Back to results
US 4,331,534 AGranted
Method of and arrangement for the de-inking of pulp suspensions
AssigneesFeldmuhle Aktiengesellschaft, E & M Lamort
InventorWolfgang Barnscheidt
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneesFeldmuhle Aktiengesellschaft, E & M Lamort
InventorWolfgang Barnscheidt
Estimating the term…
A pulp suspension of waste paper which is laden with air bubbles is introduced into a flotation cell. Fine air bubbles rise through the pulp suspension toward the top. Printing ink and other impurities are deposited on the bubbles which form a foam layer on the surface of the pulp suspension. The foam which is laden with impurities is drawn off from the surface. The fibers which have been subjected to preliminary purification in this manner sink downwardly. For reducing the number of cells connected in series to fewer than a third, while obtaining the same degree of whiteness, the fibers which were subjected to preliminary purification are drawn off and are once again supplied to the flotation cell in the form of an air-laden pulp suspension. Alternatively, instead of the air-laden pulp suspension, a water-air suspension can be injected. The air bubbles which are thus introduced once again rise toward the top and traverse the sinking fibers in a counterflow. As a result, an intensive air-pulp contact is created.
In a method of de-inking pulp suspensions by means of flotation, in which the air-laden pulp suspension is introduced into a flotation cell, the foam with the impurities forming on the surface of said pulp suspension is removed and purified pulp suspension accept is drawn off, the improvement which comprises supplying the air-laden pulp suspension to the top region of a flotation cell, drawing off a portion of the accept in the form of purified pulp suspension from the bottom region of said flotation cell, and supplying an air-water suspension to said flotation cell in the region above the accept outlet and conducting said air-water suspension in the counterflow to the sinking accept fibers.
Arrangement for de-inking pulp suspensions by means of flotation, in which the air-laden pulp suspension is introduced into a flotation cell, the foam with the impurities forming on the surface of said pulp suspension is removed and purified pulp suspension is drawn off, composed of an annular flotation cell with units assigned to said cell for the drawing off of foam and for aeration, and systems for supplying and removing pulp suspension to said annular flotation cell, wherein
Arrangement for de-inking pulp suspensions by means of flotation, in which the air-laden pulp suspension is introduced into a flotation cell, the foam with the impurities forming on the surface of said pulp suspension is removed and purified pulp suspension is drawn off, composed of an annular flotation cell with units assigned to said cell for the drawing off of foam and for aeration, and systems for supplying and removing pulp suspension to said annular flotation cell, wherein
Arrangement for de-inking pulp suspensions by means of flotation, in which the air-laden pulp suspension is introduced into a flotation cell, the foam with the impurities forming on the surface of said pulp suspension is removed and purified pulp suspension accept is drawn off, comprising two annular cells (2, 3) which are arranged essentially concentrically relative to each other and are separated from each other by a weir (24) which facilitates the overflow of pulp suspensions from said first annular cell (2) into said second annular cell (3), and by connections for introducing air-laden pulp suspension at said first annular cell (2), an accept outlet (25) in the bottom region of said second annular cell (3), at least one connection for supplying an additional air-water suspension above said accept outlet (25) of said second annular cell (3) and a device for drawing off the accumulating dirt-laden foam in the top region of both annular cells (2, 3).
Dependencies are inferred from the claim text.