Abstract: A system and method is provided for use with a duel-fuel fumigation system. The system injects a gaseous-fuel flow into the air intake stream of a diesel engine. As presented, the system is operative to meter the gaseous-fuel flow into the diesel engine based on one or more engine parameters such as, for example, exhaust gas temperature, exhaust oxygen levels, engine speed, engine load and/or engine inlet pressure. Monitoring one or more engine parameters allows fine-tuning the flow of gaseous fuel into the engine and thereby prevents loss of engine power at high-end loads while maintaining favorable emission outputs over substantially the entire operating range of the engine.

Abstract: A system and method is provided to reduce the occurrence of engine knock for engines that utilize a dual-fuel fumigation system. Typically, dual fuel systems inject a gaseous-fuel flow into the air intake stream of a diesel engine. This results in more complete combustion within the engine as well as reduced diesel fuel usage. Such dual fuel systems are susceptible to engine knocking due to premature detonation of the gaseous fuel air intake mixture that is often caused by sudden changes to the operating conditions of the engine. The present system utilizes a knock sensor to identify early stages of such engine knocking. To eliminate such engine knocking conditions, the system temporarily interrupts the gaseous fuel flow to resume operation in full diesel mode. The gaseous fuel flow is then reestablished based on the present operating conditions of the engine.

Abstract: A system and method is provided to reduce particulate and NOx emissions from diesel engines through the use of a duel-fuel fumigation system. The system injects a gaseous-fuel flow into the air intake stream of a diesel engine. This results in more complete combustion within the engine as well as reduced diesel fuel usage, which each work to reduce emission outputs of the engine. As presented, the system is operative to meter the gaseous-fuel flow into the diesel engine based on one or more engine parameters such as, for example, exhaust gas temperature, exhaust oxygen levels, engine speed and/or engine load. Monitoring one or more engine parameters allows fine-tuning the flow of gaseous fuel into the engine and thereby prevents loss of engine power at high-end loads while maintaining favorable emission outputs over substantially the entire operating range of the engine.

Abstract: An air blower assembly for a spa having a vent valve in the outlet passage from the blower, with a bi-metallic coil for opening the valve and venting the outlet when the temperature reaches a preselected danger level. The valve comprises two telescoped tubular members having elongated vent ports movable angularly into alignment, the inner member being rotatably supported on the assembly for adjustment of the set point and the outer member being rotatable about the inner member by the coil.