Abstract: Disclosed are a system and a method for precisely controlling an air fuel ratio of an oil burner, which is extensively used in a household boiler, an industrial boiler, or a heater, using an air pressure sensor. The system includes a power supplying part, a fan for supplying air required for combustion of the oil burner by receiving driving voltage from the power supplying part, a fan driving part serving as a controller which drives the fan, an air pressure sensor, which is installed at a side of a flow path of air supplied from the fan so as to detect an amount of the supplied air, and a control part for outputting an optimum RPM of the fan to the fan driving part by comparing a signal detected by the air pressure sensor with preset data related to an optimum amount of air.

Abstract: Disclosed is a combustion apparatus using an air fuel ratio sensor, which detects the operation of the air fuel sensor based on pressure of gas and air introduced into a combustion chamber and adjusts the amount of gas and air introduced into the combustion chamber using a controller based on data detected by the air fuel sensor.

Abstract: Disclosed is a gas boiler which has a simple structure, which is easy to be installed, and which is manufactured at a low cost. The typical water tank is partitioned into an upper casing and a lower casing which are capable of communicated with each other. A three-way valve and a circulation pump are mounted to the lower casing in a row in the horizontal direction, and the plurality of pipelines are arranged by using the above serial arrangement as a reference. A recess for retaining a printed circuit board box is formed in one side of the upper casing. The three-way valve is coupled to the lower casing and circulation pump is to the three-way valve. Therefore, the size of the gas boiler is minimized and the manufacturing cost thereof is economized.

Abstract: Disclosed is a washing method which can eliminate suds or foam created in the course of washing by a washing machine and can effectively prevent the creation of foam, thereby improving the washing efficiency of the washing machine. In the washing method, a part of the washing liquid is continuously recirculated and sprayed during the washing process while the washing liquid is partially drained at each predetermined time interval. In the rinsing process, a part of the rinsing water is also continuously recirculated and sprayed during the rinsing process while the rinsing water is partially drained at each predetermined time interval.