DE2041108A1 - Device for dispensing a suspension containing solids to a forming unit - Google Patents

Description

PATENT LAWYERS

Dipl.-Chem. Dr. R U FF Dipl.-Ing. J.BEIER

7 STUTTGART 1 Neckarstrasse 5O Telephone 22 70 51

17 August 1970 B / Lb

Applicant Ethyl Corporation "

330 South Fourth Street. Richmond, State of Virginia, USA

A 12 888/89

Apparatus for dispensing a suspension containing solids to a molding machine

In the manufacture of paper and other web materials it is necessary that fibers or other solids-containing liquid suspensions of the sheet or web forming unit in a beam of selected structure at the desired speed and with the correct distribution of the Solids »are fed · It is important that the suspension is deposited in a properly dispersed state on the wire screen of the forming unit to prevent the formation of defects and other defects in the formed web is avoided.

109809/02 82

BATH ORIGINAL

2OA1108

A 12 688/89

It is difficult to keep fiber suspensions with Feetetoff concentrations in the range suitable for papermaking, which normally contain between less than 1% and about 5 % solids, diapered and distributed everywhere in the flowable medium of the material. Wood fibers and other fibers used in the manufacture of paper yeast have a tendency to agglomerate, and so, despite the uniform volume flow to the forming unit, there may be unacceptable fluctuations in weight and thickness of the sheet because the fibers agglomerate on their way through the paper machine head or flow box. The fiber agglomeration is strongly dependent on the shear BaB and can be promoted by eddies and eddies, which are created by anomalous shear fields in the suspension when it is supplied to the forming unit.

In previous attempts to maintain proper fiber distribution in the flow box, auxiliary equipment was used, such as perforated rotating rollers, movable bars, and other mechanical moving devices · It has also been incorporated into the The flow model of the material uses stationary elements protruding into it, which should induce turbulence and mixing. All of these earlier methods change the shear field patterns in the flowing material and create eddies and eddies that, apart from Avon, that they have some desired separation of the Induce agglomerates, also result in undesired flocculation, stringing together and clumping of the fibers to have. Mechanical auxiliaries also have the disadvantage that they have to be serviced.

109809/0282

BATH ORIGINAL

A 12 838/89

In other earlier attempts, foul suspensions and they are formed into a jet and conveyed onto the forming wire screen in good time To maintain the condition, no mechanical movement devices were used, but those in aolchen Reached paper machine heads or flow boxes Flow patterns did not give satisfactory results.

The flow chain according to the invention creates a flow pattern » dae dit the right shear forces to create and maintain the desired distribution of Feetetoff in the material developed. The flow chain uses at least one pair of in series en-ordered elongated flow channels to control the Shear forces in the flowing material and uses a new design of the channel entrances for prevention of a Faooraufstaue.

In general, the invention comprises a device for delivering a suspension containing solids to a forming unit. sYou includes a feed head for the Materialzufuh r at a substantially constant pressure, vanigetens a pair of spaced rows of elongated Kanälenι forward the material from the feed head and a conveying passage on which elongate to the arranged in rows channels is connected, and an inlet portion for receiving the has many exiting streams of material and from these forms a material jet, and has a Auselaßteil for delivering the jet to a forming unit.

It is also a feature of the invention that the many currents flowing in the channels are in the input section of the Cut and blend output passages of the flow box, without any agglomerate-forming turbulence or a Form swirls.

109809/0 282

BAD OHiGlNAL

2OA1108

A 12 888/89

Further features of the invention emerge from the following description of embodiment form in conjunction with the claims and the drawing. In the drawing ζ ownι

Fig. 1 is a partially cut-away plan view of a Pließkaeten used for Delivery to a horizontal sheet-forming wire screen is arranged j

Fig. 2 is a section along line 2-2 of Fig. 1,

3 shows a section along line 3-3 Fig. 2,

Fig. 4 shows another embodiment of the invention! at the two pairs of in rows arranged channels are used; and

5 shows the use of the device for dispensing material between vertically arranged combined twin-shaped wire screens.

In the embodiments shown in the drawing and in particular in FIGS. 1 to 4, a flow box 4 is provided to feed paper material into a paper machine. Se should be noted that the gate direction according to the invention also can be used for other sheet and web forum processes Fibrous paper exit material is in the tapered

109809/0282

ORIGINAL

A 12 888/89

the material distribution head 1 is pumped through the material inlet line 2Bas excess material not flowing into channels 3 of the flow box 4 continues to flow through a material outlet line 6 (arrows show the material flow), where it is returned to the inlet line 2 «The material distribution head 1 is tapered, so that a relatively constant pressure is achieved along the manifold head, with substantial amounts of the incoming material being continuously withdrawn from the manifold head as the material flows to the outlet conduit 6. Since the volume of material that reaches the lower end of the distributor head is considerably smaller than the inlet volume, the cross-section of the distributor head must be tapered or reduced in order to achieve the desired constant pressure, which is necessary for the desired uniformity of the material flow into the channels 3 of the flow box is beneficial

The channels "3" are each arranged in upper and lower rows and 8 across the width of the FlioSkaetens, with inlets located at a distance from one another and unseparated exits} so that the streams of material flowing in each row of channels open up and merge into one another, while the upper and 'lower streams intersect at an acute angle at the same time and merge to form a single stream or jet. "The jet is then guided in the discharge passage 9 of the flow line to the forming unit 11. ßkaet «xt _t im weis <» ntlicli «n equal

.1-09909 / 0282

20A 1 108 - 6 -

A 12 888/89

like the sheet to be formed, and when it is desired to have the passage converge slightly towards the opening, a top wall 10 of the passage 9 is moved downward using an adjuster (not shown). An adjusting screw 22 shown in FIG. 4 represents a suitable adapting means. Forming unit 11 has a roller 12 and a Fonaungsdrahtsieb 13 *

The channels 3 of rows 7 and 8 are through the Seibon of flow separators 14 and the walls 16 of the Rows of channels limited. The flow scattering element 14 have crowned the entrance educational sections 1? (Fig. 3), which the material in the Change of direction and entry into channels 3 should help without significant turbulence or fiber thawing arises at the separation element 14. The entrance forming sections 1? include vertically arranged convexes Surface A, which is the main component from which the material flow comes, are essentially facing, and surfaces B, which are essentially facing away from the material flow are. Surface A, which is larger than surface B, is shaped and arranged to provide the desired flow of material characteristic of the canal immediately in front of it

The cross-section as trukt'jr fines of each channel 3 is rectangular in its entire length with different shape and area at different points in length. The (^ trichnittaetruktmc ^{1 of} the Eanäl · can also be other than rectangular, but fiechteokfoxoi is preferred because the "currents" in the surname · * bsv · into one another "are less disturbed. The Ztiaameiifli <eBtn of many stars with

109069/0282

BATH ORIGINAL.

2041TÖ8

A 12 888/69

A round cross-section would, for example, allow you to wipe them, into which the material would flow immediately and a disturbance in the desired flow channel would cause. Venn "to rom Xaneleingang you are going to inspect the material flow, noticed" that the cross-sectional area in the Entrance cut 18 »the sub part through surface A One separating element is constantly decreasing and the surface B of another separating element is being bordered. Behind surfaces A and B, the channel continues to converge, but not ■ or so strong · you convevgene of this Hittelabach section 19 is accomplished through the Velgung aer walls 16, whereby the parallel cross winds of the channel for achievement oelaeeen a stabilizing effect on the material «who is moving a certain distance straight ahead, After that, when "Entering the Eanal" changed the calibration, the convergent Xanal continues to accelerate and the shear effect of the volatile Hediuas flowing in an elongated canal maintains this Feeern in correct suspension · The length of the abechnitta may vary, but it is preferred «when the channel is around sehnaal eo long as wide let

On the right of Hittelabaohnitt 19 the material coaws into the di-terging-converging section 20, where the vertical walls diverge while the upper and lower walls Winds worlds converge. In this section the rectangular central structure of the flow changed by reducing its height and tergrating its width.

109809/0282 ■■ _0BielN M-

A 12 888/89

Hit the change in cross-sectional proportions however, the cross-sectional area is steadily reduced in size so that the flow on its way to the inlet part 21 of the output passage 9 is accelerated. The diverging angle of the vertical walls of section 20 should be less than 15 ° in order to separate the flowable medium from the wall and thus create turbulence avoid. An angle of approximately 8 ° is preferred.

The many channel currents in each row 7 and 8 flow at Reaching the channel ends together, taking the sides of one each stream with the sides of the neighboring streams come together · The top and bottom stream series then go instantly to form the composite, uniform jets of material which flow down the discharge passage in which a further shear action takes place, the contributes to the correct distribution of solids in the flowing material # The flowing into one another of the upper and lower Streams is supported by the staggered arrangement of the individual streams. Here is a stream of the top row not arranged exactly above a stream of the lower row 6 (see FIG. 2). From the passage 9 the beam is then placed on the moving forming wire screen 15. The Dispensing angles can be varied by adjusting the position of the flow box by conventional means (not shown) changes.

In Fig. 4-, in which corresponding parts with the same Reference numerals are denoted as in the previous figures, two pairs of canal rows are united and a double one

109809/0282

BATH ORIGINAL

Passage 27 is connected to form a flow box, which in turn is attached to a frame 26 «Dar double passage 2? has an upper entrance portion 28 for Recording of the converging material flows from the upper pair of channels 29 and a lower inlet section 31 for receiving the converging flow of material © from the lower pair of channels 32 »

The streams converging in sections 28 and 31 flow through upper and lower flow sections 33 and 35 of the passage} before they enter the discharge section 36 of passage 2? enter. The input sections 28 and 31 and the flow sections 33 and 35 are through a septum 23 separated. The Sections® 33 and 35 have a sufficient one Length and cross-sectional uniformity to ensure sufficient stabilization of the flow of material in them Sections to effect so that when the river is out the sections 33 and 35 in the atisgababschnitt 36 comes and two streams of material essentially retain their uniformity "one stream layered on top of the other through the remaining section the passage 2? and on the wire screen 13 flows »Out of the conveying section a converging passage can be made by turning its top wall 38 using an adjustment screw 22 bends down.

When using the flow box device of FIG make mulch paper «The top rows 29 For example, hardwood kraft paper and the lower rows 32 could be made of softwood kraft paper

109809/0282

BATH

20A 1 - ίο -

A 12 888/8 9

for the Hr VMb al.lung deliver a web, half of which aua Softwood material and half of hardwood material. Ee praise also provided that you have three or more different ones Feeds materials to an output passage with an entry and flow section for each material, around a paper web with layers of different materials to manufacture. The stability of the current immediately before its output on the wire screen in both multi-layer and single-layer Current is partly on the floodwire of numerous currents in the canal rows 3 »toils on the unturbulent Merging of the flows in sections 28 and 31 and partly due to the stabilized flow in the passage sections 33 and 35.

In Fig. 5, the device according to FIGS. 1 to 3 is shown, the Releases material down between two wire screens 13 and 13a. The device of the invention, so also embodiments according to Fig. 4, is for the delivery of material on the shaping wire screen at any angle, such as horizontal or etva vertical, or suitable at any other desired angle

109809/0282

BATH ORIGINAL

Claims (1)

A 12 888/89 Patents β ρ back e The device hurries to give a solids-containing solution to a forming unit, characterized in that a distributor head (1) is provided for supplying suspension material with essentially constant pressure along a length of at least one pair of heights (7, 8) elongated canal® (3) 'is connected to' the distributor head (1.) and each row (? »'8) is combined with the length of the distributor head so that the''rows (7® 8) 3ed ·« Paar® «are at an acute angle to each other & ng © ot # B © 1s, .so d« B the materia! '- (3) IsQMSQa ₉ wM ■ with the .Series. C7 «β) voa lisglictoa: Iaall © a: C3) © ia' iuegabsduröhgang C9) 'connected -is» the- © inen let part (21) »for the recording. the 'offer and an' AuelaB 11 xur Ämegabu-. -the 'combined -flows to a FoxiBiinga unit (11). 2 «Device according to Inquiry 1 ₉ thereby .defl, the <.HeterlaIflu8 In the distributor head (1) in the central part of the river runs in de & Eaoälan (3) and essentially all channels are curved (18) have »including the HichtuagsÜn-" change of the ftaterialetromea in the Ter-leeeen tea fezv divider head (1) and flow in the direction of the canal below, without a. * forms .treeentiiche Tw Bulens and Feetetoffablagerung to £ ingangsab <"echnittem (18). 109809/0282 A 12 688/89 3 · Device according to claim 1 or 2, characterized in that it is gekeun ~ draws that the cross-sectional areas of the channels (3) become steadily smaller over the total θ channel length. 4. Device according to one of the claims. 1 am 3t thereby characterizedι that the channels (3) have a rectangular one Have cross-section and eggs over an excessive length Channels the width of the rectangular cross-section and the Höho gets smaller. 5 · Device according to one of the preceding claims for the simultaneous delivery of several layers of material to a sheet-forming unit, characterized. that in the entrance part (28, 31) of the output passage (27) several Fließabechnitte (33 »35) are provided that provide for a substantially parallel flow to and into the output part (36) dea passages (27), several pairs of rows of channels (3) are provided, by doiion each pair of rows many converging Pours oineo auo dial tone material into one of the tier inlet parts (28, 31) delivers, and each pair of rows one Distribution head (1) for the material supply is seated, uo that several selected materials of the Pornungaeir · » nind in stratified stream 6. Device according to Claim 5 "daduroL gekerrnzeichne ·!", that the plied sections (28. 31) by iia Aisle (27) arranged turn (23) limited aind. 109809/0282 _BAD ORIGINAL Read 11 e