Micro mixer

A micro mixer comprising:

• a first guide flow passage having a first guide portion for guiding a first fluid to be directed in a first direction and a second guide portion connected to said first guide portion with an enlarged size of the second guide portion,
• a second guide flow passage having in the second guide portion of said first guide flow passage a discharge portion for guiding a second fluid to be directed in a direction opposite to said first direction, said discharge portion having a flow passage space narrower than the flow passage space of the second guide portion of the first guide flow passage,
• a third guide flow passage defined by the second guide portion of the first guide flow passage and the discharge portion of the second guide flow passage for guiding a mixed fluid caused by colliding the first fluid flowing in the first guide flow passage with the second fluid flowing in the second guide flow passage in a counter-flow manner to be directed in the same direction as said first direction and further for increasing the pressure of said mixed fluid,
• a mixing-promoting space communicating with said third guide flow passage for lowering the fluid pressure of the mixed fluid discharged from said third guide flow passage to promote the mixing of the mixed fluid with the aid of vortexes caused in connection with the pressure drop of the mixed fluid, and
• a fourth guide flow passage for guiding the mixed fluid in said mixing-promoting space into predetermined collecting means.