System and method for oxidant injection in rotary kilns

A valve assembly for injecting oxidant through an oxidant port in the radial surface of a rotatable kiln body, the radial surface having a cam mounted adjacent the oxidant injection port, comprising:

• a valve body disposed substantially in fixed spatial relation with the rotatable kiln body and having walls defining a valve chamber;
• a valve member movable between a first position, in which the valve is closed, and a second position, in which the valve is open;
• and
• a follower member connected to the valve member and adapted to contact a surface of the cam to move the valve member between the first position and the second position.

A process of injecting an oxidant through a radial surface of a rotary kiln in at least one location along the longitudinal axis of the kiln chamber, comprising the steps of:

• forming at least one oxidant injection port in the radial surface of the rotary kiln;
• connecting a cam to the radial surface of the rotary kiln adjacent the oxidant injection port;
• mounting an oxidant injection valve assembly proximate the rotatable kiln, the valve assembly comprising a valve body disposed substantially in fixed spatial relation with the rotatable kiln, the valve body having walls defining a valve chamber, a valve member movable between a first position, in which the valve is closed, and a second position, in which the valve is open, and a follower member connected to the valve member and adapted to contact a surface of the cam to move the valve member between the first position and the second position;
• providing pressurized oxidant to the valve chamber;
• and
• rotating the kiln to actuate the valve assembly.

A process of operating a kiln, comprising the steps of:

• providing a kiln including:
• a kiln body rotatable about its longitudinal axis and having at least one oxidant injection port extending through a radial surface of the kiln body into the interior of said kiln body;
• a burner positioned adjacent an end of said kiln body;
• a cam mounted on the radial surface of the kiln body adjacent the oxidant injection port;
• an oxidant supply system for providing pressurized oxidant;
• and
• a valve assembly including:
• a valve body disposed substantially in a fixed spatial relationship with the rotatable kiln body and defining a valve chamber in fluid communication with the oxidant supply system, and
• a follower member positioned to contact a surface of the cam to actuate the valve assembly;
• and
• generating said burner to heat portions of said kiln body interior;
• rotating the kiln to cause the cam to contact the follower member, thereby actuating the valve assembly to admit oxidant into said kiln body interior.