Anaerobic sludge digester
CA 2484411 C · Owner: Chicago Bridge & Iron Company · Inventors: Clark, Sidney E.; Currie, John R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An egg-shaped anaerobic sludge digester has upper and lower draft tubes and an optional middle draft tube. The draft tubes are arranged so that liquid can be (1) simultaneously pumped downwards through the upper (or middle) draft tube and upwards through the lower (or middle) draft tube; (2) simultaneously pumped upwards through two or more draft tubes; or (3) simultaneously pumped downwards through two or more draft tubes. When a middle draft tube is provided it can be used in place of the upper draft tube when the liquid surface in the digester falls below the top of the upper draft tube. Alternatively the middle draft tube can work as a coordinated relay conduit to move liquid either in …
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 October 8, 2004 and granted March 27, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 8, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 8, 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.