US2394378A - Riffler for cellulose stock - Google Patents

Description

Patented res. 5,1946

2,394,378 amen FOR CELLULOSE STOCK William E. Henry, Hopewell, Va., assignor to Hercules Powder Company, Wilmington, DeL, a corporation of Delaware Application August 7, 1943, Serial No. 497,789

4 Claims. (or. 92-28) This invention relates to the refining of cellu lose materials and more particularly to rifliers of the trough type which are used in conjunction with other processing equipment in the art of paper making.

Heretofore, a rifiler in the form of'a rifile trough, that is, a shallow wooden sluice equipped with a set of baflles all along the bottom and sometimes provided with a felt lining on the bottom, has been utilized to catch and retain the solid impurities in the paper stock. The rifiler, generally, is on a level, without any incline, so that the current is leisurely, being produced by the pump that draws the stock from the rifiler. In this trough the various heavy impurities that may be in the stock, such as particles of sand. metallic objects and the like, sink to the bottom and are held by the bailies or the felt or a combination of these. The capacity of the rifller should be sufiiclent to take care of the output of the digesters, or that portion of the digester output devoted to paper making and the length is governed chiefly by the amount of space able to be devoted to it, the longer the better.

The stock from the rifller is either pumped or gravitates to subsequent processing apparatus, such as diaphragm screens or other apparatus depending upon the particular process being employed. The =riiiler must be cleaned from, time to time to remove the entrapped solid impurities. The prior art riiiler devices are very difficult to clean and exceedingly expensive to maintain.

This is particularly so when it is necessary to use felt to catch and retain the solid impurities,

as the. felt mats are expensive to replace. How-' ever, a felt mat on the bottom of the rifiler still remains as the most effective means in the prior art devices to retain the solid impurities in the stock, particularl when it is necessary that the stock as discharged from the riflier be substantially free of solid impurities. It is, therefore, the principal object of this invention to improve rlmers of this general type. Another object of this invention is to provide an improved riflle trough in which the solid impurities in the stock are more effectively removed, and the cleaning of the trough may be effectively and expeditiously performed. Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims. .7

Generally described, the present invention comprises a riflle assembly having in combination supported foraminous members with a plurality of settling areas disposed therebeneath and a plurality of overflow sections disposed thereabove, said assembly being constructed in units and each unit adapted to be removed to facilitate and expedite cleaning of the settling areas.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawing forming a part of the specification wherein reference symbols refer to like parts wherever they occur: Fig. 1 is a fragmentary plan view of one form of apparatus for the em bodiment of the invention; Fig. 2 is a fragmentary sectional view taken along the section 2-2 of Fig. 1; and Fig. 3 is a transverse sectional view of the apparatus shown in Fig. 1.

In Figs. 1, 2 and 3, a sluice I with sides 3 and 5 and a bottom I is provided with a liquid impervious metallic lining 9. A perforated screen ll, disposed along the bottom of sluice I, has a plurality of supporting angle irons l3 rigidly secured to the bottom thereof. The screen II also has an angle iron l5 rigidly secured to the top thereof. A plurality of hinges ll are rigidly secured through the screen I I to the angle irons l3 and to the side 5 of the sluice I. A longitudinal member is is rigidly secured to the screen II which member is in turn provided with a handle 2 l. The handle 2| in conjunction with the hinges ll provides means for lifting the perforated screen II with its affixed members l3 and I5 and disposing the assembly to facilitate cleaning, as indicated by 23 in Fig. 3. A look member 25 for each section of the screen II is pivotally secured to the side 3 of the sluice i. This lock member serves to maintain the screen ll firmly in posltion and the pivotal connection of the lock member 25 permits the disengagement of said memher with the screen structure so that the screen structure may be placed in the position as indicated-by 23., It is, of course, understood that a rifiler is composed of a number of the above described units disposed in a sluice of considerable length, the length depending upon the particular processing problems involved, such as, the desired purity of the stock, the space available for the rifiinetc.

An example of the operation of the invention is given for removing solid impurities from paper stock. The stock is leisurely floated into the sluice I, thereupon overflowing the members l5. This leisurely now of the stock and the obstruction caused by the members l5 create in effect a stilling pool and the small solid impurities hav-- ing a density greater than the stock migrate down through the perforated screen. II and are entrapped within settling basins formed between able period of use the large particles of solid imsurface of the perforated screen H, the screen is then raised to the position indicated by 23 in Fig. 3, and the small particles of solid impurities are flushed away with wash water or removed by other suitable means;

It. is evident that there are numerous factors which will influence conditions for the most satisfactory operation of the invention, the actual limits of which cannot be established except by detailed study of each set of materials being processed and the intermediate and finished products involved. However, the rifiler device of the present invention has been found highly effective in conjunction with the treatment of cellulose materials and more particularly cotton linters. In this particular adaptation of the invention the perforated screen consisted of -inch copper sheet perforated with -inch diameter holes on A -inch centers. The angles were one inch brass angles and were welded to the perforated sheet.

The perforated sheet was approximately three feet wide and eight feet long, the width conformpurities are removed byhand from the upper foraminous member; and means for integrally removing said unit from its functioning position to a second position whereby cleaning of the sluice trough is facilitated.

2. A rifiler for use in treating a stock of cellulose materials having in combination a sluice.

trough and a plurality 'of riille units disposed therein; the sluice trough having water impervious sides and bottom members; and each of the riille units comprising a substantially plane foraminous screen member provided with a multiplicity of perforations in spaced relationship to the bottom of said trough; a plurality of sup porting and spacing members securely a'ifixed to I 3. A riffier for use in treating a stock of cellulose materials having in combination a sluice trough and a plurality of rifile units disposed therein; the sluice trough having water impering'to the width of the sluice, and the length I being such that the units could be easily lifted for cleaning purposes.

The advantages of the present invention reside in a riflier which provides a more efficient method of separating solid impurities from paper stock than has heretofore been attained and in addition provides a more expedient method for cleaning a rifller. This results in a minimum time of plant shutdown and an increase in overall plant production. A still further advantage resides in the economies of maintenance, as the efficiency of ariffler in accordance with the present invention is such that felt pads and like materials are unnecessary and the attendant high cleaning costs and replacement costs of these materials are eliminated.

What I claim and desire to protect by Letters Patent is:

1. A rifller for use in treating a stock of cellulose materials having in combination a sluice trough and a plurality of riffle units disposed therein; the'sluice trough having water impervious sides and bottom members; and each of the riffie units comprising a substantially plane foraminous screen member provided with a multiplicity of perforations in spaced relationship to the bottom of said trough; a plurality of supporting and spacing members securely aifixed'to the I bottom of the foraminous member transversely of the trough adapted to maintain said spaced relationship and provide stilling areas between said supporting members; at least one overflow member of substantial height disposed above said vious sides and bottom members; and each of the rifile units comprising a substantially plane foraminous screen member provided with a multiplicity of perforations in spaced relationship to the bottom of said trough; said foraminous member being hingedly secured to a side of the said trough and adapted to be lifted from its position in spaced relationship to the bottom of the trough to a second position in juxtaposition to the side of said trough; a plurality of supporting and spacing members securely affixed to the bottom of the foraminous member transversely of the trough adapted to maintain said spaced relationship and provide at least one stilling area between said supporting members; and at least one overflow member of substantial height aflixed I to the top of the'foraminous member adapted to provide an overflow section transversely of the trough.

4. A rifiier for use in treating a stock of cellulose materials having in combination a sluice trough and a plurality of riflle units disposed therein; the sluice trough having waterimpervious sides and bottom members; and each of the riflie units comprising a substantially plane foraminous screen member provided with a multiplicity of perforations in spaced relationship to the bottom of said trough; a plurality of supporting and spacing members of substantial height securely affixed to the bottom of the foraminous member transversely of the trough and in lower-edge proximity thereto and providing stilling areas between adjacent pairs of said supporting members; at least one overflow member of substantial height afiixed to and disposed above the foraminous member transversely of the trough; and means for integrally removing said unit from its functioning position to a second position whereby cleaning of the sluice trough is facilitated.

WILLIAM E. HENRY.

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