Bi-Fuel Air Gas Mixer Valve (AGM)

The air gas mixer has been designed by Eden Innovations LLC to provide the optimum air-to-gas ratio in a variety of engine sizes. The mixer diameter and insert are determined by the engine air flow, and the number of mixers is determined by the number of turbochargers on the engine.

The mixers use the venturi effect to “pull” gas into the engine. The gas pressure exiting the gas train is near atmospheric or slightly negative due to the pressure drop across the engine air filters. This air filter pressure drop signal is used as the reference pressure by the zero-pressure regulator via a small reference air hose.

As air passes through the mixer a lower pressure is created in the venturi throat. Gas flows through holes around the venturi throat and mixes with engine intake air in the venturi outlet (diffuser) section. The air pressure loss is also recovered in the diffuser section, resulting in a very low overall pressure drop across the entire mixer. The annular space between the mixer venturi insert and the mixer housing is supplied with fuel gas by the zero-pressure regulator and the gas flow is restricted by the fuel control throttle. The venturi throat size and the area of the holes in the venturi throat are carefully sized to limit the maximum air/gas ratio even if the fuel control throttle is wide open.

The venturi throat pressure drop increases as the airflow through the mixer increases. As this venturi pressure drop increases, the zero-pressure regulator allows more gas to pass through the gas train to maintain zero gas pressure differential between the mixer air inlet and the fuel control valve inlet. If there is little or no airflow through the mixer, no gas will be delivered to the engine intake regardless of the fuel control valve throttle position. Once the air intake diameter, outlet, and turbo inlet diameter are known, the necessary hose kit can be identified. If the diameters are not known, a hose kit will be provided with a range of inserts and hoses which can be used for most applications.

The mixer is unidirectional and will only function if properly installed with the larger diameter towards the engine air filter and smaller diameter facing the turbocharger inlet. It is generally required that engines with two or more intake systems have one mixer per intake. The mixer may be installed at any angle as required by the geometry of the original air intake system.