JP2006348460A - Slit screen and screening device equipped with the slit screen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hardly abradable slit screen, capable of aiming at the long life, also hardly being clogged and having a high dust removal effect irrespective to the kinds of foreign materials contained in fiber raw material liquid. <P>SOLUTION: This slit screen is provided by installing a multiple number of vertical long members 5 as rows, forming a refining part 20 between the adjacent vertical long members 5, refining the fiber raw material liquid through the refining part 20 by repeating compression and the removal of pressure by using an agitating blade 3 transferring along the vertical long members 5 in their installed direction as rows. In the vicinity of the refining part 20, an eddy-forming part 37 for generating a first eddy in the fiber raw material liquid by the transfer of the agitating blade 3 is formed and based on the first eddy, generates a second eddy for forming a compressed inflow of the fiber raw material to the refining part 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a slit screen and a screen device including the slit screen.

  2. Description of the Related Art Conventionally, a screen apparatus for performing a selection process for filtering a fiber raw material liquid (papermaking raw material) to extract a fiber raw material having a desired quality is known. This screen device includes a screen basket that is a filtration net and a stirrer that includes a stirring blade that rotates inside the screen basket. In the screen basket, for example, there is a slit screen in which a plurality of vertically long members are arranged side by side and a slit-like gap is formed between adjacent vertically long members (see, for example, Patent Document 1).

Japanese Patent No. 3786799

  However, in the slit screen, impurities contained in the fiber raw material liquid pressurized by the stirring blade, for example, particulate foreign matter, may directly collide with the vertically long member constituting the gap and be worn. Since the gap is required to have high accuracy, the slit screen can no longer be used if it is worn even at one place (for example, wear of 8 to 10 μm). In recent years, the fiber raw material liquid has been getting worse, and the problem of wear has become obvious due to the foreign substances contained therein.

  Further, in the slit screen, when the stirring blade passes, the fiber raw material liquid is pressurized and selected, and then the pressure is reduced and the reject remaining in the gap is removed by the backwashing action. As described above, as the fiber raw material liquid deteriorates, the content of the sticky foreign matter also increases, so the foreign matter adhering to the gap cannot be sufficiently removed by the backwashing action, and clogging is likely to occur. There is a problem.

  Therefore, the present invention provides a slit screen that has a high dust removal effect and is less likely to be clogged and highly durable, regardless of the type of foreign matter contained in the fiber raw material liquid. It is an object of the present invention to provide a screen device provided.

  As a means for solving the above-mentioned problems, the present invention provides a stirring blade in which a plurality of vertically long members are arranged side by side, a selective portion is formed between the adjacent vertically long members, and moves along the vertically long members in the side-by-side direction. In the slit screen that repeatedly pressurizes and depressurizes the fiber raw material liquid and finely selects the fiber raw material liquid through the fine selection unit, the fiber raw material liquid is first moved to the fiber raw material solution by moving the stirring blade in the vicinity of the selective selection unit. The eddy current generating part for generating the eddy current is formed, and the second eddy current that generates the press-fitting flow of the fiber raw material liquid into the fine selection part is generated based on the first eddy current.

  Further, according to the present invention, as means for solving the above-described problem, a plurality of vertically long members are arranged in parallel, the stirring blades are moved along the longitudinal members in the parallel direction, and the moving direction of the stirring blades is increased. By forming the end face of each vertically long member so as to gradually protrude, a finely selected portion and a space for generating a vortex flow are formed between the adjacent vertically long members. In the slit screen that repeats depressurization and selects the fiber raw material liquid through the selection unit, a eddy current generation unit that forms a recess in the end surface of each longitudinally long member, and generates the eddy current by the movement of the stirring blade. It is made to function as.

  In any of the above configurations, the first vortex generated in the vortex generator generates a flow that circulates in the fiber raw material liquid pressurized by the stirring blade toward the moving region of the stirring blade. As a result, a relatively large reject contained in the fiber raw material liquid is returned without being guided to the selection section. In addition, the second vortex generated by the first vortex allows the fiber raw material liquid to flow into the selection section, and the desired selection performance can be maintained.

  According to the present invention, the first eddy current is generated in the eddy current generating part, and the second eddy current is generated by the first eddy current. Therefore, a relatively large reject contained in the fiber raw material liquid is selected. It is possible to allow the fiber raw material liquid to flow into the selection section while preventing the fluid from flowing into the desired selection section and maintain the desired selection capacity.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings.

(First embodiment)
FIG. 1 shows a slit screen 1 according to this embodiment. As shown in FIG. 2, the slit screen 1 is housed in a screen machine body 2 and used, and a rotor 4 having a stirring blade 3 is disposed inside.

  As shown in FIG. 1, the slit screen 1 is formed by arranging a plurality of vertically long members 5 in a cylindrical shape and holding them with a plurality of holding members 6. (Reject) is carefully separated.

  The vertically long member 5 is formed by extruding stainless steel (SUS304, SUS316, etc.) and, as shown in FIGS. 3 and 4, through the inclined side surface 8 in which the width dimension gradually decreases from the wide portion 7, Furthermore, it has a cross-sectional shape that reaches the locking portion 10 wider than the narrow neck portion 9 via the narrow neck portion 9. The wide portion 7 includes an inclined front surface 11 that is inclined with respect to a straight line perpendicular to the axis (indicated by a one-dot chain line in FIG. 3). The inclined front surface 11 is separated from the stirring blade 3 in the direction of the arrow R2 (the direction opposite to the rotation direction R1 of the stirring blade 3; hereinafter, the counter-rotating direction R2). As shown in FIG. 5, the wide portion 7 has a first flat surface 12 and a second flat surface 13 that are cut at the side edges in the direction of the arrow R <b> 1 (the rotation direction of the stirring blade 3). The first flat surface 12 is continuous with the inclined front surface 11 via the first arc surface 14. The second flat surface 13 is continuous with the first flat surface 12, and is gradually inclined toward the direction of the arrow R2 as the distance from the first flat surface 12 increases. The closer the inclination angle of the first flat surface 12 is to the inclination angle of the second flat surface 13 (or it may be matched), the more difficult the fiber raw material liquid enters the buffer portion 21 described later. Conversely, the more the first flat surface 12 is inclined with respect to the second flat surface 13, the more easily the fiber raw material liquid enters the buffer portion 21. This setting may be changed according to the quality of the fiber raw material liquid to be used, and the former configuration may be used for a poor raw material, and the latter configuration may be used for a high quality raw material. A substantially V-shaped space (hereinafter referred to as a V-shaped portion 15) formed by the inclined front surface 11 and the first flat surface 12 of the adjacent vertically long member 5 is added along with the movement of the stirring blade 3. This is for generating a high-pressure vortex during pressure. As a result, the fiber raw material liquid enters the selective area 19 described later.

  Further, in the vertically long member 5, as shown in FIG. 5, the corner portion of the wide portion 7 is cut off in the direction of the arrow R2, and the third flat surface continues through the second arc surface 16a and the third arc surface 16b. 17 and an arcuate concave surface 18 are formed. Then, the first flat surface 12 and the second flat surface 13 of the adjacent vertically long member 5, and the second arcuate surface 16a, the third flat surface 17, the arcuate concave surface 18 and the third arcuate surface 16b form a selective region 19. It is composed.

  A region formed by the second flat surface 13 and the third arc surface 16b (strictly speaking, the minimum gap portion on both surfaces) is the fine selection unit 20 (here, the minimum gap size of the selection unit 20 is set to the target quality of the raw material). Accordingly, it is set to 0.10 to 0.30 mm.) In the selection unit 20, only the accept (good quality fiber) contained in the fiber raw material liquid is allowed to pass, and a reject (foreign matter) larger than this accept remains. The reason why one of the wall surfaces constituting the selection unit 20 is configured by the second flat surface 13 is to obtain the selection unit 20 at a predetermined interval even when the arrangement angle of the vertically long member 5 is changed.

  Further, a region formed by the first flat surface 12 and the second flat surface 13, the third flat surface 17 and the arcuate concave surface 18 is the buffer portion 21. The first flat surface 12 and the third flat surface 17 constituting the buffer portion 21 are formed so as to be inclined so that the cross-sectional area of the flow path gradually increases as the distance from the selective portion 20 increases (see θ1 in FIG. 5). Indicated by). Moreover, the buffer part 21 is formed so as to be inclined from the selective part 20 toward the direction of the arrow R1 (indicated by θ2 in FIG. 5). Here, the angle θ2 is an angle formed by a straight line along the second flat surface 13 and a straight line connecting the rotation center of the stirring blade 3 and the boundary between the inclined front surface 11 and the first arc surface 16a. However, the shape of the buffer part 21 should just be what the fiber raw material liquid is easy to recirculate | reflux in the slit screen 1 at the time of backwashing.

  The entrance portion of the buffer portion 21, that is, the gap formed between the second arcuate surface 16 a and the first flat surface 12 (strictly, the minimum gap portion on both sides. Is set to about 0.6 to 1.5 mm.) Is the auxiliary selective section 22. The gap size of the auxiliary selection unit 22 (indicated by g5 in FIG. 5) is larger than the gap size of the selection unit 20 (indicated by g1 in FIG. 5), and among the rejects that attempt to enter the buffer unit 21 Then, a reject having a size larger than that selected by the selection unit 20 is selected (coarse selection filtration).

  Further, the vertically long member 5 has two different lengths of the narrow neck portion 9, that is, as shown in FIG. 3B, the first vertically long member 5a having a longer overall length in the cross section and FIG. As shown to c), it is comprised with the shorter 2nd vertically long member 5b.

  As shown in FIG. 3A, the holding member 6 is a ring-shaped plate material made of stainless steel (SUS304, SUS316, etc.), and holding recesses 23 are formed at a predetermined pitch in the circumferential direction. The holding recess 23 can be formed with high accuracy by laser processing or electric discharge processing (or both). The shape of the adjacent holding recess 23 is different according to the two types of the vertically long members 5. That is, the holding recess 23 includes a first holding recess 23a into which the first vertically long member 5a is press-fitted and a second holding recess 23b into which the second vertically long member 5b is press-fitted. Each of the holding recesses 23a and 23b has a shape in which the vertically long member 5 can be press-fitted in the thickness direction, the inclined groove 24 corresponding to the inclined side surface 8 of the vertically long member 5, the narrow groove 25 corresponding to the narrow neck portion 9, and the locking It is constituted by a locking groove 26 corresponding to the portion 10. Then, by pressing the vertically long member 5 into the holding recess 23, it is possible to align the circumferentially direction while forming a predetermined gap dimension in the selective portion 20.

  The stirring blades 3 are provided at four equal parts in the circumferential direction, and are connected to the rotor 4 provided at the center via a connecting rod 27 so as to be inclined with respect to the longitudinal direction of the vertically long member 5. The rotor 4 is rotated by driving a motor (not shown), and the stirring blade 3 is rotated at a high speed along the inner peripheral surface of the slit screen 1 with the arc portion as a head. Each stirring blade 3 is formed in an arc shape on the side of the rotation direction (direction indicated by arrow R1), and its outer peripheral surface is constant with the inner peripheral surface of the slit screen 1 toward the counter-rotation direction (direction indicated by arrow R2). A pressure surface 28 having an interval (here, 5 to 10 mm), and gradually curved away from the inner peripheral surface of the slit screen 1 as it goes further in the counter-rotating direction from the pressure surface 28, The pressure reducing surface 29 intersects the surface.

  Then, the manufacturing method of the slit screen 1 of the said structure is demonstrated.

  First, the holding member 6 is positioned at a predetermined interval by a jig (not shown). At this time, the positions of the holding recesses 23 are matched between the holding members 6. Then, the vertically long members 5a and 5b corresponding to the holding recesses 23a and 23b are sequentially press-fitted into a cylindrical shape. Thereby, between the wide part 7 of each longitudinally long member 5a, 5b, the fiber raw material liquid by the selective part 20 which has a predetermined | prescribed gap | interval size for selectively separating the high quality fiber and foreign material of a fiber raw material liquid, and a high pressure eddy current And the buffer portion 21 for preventing the reject included in the screen from colliding with the wall surface constituting the fine selection portion 20, and the slit screen 1 is completed.

  Next, the operation of the screen device provided with the slit screen 1 having the above-described configuration will be described.

  First, a fiber raw material liquid (for example, paper pulp fiber liquid) is sequentially supplied into the screen machine body 2. Then, the rotor 4 disposed in the slit screen 1 is rotated at a high speed (circumferential speed of about 15 to 20 m / s), and the stirring blade 3 is moved along the inner peripheral surface of the slit screen 1. Thereby, the fiber raw material liquid which flowed into the slit screen 1 becomes a spiral shape by the acting centrifugal force and is affected by gravity. For this reason, the foreign material with a large specific gravity is collected to the center part. Then, a part of the remaining fiber raw material liquid from which foreign matters having a large specific gravity have been removed flows into the selective region 19 formed between the rotor 4 and the screen basket.

  The fiber raw material liquid that has flowed into the selective region 19 is pressurized when the pressure surface 28 of the stirring blade 3 passes through the opposite portion of the inner peripheral surface of the slit screen 1, and becomes a vortex in the V-shaped portion 15. The fiber raw material liquid that has become a vortex is prevented from passing a large-size reject at the entrance of the buffer section 21, that is, at the auxiliary selective section 22. That is, the large-size reject collides only at the entrance portion of the auxiliary selective section 22. Moreover, the buffer portion 21 is formed so as to be inclined from the selective portion 20 in the direction of the arrow R1. For this reason, the fiber raw material liquid does not flow directly into the buffer part 21, but flows in comfortably due to the pressure increase due to the vortex.

  The fiber raw material liquid that has passed through the auxiliary selection section 22 and has entered the buffer section 21 is released from the vortex state while maintaining a high pressure state. For this reason, it is avoided that a reject, especially a hard foreign material collides with the wall surface which comprises the selection part 20 at high speed. Therefore, wear at the selective section 20 is suppressed.

  Moreover, since the foreign material which has adhesiveness contained in the fiber raw material liquid which flowed into the buffer part 21 will cancel | dissolve an eddy current state and will flow through the buffer part 21, it will stay in the buffer part 21, or the buffer part 21 Or adhere to the wall surface. Therefore, sticky foreign matters do not flow out to the outer peripheral side of the slit screen 1 or adhere to the wall surface constituting the selective portion 20 as compared with the conventional product without the buffer portion 21.

  In addition, since the auxiliary selection unit 22 and the selection unit 20 can perform two-stage selection, it is not necessary to connect a plurality of screen devices in order to perform a plurality of selection processes as in the prior art, thus simplifying the equipment. And installation space can be greatly reduced.

  In the selection unit 20, only accepts (good quality fibers) smaller than the size desired by the user can pass, and fibers larger than the desired size remain in the buffer unit 21 as rejects. After the high-quality fibers pushed out from the gap g1 of the finely selected portion 20 flow to the outside through the gap g2 of the inclined side surface 8, the gap g3 of the locking portion 10 and the narrow neck portion 9, and further the gap g4 of the locking portion 10. The fluid flows from the screen body 2 to a pipe (not shown) and is collected. The gap dimension is formed so as to increase from the gap g1 to g4. Therefore, the liquid containing the acceptor pushed out from the gap g1 smoothly flows from the slit screen 1 to the outside, and the fiber is hardly disturbed or entangled.

  Thereafter, when the stirring blade 3 further rotates and the pressure reducing surface 29 passes, the gap with the inner peripheral surface of the slit screen 1 becomes large, and the fiber raw material liquid is in a reduced pressure state at the V-shaped portion 15. The fiber raw material liquid in the buffer portion 21 that maintains the above is pulled back toward the inner peripheral side of the slit screen 1. At this time, the flow direction of the fiber raw material liquid is along the inclination direction θ2 of the buffer portion 21 and the wall surface constituting the buffer portion 21 is inclined at a predetermined angle θ1, so that the remaining reject is smoothly slit screen. Reflux into 1. Moreover, the clogging in the selection unit 20 is also eliminated, and so-called backwashing is performed.

  In this way, the reject recovered to the inner peripheral side of the slit screen 1 without passing through the selection section 20 moves downward in the slit screen 1 and is recovered via a pipe (not shown). The waste product is processed.

  In addition, when such a series of selection processes, that is, the extrusion of the accept from the selection unit 20 by the stirring blade 3 and the collection of the rejects remaining in the buffer unit 21 and the selection unit 20 are performed, a large amount of the longitudinal member 51 is generated. Although a force acts, as described above, sufficient strength is obtained by securing a sufficient distance between the holding recesses 23 of the holding member 6. Therefore, there is no problem that the holding member 6 is damaged, the vertical member 5 is vibrated, and the vertical member 5 itself is damaged.

  In addition, when the gap size of the auxiliary selective section 22 is reduced or the length (flow path length) of the buffer section 21 is increased, it is assumed that the flow resistance increases and the selective ability decreases. In this case, it is possible to obtain a desired selection performance by increasing the rotational speed of the stirring blade 3 or reducing the distance between the stirring blade 3 and the inner peripheral surface of the slit screen 1. Therefore, when the fiber raw material liquid containing a large amount of foreign matter is carefully selected, the gap size of the auxiliary selection unit 22 is reduced, and the size of the foreign material from the buffer unit 21 to the selection unit 20 is suppressed, and the selection capability is reduced. It becomes possible to prevent. If the gap size of the auxiliary selection section 22 is increased due to wear, the selection performance can be maintained constant by resetting the rotation speed of the stirring blade 3 to be slower according to the increase in the gap size. In addition, when it is necessary to carefully select a poor fiber raw material solution, by reducing the number of foreign matters reaching the selection section 20 by preventing the decrease in the selection performance by setting the flow path length of the buffer section 21 to be large. Is also possible.

(Second Embodiment)
FIG. 6 shows a part of the slit screen 31 according to the second embodiment. In this slit screen 31, the shape of the vertically long member 33 is mainly different from that of the first embodiment.

  That is, the vertically long member 33 held by the holding member 32 has flat surfaces 35 and 36 formed at both ends of the inclined front surface 34, and a vortex generating portion 37 is formed at the inclined front surface 34. A finely-selected portion 38 is formed by the flat surfaces 35 and 36 between the adjacent longitudinal members 33. The vortex generator 37 generates a first vortex as shown in FIG. 6B by the fiber raw material liquid pressurized by the movement of the stirring blade 3. Then, the second eddy current is generated at the entrance portion of the selection section 38 by the first vortex, and the selection section 38 can perform the selection. That is, if the formation position of the eddy current generating part 37 is too close to the selective part 38, the second eddy current generated by the first eddy current becomes small (not generated in some cases). On the other hand, if the formation position of the eddy current generating part 37 is too far from the selective part 38, the rotational speed of the second eddy current becomes slow. In any case, a sufficient pressure is generated by the second eddy current, and the selective selection unit 38 cannot exhibit the desired selective selection ability. Therefore, the eddy current generating unit 37 can form a first eddy current suitable for generating a second eddy current having a high rotational speed, which can cause the selective selection unit 38 to exhibit a desired selection performance.

  When the slit screen 31 according to the second embodiment is employed in the screen device, the following operational effects are obtained.

  That is, when the fiber raw material liquid is supplied into the screen machine main body 2 and the stirring blade 3 is rotated along the inner peripheral surface of the slit screen 31, the pressurized fiber raw material liquid first causes the vortex generator 37 to flow. Flow and generate a first vortex. The first vortex flows in the counterclockwise direction in FIG. For this reason, among the rejects contained in the fiber raw material liquid, a relatively large one is returned to the moving region side of the stirring blade 3. Further, the first vortex generated in the vortex generator 37 generates a second vortex near the entrance of the selective section. The second vortex forcibly causes the fiber raw material liquid to enter the selective section 38.

  As described above, according to the screen device including the slit screen 31 according to the second embodiment, the first eddy current is generated by the vortex generator 37 to slit relatively large foreign matters contained in the fiber raw material liquid. Since it is made to circulate toward the inner side of the screen 31, it is possible to prevent a problem that the foreign matter collides with the selective portion 38 and is worn. Further, a second vortex flow is generated by the first vortex flow, and the second vortex flow provides a pressure required for allowing the fiber raw material liquid to enter the selective section 38. Therefore, the selection ability in the selection section 38 can be maintained at a desired value.

  In addition, as a shape of the said eddy current generation part 37, it is also possible to comprise as shown, for example in FIG. 7A has a substantially V-shaped cross section, FIG. 7B has a substantially trapezoidal cross section, and FIG. 7C has a substantially rectangular cross section. Regardless of the shape, it is created in consideration of the removal size due to wear so that a vortex can be generated even if foreign matter collides and wears to some extent. As a result, it is possible to use for a long period of time only by changing the shape of the portion considered to be most severely deteriorated due to wear.

(Third embodiment)
FIG. 8 shows a part of the slit screen 41 according to the third embodiment. In the slit screen 41, a selection area 46 including a selection section 43, a buffer section 44, and an auxiliary selection section 45 is formed between adjacent longitudinal members 42. A recess, that is, a vortex generator 47 is formed near the entrance of the buffer 44.

  The selection unit 43, the buffer unit 44, and the auxiliary selection unit 45 have the same configuration as in the first embodiment, and the eddy current generation unit 47 has the same configuration as in the second embodiment.

  In the screen device provided with the slit screen 41 having the above-described configuration, the selective process is performed as follows.

  That is, when the fiber raw material liquid is supplied into the screen body 2 and the stirring blade 3 is rotated along the inner peripheral surface of the slit screen 41, the stirring blade 3 is pressurized as in the second embodiment. First, the fiber raw material liquid generates a first vortex in the vortex generator 47. Then, the first eddy current generates a second eddy current in the vicinity of the inlet of the auxiliary fine selection unit 45.

  In the auxiliary selective section 45, a relatively large reject is returned to the moving path side of the stirring blade 3 by the first vortex. Accordingly, the reject collides with the wall surface constituting the auxiliary selective section 45 and is not easily worn. Further, since the fiber raw material liquid is in a pressurized state and passes through the auxiliary fine selection unit 45 by the second vortex, only fibers smaller than the gap size flow to the buffer unit 21 (rough selection filtration).

  Since the fiber raw material liquid passing through the buffer portion 21 is eliminated from the swirl state, the sticky foreign matter is likely to stay in the buffer portion 21 as in the first embodiment. Further, only the accept passes through the selection unit 43, and the reject stays in the buffer unit 44. Therefore, if the V-shaped part is in a reduced pressure state by passing through the reduced pressure surface of the stirring blade 3, the reject staying from the buffer part 44 via the auxiliary selection part 45 is recovered to the inner peripheral side of the slit screen 41. The

  Thus, according to the screen device provided with the slit screen 41 according to the third embodiment, the action of the eddy current generating part 47 and the buffer part 44 further suppresses the wear of the wall surface constituting the fine selection part 43. Can be used over a long period of time.

  In the second and third embodiments, it is preferable to further provide a reject decomposition unit 51. FIG. 9 shows an example in which a reject decomposing portion 51 is formed on the vertically long member 42 according to the third embodiment shown in FIG. The reject decomposing portion 51 is formed on the inclined front surface. Specifically, it is formed at a position that is a predetermined dimension away from the corner on the direction of the arrow R 1, is composed of an arc portion 52 and a flat portion 53, and is continuous with the vortex generator 47. Then, when the fiber raw material liquid is supplied into the screen machine main body 2 and the stirring blade 3 is rotationally moved along the inner peripheral surface of the slit screen 1, the fiber raw material liquid collides with the reject decomposing portion 51 and becomes a turbulent flow. Bundling fibers and fiber scraps contained in the fiber raw material liquid are crushed. Therefore, the amount of fibers discarded without being carefully selected can be suppressed. Further, the fiber raw material liquid containing the crushed fibers flows along the inner peripheral surface of the slit screen 1 to the vortex generating portion 47 formed between the next adjacent elongated members 41, and the third Similar to the embodiment, the first vortex flow is obtained.

  Thus, by providing the rejection decomposition | disassembly part 51, since a binding fiber etc. can be disintegrated, the fiber quantity discarded without being selected can be suppressed.

  In addition, as shown in FIG. 10, the vortex generator 47 may be formed over substantially the entire inclined front surface without providing the reject decomposition part 51.

  In the above-described embodiment, the fiber raw material liquid is configured to be pushed out from the inside to the outside of the slit screen 1. However, the fiber raw material liquid may be configured to be press-fitted from the outside to the inside. In this case, in the slit screen 1 according to the first embodiment, the wide portion 7 of the vertically long member 5 is arranged on the outer peripheral side of the holding member 6, and the stirring blade 3 of the rotor 4 is arranged on the slit screen 1. It is necessary to make it rotatable on the outer periphery.

  In the embodiment, the slit screen is cylindrical, but may be flat.

  In the above embodiment, the vertically long member 5 is press-fitted into the holding recess 23 of the holding member 6. However, after insertion, it may be fixed by other means such as caulking, adhesion, or welding.

It is a front view of the slit screen which concerns on 1st Embodiment. It is a top view of FIG. (A) is the sectional view on the AA line of FIG. 1, (b) is a cross-sectional view of the first vertically long member, and (c) is a cross-sectional view of the second vertically long member (hatching is omitted). It is the elements on larger scale which show a part of stirring blade and slit screen of FIG. (A) is the elements on larger scale of FIG. 4, (b) is the detailed figure of the selection area | region. (A) is the elements on larger scale which show the elongate member and stirring blade of the slit screen which concern on 2nd Embodiment, (b) is explanatory drawing which shows the flow state of the fiber raw material liquid. It is the elements on larger scale which show the vertically long member of the slit screen which concerns on other embodiment. It is the elements on larger scale which show a part of vertically long member of the slit screen which concerns on 3rd Embodiment, (a) shows the flow state of the fiber raw material liquid at the time of pressurization, (b) shows the flow state at the time of pressure reduction. It is a figure which shows the modification of FIG. It is a figure which shows the modification of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Slit screen 2 ... Screen machine main body 3 ... Stirring blade 4 ... Rotor 5 (5a, 5b) ... Long member 6 ... Holding member 7 ... Wide part 8 ... Inclined side surface 9 ... Narrow neck part 10 ... Locking part 11 ... Inclined front surface DESCRIPTION OF SYMBOLS 12 ... 1st flat surface 13 ... 2nd flat surface 14 ... 1st circular arc surface 15 ... V-shaped part 16 ... 2nd circular arc surface 17 ... 3rd circular arc surface 18 ... Escape recessed part 19 ... Selected area | region 20 ... Selected area 21 ... Buffer part 22 ... auxiliary selection part 23 (23a, 23b) ... holding recess 24 ... slope groove 25 ... narrow groove 26 ... locking groove 27 ... connecting rod 28 ... pressure surface 29 ... pressure reducing surface 31 ... slit screen 32 ... holding member 33 ... Longitudinal member 34 ... Inclined front surface 35, 36 ... Flat surface 37 ... Eddy current generating part 38 ... Fine selection part 41 ... Slit screen 42 ... Longitudinal member 43 ... Fine selection part 44 ... Buffering part 45 ... Auxiliary fine selection part 46 ... Fine selection area 47 ... Eddy current generation part 51 ... Rejection Part

Claims (3)

A plurality of vertically long members are arranged side by side, a selective portion is formed between the adjacent vertically long members, and pressurization and depressurization are repeatedly applied to the fiber raw material liquid by the stirring blades that move in the parallel direction along the vertically long members. In the slit screen for finely selecting the fiber raw material liquid through the selective part,
A vortex generator for generating a first vortex in the fiber raw material liquid is formed by the movement of the stirring blades in the vicinity of the fine selection section, and the fiber raw material liquid is supplied to the selection section based on the first vortex flow. A slit screen characterized by generating a second swirl that generates a press-fit flow. By arranging a plurality of vertically long members, moving the stirring blades in the parallel direction along the vertically long members, and forming the end faces of the respective vertically long members gradually projecting in the moving direction of the stirring blades. In addition, a selective section and a space for generating a vortex flow are formed between adjacent longitudinal members, and pressurization and depressurization of the fiber raw material liquid are repeated by the vortex, and the fiber raw material liquid is carefully selected through the selection section. In the slit screen that
A slit screen, wherein a concave portion is formed on an end face of each of the vertically long members, and the concave portion functions as a vortex generator that generates a vortex by the movement of the stirring blade. In a screen device that includes a cylindrical slit screen and a rotor having a stirring blade that rotates along the slit screen, and that selects a fiber raw material liquid,
The said slit screen was comprised with the slit screen of the said Claim 1 or 2, The screen apparatus characterized by the above-mentioned.

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