Hitachi Plant Engineering Construction Co., Ltd.

Seiki Mitomo

Yukio Fukushima

Shoken Takahashi

Masaaki Miyamoto

Tatsunori Saigusa

It is an object of the present invention to provide a method which is capable of reducing a crushing rate of grain when the grain such as rice is transported by means of gas through pipes. The temperature of the grain in a grain accommodation tank which is connected to a transportation pipe for grain is measured. A temperature signal indicating this temperature is sent to control means, which determines the temperature of transportation gas so that a difference between this temperature and the temperature of the grain is within a predetermined range. The determined temperature is transmitted to an intercooler so that the temperature of the transportation gas which is sent from a blower and flows through the transportation pipe is controlled to be at the determined specific temperature. Transportation of the grain by means of the transportation gas at this temperature prevents the grain from crushing.

Gas transportation method for grain

It is an object of the present invention to provide a method for reducing crushing of grain when the grain having Vickers hardness Hv in a range of 11&lE;Hv&lE;14 is transported by means of gas. The present invention is a gas transportation method for grain having Vickers hardness Hv in a range of 11&lE;Hv&lE;14, and gas transportation is performed under the condition that a velocity V of transportation gas is set at a value in a range of 10 m/s&lE;V&lE;20 m/s. Alternatively or additionally, a blending ratio &mgr; expressed as a ratio of a flow amount of the grain (kg/H) to a flow amount of the transportation gas (kg/H) is set at a value in a range of (3 V&minus;30)&lE;&mgr;&lE;(3 V&minus;20).

It is an object of the present invention to provide a changeover valve which is capable of preventing granular material from being crushed when the granular material is transported by gas through a pipe system, and more particularly a changeover valve which is capable of preventing grain from being crushed, broken, and chipped when the grain such as rice is transported by gas through the pipe system. It is another object of the present invention to provide a gas transportation pipe system for grain to which the changeover valve is applied. The changeover valve according to the present invention comprises: a valve disc in a cylinder shape including on a side part thereof a through passage which is connected to transportation passages on an upstream side and a downstream side and which is in an eccentric position deviated from a center of the cylinder; a casing for rotatably accommodating the valve disc therein; and a pair of discharge passages which are provided in the casing and connected to the through passage of the valve disc, and an inside diameter of an introducing passage of the changeover valve at an output end thereof is smaller than an inside diameter of the through passage of the valve disc and an inside diameter of the introducing passage in an output side part has a shape gradually decreasing in size toward the downstream side while an inside diameter of each of the pair of the discharge passages at an input end thereof is larger than the inside diameter of the through passage of the valve disc and an inside diameter of each of the pair of the discharge passages in an input side part has al shape gradually increasing in size toward the upstream side.

Growing community of inventors

Chiyoda-ku, Japan

Seiki Mitomo