Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
  • D21B1/00—Fibrous raw materials or their mechanical treatment
  • D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
  • D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam
  • D21B1/30—Defibrating by other means
  • D21B1/34—Kneading or mixing; Pulpers
  • D21B1/345—Pulpers

Definitions

• the invention relates to a pulper for comminution and suspension of pulp according to the preamble of claim 1.
• Pulpers of this type are mainly used to suspend air-dry pulp or waste paper.
• the registered material is intensively mixed in large pieces, webs or pressed bales with water, which is usually a mixing and crushing rotor is used.
• a pulper consists essentially of a container for the suspension and the already mentioned rotor. In many cases, it also contains a sieve in the bottom area, through which the suspension can be pumped.
• the standard type for a pulper is a vertical cylindrical tank with a concentric rotor in the floor area.
• water and the material to be dissolved is added from above and generated with the help of the rotor Trombenströmung in the suspension, ie in the central region of the fabric is sucked down from the rotor and pressed radially outward in the bottom region, resulting in a Umtriebsströmung results.
• the circumferential flow braked as this often brings only a small contribution to the resolution.
• the invention is based on the object to improve the known pulper without significant overhead, possibly in the form of a conversion of an existing pulper, in particular, the collection of the material to be improved.
• the pulper should be able to dissolve faster and / or more economically.
• Figure 1 Schematically a section through a pulper according to the invention, side view;
• FIG. 1 Pulper of Figure 1, top view.
• Figure 3 a variant in side view
• FIG. 4 top view of a flow barrier
• FIG. 5 section through a flow barrier
• FIG. 6 shows another possible form of the flow barrier
• FIG. 7 pulper with double conical bottom
• FIG. 8 A flow barrier inclined in the direction of movement.
• the pulper of Fig. 1 drawn in side elevation is a typical form of the invention.
• the pulp S is fed into a container 1 together with water W.
• a mixture of water and pulp which is already partially crushed.
• This thus provided with coarse and fine solids suspension is displaced by the rotor 2 arranged centrally in the bottom region of the container 1 in drive.
• the rotor is driven by a motor, not shown.
• Essential for this pulper according to the invention is that on the inside of the side wall 5 of the container 1 there is a substantially vertical flow barrier 8. This extends with a maximum radial projection F into the trough, which amounts to at least 6%, preferably at least 15%, of the diameter D1 of the container 1.
• the flow barrier can be formed as a rectangular angle profile which extends perpendicularly from the bottom 7 of the container 1 to above the suspension mirror 9 forming during operation.
• the front 4 of this profile is rounded.
• a flow barrier 8 in the dimensions indicated causes a strong vertical shear component to be generated on its contour which deflects the suspension to the center of the container. This creates a very well-trained intake cone in the center of rotation of the trough, which has a very favorable effect on the collection of registered raw material. In this way, the power consumption of the drive is reduced, often can be set higher fuel density and / or even better resolution can be achieved. This effect can not be compared with that of conventional reinforcing profiles on the inner wall of a pulper whose radial extent amounts to only a few percent of the trough diameter. Their contribution to the dissolution effect of the pulper is small.
• the suspension is thus pulled down by the rotor 2, so that approximately along the center line 3 of the rotor 2, a downward flow is formed.
• the suspension is conveyed radially outwardly at the bottom 7 of the container 1 and thereby reaches its side wall 5. Overall, this results in a circulation flow. It is advantageous if the center line 3 of the rotor 2 is vertical and aligned with the container 1. As is known, in this described dissolution process by hydraulic forces and by contact between the rotor 2 and pulp, the crushing and suspension of the pulp causes.
• Paper pulp pieces which have been sufficiently comminuted may, as shown here, pass through a screen plate 6 into a chamber 10 (e.g., an annular channel) and be discharged as a pulp suspension P.
• a pulper can be operated both continuously and discontinuously.
• the screen plate 6 is not essential.
• the usual consistency, ie the solids content in the suspension P is usually around 2 to 8%, preferably 4 to 7%. It is often possible by the invention, an advantageous increase in the consistency by about 1% in the resolution.
• FIG. 2 shows the pulper of Fig. 1 in top view.
• the holes of the screen plate 6 are not shown. you recognizes that only a single flow ungsbarriere 8 is present with the dimensions already indicated.
• the pulper shown in Fig. 3 differs from that of Fig. 1 essentially in that the flow barrier 8 'is provided with a front side 4 ' , which is inclined relative to the vertical at an angle ⁇ , so that at the bottom 7 of the pulper the radial projection is smaller than in the upper region where the maximum radial projection F is located. This is above the level 11, with which the pulper is operated as intended.
• Another possibility is to give the bottom 7 ' the shape of two concentric truncated cones 12 and 13 (FIG. 7). In this case, the lower truncated cone 12 is flatter than the overlying truncated cone 13th
• the flow barrier 8 ' is provided with a cover 9' which is inclined relative to the horizontal and which lies above the filling level 11, the inclination leading to the outflow of material.
• 5 shows a section through the flow barrier 8 ' on the line V in FIG. 3.
• flow barriers may also be used, e.g. with semicircular or partially elliptical cross sections, as shown by way of example in FIG.
• fig. 8 may also be an inclination of the flow barrier in the circumferential direction, preferably in the direction of rotation of the rotor 2, be advantageous, ie the upper
• An inventive pulper (of the type shown in Fig. 3) may be provided with the following dimensions, for example.
• the rotor 2 has on its moving wings an outer diameter D2 of 1000 mm. He runs close to a flat annular sieve 6, the openings of which he keeps clear of blockages.
• the flow barrier 8 is mounted, in the form of a rectangular angle profile which extends from the bottom 7 to about the upper edge of the container 1 and projects into the container.

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• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Mechanical Engineering (AREA)
• Paper (AREA)

Priority Applications (2)

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Publications (1)

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Citations (4)

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• 2008
  • 2008-01-17 DE DE200820000684 patent/DE202008000684U1/de not_active Expired - Lifetime
  • 2008-12-12 EP EP08870961.3A patent/EP2238291B1/de active Active
  • 2008-12-12 CN CN200880124943.8A patent/CN101910508B/zh active Active
  • 2008-12-12 WO PCT/EP2008/010558 patent/WO2009089878A1/de active Application Filing

Patent Citations (4)

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