When one or more secondary venturi enclosed inside the main venturi of a carburettor is called multiple venturi carburettor and this carburetion system is called a multiple venturi carburetion systems. Benefits of using this and results of multiple venturi carburetion system are listed below.
Advantages of multiple venturi carburetion system :
- Reducing condensation of the fuel :
The main jet discharges the fuel into the primary venturi in an upward direction against the downward airstream in a multiple venturi system. The airflow atomizes the fuel. The primary venturi keeps the fuel thus atomized in the primary venturi centrally located in the air stream.
In addition, a blanket of air surrounding the primary venturi and passing into the secondary venturi keeps the atomized fuel in the air stream centrally located. Through this process, the carburettor walls are protected for a certain distance from coming into contact with fuel, thus reducing condensation.
- High-speed system :
The throttle valve is sufficiently opened when the speed is to be increased from low to high. The air flows faster through the primary venturi when the throttle valve is wider open. In the portion of the jet orifice, this airflow produces a vacuum. Because of this increase in a vacuum, the main jet will discharge additional fuel. The high-speed system maintains an almost constant air-fuel ratio.
- Due to high depression created at the region of fuel nozzle better automatization, and better control of fuel.
- The excellent air-fuel mixture is achieved without any reduction in volumetric efficiency.
- The excellent low-speed full throttle operation is provided.