Flue gas mixing apparatus

1. A flue gas mixing apparatus comprising

a plurality of gas mixers provided on a flow channel cross-section of a flue gas duct into which combustion flue gas to which a reducing agent which reduces nitrogen oxide in the combustion flue gas is added is introduced and which is on an upstream side of a denitration catalyst layer of a denitration apparatus, wherein

the gas mixers have a gas flow channel in which the combustion flue gas is caused to flow, one of parallel two faces of a cuboid space being set as a gas flow-in face, the other thereof being set as a gas flow-out face, and

in the gas flow channel, each of the gas flow-in face and the gas flow-out face is segmented into at least four regions which have same symmetric areas by straight lines passing through a center of each face, and the gas flow channel includes a gas flow channel partition plate which introduces the combustion flue gas caused to flow in each of the regions of the gas flow-in face into each of the regions of the gas flow-out face at positions at which the regions are shifted one-by-one around a line segment connecting the centers of the gas flow-in face and the gas flow-out face,

the gas flow channel partition plate is formed of at least four partition plate elements which are formed into the same shape and are arranged respectively from the gas flow-in face to the gas flow-out face having edge parts lain on the gas flow-in face and the gas flow-out face, and have the line segment connecting the centers of the gas flow-in face and the gas flow-out face as a common side.

2. The flue gas mixing apparatus according to claim 1 , wherein the partition plate elements are formed of a bent plate which shuts a gas flow between the regions of the gas flow-in face and the gas flow-out face at symmetric positions.

3. The flue gas mixing apparatus according to claim 1 , wherein in the gas flow channel, each of the gas flow-in face and the gas flow-out face is segmented into four rectangular regions by two perpendicular straight lines which are parallel to sides of each face and pass through the center of each face,

in the gas flow channel partition plate, four partition plate elements are disposed by being rotated around a common side at a pitch of 90°, the common side being set at the line segment connecting the centers of the gas flow-in face and the gas flow-out face, and

the partition plate element is formed of a bent plate which shuts a gas flow between the rectangular regions of the gas flow-in face and the gas flow-out face at symmetric positions.

4. The flue gas mixing apparatus according to claim 1 , wherein in the gas mixers, four faces parallel to a gas flow flowing into the cuboid space are opened.

5. The flue gas mixing apparatus according to claim 1 , wherein edge parts of the partition plate element in contact with flat plates on outer faces of the cuboid space are fixed to the flat plates, and edge parts of the partition plate element not in contact with the flat plate on the outer faces of the cuboid space are fixed to rod-like support members.

6. The flue gas mixing apparatus according to claim 1 , wherein the gas mixers are disposed on at least part of the flow channel cross-section of the flue gas duct on the upstream side of the denitration apparatus into a plurality of stages and into a plurality of columns.

7. A flue gas mixing apparatus comprising

a plurality of gas mixers provided on a flow channel cross-section of a flue gas duct into which combustion flue gas to which a reducing agent which reduces nitrogen oxide in the combustion flue gas is added is introduced and which is on an upstream side of a denitration catalyst layer of a denitration apparatus, wherein

the gas mixers have a gas flow channel in which the combustion flue gas is caused to flow, one of parallel two faces of a cuboid space being set as a gas flow-in face, the other thereof being set as a gas flow-out face,

the gas flow channel is divided into a plural number of sub gas flow channels with partition plates which are arranged respectively from the gas flow-in face to the gas flow-out face having edge parts lain on the gas flow-in face and the gas flow-out face, formed by joining sides of a plurality of isosceles triangle plate materials together, and by bringing joint parts of the plate materials, the joint parts being concave or convex, to be adjacent to each other or to be set such that their recess parts and projection parts are sequentially alternate with respect to a gas flow direction.

8. The flue gas mixing apparatus according to claim 2 , wherein in the gas mixers, four faces parallel to a gas flow flowing into the cuboid space are opened.

9. The flue gas mixing apparatus according to claim 3 , wherein in the gas mixers, four faces parallel to a gas flow flowing into the cuboid space are opened.

10. The flue gas mixing apparatus according to claim 3 , wherein

the partition plate element is formed of

a triangular plate A which has a line segment L 1 connecting a vertex [ 100 ] and a vertex [ 011 ] as a base and has a point P 1 on a line segment L 2 connecting a vertex [ 110 ] and a vertex [ 111 ] as a vertex,

a triangular plate B which has the common side L 3 as a base and has a point P 2 on the line segment L 1 as a vertex,

a triangular plate C which has a line segment L 4 connecting a vertex [ 000 ] and the vertex [ 100 ] as a base and has the point P 2 as a vertex, and

a triangular plate D which has a line segment L 5 connecting the vertex [ 011 ] and a vertex [ 001 ] as a base and has the point P 2 as a vertex, where

three-dimensional coordinates [xyz] of respective vertices of the rectangular region of the gas flow-in face are respectively set to be [ 000 ], [ 100 ], [ 110 ] and [ 010 ] clockwise from an intersection of the two perpendicular straight lines, and three-dimensional coordinates [xyz] of respective vertices of the rectangular region of the gas flow-out face at symmetric positions of those vertices are respectively set to be [ 001 ], [ 101 ], [ 111 ] and [ 011 ] clockwise from an intersection of the two perpendicular straight lines.

11. The flue gas mixing apparatus according to claim 10 , wherein in the gas mixers, faces parallel to a gas flow flowing into the cuboid space are formed of flat plates into a tubular shape.

12. The flue gas mixing apparatus according to claim 1 , wherein in the gas mixers, one pair of two faces facing each other out of four faces parallel to a gas flow flowing into the cuboid space are formed of flat plates, and the other pair of two faces are opened.

13. The flue gas mixing apparatus according to Claim 2 , wherein the gas mixers, faces parallel to a gas flow flowing into the cuboid space are formed of flat plates into a tubular shape.

14. The flue gas mixing apparatus according to claim 3 , wwherein the gas mixers, faces parallel to a gas flow flowing into the cuboid space are formed of flat plates into a tubular shape.

15. The flue gas mixing apparatus according to claim 10 , wherein the gas mixers, faces parallel to a gas flow flowing into the cuboid space are formed of flat plates into a tubular shape.

16. The flue gas mixing apparatus according to claim 2 , wherein the gas mixers, one pair of two faces facing each other out of four faces parallel to a gas flow flowing into the cuboid space are formed of flat plates, and the other pair of two faces are opened.

17. The flue gas mixing apparatus according to claim 3 , wherein the gas mixers, one pair of two faces facing each other out of four faces parallel to a gas flow flowing into the cuboid space are formed of flat plates, and the other pair of two faces are opened.

18. The flue gas mixing apparatus according to claim 10 , wherein the gas mixers, one pair of two faces facing each other out of four faces parallel to a gas flow flowing into the cuboid space are formed of flat plates, and the other pair of two faces are opened.

19. The flue gas mixing apparatus according to claim 10 , wherein in the gas mixers, four faces parallel to a gas flow flowing into the cuboid space are opened.