SE515706C2

SE515706C2 - Method and apparatus for concentrating liquid-stressed material

Info

Publication number: SE515706C2
Application number: SE0000435A
Authority: SE
Inventors: Ebbe Hoden
Original assignee: Ebbe Hoden
Priority date: 2000-02-11
Filing date: 2000-02-11
Publication date: 2001-10-01
Also published as: AU2001232554A1; SE0000435L; SE0000435D0; WO2001059209A1

Abstract

The consistency of liquid-saturated material is increased by enclosing a string (20) of the liquid-drenched material in filter cloth (1, 2) and leading said enclosed material around a horizontal, rotating drum (16) while compressing the string between the drum and one or more pressure elements (8, 17, 18, 10). The drum (16) used is hollow and has a perforated barrel, and the string (20) enclosed in the filter cloth (1, 2) is led around the upper part of the drum. The pressure elements may conveniently comprise one or more pressure rollers (8, 17, 18, 10) that have a barrel part which can be deformed resiliently by said compression force. There is also described a device for increasing the dry substance content in accordance with the aforegoing.

Description

25 30 35 . . f . . . | . - « a» 515 706 šïïgfïï; “ 2 Vid kända förfaranden och anordningar för ökning av torrhalten av ett vätskebemängt material genom valsning av en sträng av material, medan det omges av ett silduksband, har betydande återuppsugning av ur materialet utpressad vätska inneburit problem. 25 30 35. . f. . . | . - «a» 515 706 šïïgfïï; In known methods and devices for increasing the dry content of a liquid-laden material by rolling a strand of material while it is surrounded by a screen cloth, significant re-suction of liquid squeezed out of the material has caused problems.

Det är därför ett ändamål med föreliggande uppfinning att an- visa ett förbättrat förfarande och en förbättrad anordning, varmed ovannämnda problem i åtminstone väsentlig utsträckning undvikes.It is therefore an object of the present invention to provide an improved method and an improved device, whereby the above-mentioned problems are avoided at least to a significant extent.

I nämnda syfte föreslås enligt uppfinningen att det vid ett förfarande av det inledningsvis angivna slaget användes en ihålig trumma med perforerad mantel, att den av silduk omslutna strängen ledes kring trummans överdel och att det användes en eller flera tryckvalsar med ett av komprimeringstrycket elas- tiskt deformerbart mantelparti. Med detta tillvägagångssätt vinnes, dels att i perifeririktningen förhållandevis breda kom- primeringszoner erhålles mellan tryckvalsarna och trumperife- rin, dels att genom komprimeringen utpressad vätska fritt kan avgå genom den perforerade trummanteln, vilket leder till ökade torrhalter och förenklingar i konstruktivt hänseende. Den elas- tiska deformerbarheten av tryckvalsarnas mantelområden utjämnar även trycket på den av silduk omgivna strängen, så att lokalt höga tryckpåkänningar på silduksbandet eller -banden vid kan- terna och i överlappningsområden på önskvärt sätt undvikes.For the said purpose it is proposed according to the invention that in a method of the kind initially indicated a hollow drum with a perforated jacket is used, that the strand enclosed by screen cloth is guided around the upper part of the drum and that one or more pressure rollers with one elastically deformable by the compression pressure are used mantelparti. With this approach, it is gained, on the one hand, that in the peripheral direction relatively wide compression zones are obtained between the pressure rollers and the drum periphery, and on the other hand that liquid squeezed through the compression can escape freely through the perforated drum jacket, leading to increased dry contents and simplifications in construction. The elastic deformability of the sheath areas of the pressure rollers also equalizes the pressure on the strand surrounded by screen cloth, so that locally high pressure stresses on the screen band or bands at the edges and in overlapping areas are desirably avoided.

Uppfinningen avser, såsom nämnts, även en anordning för genom- förande av det nya förfarandet. Denna utmärkes av att trumman är en med perforerad mantel försedd ihålig trumma, att den av silduk omslutna strängen är ledd kring trummans överdel och att tryckvalsen eller -valsarna har ett av komprimeringstrycket elastiskt deformerbart mantelparti.The invention also relates, as mentioned, to a device for carrying out the new method. This is characterized in that the drum is a hollow drum provided with a perforated jacket, that the string enclosed by screen cloth is guided around the upper part of the drum and that the pressure roller or rollers have a jacket portion elastically deformable by the compression pressure.

Ytterligare för uppfinningen utmärkande drag är angivna i de beroende kraven. 10 15 20 25 É3o 35 . . . . .- 515 706 3 Uppfinningen skall i det följande närmare beskrivas med hänvis- ning till ritningen, vilken starkt schematiskt visar en sidovy av en anordning enligt uppfinningen.Further features of the invention are set out in the dependent claims. 10 15 20 25 É3o 35. . . . The invention will be described in more detail below with reference to the drawing, which shows very diagrammatically a side view of a device according to the invention.

Den pá ritningen visade anordningen för koncentrering av väts- kebemängt material, såsom t.ex. fibersuspensioner, i synnerhet pappersmassasuspensioner, innefattar två i var sin ändlös bana ledda silduksband 1 och 2, bestående exempelvis av viraduk av plast. Det ena bandet 1 ledes kring brytvalsar 3-8 och är bre- dare än det andra bandet 2, som ledes kring brytvalsar 9 och 10 samt de även för bandet 1 utnyttjade brytvalsarna 6, 7 och 8.The device shown in the drawing for concentrating liquid-laden material, such as e.g. fiber suspensions, in particular pulp suspensions, comprise two screen cloth strips 1 and 2, each led in its endless path, consisting for example of plastic wire cloth. One belt 1 is guided around breaking rollers 3-8 and is wider than the other belt 2, which is guided around breaking rollers 9 and 10 and the breaking rollers 6, 7 and 8 also used for the belt 1.

Brytvalsarna 8 och 10 utgör samtidigt tryckvalsar, såsom kommer att framgå nedan. Bandens 1 och 2 rörelseriktningar är antydda med pilar 11 resp. 12.The breaking rollers 8 and 10 simultaneously form pressure rollers, as will be seen below. The directions of movement of the bands 1 and 2 are indicated by arrows 11 and 12.

Under brytvalsen 9 är belägen en symboliskt visad, med 13 be- tecknad och exempelvis från WO 99/39048 tidigare känd vikanord- ning, varmed det bredare bandets 1 längsgående kantpartier om- vikes mot detsammas mittparti. Detta mittparti har väsentligen samma bredd som bandet 2, vilket i samband med omvikningen av bandets 1 kantpartier inledes i vikanordningen 13 på sådant sätt, att det vid sidorna överlappas av bandets 1 kantpartier.Below the breaking roller 9 is located a symbolically shown, with 13 designated and for example previously known from WO 99/39048 folding device, whereby the longitudinal edge portions of the wider band 1 are folded towards the middle portion thereof. This middle portion has substantially the same width as the belt 2, which in connection with the folding of the edge portions of the belt 1 is initiated in the folding device 13 in such a way that it overlaps at the sides by the edge portions of the belt 1.

Banden 1 och 2 bildar därvid en omslutning eller kanal för en genom en ej visad tratt i pilens 14 riktning tillförd slurry av material, som skall koncentreras. För sammanhållning av banden 1 och 2 i ett detta material omslutande läge kan dessa löpa i ett mellan vikanordningen 13 och brytvalsen 7 anordnat, icke visat perforerat rör, varvid det bildas en sträng av partiellt koncentrerat material, som ytterligare koncentreras, medan det omslutes av silduksbanden 1, 2 och ledes kring en horisontell, i pilens 15 riktning roterande trumma 16, genom komprimering mellan denna trummas mantel och ett antal tryckvalsar 8, 17, 18 och 10.The bands 1 and 2 thereby form an enclosure or channel for a slurry of material to be concentrated through a funnel (not shown) in the direction of the arrow 14, which is to be concentrated. To hold the belts 1 and 2 together in a position enclosing this material, these can run in a perforated tube arranged, not shown between the folding device 13 and the breaking roller 7, whereby a strand of partially concentrated material is formed, which is further concentrated while being enclosed by the screen strips 1, 2 and is guided around a horizontal drum 16 rotating in the direction of the arrow 15, by compression between the jacket of this drum and a number of pressure rollers 8, 17, 18 and 10.

Efter slutkoncentrering av materialet medelst komprimering av detsamma mellan valsarna 8, 17, 18, 10 och trumman 16 utvikes bandets 1 kantpartier på nytt medelst en symboliskt visad, med 10 15 20 25 '-30 _35 ~ ~ . . .- 515 706 4 19 betecknad och exempelvis från WO 99/39048 tidigare känd ut- vikningsanordning. Banden 1 och 2 med mellanliggande sträng av koncentrerat material passerar därefter vidare till brytvalsarna 5 och 6, där banden säras och bandet 1 passerar runt brytvalsen 5 i riktning mot brytvalsen 4, medan bandet 2 passerar runt brytvalsen 6 i riktning mot den kombinerade bryt- och tryck- valsen 10. Strängen 20 av färdigkoncentrerat material avgår i pilens 21 riktning för eventuell vidarebehandling.After final concentration of the material by compressing the same between the rollers 8, 17, 18, 10 and the drum 16, the edge portions of the belt 1 are unfolded again by means of a symbolic display, with 10 15 25 '-30 _35 ~ ~. . 515 706 4 19 and previously known, for example, from WO 99/39048. The belts 1 and 2 with intermediate strand of concentrated material then pass further to the breaker rollers 5 and 6, where the belts are separated and the belt 1 passes around the breaker roller 5 in the direction of the breaker roller 4, while the belt 2 passes around the breaker roller 6 in the direction of the combined breaker and the pressure roller 10. The string 20 of ready-concentrated material departs in the direction of the arrow 21 for possible further processing.

Drivningen av banden 1 och 2 kan ske på ej närmare visat sätt genom drivning av trumman 16 och/eller av någon eller några av bryt- och/eller tryckvalsarna. Om så önskas, kan material- strängen omslutas medelst ett enda silduksband på exempelvis det sätt som visas i EP-B-670 747. Alternativt kan vid använd- ning av två lika breda i sidled relativt varandra förskjutna band omslutningen för materialet, som skall koncentreras, bil- das genom att ett utskjutande kantparti av det ena bandet om- vikes ett kantparti av det andra och ett utskjutande kantparti av det andra bandet omvikes ett kantparti av nämnda ena band.The belts 1 and 2 can be driven in a manner not shown in more detail by driving the drum 16 and / or one or some of the breaking and / or pressure rollers. If desired, the material strand can be enclosed by means of a single screen cloth in the manner shown, for example, in EP-B-670 747. Alternatively, when using two equally wide laterally offset bands, the enclosure of the material to be concentrated , is formed by folding an projecting edge portion of one band around an edge portion of the other and a projecting edge portion of the other band folding an edge portion of said one band.

Det är även möjligt att vid användning av två lika breda band använda separata kantband, som omvikes de varandra närbelägna kanterna av de båda förstnämnda banden. Vikanordningen och utvikningsanordningen av den typ som visas i EP-B-670 747 och WO 99/39048, vartill uppfinningen dock icke är begränsad, är gynnsamma ur såväl utrymmes- som påkänningssynpunkt i jämförel- se med successiv omformning av band från platt till rörformig sektion enligt exempelvis US-A-4 017 398.It is also possible, when using two equally wide strips, to use separate edge strips, which fold around the adjacent edges of the two first-mentioned strips. The folding device and the unfolding device of the type shown in EP-B-670 747 and WO 99/39048, to which the invention is not limited, however, are favorable from both a space and stress point of view in comparison with successive transformation of strips from flat to tubular section. according to, for example, US-A-4,017,398.

För befrämjande av effektiv koncentrering användes en ihålig trumma 16, vars mantel är perforerad, och ledes den av silduks- bandet 1, 2 omslutna materialsträngen kring trummans 16 överdel, såsom tydligt visas i ritningsfiguren. Vidare användes tryck- valsar 8, 17, 18, 10 med ett av de valda komprimeringstrycket elastiskt deformerbart mantelparti, varigenom valsnypet mellan trumman 16 och respektive tryckvals 8, 17, 18, 10 får ökad bredd, mätt i trummans 16 perifeririktning, vilket underlättar avrinning av ur strängen utpressad vätska in i trumman och mi- 10 15 20 25 íQBO - | 1 - f » . . . . .. 515 706 5 nimerar återuppsugning av vätska i materialet. Den ur materia- let utpressade vätskan tillåtes passera fritt genom den perfo- rerade trumman 16 och ut genom dennas underdel. Ett under trum- man 16 beläget tråg 22 tjänar till uppsamling av den utpressade vätskan. Tråget 22 är försett med ett lämpligt avlopp för bort- ledning av uppsamlad vätska.To promote efficient concentration, a hollow drum 16 is used, the jacket of which is perforated, and the material string enclosed by the screen cloth 1, 2 is guided around the upper part of the drum 16, as is clearly shown in the drawing figure. Furthermore, pressure rollers 8, 17, 18, 10 are used with one of the selected compression presses elastically deformable jacket portion, whereby the roller nip between the drum 16 and the respective pressure roller 8, 17, 18, 10 has an increased width, measured in the circumferential direction of the drum 16, which facilitates drainage of liquid squeezed out of the string into the drum and mi- 10 15 20 25 íQBO - | 1 - f ». . . . .. 515 706 5 nimers reabsorption of liquid in the material. The liquid squeezed out of the material is allowed to pass freely through the perforated drum 16 and out through its lower part. A trough 22 located under the drum 16 serves to collect the extruded liquid. The trough 22 is provided with a suitable drain for discharging collected liquid.

Med fördel användes tryckvalsar 8, 17, 18, 10 med en så vald elastisk deformerbarhet, att det vid det valda komprimerings- trycket erhålles nyp mellan tryckvalsmantlarna och trummanteln med en bredd, mätt i mantlarnas perifeririktning, av minst ca 5%, lämpligen mellan 5 och 30%, av tryckvalsdiametern. En enkel tryckvalskonstruktion kan erhållas genom att uppbygga varje tryckvals av ett antal pà en gemensam axel trädda gummihjul.Advantageously, pressure rollers 8, 17, 18, 10 are used with such a selected elastic deformability that at the selected compression pressure a pinch is obtained between the pressure roller jackets and the drum jacket with a width, measured in the circumferential direction of the jackets, of at least about 5%, suitably between and 30%, of the pressure roll diameter. A simple pressure roller construction can be obtained by building each pressure roller of a number of rubber wheels threaded on a common shaft.

Enligt en med streckade linjer antydd modifikation av anord- ningen kan för breddökning av nypen mellan trumman 16 och tryck- valsarna 8, 17, 18, 10 kring minst två närbelägna tryckvalsar, t.ex. 8, 17 eller 18, 10, löpande ändlösa band 23 vara anord- nade, såsom antydes med streckade linjer. Vid lämplig sträck- ning av banden 23 pressar dessa mot trummanteln, varigenom tendens till återuppsugning av utpressad vätska ytterligare minskas. Med ett sådant arrangemang av band 23 kan tryckval- sarnas 8, 17, 18, 10 elastiskt deformerbara mantelpartier er- sättas av en elastisk sammanpressbarhet i tjockleksriktningen av de kring tryckvalsarna löpande ändlösa banden.According to a modification of the device indicated by dashed lines, for widening the nip between the drum 16 and the pressure rollers 8, 17, 18, 10 around at least two adjacent pressure rollers, e.g. 8, 17 or 18, 10, continuous endless belts 23 may be provided, as indicated by dashed lines. When the belts 23 are stretched appropriately, they are pressed against the drum jacket, whereby the tendency for re-suction of extruded liquid is further reduced. With such an arrangement of belts 23, the elastically deformable jacket portions of the pressure rollers 8, 17, 18, 10 can be replaced by an elastic compressibility in the thickness direction of the endless belts running around the pressure rollers.

Uppfinningen är icke begränsad till de med hänvisning till rit- ningen beskrivna utföringsformerna utan kan realiseras på god- tyckligt sätt inom ramen för den i efterföljande patentkrav angivna uppfinningstanken.The invention is not limited to the embodiments described with reference to the drawing, but can be realized in any desired manner within the scope of the inventive idea stated in the appended claims.

Claims

10 15 20 25 .HW 35 515 706 6 -. - Q u P a t e n t k r a v

A method for increasing the dry content of a liquid-laden material, in which a strand (20) of the liquid-laden material enclosed by a screen cloth (1,2) is guided around a horizontal, rotating drum (16) during compression between it and one or more several pressure rollers (8, 17, 18, 10), characterized in that a hollow drum (16) with a perforated jacket is used, that the string (20) enclosed by screen cloth (1,2) is guided around the upper part of the drum and that a or several pressure rollers (8,17, 18,10), with a jacket portion elastically deformable by the compression pressure.

Method according to Claim 1, characterized in that a plurality of pressure rollers (8, 17, 18, 10) distributed along the upwardly facing peripheral part of the drum (16) are used.

Method according to claim 1 or 2, characterized in that liquid squeezed out of the material is allowed to pass freely through the perforated drum (16) and is collected and disposed of from an area (22) below it.

Method according to one of Claims 1 to 3, characterized in that the liquid-laden material is preconcentrated before the compression but after the enclosure thereof with a screen cloth (1,2).

Method according to one of Claims 1 to 4, characterized in that pressure rollers (8, 17, 18, 10) are used with such a chosen elastic deformability that a pinch is obtained between the roller and the drum jacket when the compression pressure is used. with a width of at least about 5%, suitably between 5 and 30%, of the diameter of the pressure roller.

Device for increasing the dry content of a liquid-laden material, comprising means (8,6) for guiding a strand (20) of the liquid-laden material enclosed by screen cloth 15 15 25 25 äs 515 706 =. X. . «~. -. I »(1,2) around a horizontal, rotating drum (16) during compression between it and one or more pressure rollers (8, 17, 17, 10, 10) pressed against the drum, characterized in that the drum (16) is a perforated jacket provided with a hollow drum, that it is made of silk (1,2) part and that the pressure roller or rollers (8, 17, 18, 10) have one of the enclosed strands (20) is guided around the overcompression pressure of the drum elastically deformable mantelparti.

Device according to Claim 6, characterized by a plurality of pressure rollers (8, 17, 17, 10, 10) distributed along the upwardly facing peripheral part of the drum (16).

Device according to claim 6 or 7, characterized in that the drum (16) allows free passage of liquid squeezed out of said material and in that means (22) for collecting and disposing of the squeezed liquid are arranged under the drum.

Device according to one of Claims 6 to 8, characterized by means for pre-concentrating the liquid-laden material before compaction but after enclosing it with a screen cloth (1,2).

Device according to one of Claims 6 to 9, characterized in that the pressure rollers (8, 17, 18, 10) have such a chosen elastic deformability that, when the compression pressure is applied, a nip is obtained between the roller and the drum jacket with a width of at least about 5%, preferably between 5 and 30%, of the pressure roller diameter.

Device according to one of Claims 6 to 10, characterized in that the pressure rollers (8, 17, 18, 10) are built up of a number of rubber wheels threaded on a common axis.

Device according to one of Claims 6 to 10, characterized by an endless belt (23) running around at least two pressure rollers (8, 17, 18, 10). 515 706 8

Device according to claim 12, characterized in that the elastically deformable jacket portion of the pressure rollers (8, 17, 17, 10, 10) is formed by elastic compressibility in the thickness direction of the endless belt (23) running around the pressure rollers.