JP2004315998A - Screening apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out excellent screening through the whole screen basket. <P>SOLUTION: The subject screening apparatus is equipped with the cylindrical screen basket 2 and a rotor 3 having stirring blades 12 rotating along the inner peripheral surface of the screen basket 2. The rotor 3 is cylindrical and has an inner space divided into a discharge raw material chamber 20 at the inner peripheral side and a pouring raw material chamber 21 at the outer peripheral side by a raw material guide pipe 20. The outer peripheral wall of the rotor 3 is equipped with pouring holes 16 for pouring a fiber raw material liquid flowed from the pouring raw material chamber 21 to a screening space 16 at the inner peripheral side of the screen basket 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a screen device used in a process of removing dust from a fiber raw material liquid in the production of paper pulp.
[0002]
[Prior art]
Conventionally, as a screen device, a rotor is provided in a screen basket, the rotor is driven to rotate, and a vane attached via a rod is rotated along the inner peripheral surface of the screen basket, so that the vane is moved from one end to the other end. There is one in which moving papermaking raw materials are carefully selected (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-285485
[Problems to be solved by the invention]
However, in the screen device, when the papermaking raw material flows from one end to the other end, it is filtered by a screen basket. As a result, there is a problem that the papermaking raw material is concentrated to be in a dehydrated state and easily remains as a residue.
[0005]
Therefore, an object of the present invention is to provide a screen device capable of performing good selection over the entire screen basket.
[0006]
[Means for Solving the Problems]
The present invention provides, as a means for solving the above problems, a screen device which comprises a cylindrical screen basket, and a rotor having stirring blades rotating along the inner peripheral surface of the screen basket, and selects a fiber raw material liquid. At
The rotor is cylindrical, and the inner space is partitioned into a raw material chamber for discharge on the inner peripheral side and a raw material chamber for injection on the outer peripheral side by a raw material guide tube, and flows into the raw material chamber for injection on the outer peripheral wall. It is provided with an injection hole for injecting the fiber raw material liquid into a selected space on the inner peripheral side of the screen basket.
[0007]
With this configuration, the light-weight suspended impurities in the fiber raw material liquid gather near the center of the spiral with the rotation of the rotor, and are discharged to the outside via the discharge raw material chamber. On the other hand, the fiber raw material liquid on the outer peripheral side is supplied from the raw material chamber for injection to the lower side of the screen basket through the injection hole, merges with the fiber raw material liquid filtered on the upper side, relieves the dewatering state, Maintain a selective environment.
[0008]
Preferably, the injection holes are formed in at least two regions above and below the rotor.
[0009]
By providing a partition section in the injecting material chamber, which is partitioned in the circumferential direction, the fibrous material liquid flowing into the injecting material chamber can be forcibly injected from the injecting hole, and is carefully selected on the lower side of the screen basket. This is preferable in that the environment can be further improved.
[0010]
When the partitioning section is inclined at a predetermined angle toward the rotation direction with respect to the radial direction of the rotor, even when the fiber raw material liquid is forcibly injected from the injection hole by the partitioning section, the load is suppressed and smooth. It is preferable in that it can be injected.
[0011]
When a raw material intake plate for guiding a fiber raw material liquid flowing in the circumferential direction with the rotation of the rotor into the raw material chamber for injection is disposed above the raw material chamber for injection, the fiber raw material liquid is supplied to the raw material chamber for injection. This is preferable because it is easy to smoothly flow downward.
[0012]
In this case, it is preferable that the inclination angle of the raw material intake plate is 5 to 45 ° with respect to a horizontal plane.
[0013]
It is preferable that the raw material guide tube be provided with a spiral guide portion on the outer peripheral surface, since the fiber raw material liquid can be more easily smoothly flowed to the lower side of the raw material chamber for injection.
[0014]
The raw material guide tube includes an expanding portion that gradually expands downward at least at a lower end portion, and the injection hole is located at a position where the fiber raw material liquid guided by the expanding portion of the raw material guide tube flows out. This is preferable in that the fiber raw material liquid flowing downward in the injection raw material chamber can be smoothly injected from the injection hole.
[0015]
It is preferable that the injection hole is formed to be longer in the circumferential direction than in the axial direction of the rotor, since the fiber raw material liquid is easily injected regardless of the rotation of the rotor.
[0016]
The injection holes are uniformly formed on at least two circumferences separated in the axial direction of the rotor, and if the partition is provided only on the lower side, the fiber raw material liquid is uniformly distributed over the entire screen basket. Is preferred in that it becomes possible to supply
[0017]
It is preferable that the injection holes are arranged so as to be displaced in the axial direction at respective positions separated in the axial direction of the rotor.
[0018]
By forming a discharge path below the rotor for discharging the fiber raw material liquid that has entered the discharge raw material chamber, it is possible to discharge the light-weight impurity mixed raw material collected at the center by the rotation of the rotor. It is preferable in that it becomes.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments according to the present invention will be described with reference to the accompanying drawings.
[0020]
1 and 2 show a screen device according to the present embodiment. In this screen device, a fiber raw material liquid supplied from above is carefully selected by rotating a rotor 3 in a screen basket 2 disposed in a screen main body 1. Each component is mainly made of stainless steel.
[0021]
The screen main body 1 is cylindrical, has upper and lower surfaces closed, an upper side surface connected to a raw material supply tube 4, and a lower side surface connected to an accept discharge tube 5 and a reject discharge tube 6. The raw fiber supply liquid before the treatment is supplied from the raw material supply pipe 4, the accept (high quality fiber) obtained by the selective treatment is discharged from the accept discharge pipe 5, and the reject discharge pipe 6 is composed of foreign matters such as sand and plastic. Reject is ejected. Further, annular guide portions 7 are respectively extended on the upper and lower inner peripheral surfaces of the screen main body 1. The screen basket 2 is held by the upper and lower guide portions 7. A bearing (not shown) is provided at the center of the bottom plate of the screen main body 1 and sealed by a mechanical seal 8, and the main shaft 26 of the rotor 3 is rotatably supported.
[0022]
The screen basket 2 has a configuration in which a plurality of vertically long members 9 are arranged side by side to form a cylindrical shape, and these are held by a plurality of holding members 10 (for details, see the slit screen in Japanese Patent No. 3386799). A predetermined gap determined based on the type of the fiber raw material liquid, the selection conditions, and the like is formed between the vertically elongated members 9.
[0023]
As shown in FIGS. 1 and 3, the rotor 3 is provided with a stirring blade 12 on the outer periphery of a rotor body 11, the inside is divided into inner and outer peripheries by a raw material guide tube 13, and a bottom member 14 is disposed on the lower side inside. This is the configuration. Then, the rotor 3 provides a selective space 15 between the screen basket 2 and the screen basket 2 for carefully selecting the fiber raw material liquid.
[0024]
The rotor body 11 has a cylindrical shape, and four injection holes 16 are equally formed at the top and bottom of the outer peripheral surface. Each injection hole 16 is a long hole, the upper injection hole 16a is long in the vertical direction, and the lower injection hole 16b is long in the circumferential direction. As shown in FIG. I have.
[0025]
The position, shape, quantity and the like of the injection holes 16 are not limited to those described above, and can be freely designed. For example, the position and size of the injection hole 16 may be changed according to the difference in the fiber concentration of the fiber raw material liquid. That is, if the fiber concentration of the fiber raw material liquid is high, it is possible to provide a more appropriate selection environment by increasing the number of the injection holes 16 and increasing the opening area.
[0026]
The stirring blades 12 are provided at four locations on the upper and lower sides of the outer peripheral surface of the rotor body 11, respectively. Each of the stirring blades 12 is formed so as to be streamlined from the upstream side to the downstream side in the flow direction of the fiber raw material liquid which flows relatively by the rotation of the rotor 3. Further, as shown in FIG. 5, the upper and lower stirring blades 12 are provided at positions shifted in the circumferential direction. A predetermined gap G is formed between the most protruding portion of the outer surface of the stirring blade 12 and the inner peripheral surface of the screen basket 2. This gap G is usually set to 5 to 15 mm. In addition, the number of the stirring blades 12 can be freely designed, and it is preferable to provide the stirring blades 12 equally at four to eight places according to the size of the screen device. Further, the stirring blades 12 can be provided continuously in the vertical direction, or the number of divisions can be increased. Although the number of divisions can be freely designed, it is preferable that the number of divisions is two to four. Therefore, the number of the stirring blades 12 provided on the rotor body 11 is preferably 8 to 32.
[0027]
The raw material guide tube 13 has a tubular shape, and includes a widened portion 17 whose diameter is increased downward at a lower portion, and a guide plate 18 which is spirally integrated with the outer peripheral surface. The raw material guide pipe 13 has a lower end opening fixed to the bottom member 14, and is supported by a raw material intake plate 19 having an upper end opening equally divided into four places. Is divided into a raw material chamber 20 and an injection raw material chamber 21 on the outer peripheral side. As shown in FIG. 4, the guide plate 18 and the raw material intake plate 19 are formed so as to be gradually inclined downward with respect to the horizontal plane. Further, the guide plate 18 is formed in a spiral shape of one rotation or more. In addition, the inclination angle a2 of the guide plate 18 and the raw material intake plate 19 with respect to the horizontal plane is set to 5 to 45 degrees depending on the use conditions. As a result, when the rotor 3 rotates, the raw material intake plate 19 smoothly takes the fiber raw material liquid into the injection raw material chamber 21, and the guide plate 18 presses the fiber raw material liquid to forcibly move the fiber raw material liquid downward. Can be. The lower part of the injection material chamber 21 is divided into a plurality of regions by a partition wall 27 corresponding to each lower injection hole 16b. The partition wall 27 is formed so as to be inclined in the rotation direction with respect to the radial direction of the rotor 3 as indicated by a1 in FIG. Thus, when the rotor 3 rotates, the fiber raw material liquid can be smoothly injected from the lower injection hole 16b into the selected space 15 while suppressing the flow resistance.
[0028]
The bottom member 14 has a configuration in which a main bearing 23 is attached to a bottom plate 22 and connected and reinforced by a connection reinforcing member 24, and is fixed to the inner peripheral surface of the rotor body 11. In the bottom plate 22, through holes 22a are formed at a plurality of positions equally with respect to the center of rotation. The through-hole 22 a communicates with the inside of the raw material guide tube 13 fixed to the upper surface of the bottom plate 22, that is, with the raw material chamber 20 for discharge. A communication tube 25 is connected to each through hole 22a, and the communication tube 25 penetrates the connection reinforcing member 24 and opens on the lower surface thereof. The upper end of the main shaft 26 is connected to the main bearing 23. The main shaft 26 is rotated by driving a motor (not shown).
[0029]
Next, the operation of the screen device will be described.
[0030]
First, a fiber raw material liquid is supplied into the screen main body 1 through the raw material supply pipe 4. Further, a motor (not shown) is driven to rotate the rotor 3 in the screen basket 2. Due to the rotation of the rotor 3, the fiber raw material liquid becomes spiral due to the centrifugal force acting thereon and is affected by gravity, and flows into a selected space 15 formed between the rotor 3 and the screen basket 2.
[0031]
The fiber raw material liquid flowing into the selected space 15 is pressurized by the rotation of the rotor 3 when the stirring blade 12 passes, and depressurized after passing. As a result, only accept passes through gaps between the vertically long members 9 constituting the screen basket 2 when pressurized, rejects clogging these gaps are removed into the selected space 15 when depressurized, and the remaining raw material moves downward. . The accept transmitted through the screen basket 2 is discharged to the outside through the accept discharge pipe 5.
[0032]
Further, the fiber raw material liquid is forcibly flown into the raw material chamber 21 for injection by the raw material intake plate 19. The fiber raw material liquid flowing into the injection raw material chamber 21 is pressurized by the spiral guide plate 18 that rotates together with the rotor 3, and is forcibly moved downward. The fiber raw material liquid is injected into the selected space 15 through the upper injection hole 16a by the centrifugal force that acts during the downward movement. As a result, the fiber raw material liquid is supplied to the remaining raw material dehydrated in the upper part of the selected space 15. As a result, the selection environment is improved, and the remaining raw materials are easily filtered.
[0033]
In the raw material chamber 21 for injection, the fiber raw material liquid moves further downward, and is smoothly changed in the horizontal direction by the expanding portion 17 of the raw material guide pipe 13. Further, the liquid is forcibly guided to the lower injection hole 16 b by the partition wall 27 and injected into the selected space 15. As described above, since the lower injection hole 16b is formed so as to be longer in the circumferential direction, the lower portion of the selected space 15 is sufficiently filled with the fiber material in cooperation with the operation of the expanding portion 17 and the partition wall 27. Liquid can be replenished. As a result, the selection environment at the lower side of the selection space 15 is also improved, and the filtration becomes easy.
[0034]
In this way, the fiber raw material liquid is supplied from the injection raw material chamber 21 to the remaining raw material via each injection hole 16. For this reason, by providing the stirring blades 12 directly on the rotor body 11, it is possible to prevent the water content of the fiber raw material liquid from being reduced due to the fine selection and being in a dewatered state despite the small volume of the fine selection space 15. it can. Therefore, it is possible to provide a good selection environment in which the entire screen basket 2 is easily filtered. In this case, since the influence of the partial stress on the screen basket 2 can be reduced, the life of the screen basket 2 can be extended.
[0035]
Above the discharge material chamber 20 of the rotor 3, a light-weight impurity-mixed material floating in the form of a spiral and floating near the liquid surface is guided to the center. As a result, the impurity mixed raw material moves downward in the discharge raw material chamber 20 and is discharged from the communication pipe 25 to the outside via the reject discharge pipe 6. The reject discharged from the reject discharge pipe 6 may be subjected to secondary or tertiary processing by another screen device.
[0036]
【The invention's effect】
As is apparent from the above description, according to the present invention, the injection material chamber and the discharge material chamber are formed in the rotor, and the fiber material liquid flowing into the injection material chamber is supplied to the screen basket through the injection hole. Since it is possible to inject the raw material into the inner peripheral side, it is possible to prevent the dehydration of the remaining raw material in the selected space and to provide a good selected environment over the entire screen basket.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a screen device according to an embodiment.
FIG. 2 is a cross-sectional view (a cross-sectional view along the line AA in FIG. 1) of the screen device according to the embodiment.
3A is a longitudinal sectional view of the rotor shown in FIG. 1, and FIG. 3B is a sectional view taken along line BB.
FIG. 4 is a partially enlarged view of a raw material intake plate and a guide plate shown in FIG. 3;
FIG. 5 is a development view of the rotor body shown in FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Screen main body 2 ... Screen basket 3 ... Rotor 4 ... Raw material supply pipe 5 ... Accept discharge pipe 6 ... Reject discharge pipe 7 ... Guide part 8 ... Mechanical seal 9 ... Longitudinal member 10 ... Holding member 11 ... Rotor body 12 ... Stirring blade Reference numeral 13: raw material guide tube 14: bottom member 15: selected space 16: injection hole 16a: upper injection hole 16b: lower injection hole 17: expanding portion 18: guide plate 19: raw material intake plate 20: raw material chamber 21 for discharge Injection material chamber 22 ... Bottom plate 22a ... Through hole 23 ... Main bearing fitting 24 ... Connecting reinforcing member 25 ... Communication tube 26 ... Main shaft 27 ... Partition wall A ... Gap

Claims (12)

A screen device having a cylindrical screen basket and a rotor having stirring blades rotating along the inner peripheral surface of the screen basket, and a screen device for carefully selecting a fiber raw material liquid,
The rotor is cylindrical, and the inner space is partitioned by a raw material guide tube into a raw material chamber for discharge on the inner peripheral side and a raw material chamber for injection on the outer peripheral side, and flows into the raw material chamber for injection on the outer peripheral wall. A screen device comprising an injection hole for injecting a fiber raw material liquid into a selected space on an inner peripheral side of a screen basket. 2. The screen device according to claim 1, wherein the injection holes are formed in at least two regions above and below the rotor. 3. The screen device according to claim 1, wherein a partition portion that is circumferentially partitioned is provided in the injection material chamber. 4. The screen device according to claim 3, wherein the partition is inclined at a predetermined angle in a rotational direction with respect to a radial direction of the rotor. 5. A raw material intake plate for guiding a fiber raw material liquid flowing in a circumferential direction with rotation of a rotor into the raw material chamber for injection is disposed above the raw material chamber for injection. 5. The screen device according to any one of 4. The screen device according to claim 5, wherein an inclination angle of the raw material intake plate is set to be 5 to 45 with respect to a horizontal plane. The screen device according to any one of claims 1 to 6, wherein the raw material guide tube includes a spiral guide portion on an outer peripheral surface. The raw material guide tube includes an expanding portion that gradually expands downward at least at a lower end portion, and the injection hole is located at a position where the fiber raw material liquid guided by the expanding portion of the raw material guide tube flows out. The screen device according to claim 1, wherein the screen device is formed. 9. The screen device according to claim 1, wherein the injection hole is formed to be longer in a circumferential direction than in an axial direction of the rotor. 10. 10. The injection hole according to claim 1, wherein the injection holes are uniformly formed on at least two circumferences separated in the axial direction of the rotor, and the partition portion is provided only on a lower side. Item 2. The screen device according to item 1. The screen device according to any one of claims 1 to 10, wherein the injection holes are arranged so as to be displaced in the axial direction at respective positions separated in the axial direction of the rotor. The screen device according to any one of claims 1 to 11, wherein a discharge path for discharging the fiber raw material liquid having entered the discharge raw material chamber to the outside is formed below the rotor.

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