Carburetor for an internal combustion engine

An improvement in a vaporization carburetor heat exchanger communicating with a secondary exhaust line leading from an exhaust line of an internal combustion engine, the improvement comprising:

• a) a first valve in the exhaust line;
• b) a second valve in the secondary exhaust line;
• and
• c) means for inversely coupling the movement of the first valve and the second valve to maintain a constant cross-sectional area for the flow of exhaust gas, such that as the first valve opens the second valve closes proportionally and as the first valve closes the second valve opens proportionally.

A method of controlling the heat exchanger temperature in a vaporization carburetor heat exchanger having a blower, comprising the steps of:

• a) placing a cooled exhaust gas recirculation line leading from an outlet of a heat exchanger to the inlet of the blower;
• b) placing a valve in a secondary exhaust line leading from an exhaust line of an internal combustion engine to the inlet of the blower;
• c) placing the blower outlet to the inlet of the heat exchanger;
• and
• d) placing temperature sensitive valve control means at the junction of the recirculation line from the heat exchanger outlet and secondary exhaust line from the exhaust line such that the valve control means adjusts the proportions of exhaust gases from the recirculation line and the exhaust line to maintain the temperature of the gases entering the inlet of the heat exchanger constant at a predetermined optimum temperature.

An improvement in a vaporization carburetor heat exchanger having a top, a bottom, a fuel vapour passage arranged in zig zag fashion and communicating with a fuel atomization chamber, a gas flow passage arranged in zig zag fashion and communicating with a secondary exhaust line leading from an exhaust line of an internal combustion engine, the improvement comprising:

• a) the fuel vapour passage having a first inlet at the top, and a first outlet at the bottom of the heat exchanger;
• b) a first blower communicating with the fuel vapour passage thereby creating a flow of fuel laden air through the fuel vapour passage;
• c) the gas flow passage having a second inlet at the bottom, and a second outlet at the top of the heat exchanger;
• d) a second blower communicating with the inlet of the gas flow passage thereby creating a counterflow of exhaust gas, through the gas flow passage, with respect to the fuel vapour flow of the fuel vapour passage;
• e) a cooled exhaust gas recirculation line leading from the second outlet to the inlet of the second blower;
• f) a valve in a secondary exhaust line leading from the exhaust line of the engine to the inlet of the second blower;
• and
• g) temperature sensitive valve control means at the junction of the recirculation line and the secondary exhaust line such that the valve control means adjusts the proportions of the exhaust gases from the recirculation line and the secondary exhaust line to maintain the temperature of gases entering the second inlet of the heat exchanger constant at a predetermined optimum temperature.