Patent ID: 7229524

Claim:
A method of feeding wood chips to a treatment vessel for production of cellulose pulp, comprising: providing a liquid lock having a liquid disposed therein forming a first liquid surface, a bottom of the liquid lock and a second liquid surface, the liquid lock being upstream of a treatment vessel, the liquid of the liquid lock blocking air passage through the liquid lock to or from the treatment vessel, feeding untreated or un-steamed wood chips at essentially ambient temperature down to the liquid lock and forming a chips column on the first liquid surface, advancing the chips column of wood chips through the first liquid surface, passing the wood chips through the liquid lock for driving off all free air surrounding the wood chips and preventing essentially all free air from passing the liquid lock, feeding the wood chips through the second liquid surface, the wood chips, essentially being without any free air disposed around the wood chips, tumbling down through a down-pipe to the treatment vessel without compressing the wood chips, exposing the wood chips to steam to remove air bound in the wood chips from the wood chips so that a quantity of air which is drawn with the wood chips to the treatment vessel is reduced to a minimum, and heating the wood chips to at least 80° C. in the treatment vessel prior to discharging the wood chips from the treatment vessel.