Patent ID: 7780143
Filing Date: 2010-08-24
Classification: F16K

Abstract:
1. A gate valve installed in a transport line for transporting fluid containing particulate material at a coal gasification plant, comprising: a valve box having an inlet portion and an outlet portion in which a channel constituting a part of the transport line is formed; a valve unit, provided between the inlet portion and the outlet portion, which extends in an opening-and-closing direction orthogonal to an axial direction of the channel, and which is movable in the opening-and-closing direction; a wedge plate provided between the valve unit and the inlet portion so as to extend in the opening-and-closing direction; a guide plate provided between the valve unit and the outlet portion so as to extend in the opening-and-closing direction; and a moving device engaged with the valve unit and configured to move the valve unit in the opening-and-closing direction, wherein the valve unit is provided with a first sliding surface at the inlet portion side and a second sliding surface at the outlet portion side, which are substantially orthogonal to the channel and substantially parallel to each other, and a valve unit channel passing through so as to form a part of the channel is provided closer to a first end than a midpoint in the opening-and-closing direction; the wedge plate is provided with a third sliding surface that is in surface contact with the first sliding surface at the valve unit side and an inclined supporting surface which is provided closer to a second end than substantially the midpoint in the opening-and-closing direction at the inlet portion side and whose height gradually reduces toward the second end, and a wedge-plate channel that passes from the inclined supporting surface toward the third sliding surface and that forms a part of the channel is provided so that the third sliding surface has a length equal to or greater than the diameter of at least the valve unit channel at the first end in the opening-and-closing direction; the guide plate is provided with a fourth sliding surface that is in surface contact with the second sliding surface at the valve unit side, and a guide-plate channel that passes through so as to form a part of the channel is provided so that the fourth sliding surface has a length equal to or greater than the diameter of at least the valve unit channel at the first end in the opening-and-closing direction; an inclined surface opposing the inclined supporting surface is formed at an inner end portion of the inlet portion; a first sealing member having elasticity is mounted between the inclined surface and a wedge-plate annular groove provided around the wedge-plate channel of the inclined supporting surface; a second sealing member having elasticity is mounted between the guide plate and the outlet portion so as to surround the channel; and the valve box is provided with a first urging member capable of urging the wedge plate to the second end in the opening-and-closing direction, and a second urging member that is disposed at the second end, in the opening-and-closing direction, of the first urging member and that is capable of urging the wedge plate to the first end in the opening-and-closing direction.