JP4314299B2 - Wire screen, centrifuge, and method for manufacturing wire screen - Google Patents

Description

  The present invention relates to a wire screen suitably used for a centrifugal separator and a method for manufacturing the same.

  Centrifugal devices are used to separate two substances with respect to a material containing at least two substances. For example, when a solid material contains water and a material is formed, a centrifugal separator is used to separate water from the solid material, that is, to dehydrate it. As a conventional centrifugal separator, as disclosed in Patent Document 1, a plurality of wedge wires are juxtaposed with each other in a predetermined opening to form a flat screen, and the liquid is separated from solids by this screen. The technology is known.

  Conventionally, as disclosed in Patent Document 2, a drum-shaped screen is formed by arranging a large number of wedge wires formed in a ring shape in parallel with a gap of a predetermined dimension in the axial direction. A technique for separating a solid and a liquid is known. Conventionally, as disclosed in Patent Document 3, a technique is known in which moisture is separated from slurry using a cone-shaped (that is, cone-shaped) screen. In this document, it is not clear whether the holes formed in the screen for allowing water to pass are circular, square, etc., or the shape of a slit that is long in one direction, but referring to the attached figure, The hole is predicted to be circular or the like.

  Conventionally, as disclosed in Patent Document 4, a cylindrical screen is arranged in a vertical shape, and the screen is rotated at high speed around an axis passing through the center of the screen, while a material is placed inside the screen. A technique is disclosed in which the water content in the material is separated by centrifugal force. Although there is no detailed explanation about the shape of the hole for dehydration formed in the screen in this document, this document relates to the same applicant as the present application, and the hole provided in the screen It is well known that it is a circular hole.

  Conventionally, as disclosed in Patent Document 5, a dewatering basket that opens in a funnel shape is provided above, and a slit (elongated hole) for dehydration is provided on the peripheral side, and dehydration is performed through the hole. The technology is known. Conventionally, as disclosed in Patent Document 6, a stainless steel wedge wire having a triangular cross section is wound into a spiral cone to form an outer cylinder, and the suspension is filtered and filtrated through the outer cylinder. The technique of separating into dehydrated cake is known.

No. 57-075866 (No. 58-183203) microfilm) (pages 1, 4 and 1) JP 58-006215 (Pages 1 and 2, Fig. 1) No. 56-131263 (Japanese Utility Model Publication No. 58-035944) microfilm) (page 3, FIG. 1) Japanese Patent Laid-Open No. 9-187678 (pages 2 and 3, FIG. 1) JP-A-5-208146 (second page, FIG. 1) JP-A-11-169616 (page 3, FIG. 1)

  The inventor applied the above-described conventional technique to the raw material in which limestone, which is a mineral, is mixed in the muddy water, and performed dehydration by centrifugation. In recent years, limestone having a very high dehydration rate has been demanded in many industrial fields. According to the results and discussion of the experiment, when a screen was formed based on each of the above-mentioned conventional techniques, water was separated from the raw material to produce limestone as a dehydrated product. It was found that could not be obtained.

  As a result of various investigations, the present inventor has found that the conventional screen is likely to be clogged, and therefore there is a limit to increasing the dewatering rate, and the shape of the screen and the shape of the hole for dewatering provided on the screen. It was found that the dehydration rate can be improved by devising the above in a correlated manner.

  The present invention has been made on the basis of the above knowledge, and an object of the present invention is to provide a wire screen capable of remarkably improving the separation ability such as a dehydration rate by preventing clogging of the screen and a method for manufacturing the same. To do.

The wire screen according to the present invention is arranged with a plurality of ring members spaced apart from each other along one axis and having different inner diameters, and fixed to the inner peripheral surface of the plurality of ring members. A plurality of wires arranged side by side so as to form a conical shape around an axis, and a slit is formed between adjacent ones of the plurality of wires, and the slit is formed from the small-diameter end of the conical shape. Continuously extending over the large-diameter end, a part of the plurality of wires is a first wire whose inner surface width is constant in the length direction, and the other wires have inner surface widths of the conical shape. A second wire that gradually increases from a small-diameter end to a large-diameter end, and at least one second wire is provided for every plurality of the first wires in the circumferential direction of the conical shape. Ri, the cross-sectional shape of the second wire Ri rectangular der, wherein the width of the large-diameter end of the second wire is larger than the width of the first wire, the first wire cross-section is wedge-shaped The wedge-shaped apex is the conical outer peripheral surface, and the base opposite to the wedge-shaped apex is the conical inner peripheral surface .

  In the above configuration, the cross-sectional shape of the wire can be a wedge shape (wedge shape or triangle), a square shape, a rectangular shape, a circular shape, an elliptical shape, or the like. A wedge shape is a shape shown, for example in FIG. 2 (a-1) and (a-2). The rectangular shape is, for example, the shape shown in FIG. In addition, the shape of the inner surface of the wire, which is a conical inner peripheral surface, is a shape in which the width (w) of the inner surface is constant in the length (L) direction, for example, as shown in FIG. (This wire is referred to as a “first wire” in this specification.) Or, as shown in FIG. 2B, the inner diameter (wx) is a conical small diameter end. The shape may change so as to gradually increase from the end to the large-diameter end (the wire having this shape is referred to as “second wire” in the present specification).

  The inner surface of the first wire is generally elongated and rectangular, although both ends may be arcuate, elliptical, or oval. In addition, it is desirable that the width of the inner surface of the second wire gradually increases, but it is desirable that the width gradually changes at a constant rate (that is, linearly with a constant slope), but the rate of change slightly changes in the length direction. It may be a thing. If the width of the inner surface of the second wire gradually increases at a constant rate, the surface shape becomes an elongated wedge shape, an elongated triangular shape, an elongated trapezoidal shape, or the like.

  In the above configuration, “fixing” is, for example, fixing by welding or fixing by an adhesive. In addition, “continuously” when slits formed between a plurality of wires continuously and straightly extend means that the slits are not interrupted, and “straightly” means The slit is not bent. The width of the slit itself may be constant from the conical small-diameter end to the large-diameter end or may gradually change. At least two ring members are used. As the number of ring members increases, the mechanical strength of the wire screen may increase, but the work of fixing the wires to the ring members may become complicated. Actually, it is desirable that there are about three ring members.

According to the wire screen of the present invention, since the slit continuously extends straight from the conical small-diameter end to the large-diameter end, it is effective that the solid matter to be dehydrated and the powder coming out of it are clogged in the slit. Can be prevented.
Further, since the slit is formed in a conical shape by fixing a plurality of wires on the inner peripheral surface of the ring member, a slit that extends continuously and straightly can be easily formed between the wires. For example, it is possible to employ a method in which (i) a gauge corresponding to the slit is prepared and a plurality of wires are sequentially fixed to the ring member using the gauge. Further, (ii) a method in which marks, for example, marking lines are formed at predetermined intervals on the inner peripheral surface of the ring member, and a plurality of wires are sequentially fixed onto these marking lines can be adopted. . Further, (iii) a method of forming recesses for positioning the wires in advance on the inner peripheral surface of the ring member at a predetermined interval, and inserting a plurality of wires into the recesses and fixing them individually can be adopted.

  In the wire screen according to the present invention, it is desirable that a plurality of recesses are provided on the inner peripheral surface of the ring member, and the wire is fitted in these recesses. In this wire screen, as described above, recesses for positioning the wires are formed in advance on the inner peripheral surface of the ring member at predetermined intervals, and a plurality of wires are individually fitted into the recesses and further fixed. It is manufactured. According to this wire screen, a wire screen provided with a slit can be very easily produced with a plurality of wires. In addition, since the positioning of the wire can be performed accurately, the width of the slit can be accurately defined. Although the number of wires used in the present invention is very large, if this embodiment is used, a wire screen can be accurately formed in a short time even if the number of wires is large.

  In the wire screen according to the present invention, it is desirable that the large-diameter end side of the slit is open to the outside. If the large-diameter side of the slit is closed rather than the open end, clogging is likely to occur in the slit due to the solid matter to be dehydrated and the powder coming out of it, and the dehydration rate may be reduced. In contrast, if the large-diameter end of the slit is an open end, clogging of the slit can be prevented, and a high dehydration rate can be maintained over a long period.

  In the wire screen according to the present invention, it is preferable that the slit gradually spreads from the small-diameter end of the conical shape toward the large-diameter end. In the present invention, the raw material subjected to the liquid removal treatment based on the centrifugal force moves from the small-diameter end side to the large-diameter end side of the conical wire screen. Therefore, clogging of the slit can be effectively prevented if the slit gradually widens from the conical small-diameter end to the large-diameter end.

  In the wire screen according to the present invention, it is preferable that some or all of the plurality of wires are wedge wires having a wedge-shaped cross section. In this case, the apex of the wedge shape becomes the outer peripheral surface of the cone shape, and the base opposite to the apex of the wedge shape becomes the inner peripheral surface of the cone shape. According to this configuration, regarding the slit formed between the first wires adjacent to each other, the width of the slit on the outer peripheral surface of the conical wire screen is wider than the width on the inner peripheral surface of the wire screen. This means that even if solid matter enters the slit from the inner peripheral surface side of the wire screen, the solid matter easily moves in the outer peripheral direction of the wide slit and is released to the outside. For this reason, clogging of the slit can be prevented.

In the wire screen according to the present invention, a part of the plurality of wires is a first wire (for example, see FIG. 2A) whose inner surface width is constant in the length direction, and the other wires have inner surface widths. A second wire (see, for example, FIG. 2B) that gradually increases from the small-diameter end to the large-diameter end of the conical shape, and every plurality of the first wires in the circumferential direction of the conical shape. It is desirable that at least one second wire is provided.
In this wire screen, a wire screen is formed by two types of wires, a first wire and a second wire. According to this configuration, by appropriately adjusting the width of the second wire (for example, wx in FIG. 2B), the slit formed between the plurality of first wires can be extended from the small diameter end to the large diameter end. The width can be adjusted freely.

  In the wire screen according to the present invention, it is preferable that the plurality of wires are first wires (for example, see FIG. 2A) whose inner surface width is constant in the length direction. In this wire screen, a wire screen is formed by one type of wire of the first wire. According to the wire screen of this embodiment, the width of the slit formed between the first wires can be adjusted by adjusting the number of the first wires to be used. According to this wire screen, since one type of wire is used, the number of parts can be kept low, which is advantageous in terms of cost. Further, when forming a recess for positioning the wire in the ring member, it is advantageous because only one type of recess is sufficient.

  In the wire screen according to the present invention, the plurality of wires are second wires (see, for example, FIG. 2B) in which the width of the inner surface gradually increases from the small-diameter end to the large-diameter end of the conical shape. It is desirable. In this wire screen, a wire screen is formed by one type of second wire. According to the wire screen of this embodiment, the width of the slit formed between the second wires can be adjusted by adjusting the number of second wires to be used. In some cases, a slit having a constant width from the small diameter end to the large diameter end can be formed. According to this wire screen, since one type of wire is used, the number of parts can be kept low, which is advantageous in terms of cost. Further, when forming a recess for positioning the wire in the ring member, it is advantageous because only one type of recess is sufficient.

  Next, a method for manufacturing a wire screen according to the present invention includes a step of arranging a plurality of ring members having different inner diameters such that their centers are positioned at a distance from each other on one axis, A wire adhering step for adhering a plurality of wires to the inner peripheral surfaces of the plurality of ring members so as to form a conical shape. In the wire adhering step, slits are continuous between a plurality of adjacent wires. The plurality of wires are fixed to the ring member so as to be formed straight.

  According to this wire screen manufacturing method, the wire screen according to the present invention can be manufactured. According to the manufactured wire screen, since the slits are continuously straight, clogging of the slits can be prevented for a long period of time, and the separation accuracy of the raw materials can be maintained high for a long period of time. The manufacturing operation is very simple because only a plurality of wires are sequentially fixed onto the inner peripheral surface of the ring member.

  In the wire screen manufacturing method according to the present invention, it is desirable that a recess into which the wire fits is provided on the inner peripheral surface of the ring member. According to this configuration, since the operator only needs to perform a uniform operation of fitting the wire into the recess, the operation is very simple. Nevertheless, the width of the slit formed between the wires can be accurately defined to a desired value.

  According to the wire screen of the present invention, since the slit continuously extends straight from the small-diameter end to the large-diameter end, it is effective that the solid matter to be drained and the powder coming out of it are clogged in the slit. Can be prevented. Further, since the slit is formed in a conical shape by fixing a plurality of wires on the inner peripheral surface of the ring member, a slit that extends continuously and straightly can be easily formed between the wires.

  Hereinafter, a wire screen and a manufacturing method thereof according to the present invention will be described based on embodiments. Of course, the present invention is not limited to the embodiment. In the following description, the drawings are referred to. In the drawings, the components may be shown in different ratios from the actual ones in order to show the characteristic parts in an easy-to-understand manner.

(First embodiment of wire screen and manufacturing method thereof)
FIG. 1 shows an embodiment of a wire screen according to the present invention. This screen 1A is used, for example, to generate a solid as a product having a low moisture content by performing dehydration from a slurry in which the solid is contained in muddy water by a centrifugal separation process. The screen 1A is formed in a frustoconical shape (that is, a conical shape with the top cut off) extending from the small diameter end 1Aa to the large diameter end 1Ab. The small-diameter end 1Aa and the large-diameter end 1Ab each having a truncated conical shape are open ends. Since this wire screen is formed using a wire having a wedge-shaped cross-section (that is, wedge-shaped or triangular-shaped), it is sometimes called a wedge wire screen.

The wire screen 1A includes a plurality (three in this embodiment) of ring members 2a, 2b, and 2c, a plurality of wedge wires 3 as first wires supported by the ring members, and those rings. And a plurality of width change wires 4 as second wires supported by the member. As shown in FIG. 2 (a) and FIG. 2 (a-1), which is a cross section taken along the line aa, the single wedge wire 3 has a wedge (wedge) cross section, and its cross section is in the length direction. It is formed by the linear linear member which is constant. The maximum width w of the wedge cross section is, for example, 1.5 mm, the thickness t is, for example, 3 mm, and the total length L of the wire 3 is, for example, 310 mm. The bottom surface of the width w in the wedge wire 3 forms the inner peripheral surface of the conical screen 1A shown in FIG.
The number of ring members 2a, 2b, and 2c is not limited to three, and the materials of the wedge wires 3 and width change wires 4 to be used, their lengths, their numbers, the width dimensions of the slits 8, and the raw material Depending on the material and the like, it is appropriately selected so that the desired separation performance can be achieved. In the case of this embodiment, good results were obtained even when the number of ring members was seven.

  On the other hand, as shown in FIG. 2 (b) and FIG. 2 (b-1) which is a bb section thereof, the single width changing wire 4 has a rectangular cross-sectional shape and the width wx of the section is the smallest. It is formed in a shape that changes continuously from a value w0 to a maximum value w1 at a uniform and uniform rate (that is, an inclination), that is, an elongated wedge shape in plan view. The cross-sectional shape shown in FIG. 2 (b-1) of the width change wire 4 may be a vertically long rectangle, a square, or a horizontally long rectangle depending on which point in the longitudinal direction the bb cross section is taken. To do. The total length L of the width change wire 4 is the same as that of the wire 3 and is, for example, 310 mm, the minimum value w0 of the cross-sectional width is 2.22 mm, for example, and the maximum value w1 of the cross-sectional width is, for example, 11.3 mm. t is 4 mm.

  One of the surfaces of the width changing wire 4 having the width wx (there are two front and back surfaces) forms the inner peripheral surface of the conical screen 1A shown in FIG. In the case of FIG. 2B, the cross section of the width change wire 4 is rectangular and the surface of the width wx is formed on both the front and back surfaces. However, the cross section of the width change wire 4 is triangular (that is, wedge shape). Or a trapezoidal shape or a pentagonal shape, only one surface of the width changing wire 4 having the width wx is formed. This one surface forms the conical inner peripheral surface of FIG.

  The ring members 2a, 2b, 2c in FIG. 1 have different inner diameters, but their structures are the same as shown in FIG. FIG. 3 shows an intermediate ring member 2b as a representative. The outer peripheral surface of the ring member 2b is a uniform plane. As shown in the partial enlarged view, a plurality of rectangular recesses 6 and a plurality of wedge-shaped recesses 7 are alternately and continuously formed on the entire inner peripheral surface of the ring member 2b. In this embodiment, seven wedge-shaped recesses 7 are formed between adjacent rectangular recesses 6. The number of wedge-shaped recesses 7 between the adjacent rectangular recesses 6 can be selected from an appropriate number other than 7 depending on the state of the raw material to be dehydrated.

  Regarding the ring member 2a on the small diameter end 1Aa side and the ring member 2c on the large diameter end 1Ab side in FIG. 1, the shape and number of the wedge-shaped recesses 7 are the same as those of the intermediate ring member 2b. The number of rectangular recesses 6 in each of the ring member 2a on the small diameter end side and the ring member 2c on the large diameter end side is the same as that of the intermediate ring member 2b. However, in order to receive the width changing wire 4 whose planar shape is an elongated wedge shape, the width w2 of the rectangular recess 6 of the ring member 2a on the small diameter end side is equal to the width of the rectangular recess 6 of the intermediate ring member 2b. Further, the width w2 of the rectangular recess 6 of the ring member 2c on the large diameter end side is wider than the width w2 of the rectangular recess 6 of the intermediate ring member 2b.

  When the screen 1A shown in FIG. 1 is manufactured, the ring members 2a, 2b, 2c of FIG. 1 are arranged at a predetermined interval around the axis X0, and the ring members 2a, 2b, 2c are wedge-shaped. The sharp edge portion of the wedge wire 3 shown in FIG. 2A is fitted into the recess 7 and further fixed by welding, adhesion or the like. Further, the width wx side of the width changing wire 4 in FIG. 2B is fitted into the rectangular recess 6 of the ring members 2a, 2b, 2c, and further fixed by welding, bonding or the like. By performing these operations on all of the wedge-shaped recesses 7 and the rectangular recesses 6 of the ring members 2a, 2b, 2c, a plurality of wires 3, 4 are arranged side by side so as to form a conical shape around one axis X0. 1A is produced.

  FIG. 4 shows a front structure of the screen 1A shown in FIG. As shown in the partially enlarged view of FIG. 4, seven wedge wires 3 are provided between a pair of adjacent width change wires 4. A slit (that is, a linear through gap) 8 is formed between the wedge wires 3 adjacent to each other. These many slits 8 prohibit the passage of the solid product component of the raw material slurry, and function as a hole that allows the passage of the component to be separated of the raw material, for example, moisture. These slits 8 are open to the outside on the large diameter end 1Ab side.

  FIG. 5 shows a side structure of the screen 1A shown in FIG. As shown in FIG. 5, the cone inclination angle α of the frustoconical shape of the screen 1A is set to about 20 °. However, this inclination angle α is selected to an appropriate value according to the state of the raw material and the target dehydration rate. The inclination angle α can be set to a desired value by adjusting the mutual distance between the ring members 2a, 2b, and 2c and the inner diameter thereof. Note that the length L of the peripheral surface of the screen 1A in the direction of the axis X0 is the length L itself of the wedge wire 3 and the width change wire 4, and is 310 mm in this embodiment.

  The width of the slit 8 formed between the wedge wires 3 is set to have a tapered shape (that is, a wedge shape) of the width changing wire 4 so that the small diameter end 1Aa side is narrow and the large diameter end 1Ab side is wide. Specifically, the slit width WS1 on the small diameter end side is set to about 0.2 mm, and the slit width WS2 on the large diameter side is set to about 0.8 mm. In addition, the opening angle of the slit 8 between the wedge wires 3 can be adjusted by adjusting the wedge-shaped opening angle β of the width changing wire 4 (see FIG. 2B). Specifically, if the opening angle β of the width change wire 4 is increased, the opening angle of the slit 8 can be decreased. Conversely, if the opening angle β of the width change wire 4 is decreased, the opening angle of the slit 8 is increased. it can.

  As described above, in the wire screen 1A of the present embodiment, the plurality of wires 3 and 4 are provided side by side so as to form a conical shape around one axis X0. Some of these wires 3 and 4 are wedge wires 3 whose inner surface width is constant in the length direction, and other wires are width-deformed wires 4 whose inner surface width varies in the length direction. The width of the inner surface of the width deforming wire 4 gradually increases from the conical small-diameter end 1Aa to the large-diameter end 1Ab, preferably with a constant inclination. One width deformation wire 4 is provided for every plurality of wedge wires 3 in the circumferential direction of the conical shape. A plurality of the width deforming wires 4 may be adjacent to each other. A slit 8 (see FIG. 5) is provided between adjacent ones of the plurality of wedge wires 3. These slits 8 continuously and straightly extend from the conical small-diameter end 1Aa to the large-diameter end 1Ab, and the large-diameter end 1Ab side of these slits 8 is open to the outside.

  Hereinafter, the usage method of the wedge wire screen 1A of this embodiment is demonstrated. In FIG. 1, the screen 1A is rotated at a high speed in the counterclockwise direction when viewed from the large-diameter opening side, as indicated by an arrow C, with the center axis X0 of the truncated cone shape as the center. Of course, the rotation direction may be the reverse direction. Then, raw material slurry (for example, a mixture of solid and water) is supplied into the rotating screen 1A (particularly near the small diameter side 1Aa). Normally, the raw material is introduced from the opening on the large diameter side 1Ab, but it is possible to introduce this from the small diameter side 1Aa.

  The raw material thus charged adheres to the inner surface of the screen 1A, that is, the inner peripheral surfaces of the wedge wire 3 and the width change wire 4 by centrifugal force applied from the rotating screen, and follows the cone-shaped inclination of the screen 1A. Move toward the large diameter end 1Ab. During the movement, moisture in the raw material is released to the outside of the screen 1A through the slit 8 between the wires 3 and 4 (see the partially enlarged views in FIGS. 4 and 5) by the action of centrifugal force. Is dehydrated, and the solid matter after the dehydration treatment is discharged to the outside from the opening on the large diameter end 1Ab side of the screen 1A and is collected as a product.

  In the present embodiment, as shown in FIG. 5, the slit 8 of the screen 1A is continuous (that is, without being interrupted) from the small-diameter end 1Aa of the frustoconical shape to the large-diameter end 1Ab (that is, without being bent). ) It extends. For this reason, it can prevent clogging in the slit 8 the solid substance which is a dehydration object, and the powder which comes out of it.

  In the present embodiment, the slit 8 is open toward the outside at the large-diameter end 1Ab. If the large diameter side of the slit 8 is closed rather than the open end, the slit 8 is likely to be clogged by the solid matter to be dehydrated and the powder coming out of it, and the dehydration rate may be reduced. On the other hand, if the large diameter end of the slit 8 is an open end, the slit 8 can be prevented from being clogged, and a high dehydration rate can be maintained over a long period of time.

  Further, in the present embodiment, the small diameter end 1Aa side of the slit 8 is narrow and gradually widens at a constant rate toward the large diameter end 1Ab side. For this reason, even if solid matter or powder thereof enters the slit 8, they are immediately discharged to the outside of the slit 8, and therefore, clogging can be prevented. In the present embodiment, the width of the slit 8 is changed from the small diameter end 1Aa to the large diameter end 1Ab. However, the present invention includes the case where the width of the slit 8 is constant from the small diameter end 1Aa to the large diameter end 1Ab.

  In the present embodiment, seven wedge wires 3 are provided between a pair of width change wires 4 adjacent to each other. However, a larger or smaller number of wedges are provided between a pair of width change wires 4. A wire 3 may be provided. In those cases, the number and arrangement positions of the rectangular recesses 6 and the wedge-shaped recesses 7 provided on the inner peripheral surfaces of the ring members 2a, 2b, and 2c are appropriately changed. In the present embodiment, three ring members 2a, 2b, and 2c are used in FIG. 1, but the number of ring members may be two or four or more.

  In the above embodiment, as shown in FIG. 2 (a-1), the screen 1A of FIG. 1 is configured using a wedge-shaped linear member having a triangular cross section, that is, a so-called wedge wire 3. Instead of the wedge wire, a wedge wire which is a wedge-shaped linear member having a pentagonal cross section as shown in FIG. 2 (a-2) or a wire having a rectangular cross section as shown in FIG. 2 (a-3). A screen can also be comprised using a shaped member. It is also possible to use a linear member having a square cross section or other cross section.

( Comparison example of wire screen)
FIG. 6 shows a comparative example of a wire screen according to the present invention. The screen 1A of the first embodiment shown in FIG. 1 includes a plurality of wedge wires 3 as first wires having a wedge-shaped cross section and a plurality of width changing wires 4 as second wires having a long and narrow wedge-shaped plane. And were formed. On the other hand, the screen 1B of this comparative example does not use the width change wire 4 of FIG. 2B, and only a plurality of wedge wires 3 shown in FIG. 2A are used as ring members 2a, 2b, and 2c. It is formed by assembling.

FIG. 7A shows an enlarged view of a part of the large-diameter end 1Bb indicated by the arrow D in FIG. 6 viewed from the front direction, and the ring member 2c appears in an arc shape. FIG. 7B shows an enlarged view of a part of the large-diameter end 1Bb indicated by the arrow E as viewed from the side, and the ring member 2c appears linearly. In this comparative example , the width of the surface of the wedge wire 3 serving as the conical inner peripheral surface is uniform from the small diameter end 1Ba to the large diameter end 1Bb, so that the small diameter of each slit 8 formed between the wedge wires 3 is. The opening angle from the end to the large diameter end is larger than the opening angle of the slit in the embodiment shown in FIG.

As described above, in the wire screen 1B of this comparative example , a plurality of wires 3 are arranged side by side so as to form a conical shape around one axis X0, and all of these wires have an inner surface width. The wedge wire 3 is constant in the length direction. A slit 8 (see FIG. 7) is provided between adjacent ones of the plurality of wedge wires 3. These slits 8 extend straight from the conical small-diameter end 1Ba to the large-diameter end 1Bb, and the large-diameter end 1Bb side of the slit 8 is open to the outside.

The manufacturing method of the screen 1B of this comparative example is basically the same as the manufacturing method of the screen 1A shown in FIG. The difference is that the wire to be used is one type of the wedge wire 3 in FIG. 2A, and the recessed portion for fitting provided on the inner peripheral surface of the ring member 2 b in FIG. 3 is also one type for the wedge wire 3. Thus, according to the screen 1B of this comparative example , since one type of wire is used, the cost of parts can be reduced, and the production of the ring members 2a, 2b, and 2c is simplified.

( Other comparative examples of wire screen)
FIG. 8 shows another comparative example of the wire screen according to the present invention. The screen 1A of the first embodiment shown in FIG. 1 is formed by using a plurality of wedge wires 3 having a wedge shape in cross section and a plurality of width changing wires 4 having a long and narrow wedge shape in plan view. Further, in the screen 1B of the comparative example shown in FIG. 6, the screen was formed only by the wedge wire 3. On the other hand, the screen 1C of this comparative example does not use the wedge wire 3 of FIG. 2A, but only a plurality of width change wires 4 shown in FIG. 2B are used as ring members 2a, 2b, 2c. It is formed by assembling.

  FIG. 9A shows an enlarged view of a part of the large-diameter end 1Cb indicated by the arrow F in FIG. 8 viewed from the front direction, and the ring member 2c appears in an arc shape. FIG. 9B shows an enlarged view of a part of the large-diameter end 1Cb indicated by the arrow G as viewed from the side, and the ring member 2c appears linearly. This screen 1C is formed by assembling only a plurality of width change wires 4 shown in FIG. 2 (b) to the ring members 2a, 2b, 2c without using the wedge wire 3 of FIG. 2 (a). . The cross-sectional shape of the width change wire 4 is not a wedge shape but a rectangular shape or a square shape. By appropriately adjusting the spread angle β of the width change wire 4, the width of the slit formed by the adjacent width change wires 4 can be made constant from the small diameter end to the large diameter end.

As described above, in the wire screen 1C of the present comparative example , the plurality of wires 4 are provided side by side so as to form a conical shape around one axis X0. All of these wires 4 are width changing wires 4 whose inner surface width changes in the length direction. The width of the inner surface of the width changing wire 4 is gradually increased from the conical small diameter end 1Ca to the large diameter end 1Cb. Slits 8 are formed between adjacent ones of these width change wires 4, and these slits 8 continuously extend straight from the small-diameter end 1Ca to the large-diameter end 1Cb. The large diameter end 1Cb side of the slit 8 is open to the outside.

The method for manufacturing the screen 1C of this comparative example is basically the same as the method for manufacturing the screen 1A shown in FIG. The difference is that the wire to be used is one type of the width change wire 4 of FIG. 2B, and the recessed portion for fitting provided on the inner peripheral surface of the ring member 2b of FIG. is there. Thus, according to the screen 1C of this comparative example , since one type of wire is used, the component cost can be reduced, and the ring members 2a, 2b, and 2c can be easily manufactured.

(Other embodiments)
In the above embodiment, a plurality of wires 3 and 4 are supported in a truncated cone shape using three ring members 2a, 2b and 2c as ring members. However, the number of ring members may be two, or four or more. If the number of ring members increases, the mechanical strength of the wire screen can be increased, but the work of fixing the wires to the ring members becomes complicated. In practice, the number of ring members is preferably about three in consideration of workability. In consideration of both workability and mechanical strength, about seven are desirable.

(Use example of wire screen)
Hereinafter, in order to make the structure and function of the wire screen of the present invention easier to understand, an example of its use will be described. In this usage example, the wire screen 1A according to the embodiment shown in FIG. 1 is used.

  FIG. 10 shows an external structure of an example of a centrifuge using a wire screen. FIG. 11 shows a front sectional structure of the centrifugal separator. In FIG. 10, the centrifugal separator 11 includes a centrifugal separator 12 that performs a centrifugal separation process, and a power unit 13 that generates a driving force for the process. Note that the structural elements described below are formed of a metal such as stainless steel or structural steel unless otherwise specified.

  A raw material supply port 14 for supplying raw materials is provided at the top of the centrifugal separator 12. In this embodiment, it is assumed that a slurry in which limestone, which is a kind of ore quarried from a mine, is contained in muddy water is input as a raw material. In this embodiment, limestone having a diameter of 20 mm or less is charged in a slurry state, and the limestone is taken out as a product in a dehydrated state. The raw material supply port 14 is equipped with a hopper 16 shown in FIG. A drain pipe 17 as a drain pipe is provided at the lower part of the centrifugal separator 12. The drain pipe 17 discharges water separated from the slurry by the centrifugal separation process to the outside. A product discharge port 18 is provided at the bottom of the centrifugal separator 12. The product discharge port 18 discharges limestone as a product in a state where moisture is desorbed (ie, dehydrated) by the centrifugal separation process.

  In FIG. 11, a speed reducer 19 is provided inside the power unit 13. The speed reducer 19 includes an outer rotor 21 and an inner rotor 22 provided therein. The rotation axes of these rotors coincide. That is, the outer rotor 21 and the inner rotor 22 have a coaxial rotating structure. The outer rotor 21 is rotatably supported on the machine frame 24 by two bearings 23 and 23. One of the inner rotors 22 is rotatably supported on the outer rotor 21 by a bearing 26, and the other is rotatably supported on the machine frame 24 by a bearing 27. With the above configuration, the outer rotor 21 and the inner rotor 22 are rotatable independently of each other.

  A pulley 28 is provided at the left end portion of the outer rotor 21. An electric motor 29 is provided outside the machine casing 24, and a pulley 31 is provided on the output shaft of the motor. A belt 32 is stretched between the pulley 28 and the pulley 31. When the motor 29 is operated and the output shaft rotates, the rotation is transmitted by the belt 32 and the outer rotor 21 rotates. For example, it rotates at a high speed of 500 to 1800 rpm.

  An arbitrary speed reduction mechanism is provided between the outer rotor 21 and the inner rotor 22, and thus the inner rotor 22 rotates in the same direction at a higher speed than the outer rotor 21. For example, the outer rotor 21 rotates at a speed higher by 1/59 than the rotational speed of the outer rotor 21, that is, at a high speed of 508 to 1831 rpm. Thus, the reason why the rotational speed is different between the outer rotor 21 and the inner rotor 22 is to make the movement of the raw material stable and smooth during the centrifugal separation process performed in the centrifugal separator 12. Details will be described later.

  As a speed reduction mechanism for rotating the inner rotor 22 faster than the outer rotor 21 by a predetermined speed, various conventionally known speed reduction mechanisms can be employed. For example, a planetary gear speed reduction mechanism, a harmonic drive speed reduction mechanism, a cyclo speed reduction mechanism, an RV speed reduction mechanism, a ball speed reduction mechanism, or any other speed reduction mechanism can be employed. In this embodiment, a cyclo deceleration mechanism is used. This cyclo reduction mechanism can be constituted by a combination of a planetary gear mechanism and an arc gear, for example.

  The front end of the outer rotor 21 protrudes into the centrifugal separator 12, and a flange 33 is fixed to the protruding portion. A basket 34 is fixed to the flange 33. The tip of the inner rotor 22 protrudes outside the outer rotor 21 inside the centrifugal separator 12. A boss 36 of the screw body 35 is fastened and fixed to the protruding portion by a cap nut 37. A slight gap is formed between the outer peripheral surface of the flange 33 fixed to the front end of the outer rotor 21 and the inner peripheral surface of the boss 36 fixed to the front end of the inner rotor 22. 36 can rotate independently without restricting other rotations.

  A semi-cylindrical drainage channel 38 is provided at the lower part of the basket 34, and the drainage pipe 17 is continuously provided at the tip of the drainage channel 38. The space on the right side of the basket 34 is a space from which the dehydrated limestone discharged from the basket 34 pops out, and a product discharge port 18 is opened as an opening in the lower portion of this space.

  A material transport pipe 39 is provided at the lower part of the raw material supply port 14 provided at the upper part of the centrifugal separator 12. An opening 39 a at the lower end of the material conveying tube 39 extends to the inside of the screw body 35. An air conveyance pipe 41 extending in the horizontal direction is provided on the right side of the screw body 35. An opening 41 a on the outside of the air carrying tube 41 opens to the outside of the centrifugal separator 12. The material transfer pipe 39 extends through the side wall of the air transfer pipe 41 to the inside of the screw body 35.

  FIG. 12A shows a side sectional structure of the screw body 35. FIG.12 (b) has shown the front structure of the screw body 35 according to the arrow H of Fig.12 (a). In FIG. 12A, the screw body 35 includes the boss 36 fixed to the tip of the inner rotor 22, the conical side wall 42 fixed to the outer peripheral surface of the boss 36, and the outer peripheral surface of the side wall 42. And a plurality of (six in the embodiment) blade members 43 are provided. The boss 36 functions as an inner wall of the screw body 35. A shielding flange 44 protruding in the radial direction is provided at a portion where the side wall 42 is fixed to the boss 36. The small-diameter end of the side wall 42 is fixed to a boss 36 that is an inner wall, and the large-diameter end is an open end. The boss 36 has a conical shape, that is, a mountain shape.

  In the vicinity of the portion attached to the boss 36 of the side wall 42, a plurality of material openings 46 for allowing the raw material to pass from the inside to the outside are provided in an appropriate size along the circumferential direction of the side wall 42. Yes. A partition member 47 is fixed on the inner peripheral surface of the side wall 42 farther from the boss 36 than the material opening 46. The partition member 47 is formed in a conical shape in which the conical inclination direction is opposite to the conical inclination direction of the side wall 42. The vicinity of the opening 39 a of the material transport pipe 39 in FIG. 11 is fitted in the opening at the tip of the partition member 47, and the opening 39 a faces the internal region of the partition member 47.

  A plurality of, in the present embodiment, two air flow partition members 48a and 48b are fixed to each other on the inner peripheral surface of the side wall 42 farther from the partition member 47 when viewed from the boss 36. These partition members 48 a and 48 b are both formed in a conical shape in the same conical inclination direction as the partition member 47. The vicinity of the front end opening of the air conveyance tube 41 enters the inside of the airflow partition member 48a on the back side as viewed from the outside. A plurality of air openings 49 are provided on the side wall 42 between the partition member 47 and the airflow partition member 48a and on the side wall 42 between the airflow partition members 48a and 48b. The open end of the airflow partition member 48b on the outer side is closed by a flange 51 that is provided in the air transport pipe 41 and protrudes in the radial direction.

  Each blade member 43 provided on the outer peripheral surface of the side wall 42 is formed in a spiral shape. The spiral shape of the blade member 43 starts from the vicinity of the base portion of the side wall 42 to the boss 36 (that is, the portion where the shielding flange 44 is provided) and ends at the large diameter end (that is, the open end) of the side wall 42. . The spiral shape of one blade member 43 may be a shape that takes exactly one cycle from the start point on the small diameter end side to the end point on the large diameter end side, or one cycle does not fall between the start point and the end point. It may be a shape that does not exist, or it may be a shape in which one period or more is accommodated between the start point and the end point. This spiral shape is such that when the screw body 35 rotates in either the predetermined forward or reverse clockwise direction, the raw material existing on the outer peripheral surface of the side wall 42 is directed from the small diameter end where the boss 36 is present to the large diameter end. It has a spiral shape to convey.

  As shown in FIG. 13, the basket 34 provided so as to cover the screw body 35 in FIG. 11 is formed by assembling and fixing the screen 1A inside a frame 52 having a conical shape and a framework structure.

  FIG. 14 schematically shows a process of manufacturing the basket 34 by attaching the screen 1A to the frame 52. FIG. 15 shows a state where the attachment of the screen 1A to the frame 52 is completed and the basket 34 is completed. In FIG. 14, among the plurality of ribs 53 constituting the frame 52, recesses 54 that are counterbore surfaces are provided on three large-diameter surfaces of the small-diameter side, the central one, and the large-diameter side. Then, the ring members 2a, 2b, 2c of the screen 1A are fitted into the respective recesses 54, and are further bolted, so that the screen 1A is fixed to the frame 52, and both are integrated. When the number of ring members 2a to 2c increases, the number of ribs 53 provided with the recesses 54 increases accordingly.

The operation of the centrifugal separator having the above configuration will be described below.
First, in FIG. 11, the raw material that is the object of the centrifugal separation process (that is, centrifugal dehydration process) is put into the hopper 16. This raw material is in a state where limestone mined in the mine is contained in the muddy water. The water content of this raw material is usually 3 to 11% by weight. The size of the mined limestone varies, but the limestone supplied to the hopper 16 is selected in advance to have a diameter of 20 mm or less. This sorting is mainly for protecting the internal structure of the centrifugal separator 11 from damage.

  Note that water may be supplied into the hopper 16 by a water supply device (not shown) at the same time when the raw material is supplied into the hopper 16. This supply of water allows the limestone in the raw material to be cleaned, thus eliminating the need to pre-clean the raw material before providing the raw material into the hopper 16. Since the centrifugal separator 11 of the present embodiment can separate (ie, dehydrate) water with very high efficiency, even if water is added to the raw material in this way, the water content of the limestone as the final product is desired. Or less.

  Further, when the raw material is put into the basket 34 as it is without adding water, the raw material tends to rotate and move as a lump at the offset position inside the basket 34, and the balance of the rotating basket 34 is lost and vibration is generated. As a result, the parts may be damaged or the separation accuracy may be lowered. On the other hand, if water is added to the raw material before the liquid removal treatment, the flow of the raw material inside the basket 34 can be promoted, and the raw material is prevented from being displaced inside the basket 34 and distributed evenly. Therefore, it is possible to prevent the balance of the rotating basket 34 from being lost and vibrations from occurring, and as a result, it is possible to prevent damage to parts and a decrease in separation accuracy.

  When the electric motor 29 is operated in the centrifugal separator 11, the output shaft rotates, and the rotation is transmitted to the speed reducer 19 by the belt 32 and the outer rotor 21 rotates. The direction of this rotation may be either a clockwise direction or a counterclockwise direction when viewed from the direction of arrow I. Moreover, the rotation speed of this rotation is an appropriate value within the range of 500-1800 rpm, for example. The rotation of the outer rotor 21 is transmitted to the inner rotor 22 by the action of a speed reduction mechanism (in this embodiment, a cyclo speed reduction mechanism) in the speed reducer 19, and the inner rotor 22 rotates. The direction of this rotation is the same as that of the outer rotor 21, and the rotational speed is a value increased by 1/59 of the rotational speed of the outer rotor 22, that is, a value within the range of 508 to 1851 rpm. The speed increasing ratio of the inner rotor 22 to the outer rotor 21 is appropriately set after examining the actual dewatering situation.

  The basket 34 fixed to the tip of the outer rotor 21 rotates around the central axis integrally with the outer rotor 21. On the other hand, the screw body 35 fixed to the tip of the inner rotor 22 rotates at a higher speed than the basket 34 around the central axis integrally with the inner rotor 22. That is, the basket 34 and the screw body 35 relatively rotate at different speeds. The raw materials (limestone and water) that have flowed through the material conveying pipe 39 are discharged from the opening 39 a into the screw body 35, particularly into the partition member 47. The discharged raw material collides with the boss 36 which is the inner wall, and further moves in the radial direction by the action of centrifugal force, passes through the material opening 46 provided at the root portion of the side wall 42, and passes through the inner peripheral surface ( That is, it is supplied into a conical annular space (that is, a dewatering region) between the screen 1A) and the outer peripheral surface of the screw body 35.

  The raw material that has entered the dewatering region is subjected to centrifugal force by the action of high-speed rotation of the basket 34 and adheres to the inner peripheral surface of the screen 1A. Further, the raw material is scraped by the blade member 43 provided on the outer periphery of the screw body 35 that rotates relative to the basket 34, and moves spirally toward the large-diameter open end while adhering to the screen 1A. While the raw material moves on the screen 1A in this way, water in the raw material is discharged to the outside through a plurality of slits 8 formed between the plurality of wedge wires 3 in FIG. 5, and the raw material is dehydrated. Generally, by this dehydration, limestone having a diameter of 10 to 3 mm is dehydrated to a moisture content of about 0.7% by weight, and limestone having a diameter of 3 mm or less is dehydrated to a moisture content of about 1.1% by weight. The boss 36, which is the inner wall, is formed in a conical shape with a high central portion, that is, a chevron shape, so that the raw material discharged from the opening 39a of the material conveying tube 39 is uniform from the top to the skirt of the boss 36. Distributed. Thereby, clogging of the raw material in the vicinity of the material opening 46 can be prevented, and a stable flow of the raw material can be realized.

  During the dehydration process based on the centrifugal force as described above, in FIG. 11, hot air, that is, a high-temperature air flow is supplied from a hot air supply device (not shown) to the air conveyance pipe 41. The supplied hot air is supplied to the inside of the screw body 35, particularly the outer region of the partition member 47 by the air conveyance pipe 41. The temperature of the hot air is set, for example, with an appropriate value within a range of 110 ° C. to 130 ° C. as a target. The hot air flows toward the side wall 42 along the air flow partition members 48a and 48b provided inside the screw body 35, and passes through a plurality of air openings 49 provided on the side wall 42 to a wide area of the screen 1A. Evenly sprayed and flows to the outside through the slit 8. The raw material moving along the inner peripheral surface of the screen 1A is dried by the high-temperature air flow, and as a result, the raw material is dehydrated.

As described above, in this embodiment, the dehydration by centrifugal force and the dehydration by drying using a high-temperature air stream can be performed to perform extremely high-efficiency dehydration. Can be dehydrated to The slit 8 (see FIG. 5) of the screen 1A in the present embodiment is not provided in the circumferential direction around the rotation axis of the screen 1A, but is continuous (that is, without interruption) in the direction along the rotation axis. Since it is provided straight (that is, without bending), limestone or the like is not clogged in the slit 8. In addition, since the large-diameter end of the slit 8 is open to the outside, even if limestone or the like enters the slit 8, the limestone is easily released to the outside at the open end. It has been found that such a configuration relating to the slit 8 is very effective with respect to the present embodiment in which dehydration by hot air drying is performed in addition to dehydration by centrifugal force.

  The water separated from the limestone by the dehydration process is collected by the drainage channel 38 to the drainage pipe 17 and discharged to a predetermined external location. On the other hand, the limestone as the product dehydrated with high efficiency by the dehydration process is collected to the outside through the product discharge port 18.

  In the above description, the wire screen according to the present invention is applied to a centrifugal separator for dehydration. However, the wire screen of the present invention can be applied to any other apparatus. For example, the present invention can be applied to a separation device that separates a first solid material and a second solid material.

It is a perspective view showing one embodiment of a wire screen concerning the present invention. It is a figure which shows one Embodiment of the wire which is a component of a wire screen. It is a figure which shows one Embodiment of the ring member which is a component of a wire screen. It is a front view of the wire screen of FIG. It is a side view of the wire screen of FIG. It is a perspective view which shows the comparative example of the wire screen which concerns on this invention. It is the elements on larger scale of the wire screen of FIG. It is a perspective view which shows the other comparative example of the wire screen which concerns on this invention. It is the elements on larger scale of the wire screen of FIG. It is a perspective view which shows an example of the centrifuge which is a usage example of the wire screen which concerns on this invention. It is front sectional drawing of the centrifuge of FIG. It is a figure which shows the screw body which is a component of the centrifuge of FIG. It is a perspective view which shows the basket which is a component of the centrifuge of FIG. FIG. 14 is an exploded view of the basket of FIG. 13. FIG. 14 is a side cross-sectional view of the basket of FIG. 13.

Explanation of symbols

1A, 1B, 1C. Wire screen, 2a, 2b, 2c. Ring members,
3. 3. Wedge wire 5. width change wire; 6. rectangular recess, 7. wedge-shaped recess; Slit, 11. Centrifuge, 12. Centrifuge, 13. Power section, 14. 16. Raw material supply port Hopper, 17. Drainage pipe, 18. 18. Product outlet, Decelerator,
21. Outer rotor, 22. Inner rotor, 23, 26, 27. bearing,
24. Machine frame 28,31. Pulley, 29. Electric motor 32. belt,
33. Flange, 34. Basket, 35. Screw body, 36. Boss,
37. Cap nut, 38. Drainage channel, 39. Material transport tube, 39a. Opening,
41. Air carrying tube, 41a. The opening of the tube, 42. Side walls, 43. Blade member,
44. 45. shielding flange; Opening, 47. Partition member,
48a, 48b. Air flow partition member, 49. Air opening, 51. Flange,
52. Frame, 53. Ribs, 54. Recess

Claims (8)

A plurality of ring members arranged at intervals along one axis and having different inner diameters;
A plurality of wires fixed to the inner peripheral surface of the plurality of ring members and arranged in a conical shape around the one axis,
A slit is formed between adjacent ones of the plurality of wires,
The slit extends continuously straight from the small-diameter end to the large-diameter end of the conical shape,
Some of the plurality of wires are first wires whose inner surface width is constant in the length direction, and the other wires are such that the inner surface width gradually increases from the small-diameter end to the large-diameter end of the conical shape. A second wire that changes,
At least one second wire is provided for every plurality of the first wires in the circumferential direction of the conical shape,
Cross-sectional shape of the second wire Ri rectangular der,
The width of the large-diameter end of the second wire is wider than the width of the first wire,
The first wire is a wedge wire having a wedge-shaped cross section, the apex of the wedge is the outer peripheral surface of the conical shape, and the base opposite to the apex of the wedge shape is the inner peripheral surface of the conical shape wire screen, characterized in going on <br/> it.   2. The wire screen according to claim 1, wherein the width of the second wire is wider than the width of the first wire in the entire region from the small diameter end to the large diameter end.   The wire screen according to claim 1 or 2, wherein a plurality of recesses are provided on the inner peripheral surface of the ring member, the wires are fitted into these recesses, and the recesses into which the second wire is fitted are A wire screen characterized by being a rectangular recess.   4. The wire screen according to claim 1, wherein the end surfaces on the large-diameter end side of the plurality of first wires adjacent to each other are spaced apart from each other, thereby interposing the first wires. A wire screen characterized in that the large-diameter end side of the slit formed on the outside is open to the outside.   5. The wire screen according to claim 1, wherein the slit formed between the first wires gradually widens from a small-diameter end to a large-diameter end of the conical shape. A wire screen characterized by that. A screen having a conical shape between the small-diameter end and the large-diameter end, and having a plurality of slits through which liquid contained in the raw material passes;
A screw body provided inside the screen;
Rotation drive means for rotating the screen and the screw body at different speeds;
A material conveying pipe for supplying raw materials into the screw body,
The screw body is
An inner wall on the side corresponding to the small diameter end of the screen;
A side wall extending from the inner wall to the large-diameter end of the screen;
A blade member provided on the side wall and facing the inner peripheral surface of the screen;
A material opening that is provided in a portion of the side wall close to the inner wall and allows a raw material to pass through;
The screen
A plurality of ring members arranged at intervals along one axis and having different inner diameters;
A plurality of wires fixed to the inner peripheral surface of the plurality of ring members and arranged in a conical shape around the one axis,
A slit is formed between adjacent ones of the plurality of wires,
The slit extends continuously straight from the small-diameter end to the large-diameter end of the conical shape,
Some of the plurality of wires are first wires whose inner surface width is constant in the length direction, and the other wires are such that the inner surface width gradually increases from the small-diameter end to the large-diameter end of the conical shape. A second wire that changes,
At least one second wire is provided for every plurality of the first wires in the circumferential direction of the conical shape,
The cross-sectional shape of the second wire is rectangular, and
The slit formed between the plurality of first wires extends straight and continuously from the small diameter end side to the large diameter end side within the conical surface of the screen. . Disposing a plurality of ring members having different inner diameters so that their centers are spaced from each other on one axis;
A wire fixing step of fixing a plurality of wires on the inner peripheral surfaces of the plurality of ring members so as to form a conical shape,
In the wire fixing step, the plurality of wires are fixed to the ring member so that a straight slit is continuously formed between the plurality of adjacent wires.
A part of the plurality of wires is a first wire whose inner surface width is constant in the length direction;
The other wire is a second wire that changes so that the width of the inner surface gradually increases from the small-diameter end to the large-diameter end of the conical shape,
In the wire fixing step, at least one second wire is provided for every plurality of the first wires in the circumferential direction of the conical shape,
Cross-sectional shape of the second wire Ri rectangular der,
The width of the large-diameter end of the second wire is wider than the width of the first wire,
The first wire is a wedge wire having a wedge-shaped cross section, the apex of the wedge is the outer peripheral surface of the conical shape, and the base opposite to the apex of the wedge shape is the inner peripheral surface of the conical shape The method for manufacturing a wire screen , wherein the first wire is fixed to the ring member . 8. The method of manufacturing a wire screen according to claim 7 , wherein a recess into which the wire is fitted is provided on an inner peripheral surface of the ring member, and the recess into which the second wire is fitted is a rectangular recess. A method for manufacturing a wire screen.

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