Stirrer producing intermittent jet flow

A stirrer comprising:

• a supporting tube;
• a hollow housing supported by the supporting tube, the hollow housing including a sucking chamber and a sucking port, wherein the hollow housing is configured to suck a fluid to be processed into the sucking chamber via the sucking port then to introduce it to a stirring chamber via a comparting wall;
• a rotating rotor provided with a plurality of blades and accommodated in the stirring chamber;
• and
• a screen arranged around the rotor, wherein the screen is tapered towards a central axis of the supporting tube and is arranged around the rotor;
• wherein:
• the rotor and the screen are provided within the hollow housing,
• each blade includes an edge portion at an outermost circumferential surface thereof,
• the screen comprises a plurality of slits in a circumferential direction thereof and a screen member located between the slits that are located in a neighborhood to each other,
• a clearance from the edge portion of each blade to the screen is a constant value,
• the edge portion of each blade and each slit have a matching region where they are in the same position and overlapped with each other in a longitudinal direction of the respective slit,
• of the rotor and the screen, at least the rotor is rotated so as to relatively rotate the rotor and the screen thereby ejecting a fluid to be processed in the stirring chamber from inside the screen to outside thereof through the slits as an intermittent jet flow, and
• the stirrer satisfies following condition 1 and condition 2:
• (Condition 1)
• in the matching region, a relationship among a width (b) of the edge portion of each blade in a rotational direction, a width (s) of the respective slit in a circumferential direction, and a width (t) of the screen member in a circumferential direction is shown by b≥2s+t, and
• (Condition 2)
• in the matching region, a relationship between the width (b) of the edge portion of each blade in a rotational direction and a maximum inner diameter (c) of the screen is shown by b≥0.1c.