Decomposition tube for exhaust treatment systems

An exhaust g treatment system for treating exhaust gas from an engine, comprising:

• an inlet tube for receiving the exhaust gas from the engine;
• a particulate filter fluidly coupled to receive the exhaust gas from the inlet tube;
• a selective catalytic reduction system coupled to receive the exhaust gas from the particulate filter, wherein the selective catalytic reduction system comprises:
• a decomposition tube with a housing defining an exhaust flow path for the exhaust gas;
• a reductant nozzle coupled to the housing and configured to deliver a spray of reductant into the exhaust flow path;
• a mesh basket mounted proximate the reductant nozzle;
• wherein the mesh basket defines a side wall and a bottom wall to enclose and intercept the reductant spray;
• wherein the mesh basket is made of interwoven wires in a grid configuration through which are intervening spaces for reductant droplets to pass through the intervening spaces in the side wall and the bottom wall of the mesh basket and into the exhaust flow path prior to impinging on the housing wall;
• and
• wherein the mesh basket extends into the exhaust flow path to have only a portion of the exhaust gas passing through the mesh basket, and
• a catalyst device fluidly coupled to receive the mixture of the reductant and the exhaust gas from the decomposition tube and configured to reduce NOx in the exhaust with the reductant;
• a baffle arranged downstream of the mesh basket to mix the reductant from the mesh basket with the exhaust gas;
• and
• an outlet tube coupled to receive the exhaust gas from the selective catalytic reduction system.