In a microreactor in which a plurality of fluids L 1 and L 2 are led through their respective feed channels to merge in one reaction channel and react with each other while circulating, a spiral reaction channel is formed by cutting a spiral screw thread on either the outer surface of a round-bar-shaped core member or the inner surface having a circular cross section of an outer cylindrical member and engaging the outer surface of the core member in close contact with the inner surface of the outer cylindrical member.
1. A microreactor which leads a plurality of fluids through respective fluid feed channels of the fluids to merge in one reaction channel and causes the fluids to react with each other while circulating, said microreactor comprising:
a round-bar-shaped core member of which outer surface has a circular cross section;
a first cylindrical member of which inner and outer surfaces have circular cross sections, said round-bar-shaped core member being inserted in said first cylindrical member; and
a second cylindrical member of which inner surface has a circular cross section, said first cylindrical member being inserted in said second cylindrical member,
wherein a reaction channel is formed as first and second spiral channels connected in series, said first spiral channel being formed by cutting a first spiral screw in any one of the outer surface of said round-bar-shaped core member and the inner surface of said first cylindrical member and engaging the outer surface of said core member in contact with the inner surface of said first cylindrical member, said second spiral channel being formed by cutting a second spiral screw in any one of the outer surface of said first cylindrical member and the inner surface of said second cylindrical member and engaging the outer surface of said first cylindrical member in contact with the inner surface of said second cylindrical member,
wherein a start part or intermediate part of said reaction channel is provided with a mixing section formed into a channel structure where said plurality of fluids can be mixed, and
wherein said mixing section is made up of first convex sections protruding in a collar form in the diameter direction and second convex sections protruding in a collar form in the diameter direction arranged in a staggered configuration in the flow direction of said plurality of fluids.
2. The microreactor according to claim 1 , wherein the circle-equivalent diameter (Wa) in an average cross-sectional area in the diameter direction of said reaction channel is 1 μm or more and 1000 μm or less.
3. The microreactor according to claim 1 , wherein when the fluid is circulated through said reaction channel so that a total flow rate of the fluid after a merge becomes Q (m 3 /sec), the length PL (m) of the reaction channel is set so as to satisfy V/Q≧0.1, where V (m 3 ) is the volume of the reaction channel.
4. The microreactor according to claim 1 , wherein said plurality of fluids feed channels are formed into a multi-cylindrical structure.
5. The microreactor according to claim 1 , further comprising a temperature control device which controls the reaction temperature of the fluids that flow through said reaction channel.