Extending Lean Limit with Mass-Timed Compression Ignition Using a Catalytic Plasma Torch

Research on the Catalytic Plasma Torch (CPT) ignition system was conducted this last year at BKM, Inc. in San Diego. The results showed that under certain conditions CPT can not only time ignition properly, but also extend the lean stability limit. This concept is based upon compression ignition of the charge in the CPT's integral pre-chamber. Compression ignition is induced by timed catalytic reduction of the pre-chamber's activation energy. This produces almost instantaneous combustion in the pre-chamber and is divided into multiple high velocity torches to rapidly ignite the main chamber charge. The timing of the ignition event is based on the location of the heated catalyst in the pre-chamber and the mass of the charge inducted into the cylinder. The base timing curve can be modified via current control which effects the catalyst activity. Dynamic modification of the timing event is accomplished by using the catalyst as an in-cylinder hot wire anemometer. In this mode, the activity of the catalyst, and thus the timing, is inversely proportional to the mass of the charge. This system works with multiple fuels in any homogeneous charge engine and differs from hot surface ignition in that it is not timed via fuel injection. This device replaces conventional ignition components such as the distributor, breaker system, high-tension wires and spark plugs. In addition, this system contains no moving parts or sophisticated electronic controls and can run under load without external energy and is entirely water proof.