Hitachi Shipbuilding and Engineering Co., Ltd.

Mitsui Liquefied Gas Co., Ltd.

Hiroshi Hayasaka

Yoshitoshi Sekiguchi

Noboru Okigami

Harushige Tamura

Takeo Fujioka

Takeshi Yoshimitsu

Toshitsugu Koyama

A method comprising injecting a primary fuel and air into a furnace to burn the fuel and form a first-stage combustion zone, the air being supplied at a rate in excess of the stoichiometric rate required for the combustion of the fuel, and injecting a secondary fuel into the furnace around or downstream of the first-stage zone at a rate approximately equal to the stoichiometric rate required for the consumption of the excess oxygen resulting from the combustion in the first-stage zone the fuel being diluted with the surrounding combustion gas and to form a second-stage combustion zone around or downstream of the first-stage zone.

Multi-stage combustion method for inhibiting formation of nitrogen oxides

A system for burning a liquefied gas comprises a burner gun for spraying the liquefied gas into a combustion space, a pump for feeding the gas under pressure, pipe means connecting the burner gun with the pump, and a flow regulating valve provided in the pipe means, wherein the portion of the pipe means downstream from the valve has its inner diameter so determined in relation with the flow rate of the gas that the state of the gas flow through said portion falls within fog flow zone or bubble flow zone on Baker's two-phase flow diagram. In the system of the invention, unstable combustion of the liquefied gas due to vapor lock in the pipe means can be prevented even when the gas supply pressure is below the vapor pressure of the gas. Besides, the calorific value obtained with the system is variable over a wider range than with a conventional system. Thus the system has a remarkable industrial value.

System and method for burning liquefied gases

A method comprising injecting a primary fuel and air into a furnace to burn the fuel and form a first-stage combustion zone, the fuel being diluted with surrounding combustion gas and the air being supplied at a rate in excess of the stoichiometric rate required for the combustion of the fuel, and injecting a secondary fuel into the furnace around or downstream of the first-stage zone at a range approximately equal to the stoichiometric rate required for the consumption of the excess oxygen resulting from the combustion in the first-stage zone the fuel being diluted with surrounding combustion gas and to form a second-stage combustion zone around or downstream of the first-stage zone.

Growing community of inventors

Osaka, Japan

Hiroshi Hayasaka