Plate design for mixer sparger

An apparatus for mixing at least two gases comprising:

• at least one first plate having a first side and a second side, wherein the first plate has a first plate main channel defined in the first side and the first plate main channel has an inlet and a plurality of outlets, and a plurality of first plate secondary channels defined in the first side wherein each first plate secondary channel has an inlet in fluid communication with a corresponding first plate main channel outlet, and a first plate secondary channel outlet wherein the secondary channel outlet is elongated and extends through the plate to the second side;
• and
• at least one second plate having a first side and a second side, wherein the second plate has a second plate main channel defined in the first side and the second plate main channel has an inlet and a plurality of outlets, and a plurality of second plate secondary channels defined in the first side wherein each second plate secondary channel has an inlet in fluid communication with a corresponding second plate main channel outlet, and a second plate secondary channel outlet, and the secondary channel has a section that is oriented to be non-parallel to the first plate secondary channels when the first plate is stacked on the second plate;
• wherein at least a portion of each first plate secondary channel outlet is in fluid communication with a second plate secondary channel, with a portion of the second plate secondary channel forming a mixing section, and where the first and second plates are stacked in an alternating sequence with the first plate second side in contact with the second plate first side, and held together to form a gas sparger having a first gas inlet, a second gas inlet, and a plurality of mixed gas outlets.