Note: Descriptions are shown in the official language in which they were submitted.
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SPECIFICATION
TITLE OF THE INVENTION
SCREEN APPARATUS
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001]
The present invention relates to a screen apparatus for
refining a paper-making material by feeding it outward of the
screen from the inside thereof , and more particularly to a
screen apparatus whose capacity for separating foreign matter
f rom f ibers in the paper-making material that are acceptable
in the quality has been enhanced.
2. Description of Related Art
[0002]
Conventionally, in a so-called "outward type" screen
apparatus (centrifugal type) which refines, for example,
paper-making material by feeding it outward of the screen from
the inside thereof, a paper-making material loaded within the
screen is agitated by means of an agitating member provided on
the screen, and then foreign matter in the paper-making
material is removed through the screen so as to refine the
paper-making material (see, for example, patent document 1).
Patent document 1: Japanese Patent Application Laid-Open
No.2004-137621 (FIG. 1)
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[0003]
However, in such a "screen apparatus having a cylindrical
screen whose end portions are both open" , no component exists
for obstructing the flow of the paper-making material
downstream from an end portion at which the screen is open, and
thus the paper-making material is discharged out of the casing.
Accordingly, from the viewpoint of enhancing efficiency in
separation on the part of the screen there has been room for
improvements.
SUMMARY OF THE INVENTION
[0004]
The present invention sets out to provide a screen
apparatus which eliminates the problem described above.
[0005]
To achieve the above object,a first aspect of the present
invention provides a screen apparatus comprising :a sealed
casing having a paper-making material supply port, a refined
paper-making material discharge port positioned above the
paper-making material supply port and a foreign matter
discharge port positioned above the refined paper-making
material discharge port;a screen for dividing the interior of
the sealed casing into a first chamber and a second chamber and
for separating foreign matter existing in the paper-making
material, the screen being of a cylindrical shape and with end
portions that are both open, the screen having circular holes
or slit-like openings on a side face thereof and stood within
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the sealed casing in such a way that a direction of height
thereof faces a vertical direction, both open end portions of
the screen having an upper opening portion and a lower opening
portion with the upper opening portion positioned below the
foreign matter discharge port and the lower opening portion
positioned above the paper-making material supply port;a
paper-making material supply passage connected to the
paper-making material supply port in order to supply
paper-making material to a first chamber from a downward
direction;a rotor disposed inside the screen within the first
chamber and having an agitating member for agitating the
paper-making material within the sealed casing; a refined
paper-making material discharge passage connected to the
refined paper-making material discharge port and also
connected to the second chamber so as to guide paper-making
material that has been refined out of the sealed casing via the
screen;a foreign matter discharge passage connected to the
foreign matter discharge port and also connected to the first
chamber so as to guide out of the sealed casing foreign matter
existing in the paper-making material and which does not pass
through the screen; and a water supply passage mounted onto the
sealed casing so that a water spouting port opposes the top end
face of the rotor.
[0006]
According to a second aspect of the invention , in the
first aspect , a ring portion provided at a midway position on
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the screen, the screen being divided by the ring portion into
an upstream screen portion and a downstream screen portion,
the ring portion being provided with a diluted water
introduction port for introducing diluted water into the first
chamber; a diluted water passage provided via the sealed
casing and connected to the diluted water introduction port;
and an uneven portion provided on a side opposing a rotor of the
ring portion, wherein a convex portion of the uneven portion is
provided so as to project from an inside wall face of the screen,
and the uneven portion has a front end portion of the convex
portion and a rear end portion of the convex portion that
relative to a vertical direction of the casing is positioned
lower than the front end portion of the convex portion, and
which front end portion is tilted in such a way that relative to
a rotational direction of the rotor the front end portion of
the convex portion is nearer the rear end portion of the convex
portion.
[0007]
According to a third aspect of the invention in the first
aspect , a ring portion provided at a midway position on the
screen, the screen being divided by the ring portion into an
upstream screen portion and a downstream side screen portion,
the ring portion being provided with a diluted water
introduction port for introducing diluted water into the first
chamber; a diluted water passage provided via the sealed
casing and connected to a diluted water introduction port; and
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an uneven portion provided on a side opposing a rotor of the
ring portion,wherein a convex portion of the uneven portion is
provided not to project from an inside wall face of the screen
and the uneven portion has a front end portion of the convex
portion and a rear end portion of the convex portion that
relative to a vertical direction of the casing is positioned
lower than the front end portion of the convex portion, and
which front end portion is tilted in such a way that relative to
a rotational direction of the rotor the front end portion of
the convex portion is located nearer than the rear end portion
of the convex portion.
[000s]
Because the screen apparatus of the first aspect includes
a water supply passage that is mounted on the sealed casing in
such a way that a water spouting port opposes the top end face
of the rotor, water colliding with the top end f ace of the rotor
flows in a substantially horizontal direction, thereby
hampering the flow of a paper-making material processing
toward the refined paper-making material discharge port from
the opening portion at the top of the screen. In other words,
this action forces back upstream of the first chamber fibers,
which were flowing out to the foreign matter discharge port by
reject sealing, thereby enhancing the capacity of the screen
apparatus for separating foreign matter from fibers of an
acceptable quality contained in the paper-making material.
[0009]
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In the screen apparatus of the second aspect, in addition
to the effects of the invention of the first aspect, diluted
water from the diluted water introduction port acts to hamper
the flow of a paper-making material flowing downstream,
thereby enhancing the capacity of the screen apparatus for
separating f oreign matterfrom fibers of an acceptable quality
contained in the paper-making material. Further, the
paper-making material passes through the screen upstream and a
paper-making material whose density has been intensified is
diluted with diluted water so as to enhance the capacity of the
screen apparatus for separating fibers of an acceptable
quality. Further, the convex portion of an uneven portion
provided on the side facing the rotor of the ring portion is
tilted in such a way that relative to the rotational direction
of the rotor a front end portion of the convex portion is
positioned closer than the rear end portion of the convex
portion. Consequently, pieces in the paper-making material
that have not yet melted and that collide with the convex
portion are not only separated but also brought back upstream
of the paper-making material, thereby further enhancing the
capacity of the screen apparatus for separating foreign matter
from fibers of an acceptable quality that are contained in the
paper-making material.
[0010]
In the screen apparatus of the third aspect, in addition
to the effects of the invention of the first aspect, diluted
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water from the diluted water introduction port acts to hamper
the flow of a paper-making material flowing downstream,
thereby enhancing the capacity of the screen apparatus for
separating foreign matter f rom f ibers of an acceptable quality
that are contained in paper-making material. Further, the
paper-making material passes through the screen upstream and a
paper-making material whose density has been intensified is
diluted with diluted water so as to enhance the capacity of the
screen apparatus for separating fibers of an acceptable
quality. Further, the convex portion of the uneven portion
provided on the side facing the rotor of the ring portion is
tilted in such a way that relative to the rotational direction
of the rotor a front end portion of the convex portion is
positioned closer than the rear end portion of the convex
portion. Consequently, pieces in the paper-making material
that have not yet melted and that collide with the convex
portion are not only separated but also brought back upstream
of the paper-making material, thereby further enhancing the
capacity of the screen apparatus for separating foreign matter
from fibers of an acceptable quality that are contained in the
paper-making material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019]
FIG. 1 is a schematic sectional view of a screen apparatus
according to an embodiment of the present invention;
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FIG. 2 is a schematic sectional view taken along the line
2-2 of FIG. 1;
FIG. 3 is a schematic view of a screen in the vicinity of a
ring portion as seen from the inside of the screen;
FIG. 4 is a schematic partially enlarged sectional view
showing part of FIG. 1 in enlargement;
FIG. 5 is a schematic sectional view taken along the line
5-5 of FIG. 4;
FIG. 6 is a schematic sectional view of a screen apparatus
according to another embodiment different from FIG. 1;
FIG. 7 is a schematic plan view of a rotor of FIG. 6;
FIG. 8 is a schematic partially enlarged sectional view
showing part of FIG. 6 in an enlarged form;
FIG. 9 is a schematic partial sectional view of a screen
apparatus according to another embodiment that is different
from FIG. 8;
FIG. 10 is a schematic partial sectional view of a screen
apparatus according to another embodiment that is different
from FIG. 5;
FIG. 11 is a schematic partial sectional view of a screen
apparatus according to another embodiment that is different
from FIG. 4; and
FIG. 12 (a) is a schematic sectional view taken along the
line 12-12 of FIG. 11, and FIG. 2(b) is a view of a ring portion
of FIG. 12 (a) as seen from the inside of the screen.
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011]
An embodiment of the screen apparatus of the present
invention will be described with reference to the accompanying
drawings.
With reference to FIGS. 1-5, symbol S denotes a screen
apparatus that has a sealed-type casing 1 including a
paper-making material supply port la, a refined paper-making
material discharge port lb located above the paper-making
material supply port la, a foreign matter discharge port lc
located above this refined paper-making material discharge
port lb and a heavy foreign matter discharge port ld.
This screen apparatus S is a so-called "outward type"
screen apparatus (centrifugal type) which refines a
paper-making material by feeding it outward from inside of the
screen 2 in order to remove foreign matter (for example,
plastics) contained in the paper-making material (for example,
old newspapers and old corrugated board).
[0012]
The interior of the sealed-type casing 1 is divided by a
screen 2 into a first chamber lA and a second chamber 1B.
This screen 2 is intended to separate foreign matter in
the paper-making material. The screen 2 is of a cylindrical
shape, its end portions are both open, its side face has
circular holes or slit-like opening portions and it is stood
within the sealed casing 1 in such a way that the direction of
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its height faces a vertical direction. Both open end portions
of the screen 2 include an upper opening portion 2A and a lower
opening portion 2B. As shown in FIG. 1, the upper opening
portion 2A is located below the foreign matter discharge port
lc and the lower opening portion 2B is located above the
paper-making material supply port la.
Symbol R shown in FIGS. 1-5 denotes a ring portion
provided midway on the screen 2, the screen 2 is divided into an
upstream screen portion 21 and a downstream screen portion 22
by this ring portion R and the ring portion R has diluted water
introduction ports R1 (for example, a plurality of) for
purposes of introducing diluted water into thefirst chamber
1A.
Reference numeral 20 denotes a diluted water passage for
introducing diluted water, a passage which is connected with
the diluted water introduction port R1 and is provided via the
sealed casing 1. A face of the ring portion R that faces the
rotor 7 includes convex portions RT that project from the face
of the screen 2 and concave portions RO (see FIGS. 3, 5).
[0013]
A convex portion RT provided on a side facing the rotor 7
of the ring portion R in such a way that it projects from the
face of the screen 2 has a front end portion X of the convex
portion and a rear end portion Y of the convex portion that is
positioned at a lower position relative to the vertical
direction than the front end portion X of the convex portion,
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and that is tilted in such a way that relative to the rotational
direction of the rotor 7 (see the direction of an arrow in FIG.
3) the front end portion X of the convex portion is positioned
closer than the rear end portion Y of the convex portion. The
inclination angle is, for example, 3 and 45 .
As a result, pieces contained in a paper-making material
that have not yet melted and that collide with the convex
portion RT are not only separated but are also made to return
upstream of the paper-making material, and in consequence the
effect of separation between foreign matter and acceptable
fibers in the paper-making material.
The aforementioned convex portion RT and a concave
portion RO could also be described as an uneven face provided
on a side facing the rotor 7 of the ring portion R. The convex
portion RT of this uneven face is provided to project from the
inner wall face of the screen 2 and has the front end portion X
and a rear end portion Y that is positioned lower than the front
end portion relative to the vertical direction of the casing 1.
The convex portion RT is tilted in such a way that relative to
the rotational direction (see the direction of arrow in FIG. 3)
of the rotor 7 the front end portion of the convex portion RT is
located nearer the rear end portion Y of the convex portion RT.
[0014]
Reference numeral 3 in FIG. 1 denotes a paper-making
material supply passage which is connected to the paper-making
material supply port la in order to supply a paper-making
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material to the first chamber 1A from a downward direction.
Reference numeral 4 denotes a refined paper-making material
discharge passage connected to the refined paper-making
material discharge port lb in order to guide the refined
paper-making material outside the sealed casing 1 via the
screen 2. Reference numeral 5 denotes a foreign matter
discharge passage that is connected to the first chamber 1A and
that is also connected to the heavy foreign matter discharge
port lc in order to guide foreign matter (for example,
relatively light foreign matter) existing in the paper-making
material and which does not pass through the screen 2 outside
the sealed casing. Reference numeral 6 denotes a heavy foreign
matter discharge passage that is connected with the first
chamber 1A and that is also connected to the heavy foreign
matter discharge port ld in order to guide relatively heavy
foreign matter existing in the paper-making material and which
does not pass through the screen 2 outside the sealed casing 1.
[0015]
Reference numeral 7 denotes a rotor, which is disposed
inside the screen 2 within the first chamber 1A and has on its
outer periphery an agitating member 7a for agitating the
paper-making material in the sealed casing 1. The rotor 7 has
an upstream portion 70 on the upstream side and a downstream
portion 71 on the downstream side and agitating members 7a
provided on the outer peripheries of the upstream portion 70
and of the downstream portion 71 are tilted. The tilt is set in
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such a way that a bottom portion 7A of a substantially linear
portion of the agitating member 7a advances more in the
rotational direction of the rotor 7 than a top portion 7B. A
rotation from the motor is transmitted via a belt 8 and a
rotating shaft 9 so as to rotate the rotor 7.
Reference numeral 10 in FIG. 1 denotes a water supply
passage provided on the sealed casing 1 in such a way that a
water spouting port l0a opposes a top end face 7T (more
preferably, in such a away that the water spouting port l0a
opposes the center of the top end face 7T of the rotor 7).
[0016]
Thus, when a paper-making material is supplied into the
sealed casing 1 from the paper-making material supply passage
3 and a rotation of a motor (not shown) is transmitted through
the belt 8 and the rotating shaft 9 so at to rotate the rotor 7,
foreign matter in the paper-making material cannot pass
through the screen 2 and is deposited within the first chamber
1A. The paper-making material which passes through the screen
2 is guided into the sealed casing 1 through the second chamber
1B and the refined paper-making material discharge passage 4.
The flow of paper-making material proceeding downstream
is hampered by diluted water supplied from the diluted water
introduction port Rl midway on the screen 2, thereby enhancing
the capacity of the screen apparatus for separating foreign
matter in the paper-making material from fibers of an
acceptable quality. Further, paper-making material passes
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through the screen 2 upstream so that paper-making material
whose density has been intensified is diluted by diluted water
so as to intensify the effects of separating fibers of an
acceptable quality. Further, pieces that have not yet melted
and that are contained in the paper-making material collide
with the convex portions RT provided on the side facing the
rotor 7 of the ring portion R are forced back upstream of the
paper-making material, thus enhancing the effects of
separating foreign matter from fibers of an acceptable quality
in the paper-making material.
Because the water spouting port l0a of the first water
supply passage 10 provided on the sealed casing 1 opposes the
top end face 7T of the rotor 7 downstream of the screen 2 within
the f irst chamber 1A, water colliding with the center of the
top end face 7T of the rotor 7 flows in a substantially
horizontal direction so as to hamper the flow of the
paper-making material proceeding toward the foreign matter
discharge port lc from the opening portion 2A above the screen
2. In other words, this action forces back upstream of the
first chamber 1A fibers, which were flowing out to the foreign
matter discharge port lcby reject sealing, thereby enhancing
the capacity of the screen apparatus for separating foreign
matter from fibers of an acceptable quality in the
paper-making material.
The foreign matter discharge passage 5 and the heavy
foreign matter discharge passage 6 are appropriately adjusted
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in degrees of opening, or are opened or closed, by valves (not
shown) for opening and closing the passages so as to guide
foreign matter deposited within the first chamber 1A out of the
sealed casing 1.
[0017]
Although according to the above-described embodiment, an
end portion of the lower portion 7A of the agitating member 7a
on the downstream side is extended up to a position opposing
the diluted water introduction port R1 (see FIG. 1), the
present invention need not restricted and, as shown in FIG. 6,
it is permissible to eliminate the portion of the agitating
member 7a that opposes the diluted water introduction port Ri.
Although the top end face 7T of the rotor 7 is formed on a
flat surface (see FIG. 1), the present invention need not be
restricted to this example, and it is permissible to provide
projections (scraping blades ) 7 Z, as shown in FIGS. 6-8, and
change the flow direction of water from the water spouting port
l0a to a horizontal direction with the use of centrifugal force
by the projections (scraping blades) 7Z, thereby intensifying
the effects of reject sealing described above. Further, the
arrow shown in FIG. 7 indicates the rotational direction of the
rotor 7.
It is permissible to provide a guide G for guiding water
from the water spouting port l0a around the water spouting port
10a so as to guide water from the water spouting port l0a to the
vicinity of the projections (scraping blades) 7Z so that the
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face of the guide G opposes the top end face 7T of the rotor 7.
Although an opening width W in the circumferential
direction of the ring portion R of the concave portion RO shown
in FIG. 5 is set so as to be less than the length L of the flat
face in the circumferential direction of the ring portion R of
the convex portion RT, the present invention is not restricted
to this example. As shown in FIG. 10, the opening width W in
the circumferential direction of the ring portion R of the
concave portion RO may also be set so as to be greater than the
length L of the flat face in the circumferential direction of
the ring portion R of the convex portion RT.
[0018]
Although in the embodiments described above the convex
portion RT is provided so as to project from the face of the
screen 2 to the side facing the rotor 7 of the ring portion R,
the present invention need not be restricted to this example.
As shown in FIGS. 11, 12, the convex portion RT of the uneven
face may also be provided on the side facing the rotor 7 of the
ring portion R in such a way that it does not project from the
inside wall face of the screen 2. Because the type shown in
FIGS. 11, 12 is the same as the one described in FIGS. 3-5,
except that the convex portion RT is not projected from the
face (inside wall) of the screen 2, identical reference
numerals have been attached to the same components as those
described in FIGS. 3-5, and a description thereof has
accordingly partly omitted.
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In other words, the convex portion RT has a f ront end
portion X of the uneven portion and a rear end portion Y which
relative to the vertical direction of the casing 1 is
positioned at a position lower than the front end portion X of
the convex portion RT and is tilted in such a way that relative
to the rotational direction of the rotor 7 (see the direction
of an arrow shown in FIG. 12 (b) ) the front end portion X of the
convex portion RT is nearer than the rear end portion Y of the
convex portion RT.
Further, a concave portion RO is located between
adjoining convex portions RT and a plurality of each of the
convex portions RT and of the concave portions RO are provided
on the ring portion R.
The convex portion RT described in FIGS. 11, 12 can
enhance the capacity of the screen apparatus for separating
foreign matter from fibers of an acceptable quality in
paper-making material like the convex portion RT described in
FIGS. 3-5, because pieces that have not yet melted and that are
in the paper-making material collide with the convex portion
RT are not only separated but also brought back upstream of the
paper-making material.
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