FR2480132A1 - SHEET BASKET - Google Patents

Abstract

VERY THIN SLOTTED SIEVE FOR SORTING APPARATUS, AND ITS MANUFACTURING PROCESS. THE SLOTS 2 OF THE SIEVE ARE FIRST SHAPED BY MECHANICAL MACHINING IN THE SIEVE SHEET OR BASKET, WITH AN EXCESS OF APPROXIMATELY 0.1MM IN RELATION TO THE DEFINITIVE WIDTH OF THE SLOTS, AND APPLY, AT LEAST ON THE OUTFLOW SIDE OF THE SIEVE AND BY APPLICATION OF MICROMETRIC PARTICLES, A COATING 3 THANKS TO WHICH WE OBTAIN THE DEFINITIVE WIDTH OF THE SLOTS 5 SO AS TO AVOID DIFFICULT MACHINING OPERATIONS IN THE CASE OF VERY THIN SLOTS, WHICH ENSURES AT THE SAME TIME A DECREASE IN THE COST PRICE. APPLICATION ESPECIALLY TO FLAT OR CIRCULAR-ROTATING SIEVES USED IN PAPER MANUFACTURING.

Description

The invention relates to a sieve, in particular a basket of

  wise, of a particular design.

  The paper industry is demanding more and more recently

  tales or baskets for sieving or filtering with very fine slits.

  Until now, sieves of this kind were mainly manufactured

  by mechanical milling or saw cutting. It is understandable

  that in cases where very thin slits of a width of about 0.2 mm or below are required,

  for this purpose, for example saw blades or cutting discs.

  wise, requirements that can no longer be met.

  The problem that the present invention aims to solve is to provide an adequate method of manufacturing a sieve, which is both a relatively low cost of production and nevertheless allows

  to make a slit of uniform width.

  This problem is solved according to the invention by a method of the kind mentioned in the preamble above but which also has the advantage of allowing the realization of the draft angle of the sieve slots, so the enlargement of those in the direction of the flow of the screen, not pl! s by the effect of a prior mechanical machining, but by the formation of these fendes, allowing

  to virtually eliminate this angle of displacement.

  Reference will now be made to the attached drawing for a descrip-

  more detailed description of the invention. In the drawing: FIGURE 1 shows in cross-section a fragment of a tamisla tele section being made in the transverse direction of a longitudinal slot in its preliminary form; FIG. 2 shows an identical section of the sieve with the slots in the final state, and FIG. 3 shows a section made perpendicular to the

sections of the previous figures.

  On the various FIGURES of the drawing, there is shown in 1 a sieve head, in 2 the narrow slots made in this tale for sieving, and in 3 the coating applied to t8le 2. To achieve the following slots The invention generally proceeds in such a way as to first form a relatively wide groove 4 in the sheet, by milling in the outlet face of the fluid, so that a thin thickness of metal remains between the bottom of the pipe. groove 4 and the inlet face of the sieve. Then, it is eliminated, by a mechanical machining process, that is to say by removal of

? 4801 2

  -2-, this residual thickness !! e of the t3le, -_cujo0tz years the meaning

  the width of the slit, with a width e _cedent! following 1'n-

  veantion, from about 0.1 to 0.2 a-url. I.a fïit, of -t -. -s of t C-s s ...

  subsequently carried out by means of an exhibition. nuen-

  This means that there is still a gap in the width of the screen, where the cover plate 3 remains in place so that it can be removed. On the Pigure 2, we have reprogrammed SO 2 S

  the form he presents after the applcc. ' nar o gavanoplas-

  tick of u-n denet.nétaiiq: .-. u the ifce .- ::: -. to be from

  the day for tami-sIl e. r2s.nlie, a -. t e U: -. e tC-

  2, a "debore: ent" of the rec -nten_.n-.ao: a-_ rc-mos ga example of chromium or nickel, this iuJ- SO.-. conquenca d co-e féir

  at the slit of the sieve its smallest dimension 1ed: o; e this de-

  Bilateral border, this slot is. s: cd-

  the output of the thread 2 fuse; and finally,

  your 2 are not ccux7erîas by this r - - e: -: ......... on

  e, - you, thanks to the idea n - avoi ": - - -:.; .... f ....

  * Fertility * * * * * - *

  -: - s the side between the fu of De n: nmeo pr.a: reco '- ::, g :. such as spraying or pa-re-a. dars A bath of synthetic resin, suiu. In this connection, it is possible, in some cases, for the vacuum metallization process to be carried out at room temperature. z c.does not a pro. If this is not applicable, it will be necessary to pre-drill the angle of clearance of the sieve slots according to a processing procedure or any other

  at least of demounting mechanically purified in mabe

riau full.

  In the case of a rotationally rotating sieving basket

  it will be possible, against the third party, to pay for it.

  a plastic counter-electrode (on the inlet side of the fluid to be sieved) from the screen wall, a counter-electrode of corresponding shape (with symmetrical rotation,

depending on the case).

  If immersion coating is considered in a bath composed of a coating material which will subsequently be hardened, the procedure may be

  a sieving basket with symmetrical rotation, intended to be

  poured from the outside inside by the fluid to be sieved, this basket 248O 1i32 is rotatably supported above the bath, its axis being kept parallel to the surface of the coating liquid, so that the basket

  only come into direct contact with this liquid with its

  The lower part of the periphery of the basket is rotated, and the basket is rotated at a rate lower than the rate of flow of the coating liquid. Thus, a completely uniform coating layer is obtained. In this case too, if one wishes to form not too thin slots, such as realizes a

  overflow determined on the narrow slots 2, it can also be

  denote a metal removal realization of the angle of

pug slits from the sieve.

  The process according to the invention is suitable both for the manufacture

  flat-sieving tales than that of symmetric rotation sieving baskets, and

  each case the most appropriate method, according to the conditions

  described above or the expected success in achieving this

  result in the simplest and most economical way.

  The process according to the invention is designed more particularly to produce very fine sieve slots, that is to say with a width of the order of 0.1 to 0.2 mm, which corresponds to a

  excess material of about 1.5 to 2 tenths of a mm. This is

  however, also comes essentially, for example, when considering a synthetic resin coating or coating even for higher slot widths, which also accept

  a larger allowance, in particular to ensure

  edging of the coating layer above the slots of the basket made by removing metal with an extra thickness to provide the clearance angle otherwise necessary this slot. it

  avoids burrs and sharp angles.

-4 -

Claims (13)

R E V E N D I C A T I 0 N S   1. Process for producing a sieve, in particular but not ex-   clusively for sorting apparatus or separators comprising a   symmetrical rotation sieving basket of the kind used in the   paper industry, characterized in that the sieving slits in the sheet for forming the sieve, or in the sieving basket, are first formed by a mechanical machining process, giving   at these slots a width slightly greater than the definitive width   This is followed by a coating of the plate or sieving basket, at least on the inlet side of the fluid, with a material whereby the desired final width is obtained. sieving slots.   2. Method according to Claim 1, characterized in that   the coating is carried out by deposition of micrometric particles.   3. Method according to either of Claims 1 or 2,   characterized in that the width of the slots obtained mechanically   exceeds that of the final slots by about 0.15 mm.   4. Method according to any one of Claims 1 to 3,   characterized in that first grooves (4) are formed   latively wide on the outlet side of the fluid to be sieved from the sheet or sieve basket, after which, by another removal of material, in the thickness between the bottom of the groove and the wall of the basket, the inlet side of the fluid to be sieved, the sieving slots (2, 5) are first made with the excess thickness   necessary in both width and length.   Process according to any one of Claims 1 to 4,   characterized in that the deposit is made by electroplating.   - 6. Process according to Claim 5, characterized in that consists of chromium plating.   7. Process according to Claim 5, characterized in that consists of a nickel plating.   Process according to any one of Claims 1 to 4,   characterized in that the coating is carried out by application of   metallic materials by vacuum vaporization.   9. A process according to any one of Claims 1 to 4,   characterized in that the coating is carried out by sprinkling or   jection of paint or synthetic resin.   Method according to any one of Claims 1 to 4,   characterized in that the coating is carried out by application of a 2 480132 curable synthetic resin.   11. Method according to claim 10, characterized in that the coating is carried out by immersion in a liquid synthetic resin. 12. Process according to claim 10, characterized in that, in the case of a sieving basket with symmetrical rotation, the latter is suspended above a quenching bath and is imparted to it with a rotational movement, so that only its lowest peripheral portion soaks with its outer surface in the bath, and the rotational speed is chosen so that the quenching speed of the quenched portion of the screening basket is less than the speed   flow of the synthetic resin.   Method according to any one of Claims 1 to 12,   characterized in that only the inlet or tributary side of the screen wall is coated to produce an overflow of the layer   of coating directly at the sieving slots.