DE1031625B - Method and device for the continuous washing of pulped pulp fibers - Google Patents

Description

GERMAN

There are methods and devices for the continuous washing of pulped pulp fibers in an upright position, e.g. B. known cylindrical vessel with conveying means, the pulp fibers and the detergent is passed through the vessel in countercurrent. Here is, in particular by counter-rotating screws, the lye is squeezed out of the material, so that there is already an extensive Leaching of the mixture results. Then the material is then additionally through out a wash column. However, there is a great risk that solid stoppers or plugs will become solid that can only be loosened up in the further processing step. By such a However, the formation of plugs or nests in the material inevitably results in creepage distances and thus disadvantageous Bypass routes of the washing liquid. The detergent can therefore only insufficiently with what is to be washed Come into contact with the material.

These disadvantages are in accordance with the invention in a simple and advanced manner in the new process thereby avoided that the pulp fibers with the waste liquor in the lower part of the tower-like vessel washed in and by a known per se which can be regulated with regard to its rotational speed helical conveying means are promoted to the tower head; the pulp fibers are then added during their transport through the vessel by means of known fixed, adjustable, rotatable or pendular hold-up arranged in the interior of the vessel loosened and circulated.

The new method therefore now ensures that any nests or such as plug formations occurring in particular in the base of the tower, as well as mechanical impairments the fibers are definitely avoided by squeezing them out. Furthermore, the adjustable screw-like conveyors allow the process to meet the respective operating requirements quickly and easily Way to be customized. In addition, the pulp fibers are not only fed in countercurrent through the Detergent transported through from the lower part of the tower-like vessel to its head part, but this also ensures that the pulp fibers are loosened during their transport and as far as possible also be circulated.

A known single-leg diffusion tower is used as the device used to carry out the method used. In these, the pulp fibers mixed with mother liquor are transferred to the lower part of the Tower flooded, z. B. pumped in, and in countercurrent, d. H. So from the top of the tower, fresh water fed. Inside the tower is how to proceed and apparatus

for continuous washing

of pulped pulp fibers

Applicant:

Brunswick

Mechanical engineering institute A. G.,

Braunschweig, Bahnhofstr. 5

Willy Kaether, Braunschweig-Melverode,
and Franz Mushack, Wolfenbüttel,
have been named as inventors

known to be a funding, z. B. a screw conveyor, arranged whose speed of rotation, is preferably adjustable from 0.5 to 6 revolutions per minute. This creates the pulp fiber-lye mixture conveyed steadily from bottom to top through the tower, taking into account the action of the Exposed to fresh water. The higher the pulp fibers migrate up in the tower, the more more they are freed from the mother liquor and come up on their wandering through the tower in contact with ever cleaner fresh water. By coordinating the revolutions of the Funding and appropriate addition of fresh water can be achieved in a relatively simple manner that the pulp fibers are practically completely free of mother liquor when they reach the top of the tower so that post-treatment with heat is no longer necessary. A new one can always be found in the base of the tower Mother liquor - pulp fiber mixture fed and practically pure pulp fibers can also steadily be discharged at the tower head.

The idea of the invention also results in a considerable increase in performance the known methods and a lower consumption of fresh water. The mixture of fresh water and lye is discharged by pumping in the tower flow. Inside the tower, as is well known, additional so-called hold-open plates are fixed, adjustable, rotatable or pendulum, each lie between two screw flights of the screw conveyor. This, as well as the adjustable speed of rotation the conveying means an additional loosening of the material to be treated is achieved and the promotion of the same through the tower

809 529/275

and thus also supports the washing process.

In order to enable further adaptation to the respective operating conditions, the slope the screw conveyor can be regulated from the outside and, in particular, can be adjusted flat.

The drawing shows an embodiment in a schematic representation of a longitudinal section through a single column tower for washing pulp fibers.

In the interior of the cylindrical single column tower α a screw conveyor b is arranged on the shaft c . The speed of rotation of this screw b is adjustable. The pulp fibers still mixed with the mother liquor are washed into the conical tower base d by means of a pump e . They then reach the screw b and are conveyed through the tower against the fresh water introduced at point g of the tower head. The washed cellulose fibers are discharged from the tower at point h of the tower head, while the water enriched with the mother liquor is drained off in the tower foot. At several points of the tower a , hold-openers i are provided between each two turns of the screw b.

Claims (4)

Patent claims: 1. Process for the continuous washing of pulped pulp fibers in an upright position standing, z. B. cylindrical vessel with conveying means, the pulp fibers and the detergent are passed through the vessel in countercurrent, characterized in that the cellulose fibers washed in with the waste liquor in the lower part of the tower-like vessel and through a screw-like, known per se, which can be regulated with regard to its rotational speeds Funds are promoted to the tower head and the pulp fibers during their transport through the vessel by means of known, fixed, adjustable, rotatable or oscillating, The retainer arranged in the interior of the vessel is loosened and circulated. 2. The method according to claim 1, characterized in that the waste liquor-fiber mixture means a controllable pump is washed into the lower part of the vessel. 3. Apparatus for performing the method according to claim 1 and 2, characterized in that a single column tower (σ) known design with inside arranged screw conveyor (b) is used that the speed of rotation of the screw conveyor (b), preferably from 0.5 to 6 revolutions per minute, is adjustable and that inside the tower (α) one or more known fixed or adjustable or rotatable or oscillating hold-ups (i) are arranged between each two screw flights of the screw conveyor (b) . 4. Apparatus according to claim 3, characterized in that the pitch of the screw conveyor (b) is adjustable from the outside. Λ Considered publications:
German Patent No. 515,961;
German patent application P 88 IVb / 55b;
Austrian Patent No. 93 639;
Swedish Patent No. 136 886. 1 sheet of drawings © 809 528/275 5.58