Flow passage structure

A flow passage structure having a plurality of flow passageways therein, the flow passageways for circulating a first fluid and a second fluid in such a manner that the fluids are mixed with each other, comprising:

• a substrate having a front surface and a back surface facing in the opposite direction to the front surface;
• a first sealing plate bonded to the front surface of said substrate;
• and
• a second sealing plate bonded to the back surface of said substrate, wherein
• on the front surface of said substrate, a plurality of first groove portions arranged so as to extend in a particular direction side by side in parallel to each other is formed,
• on the back surface of said substrate, a plurality of second groove portions arranged on the back side of the first groove portions so as to extend in parallel to the first groove portions, and a plurality of third groove portions arranged on the back side of the first groove portions so as to extend in parallel to the first groove portions, the third groove portions being spaced from the second groove portions in the longitudinal direction of the second groove portions are formed,
• in a part of said substrate where ends of the second groove portions on the side of the third groove portions are placed, a plurality of first hole portions penetrating said substrate from the front surface to the back surface, the first hole portions for causing the second groove portions to communicate with the first groove portions placed on the front side of the second groove portions is formed,
• in a part of said substrate where ends of the third groove portions on the side of the second groove portions are placed, a plurality of second hole portions penetrating said substrate from the front surface to the back surface, the second hole portions for causing the third groove portions to communicate with the first groove portions placed on the front side of the third groove portions is formed,
• said first sealing plate is bonded to the front surface of said substrate so as to seal openings of the first groove portions on the front surface side,
• said second sealing plate is bonded to the back surface of said substrate so as to seal openings of the second groove portions on the back surface side and openings of the third groove portions on the back surface side,
• each of said passageways includes:
• a first inlet path into which the first fluid is introduced, the first inlet path being formed by a part of the first groove portion which is placed on the opposite side of the second hole portion with respect to the first hole portion;
• a second inlet path into which the second fluid is introduced, the second inlet path being formed by a part of the second groove portion where the first hole portion is not formed;
• a first junction portion formed by a part where the first hole portion causes the first groove portion and the second groove portion to communicate with each other, the first junction portion for joining the first fluid flowing through the first inlet path and the second fluid flowing through the second inlet path in the thickness direction of said substrate;
• a first joined fluid flow passage through which a fluid made by joining both the fluids in the first junction portion flows, the first joined fluid flow passage being formed by a part of the first groove portion placed between the first hole portion and the second hole portion;
• a branch portion formed by a part where the second hole portion causes the first groove portion and the third groove portion to communicate with each other, the branch portion for dividing the fluid flowing through the first joined fluid flow passage into two fluids in the thickness direction of said substrate;
• a first branch path through which one of the two fluids divided by the branch portion flows, the first branch path being formed by a part of the first groove portion placed on the opposite side of the first hole portion with respect to the second hole portion;
• and
• a second branch path through which the other of the two fluids divided by the branch portion flows, the second branch path being formed by a part of the third groove portion where the second hole portion is not formed, and
• a corresponding diameter of the first branch path and a corresponding diameter of the second branch path in each of said passageways are smaller than a corresponding diameter of the first joined fluid flow passage in the passageway.