Abstract: The fuel injection apparatus of the invention comprises a unit injector for injecting fuel to a combustion chamber of an internal combustion engine. An injection pump chamber and a timing chamber are defined in the unit injector, a quantity of fuel, adjusted in accordance with a drive condition of an engine, being supplied to these chambers. Fuel in the injection pump chamber and the timing chamber can be pressurized by an injection plunger and a timing plunger operated by pressure from the same pressure source. When the fuel in the injection pump chamber is pressurized to a predetermined injection pressure, fuel in the injection pump chamber is injected to the corresponding combustion chamber of the engine. The timing chamber is connected to a relief path, and a check valve, which can be opened at a pressure lower than the injection pressure, is provided in the relief path.

Abstract: A steel refining method of the type in which the steel is refined through an interfacial reaction between the molten steel in a vessel and a slag on the molten steel. The method simultaneously employs both of blowing of an inert gas into the molten steel from the bottom of the vessel to stir the molten steel by bubbling and blowing an inert gas from the upper side of the vessel into the zone on which the movement of the slag is dull. Consequently, the stirring effect on the molten steel is enhanced to promote the refining reaction. The inert gas can contain a desulfurization agent.