Abstract: A system is described for storing ammonia and injecting it into the exhaust gas stream of an engine to reduce nitrogen oxides. The ammonia is stored as a liquid mixture (70) of ammonia and water in a container (50). In one system, the mixture passes through a tube with a portion (62) in contact with the exhaust gas pipe (16) to heat the mixture and separate the ammonia from the water, with the ammonia being further heated at a nozzle (84) to activate the ammonia before injection into an upstream portion of the exhaust gas pipe.

Abstract: A diverter (60) is provided, which is of low cost and which is effective in more evenly distributing exhaust gasses passing from a small diameter upstream exhaust gas pipe section (42) into a much larger diameter catalytic converter assembly (20). The diverter includes a diverter element (70) and mounting brackets (72). The diverter element has a central hole (82) and has conical walls with an included angle of at least 70°, the conical walls having a plurality of holes (90). The large conical angle (G) of the diverter effectively directs exhaust gases to the periphery of the large diameter catalytic converter but blocks a radially intermediate portion of the catalyst, while the holes in the conical diverter walls allow sufficient exhaust gases to reach the radially intermediate portion of the catalyst.

Abstract: In the operation of a diesel engine, a mixture of air and fuel is flowed into each cylinder during the intake stroke when air alone normally would be flowed in. However, the mixture is lean so it does not ignite as the mixture is compressed and heated. Sufficient additional fuel is injected into the cylinder near the top of the compression stroke to increase the amount of fuel so the hot mixture ignites. As a result, most of the air and fuel has intimately mixed prior to ignition.

Abstract: An apparatus for atomizing liquid fuel while mixing it with air, and varying the amount of each while maintaining a substantially constant fuel/air ratio for the intake manifold of an engine. The apparatus includes a frame (16) forming a passage (14) with a throat (44), with a second wall (56) of the passage being moveable toward and away from a stationary first wall (54) of the passage to vary the cross-section of the passage and thereby vary airflow. A fuel-carrying tube (24) has a proximal end (60) fixed to the first stationary wall and has a distal portion (62) that extends through a bore (64) in the moveable wall and with the moveable wall being slideable around the tube. The tube has at least one aperture (70) for flowing fuel into the passage, with the exposed aperture area being progressively increased as the moveable wall moves away from the stationary wall to flow a progressively increasing amount of fuel into the passage.

Abstract: A method and apparatus are provided for reducing pollutants and especially nitrogen oxides, or NOx, in the exhaust gases of an engine. The apparatus includes a device for injecting ammonia into a conduit that extends between cylinder exhaust valves and a catalytic converter, to mix the ammonia with the exhaust gases. Ammonia injection occurs at a location a plurality of inches downstream of the exhaust valves to avoid burning of the ammonia by flames. The injection preferably occurs at a location where the exhaust gases are at a temperature of at least about 1200.degree. F. to cause considerable reaction of the ammonia with NOx in the exhaust gases prior to the gases reaching the catalyst, so less NOx must be removed along the catalyst.