those for the rectangular muffler  10  shown in  FIGS. 5 and 4  respectively. The rectangular and round mufflers  10  can be constructed using either flat tubes, one piece of corrugated plate with a flat surface or U-shaped plates. The rectangular muffler  10  can also be constructed using flat plates. 
         [0045]      FIG. 14  is a schematic of another embodiment of the invention. This figure shows a series of sets of stacked plates  45  as shown in the earlier figures, but in a separated configuration. The separation x n  between subsequent sets of plates allows each set of stacked plates  45  to maintain the maximum increase in temperature along its axial length and prevents the outlet temperature of each set of stacked plates  45  from cooling. This allows the temperature of the exhaust gas at the outlet of the stacked plates to be controlled by maintaining or increasing the optimum length of the plates. 
         [0046]    Various configurations for separating the sets of stacked plates  45  may be employed. Two examples shown in  FIG. 14  are:
       The rectangular and round mufflers with a series of sets of stacked plates  45  have tapered sections  55  separating each set of stacked plates  45 .   the round mufflers with a series of stacked plates  45  can have a ⅛″ (3 mm) smaller diameter tube  56  with a specific length fitted inside the muffler body to separate each set of stacked plates  45 .       
 
         [0049]    In use, the exhaust gases flow through the muffler  10  and heat up the plates  45 , which in turn increases the temperature of the gas flow. The applicant has found that through utilising the arrangement of stacked plates, the core temperature of the muffler body  30  can be, depending on the configuration utilised, increased between four to ten times greater than the exhaust gas temperature in a pipe of the same size. The increased temperature results in the break down and reduction of the toxic pollutants: HC, CO, NO x . 
         [0050]    As this device is a ‘straight through’ flow for the exhaust gas, the gases are not restricted (as they are for example by the restrictive passages in a baffled muffler or by the small restrictive passages in a catalytic converter) and therefore there is no power loss due to the slowing of the exhaust gases in some conventional muffler/catalytic converter systems. Also, the hotter core temperature of the muffler  10  increases the gas speed by virtue of the hotter gas temperature. This results in more power being available to the vehicle engine but also greater fuel economy. 
         [0051]    One configuration of muffler  10  has plates  45  separated by a distance d of 2.5-3.5 mm and a length of between 35-45 mm. The muffler  10  with this configuration will be referred to as an “EV16”. It was found that the temperature of the EV16 muffler core was 8 times higher than the temperature of a typical exhaust pipe of the same diameter. Eg, the temperature of a typical exhaust pipe is about 100° C. while the temperature of the EV16 muffler core was about 800° C. 
         [0052]    The EV16 muffler was similar to the configuration shown in  FIG. 14 : it was a series of 4 sets of stacked plates. The distance d between the plates  45  was 3 mm and the length of the plates was 40 mm. The separations x 1 ,x 2 etc  between each set of stacked plates  45  was 10-50 mm. The gas emission was analysed by a Bosch gas analyser. The engine the muffler  10  was fitted to was a 2.4 litre Diesel 4 cylinder in a 1991 Toyota Hilux Utility with a peak RPM of 4700. Note: CO, HC, NO x  are toxic emissions while O 2  and CO 2  are harmless emissions. The tests on the EV16 produced the following results (similar results were obtained for a petrol vehicle): 
         [0000]    
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Before: Results with standard exhaust system. 
               
             
          
           
               
                   
                 Gas 
                 RPM 1400 results 
                 RPM: 2700 results 
               
               
                   
                   
               
               
                   
                 CO 
                 0.012% 
                 0.071% 
               
               
                   
                 HC 
                  1 ppm 
                  −1 ppm 
               
               
                   
                 NO x   
                 120 ppm 
                 267 ppm 
               
               
                   
                 O 2   
                 15.84% 
                  2.70% 
               
               
                   
                 CO 2   
                  3.60% 
                 13.35% 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 After: Results with the addition of a series of four 
               
               
                 2½ × 3 inch long EV16 mufflers of above description and 
               
               
                 fitted to standard exhaust system with no other modifications. 
               
             
          
           
               
                   
                 Gas 
                 RPM 1400 results 
                 RPM: 2700 results 
               
               
                   
                   
               
               
                   
                 CO 
                 0.006% 
                 0.016% 
               
               
                   
                 HC 
                  −1 ppm 
                  −0 ppm 
               
               
                   
                 NO x   
                 115 ppm 
                 106 ppm 
               
               
                   
                 O 2   
                 16.17% 
                 15.43% 
               
               
                   
                 CO 2   
                  3.32% 
                  3.83% 
               
               
                   
                   
               
             
          
         
       
     
         [0053]    Results show 78% lower CO emission, 60% lower NOx emissions and no change to HC emissions. The particulate (smoke) emissions reduced to the point that they were not visible. Therefore, this muffler  10  reduces the toxic emissions with carbureted, fuel injected or gas vehicles that do not use a catalytic converter as well as substantially reducing the exhaust smoke from diesel emissions. Further toxic emission reduction could have been obtained by increasing from four the number or sets of stacked plates. The EV16 also substantially reduces cold start emissions in vehicles without a catalytic converter or other emission control devices. 
         [0054]    Another muffler configuration has plates separated by a distance d of between 5.5 and 6.5 mm. The muffler with these plate distances will be referred to as an “EV8”. It was found that the temperature of the EV8 muffler core was 6 times higher than the temperature of a typical exhaust pipe of the same diameter. Eg, the temperature of a typical exhaust pipe is about 100° C. while the temperature of the EV8 muffler core was about 600° C. 
         [0055]    It was found that a distance d of less than 2.5 or greater than 3.5 millimetres reduced the temperature of the muffler core. It was also found that a plate length of longer than 40 mm reduces the outlet temperature of the muffler core, and the reduction in temperature continues the longer the plate is over 40 mm. This allows the muffler core to be tuned to a specific outlet temperature. 
         [0056]    The EV8 muffler  10  was 2½×6 inches long with plates separated by a distance d of 6 mm and was fitted in front of a catalytic converter with no other modifications. The vehicle used was a 2004 Toyota Corolla Sportivo with a 1.8 litre 4 cylinder VTEC engine, with peak RPM of 8000, which uses a catalytic converter and runs on premium unleaded fuel. The results are shown in Tables 3 and 4. 
         [0000]    
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 Before: Results with standard exhaust system 
               
               
                 and standard OEM catalytic converter. 
               
             
          
           
               
                   
                 Gas 
                 RPM 800 results 
                 RPM: 2500 results 
               
               
                   
                   
               
               
                   
                 CO 
                 0.10-0.27% 
                 0.29-0.43% 
               
               
                   
                 HC 
                 338-395 ppm 
                 51-78 ppm 
               
               
                   
                 O 2   
                 0.61% 
                 0.46% 
               
               
                   
                 CO 2   
                 14.73% 
                 14.73% 
               
               
                   
                 Lambda 
                 1.01 
                 1.01 
               
               
                   
                 AFR 
                 14.7 
                 14.6 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 4 
               
             
             
               
                   
               
               
                 After: Results with the addition of a 2½ × 
               
               
                 6 inch long EV8 muffler in conjunction with an aftermarket 
               
               
                 or standard OEM catalytic converter and fitted to standard 
               
               
                 exhaust system with no other modifications. 
               
             
          
           
               
                   
                 Gas 
                 RPM 800 results 
                 RPM: 2500 results 
               
               
                   
                   
               
               
                   
                 CO 
                 0.00-0.02% 
                 0.00-0.01% 
               
               
                   
                 HC 
                 25-42 ppm* 
                 3-5 ppm* 
               
               
                   
                 O 2   
                 0.68% 
                 0.31% 
               
               
                   
                 CO 2   
                 15.02% 
                 15.51% 
               
               
                   
                 Lambda 
                 1.03 
                 1.01 
               
               
                   
                 AFR 
                 14.9 
                 14.7 
               
               
                   
                   
               
               
                   
                 Results show 98% lower CO emissions, 94% lower HC emissions and 85% lower NO x  emissions. The NO x  emissions were calculated from the diesel results in Table 2. 
               
               
                   
                 *Level of HC emissions in the atmosphere was 3-4 ppm 
               
             
          
         
       
     
         [0057]    After this test, the EV8 muffler and catalytic converter were also tested on the 2.4 litre diesel vehicle, with the following results. 
         [0000]    
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 5 
               
             
             
               
                   
               
               
                 After: Results with the addition of a 2½ × 6 inch 
               
               
                 long EV8 muffler in conjunction with an aftermarket catalytic converter 
               
               
                 and fitted to standard exhaust system with no other modifications. 
               
             
          
           
               
                   
                 Gas 
                 RPM 1400 results 
                 RPM: 2700 results 
               
               
                   
                   
               
               
                   
                 CO 
                 0.011% 
                 0.019% 
               
               
                   
                 HC 
                  0 ppm 
                  1 ppm 
               
               
                   
                 NO x   
                 141 ppm 
                 128 ppm 
               
               
                   
                 O 2   
                 16.20% 
                 15.65% 
               
               
                   
                 CO 2   
                  3.47% 
                  3.86% 
               
               
                   
                   
               
             
          
         
       
     
         [0058]    These results show that with diesel vehicles the EV16 muffler alone reduces toxic emissions more than the EV8 muffler and catalytic converter combination or catalytic converters used alone. 
         [0059]    After the tests were completed for the EV8 muffler, the catalytic converters were examined and it was found that substantially no damage had been sustained by the catalytic converter, as is usual with general vehicle use, indicating that the use of the EV8 muffler protects the catalytic converter from, for example, misfire, carbon contamination from excessive short trip driving, rich fuel mixture, high hydrocarbon (HC) emissions, oil contamination, contaminated fuel, high sulphur fuel, leaded fuel, engine coolant, chemical additives, silicone contamination from sealants and thermal shock. Any of these factors damage the catalytic converter and render it useless which increases pollution. Therefore, this device  10  could allow the fitting of a catalytic converter to carburetted vehicles to permit reduced toxic emissions without damaging the catalytic converter. 
         [0060]    This device also assists in the operation of the catalytic converter which requires a temperature above 400° C. to work effectively which usually takes 15 minutes of engine running time to generate this temperature. The operation of the muffler  10  in front of the catalytic converter produces the optimum catalytic converter operating temperatures far quicker; it was found that the operating temperature of the catalytic converter was reached in 2 minutes by the EV8 muffler which substantially reduced cold start emissions. The length of the plates  45  is important in this regard to immediately produce the optimum temperature gas input to the catalytic converter and prevent the catalytic converter from exceeding its operating temperature. It was found that the temperature of the plates  45  was about 600° C. for the first 40 mm of the plates  45 , then dropped to about 300-400° C. at 125 mm. 
         [0061]    Further, use of the EV8 allows the catalytic converter to be moved 2.5 metres further away from the engine while producing the same results. 
         [0062]    In summary, the configurations tested were: 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Muffler 
                 Applications 
                 Length 
                 Width 
                 Requirements 
               
               
                   
               
             
             
               
                 EV8 
                 Fuel injected and gas 
                 6½″ 
                 ¼″ wider than the 
                 1 × EV8 muffler is required 
               
               
                   
                 vehicles fitted with a 
                 (165 mm) 
                 inlet pipe diameter 
                 per side 
               
               
                   
                 catalytic converter 
                   
                 For example, 2″ EV8 
                 EV8 muffler must be fitted 
               
               
                   
                 2″, 2½″, 3″ exhaust 
                   
                 muffler has 2¼″ 
                 in FRONT of the catalytic 
               
               
                   
                 systems 
                   
                 width, 2½″ EV8 
                 converter 
               
               
                   
                   
                   
                 muffler has 2¾″ 
               
               
                   
                   
                   
                 width, etc 
               
               
                 EV16 
                 Carbureted, fuel injected, 
                 3½″ 
                 ½″ wider than the 
                 4 × EV16 mufflers are 
               
               
                   
                 gas and diesel vehicles 
                  (90 mm) 
                 inlet pipe diameter 
                 required per side 
               
               
                   
                 NOT fitted with a catalytic 
                   
                 For example, 2″ 
                 Additional EV16 mufflers 
               
               
                   
                 converter 
                   
                 EV16 muffler has 
                 may be used to further 
               
               
                   
                 Diesel vehicles fitted with a 
                   
                 2½″ width, 2½″ 
                 reduce toxic emissions, 
               
               
                   
                 catalytic converter and 
                   
                 EV16 muffler has 3″ 
                 increase power or reduce 
               
               
                   
                 particulate (smoke) filter 
                   
                 width, etc 
                 noise 
               
               
                   
                 2″, 2½″, 3″, 4″, 5″, 6″ 
               
               
                   
                 exhaust systems 
               
               
                 EV164 
                 Same as EV16 
                 9¼″ 
                 Same as EV16 
                 1 × EV164 muffler is 
               
               
                   
                   
                 (235 mm) 
                   
                 required per side 
               
             
          
           
               
                   
                 NOTE 
                 Additional EV164 mufflers 
               
               
                   
                 EV164 muffler uses 4 × EV16 mufflers built into 1 muffler 
                 may be used to further 
               
               
                   
                 Using either 1 long EV164 muffler or 4 short EV16 mufflers per side 
                 reduce toxic emissions, 
               
               
                   
                 produces the same results. However, the short EV16 muffler allows 
                 increase power or reduce 
               
               
                   
                 more mufflers to be fitted to any part of the exhaust system to 
                 noise 
               
               
                   
                 further reduce toxic emissions, increase power or reduce noise 
               
               
                   
                   
               
             
          
         
       
     
         [0063]    It was also found that the positioning of the muffler  10  in the exhaust system may have relevant effects. For example, the muffler may be positioned into each primary pipe of the exhaust manifold/header which, by bringing the muffler closer to the exhaust port, allows the muffler to warm up more quickly and operate at a higher temperature, whereby it can work more efficiently in reducing emission of pollutants (both cold start emissions and operating emissions) and noise. The higher temperature of operation of the muffler when so positioned also increases the gas velocity through the muffler which has the upstream effect of increasing the level of gas scavenging and purging in the cylinder, thereby improving engine performance. Nonetheless, the small size of the muffler  10  means that it can be fitted to any part of the exhaust system. However, in a vehicle fitted with a catalytic converter, in order to achieve the benefits to the catalytic converter, the muffler  10  must be fitted before the catalytic converter. 
         [0064]    While it will be understood that the focus of the description above has been related to the reduction in toxic emissions, the device  10  also is beneficial in reducing the noise emitted from the outlet pipe  25 . This is a result of the sound waves entering through the inlet pipe  20  reducing in amplitude due to reflecting off the plates  45  inside the muffler body  30 . It was found in the tests that the EV mufflers reduced the exhaust noise by 5 db (36%) and increased the power by 3%. It was found that this power increase and noise reduction whether the exhaust system is a standard, restrictive or performance type. 
         [0065]    The muffler  10  may replace existing mufflers or used in conjunction with them to provide the extra noise reduction. The results indicated above also work for modern vehicles using restrictive exhaust systems. Additional mufflers  10  may be fitted along the exhaust system (eg at the middle or end) to increase the gas speed at these points to provide an increase in power. 
         [0066]    It is to be noted that this muffler  10  does not have perforated tubing; moving parts; spiral, turbine or venturi shapes; sound absorption material; speakers, electronics or computers; electrical heating devices; require expensive metals; and does not work like conventional mufflers or catalytic converters. 
         [0067]    It will be realised by persons skilled in the art that numerous variations and/or modifications may be made to this exhaust muffler device as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. 
         [0068]    For example, as shown, while the examples provided have described the device in use with an internal combustion engine, the device is equally suited to exhaust stacks and the like. Further, the body of the muffler can be rectangular or cylindrical in cross-section. The plates may not necessarily be flat but could be corrugated, elliptical in cross section or any other suitable configuration.