Patent ID: 8986504
Filing Date: 2015-03-24
Classification: D21C

Abstract:
1. A digester apparatus for delignifying wood chips to form wood pulp comprising: a vessel; a first downcomer extending into said vessel for delivering a first fluid into said vessel, the first fluid being generally at a first temperature when passing into said first downcomer; a second downcomer extending into said vessel and located about said first downcomer; a third downcomer extending into said vessel and located about said second downcomer for delivering a second fluid into said vessel, the second fluid being generally at a second temperature different from the first temperature when passing into said third downcomer; and structure for preventing continuous liquid flow through said second downcomer such that said second downcomer defines an insulating region between said first and third downcomers so as to reduce heat transfer between said first and third downcomers.