Apparatus for degassing paper stock

Claim 1

Apparatus for degassing a suspension of cellulosic fibers forming a stock for paper making, the apparatus comprising a closed tank having a partition extending upward from the lower part of the tank and dividing the tank into a first chamber and a smaller second chamber, each chamber having a stock discharge outlet, means for feeding the stock to the tank, said partition means having a free gas passageway at the top of the tank between the two chambers, gas evacuation means for maintaining substantially equally low gas pressures in the two chambers, a stock consumer connected to said stock outlet of the first chamber, said partition further having a restricted opening extending from the bottom of the tank for passage of stock from the first chamber to the second chamber, a recycle line for recycling stock from said stock outlet of the second chamber back to the tank, means for sensing the stock level in the first chamber, and valve means located in said recycle line and operable under control of said sensing means to maintain said stock level constant.