Backwash
CA 2535360 C · Owner: Siemens Industry, Inc. · Inventors: Cao, Zhiyi; Beck, Thomas William; Johnson, Warren Thomas
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of backwashing a membrane filtration module (4) said module (4) , including one or more membranes (5) located in a feed-containing vessel (3) the membranes (5) having a permeable wall which is subjected to a filtration operation wherein feed containing contaminant matter is applied to one side of the membrane wall and filtrate is withdrawn from the other side of the membrane wall, the method including: removing liquid from the feed-containing vessel (3) until the level of liquid in the feed-containing vessel (3) falls to a first level (L2) below an upper level of the membranes; suspending the filtration operation; performing a liquid backwash of the membrane wall until …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed August 27, 2004 and granted February 12, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 27, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 27, 2026.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.