Fuel reforming system

A fuel reforming system for converting a mixture of air and a fuel into a reformed gaseous mixture rich with free hydrogen and feeding the reformed gaseous mixture into an internal combustion engine, said system comprising:

• a fuel circuit having a downstream end adapted to be connected to an internal combustion engine;
• a carburetor disposed in said fuel circuit for producing a rich mixture of air and the fuel at an air-fuel ratio smaller than the stoichiometric air-fuel ratio of the mixture;
• said carburetor comprising a substantially horizontal primary air intake passage, a substantially closed space, a diaphragm extending across said space to divide the same into upper and lower chambers, a suction piston connected at one end to said diaphragm and extending into said primary air intake passage for movement transversely of the axis thereof to provide a variable venturi in said primary air intake passage, a second passage interconnecting said upper chamber and said primary air intake passage downstream of said venturi, a third passage communicating said lower chamber and the atmosphere, spring member disposed in said upper chamber for downwardly urging said diaphragm, a float chamber for said fuel, a nozzle extending from said float chamber to said venturi and open to said venturi to cooperate therewith to produce the rich air-fuel mixture, a needle movable with said suction piston to control the cross-sectional area of the opening of said nozzle in said venturi, a secondary air intake passage bypassing said venturi and connected to said primary air intake passage downstream of said venturi to supply a secondary air to the rich air-fuel mixture produced in said venturi, a temperature measuring chamber adjacent said secondary air intake passage, means disposed in said temperature measuring chamber and being expansible and contractible in response to the variation in the temperature in said temperature measuring chamber, and a valve member operatively associated with said expansible and contractible means to control the cross-sectional area of said secondary air intake passage for thereby controlling the air-fuel ratio of the air-fuel mixture produced in said venturi;
• a throttle valve disposed in said fuel circuit downstream of said carburetor;
• a spark plug disposed in said fuel circuit downstream of said throttle valve and being adapted to be operated, when required, to ignite and burn the rich air-fuel mixture;
• a reactor vessel disposed in said fuel circuit downstream of said spark plug and containing a catalyst for facilitating a catalytic reformation of the air-fuel mixture into the reformed gaseous mixture;
• and
• means for causing atmospheric air to flow through said reactor vessel in heat exchange relationship with said catalyst and then through said temperature measuring chamber;
• said carburetor being arranged such that, when said catalyst is at a first temperature high enough to activate said catalyst, the air-fuel ratio of the mixture controlled by said valve member is much smaller than the stoichiometric air-fuel ratio of the mixture and such that, when said catalyst is at a second temperature lower than said first temperature, the air-fuel ratio of the mixture controlled by said valve member is still smaller than the stoichiometric air-fuel ratio but so large as to allow a part of the mixture to be ignited by said spark plug to produce heat in said fuel circuit.