Device for selectively separating particles in a liquid, in particular for cleaning fibrous paper suspensing

A device for separating particles in a liquid, in which the suspension to be cleaned is supplied to a chamber of revolution (1) rotating about a longitudinal axis (2), of the type comprising:

• suspension supply means including first fixed means (5) for supplying the suspension, arranged along the longitudinal axis (2) of a chamber of revolution (1), having first means (6) for deviating the suspension current towards the periphery of the chamber (1);
• means for driving said chamber (1) in rotation about its longitudinal axis (2);
• second fixed means (9,10) for discharging the cleaned suspension and different separated fractions, arranged along the longitudinal axis (2) of said chamber (1), having second deviating means (7,8), a means (13) for discharging a lightest component being arranged on the longitudinal axis of rotation (2);
• and
• said second deviating means (7,8) provided upstream of the second fixed means (9,10) intercepting most of the throughput of the suspension in the region of the periphery of the chamber (1), then deviating it towards the longitudinal axis of rotation (2) so as to recover most of the kinetic energy of rotation;
• said second fixed means (9,10) being situated at the opposite end to that of the chamber (1) from the supply means (5,6) and being arranged at the periphery of said chamber (1);
• a central body (11) of revolution being arranged inside the chamber, along the longitudinal axis of rotation of said chamber (1), between the first fixed means (5) supplying the suspension and the second fixed means (9-10) discharging said cleaned suspension, said central body of revolution (11):
• being mounted for rotation about its axis and having a general diabolo shape including a portion, which, from the inlet means (5,6), converges towards the outlet means (7-10) terminating in a smallest cross-section;
• and wherein a radial passage means (12, 33-42) is arranged in the vicinity of the smallest cross-section of said central body of revolution (11) has an inlet radially remote from said axis of rotation and is connected to an axial outlet duct (13, 47) whereby said radial passage means (12, 33-42) provided in the general diabolo-shaped central body of revolution converts the residual energy of the vortex dynamic and static pressures into static pressure which avoids the counterpressure on the outlet side and therefore enables the inlet pressure to be correspondingly reduced resulting in an appreciable saving in energy.