| 摘要 |
<p>A method of chemically cleaning normally immersed suction driven filtering membranes (24) involves backwashing a chemical cleaner through the membranes while the tank is empty in repeated pulses in which the chemical cleaner is pumped to the membranes (24) separated by waiting periods in which chemical cleaner is not pumped to the membranes (24). The duration and frequency of the pulses is preferably chosen to provide an appropriate contact time of the chemical, preferably without allowing the membranes (24) to dry between pulses and without using excessive amounts of chemical. In other aspects, such membranes (24) preferably used for filtering water to produce potable water in a batch process are backwashed with a chemical cleaner substantially at the same time as the tank is being drained. The chemical cleaner is optionally supplied in pulses.</p> |
