Patent ID: 9238888
Filing Date: 2016-01-19
CPC Classification: B01D,B03D,B04C,D21D

Claim Text:
1. A method for producing or treating cellulose suspension by means of cleaning the cellulose suspension from light impurities in a reverse cleaning stage, the method comprising the steps of: cleaning the cellulose suspension from light impurities by means of at least one hydrocyclone for reverse cleaning cellulose suspensions from light impurities, the hydrocyclone including a base end and an apex end and a separation chamber having an elongated shape between the base end and the apex end, at least one net arranged at the base end and at least one underflow outlet at the apex end and at least one overflow outlet at the base end, the overflow outlet being provided with an additional, light reject outlet arranged concentrically to a length axis of the hydrocyclone, the underflow outlet at the apex end producing a thickened accept fraction, the light reject outlet producing a light reject fraction taken out in a central core of the overflow outlet, and the overflow outlet at the base end producing a middle fraction and taken out coaxially with the light reject fraction in the overflow outlet, and diluting the cellulose suspension upstream of the hydrocyclone with all of the middle fraction from the overflow outlet.