Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROOUND OF THE INVENTION
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The present invention relates to a new and
improved construction of a stock pulper installation having
a stock pulper for pulping and sorting waste paper.
The stock pulper installation of the invention is
of the type wherein the stock pulper comprises a container
for receiving a stock suspension which has been pretreated
in a pulper or stock slusher. In the container a rotor is
movable along a sieve or screen behind which there is located
an outlet for good stock. The stock pulper has an outlet
opening for light contaminants, also referred to as light
weight contaminants or impurities, which are to be separated
and an outlet opening for heavy contaminants, also referred
to as heavy weight contaminants or impurities, which are to
be separated.
A stock pulper of this type is disclosed, by way
of example, in the commonly assigned, United States Patent
3,942,728, granted March 9, 1976. With state-of-the-art
stock pulpers there was connected, as a general rule, at the
outlet for the heavy contaminants to be separated a sluice
which had to be periodically opened.
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It has been found that in the presence of a -~
great deal of heavy contaminants, or also for operational --
reasons, the withdrawal o~ the heavy contaminants from the
related outlet opening can be accomplished continuously, or,
in the case of automatically arising, regular interruptions
periodically.
Therefore, for this purpose there has been
proposed according to United States Patent No. 4,017,033,
granted April 12, 1977 and corresponding to West German , -
Patent Publication No. 2,514,162, connecting a hydrodyclone -
with the outlet opening for the heavy contaminants and in
which there are separated the heavy contaminants, whereas
the stock suspension freea of the contaminants is fed back
again into the installation for the processing of the waste
paper. With this prior art installation however there i5
present the drawback that, in order to ensure for a somewhat
successful operation of the hydrocyclone, the stock pulper
must be operated at an extremely high pressure, something
disadvantageous not only for reasons of energy consumption.
On the other hand, if there is arranged a pump between the
stock pulper and the hydrocyclone then this pump is exposed
to pronounced wear due to the heavy particles which are
separated.
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SU~$~RY OF THE INVENTION
Therefore, with the foregoing in mind it is a
primary object of the present invention to provide an im-
proved construction of stock pulper installation which is
not associated with the aforementioned drawbacks and limit-
ations of the prior art proposals.
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Another and more specific object of the present
invention aims at the provision of a new and improved con-
struction of stock pulper installation which overcomes the
aforementioned shortcomings and wherein there is possible a
faultless separation of the heavy contaminants effluxing
from the stock pulper independent of the pressure conditions
prevailing in the stock pulper.
- The apparatus of the present invention which
allows achieving these objectives is manifested by the features
that, a separation device for separating the heavy contamin-
ants is connected with the outlet opening for the heavy
contaminants, this separation device containing a motor driven
rotor for producing a centrifugal action or effect.
With such type separation device the motor driven
rotor generates the turbulent movement or vortex flow leading
to the formation of the requisite centrifugal action,without
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any dependency upon the pressure prevailing in the stock
pulper and independent of the flo~ velocity of the liquid
or suspension flowing from the stock pulper to the separation
device. Additionally, the centrifugal action is also ex-
tensively independent of the density of the stock suspension
effluxing from the outlet opening for the heavy contaminants.
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Preferably, the rotor of the separation device
can be simultaneously structured in the manner of a pump
impeller and is suitable for conveying the stock suspension
out of the separation device. Such type separation device
has been disclosed, by way of example, in British Patent
No. 1,465,888. Due to such type design of the separation
device there is augmented the flow of the stock suspension
out of the separation device, so that in a great many in-
stances there is not required any special pump for further
conveying.
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The outlet of the separation device or separator
can be connected with the inlet line or conduit of the stock
pulper. In this way there is realized a particularly simple
construction of the inventive stock pulper installation.
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sRIEF DESCRIPTION OF THE DRA~ING
The invention will be better understood and objects
other than those set forth.above, will become apparent when `
consideration is given to the following detailed description ;-
thereof. Such description makes reference to the annexed
drawing wherein the single Figure schematically illustrates .
an exemplary embodiment of inventive stock pulper installation
forming part of an installation for processing waste paper.
DETAILED DESCRIPTION OF THE PREFERRED EM~30DIMENTS
Describing nQW the drawing, the stock pulper in-
stallation shown by way of example therein, will be seen to
comprise a stock pulper 1 which, as already mentioned, can be
designed in the manner as taught in the aforementioned commonly
assigned, United States Patent No. 3,942,728, granted March 9,
1976. This stock pulper 1 embodies a container 2 to which
there is delivered a stock suspension, which has been pre ;.
treated in a conventional stock slusher or pulper 3, by ;~
means of an inlet line 4 equipped with a pump 5. The inlet
line or conduit 4 leads to a tangential inlet opening 6 of
the container 2. Within the container 2 th.ere is rotatably
o~ ~Df~ b/8
~, mounted a rotor 7 to be movable~along a sieve or screen 8 in
the form of a perforated plate. This sieve or screen 8 bounds
or delimits, in relation to the remainder of the container 2,
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a withdrawal chamb.er or space 10 for good stock. from which
there can be removed the good stock hy means of an outlet
opening 11 for further use, for instance for fabricating
new paper. The rotor 7 is attached to a shaft 12 which is
rotatably mounte~ in a bearing housing 13 and equipped with
a belt pulley 14 or equivalent structure serving for driving .
the rotor 7 by means of any suitable and therefore not par-
ticularly illustrated drîve motor.
As also seen by referring to the drawing, th.e
container or housing 2 of the stock pulper 1 is provided
with an outlet opening 15 for light contaminants and with an ;
outlet opening 17 for heavy contaminants, the outlet opening
17 being located at the circumference or periphery of the :
container 2. As to further details of this structure refer~
ence may be had to the aforementioned United States Patent ~`
No. 3,942,728, granted March 9, 1976. However, it should be
understood that the stock pulper 1 need not he exclusively
designed in the illustrated manner. Thus, for instance, it
can be arranged so as to have its axis vertical, and the ~'
outlet opening 15 need not be located in the container or
housing 2 opposite the rotor 7. According to a proposed con-
struction of the stock pulper the outlet opening can be
formed by a hollow shaft of the rotor 7.
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AS taught by the invention there is connected
with the stock pulper 1, by means of a short connection line
or conduit 18, a separation device or separator 20 for
separating the heavy contaminants from the infed stock
suspension, these heavy contaminants being passed through
the connection line or conduit 18. This separation device
or separator 20 contains a vertically arranged housing 21 in
the form of a body of revolution in which there is rotatably
arranged a rotor 22. The lower end of the housing 21 is of
substantially conical configuration having a downwardly direc-
ted conical or cone tip and is equipped with a sluice 23 or
equivalent structure for removing the separated heavy con-
taminants. The rotor 22 has a shaft 24 rotatably mounted in
the housing 21 and at which there is attached a drive belt
pulley 25. Part of the shaft 24 of the rotor 22 is designed
~as a hollow shaft 24'' whose hollow shaft channel 24a leads
out of the internal space 21a of the housing 21 into an out- `
let chamber or compartment 26, and the exit portion or
opening 24' of the hollow shaft 24'' is radially outwardly
directed into the chamber 26, as shown.
Such type separation device is known from the
aforementioned British Patent No. 1,465,888 to which like-
wise reference can be specifically made for further details.
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From the outlet chamber 26 of the separation
device 2Q there leads back into the inlet line or conduit
4 a return flow line or conduit 27 equipped with a pump
28 and a valve 30 or equivalent structure.
During operation bales B of waste paper are
introduced into the stock slusher or pulper 3, which, while
: infeeding water, as generally indicated by the arrow W, are
slushed and dissolved therein. The thus formed stock sus-
pension is fed by means of the inlet line or conduit 4 into
the stock pulper 1. The good stock which is contained there-
in is then withdrawn for further use by means of the outlet
opening 11. Light contaminants are withdrawn in known manner
: through the outlet opening 15.
The heavy contaminants which have been caught at
the region of the outlet opening 17 by a pocket formed in :.
conventional manner at the stock pulper 1 arrive by means
of the connection line or conduit 18 at the separation device
20. If desired, the dilution water for thinning the stock
suspension carrying the heavy contaminants can be introduced
by means of a water line or conduit 31.
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An intensive turbulence or vortex flow is formed
within the separation device 20 by the rotation of the rotor
22, which turbulence is independent of the flow velocity of
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the stock suspension through the connection line or conduit
18. Since this flow velocity does not play any role, it is
possible for the container 2 of the stock pulper 1 to be
operated at a low pressure, so that not only is the container
itself relievedof any appreciable pressure load, but also
all of its seals and so forth.
In the separation device 20 the heavy contaminants
are separated from the stock suspension, without coming
into contact with the rotor 22. Specifically, these heavy
contaminants are immediately acted upon, after their entry
into the container 21, by the turbulent flow and moved along
the inner wall of the container 21 to its lower region and
then into the sluice 23. The stock suspension or liquid
thus freed of the heavy constituents or particles then arrives
back at the inlet line or conduit 4 by means of the return
flow line or conduit 27. In many cases, owing to the pumping
action of the radially outwardly directed end of the opening
24' of the hollow shaft 24'', it is possible to omit the
arrangement of the pump 28, since the pumping action gener-
ated by the hollow shaft is sufficient for conveying purposes.
It should be understood that the inlet opening
and the outlet opening of the separation device 20 can be
arranged tangentially with respect to the housing 21, some-
thing which has only been schematically indicated in the
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drawing to preserve clarity and simplification of the
illustration. As a result, the iflow of the stock:suspension
or liquid in the housing and out of such housing can be
augmented.
It also should be understood that as the separa-
tion device 20 it is not absolutely necessary to use the
aforementioned equipment as disclosed in the previously
cited British Patent No. 1,465,888, and which has been shown -
in the drawing. Thus, in place of this device, whenever
there can be accepted a less favorable mode of operation,
there also can be used another known separation device having
a rotor by means of which the good stock is not withdrawn , .
through a hollow shaft of the rotor.
