Apparatus for thickening papermaking pulp in water has a pair of spaced-apart rolls (20, 22) and a woven wire belt (30) trained around these rolls. The pulp is supplied at the first roll (20) for centrifugal extraction and is carried by the belt to the second roll (22) for further water extraction and thickening, and is then discharged from the apparatus. In one embodiment, the first roll (20) is formed with an open surface, and the suspension is delivered to the belt at least partially by flowing through the first roll from a headbox (40) in the on-running wedge zone. The second roll (22) is porous and has auxiliary water-removing appliances associated therewith, including blow boxes for forcing air either inwardly or outwardly of the second roll.
展开▼
