US3104999A - Cylinder mold vat assembly - Google Patents

Description

Sept. 24, 1963 R. A. SLOMAN 3,104,999

CYLINDER MOLD VAT ASSEMBLY Filed Oct. 10, 1960 IN VEN TOR. ROBERT A. SLOMAN ATTDQNEY United States Patent 3,104,999 CYLINDER MOLD VAT ASSEMBLY Robert A. Sloman, Glens Falls, N.Y., assignor to The Sandy Pill Iron & Brass Works, Hudson Falls, N.Y., a corporation Filed Oct. 10, 1960, Ser. No. 61,709 1 Claim. (Cl. 162-323) The present invention relates to new and useful im provements and structural refinements in a mold vat and in an improved stock distributor therefor as well as in a new and novel method of stock distribution. The invention is directed particularly to the provision of an approach flow chamber of new and novel design having general utility in the arts.

The invention relates to the manufacture of felted web and sheet products from fluid suspensions of fibrous materials and has particular relation to the manufacture of paper on a cylinder papermaking machine by means of an aqueous suspension of paper-making fibers, which is supplied to a web-forming region through which the cylinder is rotated. The mat of fibers is applied to the cylinder, as by flowing thereon a layer of stock, which is then caused to drain through the cylinder, the stock so applied containing the required amount of fiber in an amount of water suflicient to produce the proper distribution of the fibers in the web, and with sufiicient drainage of the water being effected during the period of time that the formed web remains on the cylinder so as to produce a coherent sheet, capable of being couched off therefrom.

The invention resides in the particular construction, arrangement, combination, and relationship of the various components of a flow vat having a unique design of approach flow chamber, as exemplified in the detailed disclosure hereinafter set forth wherein the objects of the invention, as herein defined, will be apparent.

It will be helpful to an understanding of my present invention to first briefly consider some of the essential points and more important features and aspects thereof, so that same may be kept in mind during the subsequent reading of the detailed description of the practical embodiment of my improvements and of the illustration thereof in the hereunto annexed drawing.

The particular embodiment of the invention embraces the concept of a stock inlet for controlling astream of stock flowing into a cylinder mold vat of a cylinder machine so that high velocities, provided to prevent any bundling or lumping of the conveyed fibers, are progressively reduced to moderate velocities flowing into the mold circle without losing the useful dispersion of the fibers in the flew which produces a random directionality of the fibers leading to a satisfactorily felted web. In short, flocculation is prevented by means of an explosion or energy-absorbing chamber wherein the flow is first accelerated and is thereafter decelerated in velocity for purposes of keeping the stock in suspension.

Referred to herein as an approach chamber or energy absorption chamber, it is of a design capable of reducing the undesirable agitation caused by velocity of the discharge occurring at the orifice leading into such chamber.

Without intending to place undue limitations upon the scope of the invention beyond what may be required by the state of the prior art, the invention may be briefly described as consisting of a means for correcting the diflicult problem of obtaining a uniform feed across the entire width of a cylinder machine.

In a cylinder machine, stock is fed to the vat circle in a relatively quiescent condition, since turbulence in the feed from the feed box interferes with uniform deposition of the web on the mold. In achieving or maintaining such a quiescent condition, difliculty has been experienced "ice heretofore in that the stock tends to settle out, clot, lump, and in general, become non-uniformly distributed across the width of the feed box.

Improved stock distribution and fluid flow is therefore the obvious desideratum.

The present invention envisions procedures and methods for controlling the velocity relationships of the stock prior to arriving at the web-forming region. Of particular importance in this regard is the discovery that effective control of energy components in the flowing stream can be effected by adjustment of the passages through which the stock flows preceding delivery to said webforming region.

The fiow distributor hereof converts a fast flowing stock stream of relatively small cross-section to a slower flowing stock stream of relatively large cross-section by passage thereof through a primary approach or turbulence chamber, impinging same against a baffle and directing it through a rectifier, then leading it through a restricted throat or passageway where it is again converted into a fast flowing stock stream only to be introduced into a secondary approach or turbulence chamber where it once again is converted to a slower flowing stool; stream of large cross-section, and thence through a somewhat restricted throat or passageway having a rectifier disposed therein where the flow stream is once more accelerated, and all before passage in the normal manner of uniform flow to the vat circle of the conventional cylinder machine. 7

One or more flow rectifiers aid in the establishment of a uniform direction of flow of the paper stock and function as improved means for insuring better distribution of the fibers thereof as the stock flows through the head box in order to produce paper webs with closely regulated, uniform width-wise, profiles, I having discovered that uniform quiescent flow of stock in a cylinder machine can be accomplished without settling or segregating thereof within the feed box by providing a generally vertical passageway in the approach portion of the flow chamber composed of a pair of interconnecting approach chambers, each having a venturi throat arrangement leading thereinto. 4

In contrast with prior art constructions, the stock hereof ispassed through the pair of approach chambers in manner so that the stock is agitated, at points therealong, to constitute a confined, relatively high energy or high velocity flowing stream and, at other points therealong, the stool; is allowed to slow down or to decelerate in its movement, all so that the flow and character of the pulp stream as it flows through the head box for deposit at the web forming region offers a uniformity in basis weight, formation and strength, caliper, bulk and final moisture content.

Thus, it is an object hereof to provide a means for assisting in the supplying of papermaking stock to a papermaking machine under controlled conditions of substantially uniform velocity flow across the width of the machine so as to give a high degree of uniformity of weights and fiber distribution in the web or sheet.

An' additional salient object hereof is to provide a method for controlling the flow conditions of stock approaching the forming member to cause delivery of the stock to the forming member at a predetermined velocity while avoiding flocculation of the stock and minimizing the development of eddy currents and other non-uniform flow conditions.

While the velocity of the stock is normally controlled by the head or pressure, in this invention, the velocity is momentarily accelerated and then decelerated as it passes through the approach chambers and the rectifying means therewithin. That is, the velocity is changed by being speeded up as it enters an approach chamber and thereafter drops back to its initial velocity. Likewise as it passes through the rectifying means, its velocity is speeded up as it passes therethrough and then drops back to its initial velocity once it has passed therebeyond.

Where stock is flowed in a straight run, it tends to flock together again and to make clumps and to present a streaked unsightly and hard-to-manage formation and this invention is directed to the correction of such objectionable features by interrupting the fibers' and upsetting their tendency to align or flock.

Passage through the rectifying means hereof induces accelerated movement of the stock and a micro-turbulence. For example, in the case of a perforated or holey roll, the stock is forced to jump up in speed to pass into the roll at the entrance side thereof and subsequently is forced to jump up in speed to pass from the roll at the exit side thereof, all resulting in small'turbulen-t streams coming out of the rotating roll which break the flock or bunching of the fibers together and defiock so as to avoid streaking. However, in the use of rectifying means alone, the desired results are not completely attained owing to the back eddying which occurs. Pulp usually gathers on one side of the rectifier and then slips ofi therefrom in thickened quantities, thereby affecting the formed paper sheet. Too, eddies are frequently set up so as to cause uneven flow.

The invention 'rnay be embodied .in any stock dis tributor wherein stock is taken from a conduit of small crossasection into a first or primary approach chamber having a lower width substantially the width of the entrance or'ifice of the said conduit and an upper width greater than said lower width, and is then forced in a stock flow path through a right angle turn and through a restricted throat of reduced cross sectional area and thence into a secondary approach chamber likewise having a lower Width substantially the Width of the restricted throat and an upper width greater than said lower Width. Upwardly of or adjacent said upper widths, the approach chambers are each provided with a rectifier means disposed therein where the flow stream is once again accelerated.

The restricted throat is generally disposed horizontally relative to and between the substantially vertically disposed approach chambers and same operates as a venturi which is conveniently formed with two opposedrwall members in manner so: that the shape and size of the throat can be changed. by modifying the shapes of the opposite wall members. a

The velocity of the stock, as it flows into the primary approach chamber and subsequently through the venturi into the secondary approach chamber, is tremendously increased, thereby preventing any settling out or separation of fiber bundles and spreading and mixing of the stock to prevent the development of any uneven stock conditions at the making board or weir.

These and other (features of the invention will be made more apparent in the following description of a certain prefenred embodiment of the invention as applied to a cylinder paper making machine.

In the accompanying drawing, the FIGURE is a sectional elevational view illustrating the cylinder in somewhat diagrammatic =form and showing the primary and secondary approach chambers of the invention and their positions relative, thereto.

The reference numeral designates generally the stock box of the vat of the cylinder machine, the vat having spaced opposite vertically extending side walls 12, a vertically-extending'front end wall 14, and a verticallyextending rear end wall 15. r

The vat is provided with the usual more or less semicircularly formed bottom wall 20. extending between the front andrear end walls :14 and 15 and between the spaced side walls 12 and 12. Said arcuate wall and A side Walls 12 and .12 define a vat circle or mold compartment 22 within the vat.

A cylinder mold 3% comprising, as is known, a hollow built up drum covered with a wire mesh, is rotatably mounted on a shaft 32 in the vat circle 22 and is sup ported on suitable bearings (not shown) carried by the opposite side walls ;12 and 12.

The partition wall 24} may be provided with spaced downwardly depending portions 32 and 32 and a transversely extending portion s 4 connecting therebetween to provide a trap or sump 36 at the bottom of the vait circle 22, which trap may be drained through a quick-opening dump valve located at the front end of the vat which dump valve drains to a gutter on the machine floor or may be connected to a drain pipe.

The interior of the cylinder mold 30 discharges through an opening 49 in both side Walls 12, which openings are supplemented by a second and third opening 42 and 44. r

The openings 49, 42 and 44 control the drainage ofthe white water out of the interior of the cylinder mold, the water flowing through both ends of the mold in known manner.

A drain pipe 5t may be provided in the chamber beneath the vat circle and, as is known, the arrangement is such that the drain pipe 50 drains the greater portion of the white water from the interior of the cylinder mold. A subsidiary or auxiliary drain pipe 51 may be provided with a conventional gate or weir (not shown) for the control of the drainage of part of the white water into said drain pipe 51 at a rate sufiicie'nt to maintain the desired white water level in the cylinder mold.

The stock box ill of the vat is provided. with an entrance or primary approach chamber 6t) which may be disposed somewhat below the plane of the central axis of the cylinder 30 and directly above a laterally-extending intake orifice 62.

Said orifice 62 is connected to an inlet (not shown) through which the paper making stock is fed, under force of a suitable pumping device (not shown), so as to be directed vertically upwardly into said primary approach chamber 60.

The primary approach chamber is defined in part by an inclined lower portion 64 of the inner wall portion of the front end wall 14, an inclined lower portion 66 of a generally vertically extending wall spaced inwardly of the front end wall 14, and adjacent portions of the opposite side walls 12, 12, the portions 64 and 66 diverging upwardly across the width of the stock box.

A horizontally-extending wall or baffle portion 68, which is a continuation of the lower wall portion 66 defines a roof and functions as a deflecting wall, it extending across the width of the stock box. Said Wall portion 68 extends toward a horizontally-extending wall portion 70, which is a continuation of the lower wall portion 64. The plane of wall portion 68 is spaced slightly above the plane of wall portion 70 in manner to form a restricted throat 72 therebetween.

As aforesaid, wall portions 64 and 66 diverge upwardly across the width of the stock box, and the wall portion 68 likewise extends thereacross, so as to define, with the cooperating sidewalls 12 and 12, the said primary approach chamber 60.

The primary approach chamber 66, sometimes identified as a first flow conduit, or primary turbulence chamber defines an expansion chamber across the full width of the vat for receiving the stock through the entrance portion 68 and deflected thereby. The stock is then forced back downwardly and/ or laterally through a right angle turn. 7 i

-It is to be appreciated that the impinging of stock against the horizontal wall or bafile portion 68 imparts a lateral component to the stock flow so as to further distribute the stock at the point of maximum restriction, i.e. the throat 72. The restricting of the stock flow area at the throat 72 serves to unify the flow throughout the width of the stock vat in this region and thus serves to compensate for irregularities in stock flow thereat.

Upwardly of the wall portion 70, an upper portion 74 of the inner wall of the front end wall 14 extends upwardly and inclines outwardly to diverge from an outwardly inclining upper portion 76 of the generally vertically extending wall extending inwardly of said front end wall, all to provide an upper secondary approach chamber 80.

The said upper portions 74 and 76 diverge upwardly across the width of the stock box to define, with the side walls 12 and 12, the secondary approach or turbulence chamber 80 having, as an entrance orifice, the throat 72 which is of small cross sectional area so as to direct a high velocity stream of stock into the chamber 80 having a relatively larger cross sectional area for accommodating a relatively slower upward flow of stock.

It will thus be observed that the stock flows through the restricted throat 72 to contact the wall portion 74 generally normal to the stock flow from the restricted zone or area so as to again deflect the stock at a right angle in the stock flow path.

It is to be appreciated that the primary approach chamber 60 is ofiset vertically relative to the secondary approach chamber 80 with the axis of the throat 72 therebetween being substantially horizontally disposed. Thus, the stock flow path within the primary approach chamber is generally vertically and upwardly and then defines a first right angle turn into and through the throat 72 of reduced cross sectional area and then defines a second right angle turn into the secondary approach chamber.

The uppermost section 82 of the upper portion 74 of the inner wall of the front end wall 14 converges inwardly and terminates in a horizontal plane spaced above the upper terminal of the spaced upper portion 76, which portion diverges upwardly and away from said section 82 throughout the width of the vat.

The inner and upper end of the upper portion 76 is connected to the adjacent side of the arcuate wall 20 and a wing board assembly, designated generally by 93, of conventional design, is fixed to the juncture thereof.

A rotatable rectifier roll 110 may be journalled in the opposing side walls 12 and 12 so as to be disposed within the primary approach chamber 60 in manner to extend across the stock box in closely spaced position adjacent the throat 72.

Similarly, a rotatable rectifier roll 120 may be journalled in the opposing side walls 12 and 12 so as to be disposed within the secondary approach chamber 80 in manner to extend across the stock box in closely spaced position adjacent and between the diverging walls 74 and 76.

Said rectifier rolls are perforated rolls of known type and have the customary rectifier design and function and are driven by any suitable means, such as electric motors (not shown). They are positioned in close running relationship with the adjacent walls so as to bridge the stock flow running through the respective primary and secondary approach chambers in manner whereby substantially all of the stock flowing therethrough will pass through the respective rectifier roll and serve to even out the distribution and help to prevent the possible accumulation of fibers in bundles throughout the width of the cylinder,

It will be appreciated that the plurality of vertically disposed passageways 6t) and 80 are arranged in communication with each other in manner whereby the pulp may be adapted to flow from the chamber 69 to the cylinder compartment 22.

In the operation of the instant construction, paper making stock is forced through a conduit leading from a source of stock supply (not shown) by means of a suitable pumping device (not shown) connected to the orifice 62 and into the primary approach chamber 60 of the vat.

As the pulp leaves the orifice 62, the velocity of the discharge creates a considerable turbulence and results in the progressive alignment of the pulp fibers in the direction of the pulp stream, only to be disposed in a random fashion as they strike baffle 68.

I clairn:

in combination with a paper machine including a vat and a rotatable fiber-collecting web-forming cylinder therein, a stock distributing means for delivering a flowing stream of stock to the vat and comprising, spaced forward and rearward walls and spaced opposite end walls defining an enclosed generally vertically-extending fiow conduit and including a pair of vertically upwardlyextending and angularly-related and interconnected approach chambers each of increasing cross-sectional area for progressively reducing the stock velocity, the approach chambers of said pair thereof including a lowermost primary turbulence chamber defined by upwardly diverging portions of the forward and rearward walls and a stock supply intake of restricted dimension at the lower end thereof connecting to a conduit leading from a source of supply stock and also having an uppermost horizontally-extending deflecting wall for imparting a lateral component to the stock and an uppermost secondary turbulence chamber ofiset vertically relative to the 7 primary turbulence chamber and defined by upwardly diverging portions of the forward and rearward walls and having an open upper exit end for discharging stock to the web-forming region of the paper machine, a generally horizontally-disposed restricted throat interconnecting the upper end of the primary turbulence chamber and the lower end of the secondary turbulence chamber adjacent said horizontally-extending deflecting wall, first rotatable rectifier means disposed within said primary turbulence chamber closely adjacent said deflecting wall in closely spaced position adjacent said restricted throat, and second rotatable rectifier means disposed within said secondary turbulence chamber closely adjacent the exit.

References Cited in the file of this patent UNITED STATES PATENTS 1,964,291 Kutter June 26, 1934 2,156,445 Baxter May 2, 1939 2,677,991 Goumeniouk May 11, 1954 2,747,471 Corbin et al May 29, 1956 2,894,581 Goumeniouk July 14, 1959 2,911,041 Beachler Nov. 3, 1959 2,970,938 Erbach Feb, 7, 1961 2,993,538 Mustonen July 25, 1961 3,014,527 Beachler Dec. 26,1961

FOREIGN PATENTS 1,137,547 France Ian. 14, 1957 851,301 Germany Oct. 2, 1952 855,502 Germany Nov, 13, 1952

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