Method and apparatus for extracting liquid present in a humid mass

An apparatus for extracting a liquid by pressing a humid mass, said apparatus comprising at least one extraction channel for liquid removal, which extraction channel is provided with:

• at least one inlet for feeding the extraction channel with the humid mass to be treated;
• walls provided with holes for allowing liquid contained in the humid mass being pressed to evacuate from said extraction channel, the humid mass gradually becoming a dehydrated mass;
• and
• at least one outlet for discharging the dehydrated mass, in the form of a cake, obtained by pressing the humid mass in the extraction channel, the cake having a lower liquid content than the humid mass;
• wherein the outlet has a downstream end which is further provided with an opened portion in one or more of lateral sides of said downstream end and/or in a bottom of said downstream end, and
• wherein said downstream end is further provided in said opened portion with a device applying a level of constraints to the dehydrated mass in the channel to control the holding up the dehydrated humid mass arriving at said outlet, and
• wherein said device further comprises:
• a first device for measuring the entrainment force exerted by the friction generated, on said extraction channel, by the humid mass being dehydrated, and/or measuring of the pressure within the extraction channel and/or measuring of the pressure on the walls of said extraction channel;
• and
• a second device to regulate constraints to said dehydrated mass, at the outlet of said extraction channel, as a function of said entrainment force and/or pressure measured with said first system, for controlling the holding up of the dehydrated mass arriving at the outlet of the channel, and for managing the level of constraints generated to said dehydrated mass at the outlet of the extraction channel.