Miura Co., Ltd.

Miura Institute of Research & Developement Co., Ltd.

Shigehiro Watanabe

Tomohisa Takeda

Toshihiro Kayahara

Noboru Takubo

Kanta Kondou

Kazuhiro Ikeda

Tatsuya Fujiwara

Keiichi Fujita

Toshiaki Ochi

Takashi Sogabe

Makoto Shiba

A venturi nozzle (), disposed upstream from a blower (), for mixing combustion air and fuel gas by intake pressure of the blower (), comprising: a nozzle portion () with a shape that is narrowed in diameter downstream and into which combustion air is introduced; a mixing portion (), disposed downstream from the nozzle portion (), with a shape that is enlarged in diameter downstream and into which combustion air and fuel gas are mixed; and a fuel gas inlet (), disposed between the nozzle portion () and the mixing portion (), into which fuel gas is introduced; wherein a plurality of ridges () extending in a circumferential direction and arranged at predetermined intervals in a flow direction of combustion air are formed on an inner surface of the nozzle portion ().

Venturi nozzle and fuel supply device comprising venturi nozzle for controlling a ratio between a fuel gas and an air flow

Provided is a needle valve in which a gap between a valve casing and a needle is reliably sealed and an origin of the needle can be readily obtained with high precision. A needle () is screwed into a cylindrical rotor () of a stepping motor () so as to be retractable, and a rotation regulating member () prevents the needle () from rotating together with the rotor (). Accordingly, in a case of driving the motor () to rotate the rotor (), the needle () vertically moves without rotating. A lower limit sensor () and an upper limit sensor () detects a detection target piece () provided to the rotation regulating member (), so a lower limit position and an upper limit position of the needle () are obtained. The motor () is controlled such that, after the motor () is driven until the lower limit sensor () detects the detection target piece (), an origin sensor () monitors an origin detection plate () so as to stop at a predetermined rotation stop position. Thus, an origin of the needle () is obtained.

Needle valve

There is provided a valve enabling complete prevention of leakage and a backflow and having durability and less noise, and further there may be implemented a valve capable of predicting the tendency of occurrence of damage on the functions of the valve before the functions of the valve are actually damaged. In a valve having a valve chamberformed between a fluid inletand a fluid outleta valve elementdisposed in the valve chamberis composed of an elastic member and an inelastic member.

Valve

In a water-tube boiler in which pollutant (especially NOx) emissions are reduced, a plurality of water tubes arranged in an annular shape are provided. At least some of the water tubes thereof are spaced apart along an annulus so as to provide a plurality of gaps therebetween. A combustion-reaction ongoing gas passes through these gaps, and a temperature thereof is lowered to 1400.degree. C. upon contact with the water tubes. The boiler further includes a second plurality of water tubes arranged in an annular shape outside of the first plurality of water tubes. By adjusting the arrangement of the water tubes along respective annuli and/or adjusting an orientation of the tubes along their length (so as to be straight, tilted, or bent), control of the exhaust emissions is enhanced.

Water-tube boiler

Discloses a heat-insulating structure for combustion equipment of such a type that a burner element of combustion equipment is insertedly disposed at an installation opening of thermal equipment such as a boiler, with a view to simplified structure and enhanced workability. In combustion equipment (B) having a burner element (20) insertedly disposed at the installation opening (1) of the thermal equipment (A) via the support frame (30) a thermal insulator (50) flush with the burner element (20) on the thermal equipment (A) side is disposed between the installation opening (1) and the outer side face of the support frame (30).

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Matsuyama, Japan

Shigehiro Watanabe