EP0598187B1 - Pulper particularly for treating domestic waste - Google Patents

Abstract

The invention relates to a pulper, particularly for pulping domestic waste or paper; having a preferably cylindrical or angular container (2) with a vertical axis; having a rotor (4), which likewise has a vertical axis, arranged in the upper part of the container; having a coarse waste trap (20) which can be moved into the inner space of the container. The invention is characterised by the following features: a trough (10) for receiving the coarse waste trap (20) is connected to the inner space of the container; the coarse waste trap can be moved out of the trough into the inner space of the container by pivoting it about a horizontal axis. <IMAGE>

Description

The invention relates to a pulp pulper according to the preamble of claim 1. Such pulp pulpers are e.g. became known from DE 32 25 026 C2.

The container of such a pulping device generally has the shape of a cylinder, the axis of which is vertical, which has a bottom at the bottom and which is open at the top. The rotor is generally in the bottom area. Its axis of rotation usually coincides with the longitudinal axis of the container, but an eccentric arrangement is also possible. In general, the rotor consists of a flat disc. The shredding blades are arranged in the manner of rotor blades of a centrifugal pump.

During operation, the fibers to be treated, ie to be dissolved, are introduced into the container, for example organic waste, and also a liquid, generally water. Through the work of the rotor, the fibrous materials are torn apart and crushed and mixed with the liquid, so that a suspension is formed. The rotor sets the suspension in a strong flow. This has - seen in an axial section through the pulp dissolver - a toroidal shape, with a radial flow initially forming in the rotor area towards the container wall, which then rises to flow radially inward again in the area of the surface, and from there down to the center of the rotor. This flow pattern is desirable; Because of the downward flow, the solids in suspension repeatedly reach the rotor area, where they are processed.

The processing of fibrous materials, especially household waste and waste paper, brings with it special problems that begin when it is dissolved. The proportion of specifically light impurities, especially plastic and waterproof papers, is particularly unpleasant.

From DE-OS 30 24 485 a device for removing the coarse and heavy waste in paper preparation is known, which has a flat sieve screen extending over the entire width of a container for collecting the coarse and heavy waste, which on a rope of a trolley is arranged. The sieve rake has tines which are arranged in straight sieve bars, the sieve bars running at least approximately parallel at a distance from one another. The sieve is at least partially acted upon by the paper pulp from both sides of the rake, so that the sieving effect of the foreign bodies is extremely time-consuming, since the foreign bodies can only be caught on the tine side of the sieve rack for lifting out, because the foreign bodies must at least temporarily remove the sieve flow through, which delays the flow rate and thus the sieving process due to the resulting resistance. In addition, in the device according to DE-OS 30 24 485 on the one hand foreign bodies can flow through the sieve nicks between the relatively far apart hook-shaped tines, and on the other hand the foreign bodies lay around the sieve bars and hook on the curved tines so that a Unloading the foreign body is difficult and in particular cannot be done without laborious manual work.

From DE-OS 28 18 778 a different type of device for removing coarse and heavy dirt is known, in which rake-like tines are attached to a removal device rotating about a horizontal axis.

In the known fiber dissolvers, the device for fishing out the coarse dirt has particular problems. The known coarse dirt traps are structurally very complex at first. The coarse dirt trap according to DE 32 25 026 C2 has a rake. The tines of this rake point downwards in a first phase; the coarse material loops around the tines. In a second phase, the rake is pivoted about a vertical axis so that the tines point upwards; now the rake with the coarse dirt attached to it can be moved out. A telescopic device is used to drive out. In a third phase, the rake must be swung out of the area of the container. In addition, the rake must be turned again about the horizontal axis mentioned so that the dirt slides off the tines.

It follows from this that the individual cleaning interval takes a relatively long time. The cleaning interval often lasts as long as the dissolving interval.

Another disadvantage is that the radial position of the rake with respect to the vertical axis of the rotor is predetermined once and for all by the design. Instead, radial positioning of the rake, depending on the type of fiber, would be desirable in order to achieve an optimal catching effect. Mechanically, this would only be possible with further effort.

The invention has for its object to design a pulp pulverizer according to the preamble of claim 1 that it is overall simpler and therefore cheaper. This applies particularly to the coarse dirt trap. Above all, this should be designed in such a way that the cleaning intervals become shorter, and that radial positioning is carried out, depending on the needs of practice, without additional design effort can be.

This object is solved by the characterizing features of claim 1.

Accordingly, a trough for receiving the coarse dirt trap is connected to the interior of the container; furthermore, the coarse dirt trap can be moved into the interior of the container from the trough by pivoting about a horizontal axis.

Such a pulp dissolver works as follows: First, the material to be dissolved is introduced into the interior of the container and diluted with water. The rotor starts to run. The coarse dirt trap is in the waiting position outside the interior, namely in the trough.

After the dissolving process, the suspension formed in the interior is drawn off through a sieve. Then the slide between the container and the trough opens. The remaining mass is filled up with dilution water to the immersion depth of the coarse dirt trap. The coarse dirt trap is then swiveled out of the trough into the interior of the container. The rotor continues to run. The coarse dirt loops around the catch elements of the coarse dirt catcher. These catch elements are generally rods or tines. In a further phase, the coarse dirt trap is pivoted in the opposite direction, whereby it emerges from the diluted suspension. The swivel angle is dimensioned such that the coarse dirt trap with the coarse dirt adhering to it is located above the upper edge of the trough.

In a final phase, the coarse dirt is wiped off the coarse dirt catcher, generally by a special wiping device.

The advantages of the embodiment according to the invention are that the coarse dirt trap is constructed much more simply than in the prior art. The pivoting movement can be realized much more easily than the previously described movements of the previously known coarse dirt trap. There is no need to turn the catch elements. This makes the construction cheaper.

Another advantage is that the catch elements of the coarse dirt trap can be brought into any position in the radial direction, e.g. right up to the rotor, where the catch effect is optimal.

Due to the structure described, the coarse dirt trap only covers a short distance. This shortens the cleaning interval considerably.

Another advantage of the coarse dirt trap is that the container - except for the open opening when entering - is completely closed and therefore odor-proof. Odor-tightness is also guaranteed between the container and the trough during the discharge of the coarse dirt, since the flushing water level is above the swivel opening of the coarse dirt collector. With the previously known rake, such a sealing could only be achieved with great technical effort due to the sequence of movements.

Another advantage is that with a corresponding design of the coarse dirt trap and with a corresponding arrangement of the horizontal pivot axis, the removal of the coarse dirt from the catch elements and thus its unloading can take place on two diametrically opposite sides of the pulp dissolver. This means that the coarse dirt can be dumped, for example, on the side on which the pulp dissolver is loaded with waste. This can be advantageous if you are on this side of the pulp breaker there is a ramp that can be used both for driving up fresh waste and for moving away coarse dirt. This is not a problem with the intermittent mode of operation of the pulp dissolver.

The invention is explained in more detail with reference to the drawing. The following is shown in detail:
Figure 1 shows a side view and a schematic representation of an overall system for dissolving household waste. FIGS. 2-5 show 4 different working phases of a fiber pulper according to the invention. Figure 6 shows a top view of the container and trough. It can be seen from FIG. 6, inter alia, that the trough 10 has a rectangular shape when viewed from above. The container 2 is octagonal. This has the following reason: If the entry is household waste, the use of stainless steel is excluded. However, the wetted surfaces must be lined with a material that is resistant to corrosion and wear. Flat surfaces are easier to line than round ones.

The system according to FIG. 1 comprises a pulp dissolver 1 with a container 2, which rests on four columns 3. A rotor 4 in the form of a helix is located in the interior of the container. In the lower part of the container there is a cylindrical screen plate. On the outer circumference of the opening screw (not shown here) of the rotor (see FIG. 5) there are clearing elements 6 which are firmly connected to the rotor 3 and rotate with it. They keep the sieve plate 5 free from blockage when pumping out the suspension.

A trough 10 is assigned to the pulp dissolver 1. As can be seen, the outer wall of the trough 10 is designed as a quarter circle. Seen from above, the trough forms a rectangle - see FIG. 5. The trough 10 is conductively connected to the interior of the container 2.

A coarse dirt trap 20 is pivotally mounted in the upper part of the pulp dissolver 1. Accordingly, it can perform a circular arc movement according to arrow 21. The coarse dirt trap 20 includes i.a. a catcher 22 with prongs 23.

In the lower part of the bottom of the container there is a heavy dirt sluice 7 radially outside the cylindrical sieve 5 and a discharge 8 for the suspension from the space inside the cylindrical sieve 5.

The system also has a ramp 30. This is used to drive up fresh household waste. However, it can also be used to remove coarse dirt. For this purpose, the coarse dirt catcher 20 has to be pivoted through 270 ° from its position shown, so that the prongs 23 of the catcher 22 point towards the ramp 30.

A precomminution device 9 is connected upstream of the pulp pulverizer 1, which is only indicated schematically here.

FIG. 2 shows the phase of dissolving in the case of a fiber pulper according to the invention. Garbage was introduced into the container 2 from above, water was added, and the rotor 4 was put into circulation. The resulting suspension has a consistency of, for example, 7-10%. During the dissolving process, the coarse dirt trap 20 is in the waiting position in the trough 10. The slider 24 located between these two is closed. The trough is connected to a dilution water line 25. The dilution water supplied here can be return water, which accumulates at some point in the course of the process.

In the phase shown in Figure 3, a large part of the Gutstoffes from the screen plate 5 enclosed space through a line 5.1. The heavy dirt accumulated was also drawn off through the lock 7. Slider 24 is in the open position. The coarse dirt trap 20 is pivoted from the trough space into the container interior, in such a way that the prongs 23 of the catcher 22 are vertical and point downward, and that the catcher 22 is very close to the sieve plate 4. Dilution water flows from the trough 10 into the interior of the container and ensures that a minimum amount remains in this interior. The rotor 4 continues to rotate, so that the light impurities loop around the prongs 23 of the catcher 22.

In Figure 4 it can be seen that the coarse dirt trap 20 has been pivoted out of the interior of the container 2 and also out of the trough 10. The rake is now located above the lower edge of the trough 10. The catcher 22 moves past the nozzles of the dilution water line 25 when pivoting out. Splash water can be added to rinse off the fibrous materials adhering to the coarse dirt.

Figure 5 shows the phase in which the coarse dirt is released by the rake. A scraper device 27 is provided which can be actuated by a lifting cylinder unit in order to scrape off the coarse dirt from the prongs 23 of the catcher 22. It falls into a drip pan 28.

The operation is shown intermittently here. However, continuous operation is also possible.

As you can see, the rotor 4 is overhung. The storage shown here, which is located above, has proven to be particularly advantageous. The rotor 4 thus dips into the interior of the container 2 from above.

The further use of the suspension freed from heavy dirt and coarse dirt is not the subject of this invention. As is known, there are numerous systems for this. For example, the biomass obtained can be thickened and fed to a digester. It can also be deposited as a rotte heap. Finally, anaerobic digestion can be used to obtain biogas.

Claims (7)

1. Fibre dissolver, in particular for dissolving waste or paper, comprising

   1.1 a preferably cylindical or cornered container (2) with vertical axis;

   1.2 a rotor (4), which is arranged in the upper portion of the container and which also has a vertical axis;

   1.3 a device for gathering coarse dirt (20), which is driven into the container (2);
   characterized by the following features:

   1.4 a trough (5) for receiving the device for gathering coarse dirt (20) is connected to the interior space of the container (2);

   1.5 the device for gathering coarse dirt (20) is driven from the trough (10) into the interior space of the container (2) by being pivoted around a horizontal axis.
2. A fibre dissolver according to Claim 1, characterized in that the interior space of the container (2) can be shut off from the trough (10).
3. A fibre dissolver according to one of Claims 1 or 2, characterized in that the bottom of the trough (10) is arcshaped, as seen in a vertical cross-section, and that the trough (10) has a rectangular contour, as seen in a horizontal cross-section.
4. A fibre dissolver according to one of Claims 1-3, characterized in that the device for catching coarse dirt (20) comprises a catcher (22) the prongs (23) of which are, whilst positioned inside the container (2), essentially vertical and oriented downwards.
5. A fibre dissolver according to one of Claims 1-4, characterized in that the device for catching coarse dirt (20) is pivotal by at least virtually 270°.
6. A fibre dissolver according to one of Claims 1-5, characterized in that the fibre dissolver (20) is associated with a scraper (27) for scraping off the coarse dirt.
7. A fibre dissolver according to one of Claims 1-6, characterized in that the rotor (4) is suspended in a flying position in the upper area of the interior of the container or above the container (2).

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