Exhaust aftertreatment apparatus

An exhaust aftertreatment apparatus comprising:

• a) a reactor portion which is tubular with an inlet opposing an outlet, and has a flow axis parallel with a longitudinal axis of the reactor portion;
• b) a mixer located within the reactor portion, the mixer including:
• i) an outer tube having a diffuser affixed or integral thereto, wherein the diffuser is located opposite the outlet of the reactor portion;
• ii) an inner tube located within the outer tube and having an intermediate flow diverter affixed or integral thereto;
• iii) an outer passage formed between a wall of the reactor portion and the outer tube;
• iv) an intermediate passage formed between the outer tube and the inner tube;
• v) an inner passage formed within the inner tube;
• vi) one or more brackets which retain the outer tube within the reactor portion and about the inner tube, and wherein the one or more brackets include one or more ring brackets;
• and
• c) an injector in fluid communication with the reactor portion and upstream from the mixer, wherein the injector is configured to spray a reactant into the reactor portion such that it mixes with an exhaust stream in the mixer;
• wherein the diffuser expands toward the outer passage so as to direct the exhaust stream and the reactant toward the outer passage such that the exhaust stream and the reactant flow away from the inlet and toward the outlet while flowing through the outer passage;
• wherein the intermediate flow diverter extends from the wall of the reactor portion at the outlet toward the inner tube and is configured to direct the exhaust stream and the reactant from the outer passage toward the intermediate passage such that the exhaust stream and the reactant flow away from the outlet and toward the inlet while flowing through the intermediate passage;
• wherein the outer tube is separate and distanced from the intermediate flow diverter to provide for fluid communication between the outer passage and the intermediate passage;
• wherein an inner flow diverter is formed as a surface of the diffuser which faces toward the outlet of the reactor portion and is configured to direct the exhaust stream and the reactant from the intermediate passage to the inner passage;
• wherein the one or more brackets include one or more inner brackets and the one or more inner brackets are located about an exterior of the inner tube and within an interior of the outer tube;
• and wherein the one or more ring brackets include one or more outer brackets which have a hollow interior in which the outer tube resides.