| 摘要 |
PROBLEM TO BE SOLVED: To provide membrane separation equipment in which circulation flows are formed stably and smoothly, and cleaning effect of a membrane surface is improved.SOLUTION: Membrane separation equipment 1 comprises as follows. In a treatment tank 2, two or more membrane units 3a-3d and air diffusers 14a-14d that generate a circulation flow 4 circulating in a vertical direction are disposed, each of the membrane units 3a-3d has two or more membrane elements 8 arranged to open a space that becomes a channel of the circulation flow 4, a downflow 20 flows in a channel between membrane elements of at least one membrane unit 3a, 3C, and an upflow 21 flows in a channel between membrane elements of a remainder membrane unit 3b, 3d. A ratio of &egr;d/&egr;r of a void fraction &egr;r of the channel between the membrane elements in which the downflow 20 flows to a void fraction &egr;d of the channel between membrane elements in which the upflow 21 flows is in a range from 0.7 to 1.2. |
