초록 ▼

A system for mixing fumigation fuel with the intake air in a compression ignition engine includes a variable area venturi in an engine intake air duct to draw controlled amounts of a pre-mixed fumigation fuel/air mixture into the main air stream in proportion to the amount of suction created downstr

A system for mixing fumigation fuel with the intake air in a compression ignition engine includes a variable area venturi in an engine intake air duct to draw controlled amounts of a pre-mixed fumigation fuel/air mixture into the main air stream in proportion to the amount of suction created downstream of the variable area venturi by the engine air flow. The variable area venturi creates a pressure depression proportional to the engine air flow motivating the fumigation fuel/air mixture to flow into the engine along with the main air stream at a rate related to the engine load and speed. The variable area venturi includes a housing having a downstream branch connected to a conventional demand-type mixer which is supplied with the fumigation fuel via a demand-type regulator, and air through a filter from the atmosphere. The variable area venturi is formed by a spring-loaded, normally closed flapper valve which variably opens in response to air drawn through the housing by the engine. The variable area venturi thus created provides a proportional control of the fumigation fuel introduced into the main air stream over a wide range of engine operating conditions with relatively small pressure drops.

대표청구항 ▼

A variable area venturi apparatus for variably metering a constant proportion fumigation fuel/air mixture into a main air flow supplied to a compression ignition engine having an intake manifold, comprising: a housing defining an inner surface and having an air intake port, an output port for being

A variable area venturi apparatus for variably metering a constant proportion fumigation fuel/air mixture into a main air flow supplied to a compression ignition engine having an intake manifold, comprising: a housing defining an inner surface and having an air intake port, an output port for being coupled to the intake manifold, a main passageway between the air intake port and the output port through which the main air flow to the engine occurs, and a branch port coupled for enabling the constant proportion fumigation fuel/air mixture to be drawn into the main passageway to be variably mixed with the main air flow; a variable restrictor means in the main passageway defining a variable area throat, the restrictor mean variably opening and closing to open and close the throat in response to air flow drawn through the main passageway by the engine for creating a variable pressure drop downstream of the throat, the branch port being positioned between the throat of the restrictor means and the intake manifold, the amount of constant proportion fumigation fuel/air mixture being drawn into the main passageway varying in response to the variable pressure drop to vary the proportion of fumigation fuel mixed with air supplied to the intake manifold.