SE126063C1

SE126063C1 -

Info

Publication number: SE126063C1
Authority: SE
Publication date: 1949-01-01

Description

Uppfinnare: N. R. Norroander. Inventor: N. R. Norroander.

Vid tillverkning ,av starkelse ur vegetabiliska ramaterial, t. ex. potatis, sonderrivas potatisens cellvavnader en eller flera ganger, sa att starkelsekornen kunna utslammas med yatten och skiljas frail ramaterialets cellvaynader. Det erhallna starkelseslammet innehaller forutom starkelsen aven smâ stye-ken av cellyavnader (fibrer) samt utfallda aggYiteamnen i form av flockar och klumpar, som kunna vara fria eller hafta fast yid starkelsekornen. Della slam, rastarkelseslammet, underkastas i regal forst en koncentralion, sa att huvuddelen av yatskan i slammet avskiljes Iran starkelsen, varefter den sistnamnda anyo ,uppslammas i nytillfort yatten. Genom sedimentation i exempelyis kar eller rannor eller genom behandling i centrifuger skiljes starkelsen upprepade ganger fran det vatten eller den vatska, van i starkelsen efter -varje behandling any°, uppslammas. H5.rigenom borttvattas yattenlOsliga amnen, t., ex. harrorande frail p.otatisens fruktsaft, yarjamte ovannamnda fibrer och aggviteamnen avskiljas och avlagsnas frail starkelsen. Denna separering mbjliggores genom att fiberoch figgvitepartiklarnas massa i forhallande till deras vatskemotstand yid passage genom Yfitskan ãr relativt liten. In the manufacture of starch from vegetable raw materials, e.g. potatoes, the cell tissues of the potato are probed one or more times, so that the starch grains can be slurried with the yatten and separated from the cell tissues of the raw material. The obtained starch sludge contains, in addition to the starch, also small pieces of cell carvings (fibers) and precipitated agglomerates in the form of flocks and lumps, which can be free or adhere to the starch grains. Della sludge, the rastarkelse sludge, is first subjected to regal a concentralion, so that the majority of the yatskan in the sludge is separated from the Iran starch, after which the latter anyo, is slurried in newly supplied yatten. By sedimentation in, for example, vessels or gutters or by treatment in centrifuges, the starch is repeatedly separated from the water or liquid used in the starch after each treatment is suspended. H5.through the yattenlOsliga subjects are washed away, e.g. harrorande frail p.otatisens fruit juice, yarjamte the above-mentioned fibers and aggviteamnen are separated and the frail starch is removed. This separation is made possible by the fact that the mass of the fiber and fig white particles in relation to their liquid resistance during passage through the Yfitskan is relatively small.

Avskiljningen av de frammande amnena frau starkelsen skulle yarn en enkel proeedur .om starkelsekornen yore enhetliga till sin storlek. SA, fir emellertid ej fallet, utan starkelsekornens storlek varierar i regel mellan 0,05-0,002 mm. diam., yilket innebar, att de minsta kornens massa .endast är omkring en sextiotusendel av de storsta kornens massa. Jamf ores forhallandet mellan massa och yitskemotstand for de olika kornstorlekarna med samma forhallande for faroreningarn.a finner man, att for de storre starkelsekornen delta forhallande blir storre an for en del av .fororeningarn.a, medan. forhallandet for de minsta starkelsekornen daremot blir lika med eller mindre an for de finfordelade fororeningarna. Om man later ett starkelseslam sedimentera i ett karl, Midas darfor underst ett skikt av tamligen ren, grovkornig starkelse, darnast ett skikt .av grOvre fOroreningar och Over detta ett .annat skikt ay myc ket finkornig starkelse, bemangt med mera finfordelade fororeningar. The separation of the emerging substances from the starch would be a simple procedure if the starch grains were uniform in size. SA, however, is not the case, but the size of the starch grains usually varies between 0.05-0.002 mm. diam., which meant that the mass of the smallest grains is only about sixty thousandths of the mass of the largest grains. If the ratio between mass and surface resistance for the different grain sizes is compared with the same ratio for the hazardous impurities, it is found that for the larger starch grains the delta ratio becomes larger than for some of the impurities. the ratio of the smallest grains of starch, on the other hand, is equal to or less than that of the finely divided pollutants. If a starch sludge is allowed to settle in a man, Midas therefore has a layer of fairly pure, coarse-grained starch, then a layer of coarse impurities and over this another layer of very fine-grained starch, laden with more finely divided impurities.

Ph samma salt inses, att cm man ur ett rastarkelseslam medelst en koncentrator, t. ex. en centrifugalseparator, avskiljer all forhandenvarande starkelse ur slammet, komm,a ayen betydande mangder fOroreningar ,att medfolja starkelsekoncentratet, vangenom reningen .av huvuddelen av starkelsen f Orsvaras Foreliggande uppfinning avser att undanroj a dessa olagenheter. Enligt uppfinningen uppdelas starkelseslammet genom fraktionerad koncentrering i centrifug i fraktioner .ay olika starkelsekornstorlek, d. v. s. .dels i en huvudfraktion grovkomigt starkelsekoncen, trat, som renas och tvattas, samt dels i en eller flera mindre fraktioner .av relativt finkornig starkelse, s.om medfoljer vatskefasen frau den fraktionerade koncentreringen, oak underkastas koncentreringen 1 en ,eller flera ccntrifugalseparatorer, arbetande med hogre separationseffekt an den forstnamnda cep.- trifugen. Slutligen renas eller tvattas den finkorniga starkelsen, varvid avloppsvatska frhn reningen eller tvattningen av huvudfraktionen prate .avloppsyatska och medfoljande starkelse fran reningen ,eller tvattningen ay det finkorniga koncentratet eller jamte sjalva koncentratet fores till ,och underkastas koncentrering 1 den eller de med hog separationseffekt .arbetande centrifugalsep,aratorerna. Ph the same salt is realized, that cm one from a rastarkelseslam by means of a concentrator, e.g. a centrifugal separator, separates all available starch from the sludge, a significant amount of contaminants, to accompany the starch concentrate, through the purification. of the majority of the starch f Orsvaras The present invention aims to eliminate these imperfections. According to the invention, the starch slurry is divided by fractional concentration in centrifuge into fractions of different starch grain sizes, i.e. partly into a main fraction coarse-grained starch, funnel, which is purified and washed, and partly into one or more smaller fractions of relatively fine-grained starch, the liquid phase from the fractional concentration, oak is subjected to the concentration in one or more centrifugal separators, operating with a higher separation effect than the first-mentioned cep. trifuge. Finally, the fine-grained starch is purified or washed, whereby effluent from the purification or the washing of the main fraction is treated. centrifugalsep, the arators.

Sasom exempel ph .uppfinningens utfiirande kan foljande anforas med hanvisning till bifogade ritning: Efter rivning av potatisen, utslamning av sthrkelsen ur cellvaynaderna samt silning ay rastarkelseslammet pa kant salt underkastas slammet en fraktionerad koncentration 1 centrifugalseparator A (eventuellt utrustad med en anordning for tvattning av starkelsekoncentratet), varvid avskiljningsgraden a-vpassas pa sadant salt, att t. ex. 0,1 —2 % ay starkelsen (i huvudsak bestaende av finkornig sadan) finales ayga med yatskan genom ledningen B. Huvudfraktionen, d. v. s. koncentratet .ay starkelse (relativt grovkornig sadan) oyerfores till en reningseentrifug C med tat trumma, forsedd med anordning for 2— — »a-vskalning» av vatskeskikt, avskilda fibrer ,och finkornig starkelse. Efter avcentrifugering av starkelsekoncentratet, som tillvaratages, avskalas de namnda skikten (»avloppsvatska») och foras genom ledningen D till ledningen B for den frail fraktioneringskon- centratorn A komman.de vatskan, -vilken sa-Som namnt innehaller den mindre, finkorniga fraktionen av starkelsen. Eventuellt kan den n.annula .avloppsvatskan (som alien innehaller en del starkelse) forst samlas i en behallare, varifran den i en utjamnad str6m tillfores den finkorniga fran den fraktionerade koncentreringen harrorande starkelsefraktionen. Vateskikt ,och fiber skikt kunna aven uppsamlas var for sig. Efter uppslamning i vatten av i centrifugtrumman kvarvarande finkornigt starkelseskikt fornyas skiljningen, .och vatska och fiberskikt .avledas .enligt .ovan. Denna be-handling kan upprepas ett godtyckligt antal .ganger. Fran reningsapparaten C avgar starkelsen vid E, medan vatten tillfores vid F. As an example of the practice of the invention, the following may be stated with reference to the accompanying drawing: ), whereby the degree of separation is adjusted to such a salt, that e.g. 0.1-2% ay of the starch (mainly consisting of fine-grained soda) is finally added to the yatskan through line B. The main fraction, ie the concentrate. - - "a-vskalning" of liquid layers, separated fibers, and fine-grained starch. After centrifugation of the starch concentrate which is recovered, the named layers ("waste liquor") are peeled off and passed through line D to line B for the frail fractionation concentrator A in the liquid which, as mentioned, contains the smaller, fine-grained fraction of the strength. Optionally, the n.annula .wallwater (which the alien contains some starch) can first be collected in a container, from which it is fed in a balanced stream to the fine-grained from the fractionated concentration harrowing the starch fraction. Hydrogen layers, and fiber layers can also be collected separately. After slurry in water of the fine-grained solid layer remaining in the centrifuge drum, the separation is renewed, and liquid and fibrous layers are diverted. This treatment can be repeated any number of times. From the purifier C, the starch emits at E, while water is supplied at F.

De samlade, finkornig starkelse innehallande vatskemangderna frail fraktioneringskoncentrator och reningscentrifug separeras kentinuerligt i en annan centrifugalkoncentrator G med hogre separationseffekt an separatorn A. Det erhallna koncentratet av finkornig starkelse, fibrer ,och utfallda aggviteamnen underkastas lampligen en langsam omroring for att underlatta fororeningarnas sammankittning, sa att en vasentlig del darav kan :avskiljas genom silning. Det uppsamlade koncentratet uttages vid H .och renas darefter i apparaten J med vatten fran K, varefter starkelsen uttages vid L, medan starkelseh.altigt vatten fores genom ledningen N tillbaka till centrifugen G for all underkastas ny centrifugering tillsammans med fraktionen fran ledningen B. Fran centrifugen G avgar vattnet vid M. Avloppsvatskan fran renaren J f 6- res salunda i cirkulation genom den hogeffektiva separatorn G. Renaren j kan utbildas pa ,olika satt. Den kan t. ex. besta av en behallare med snedstallda planparallella plattor eller koncentriska platar i form av stympade koner, som pa kant satt underlatta starkelsens sedimentation ur det fran H kommande koncentratet. De underlatta aven starkelsens nedcilidnina mot utloppet L och derma nedglidning kan ske motstroms vatten fran K. Enligt en enklare utforingsforrn kan renaren besta av en rektangular lada med. tilloppet H I Or koncentrat i ena .och uttaget N i andra an-den. Under passagen genom 'Man sedimenterar starkelse, som under tillforsel .ay vatten frail K kan uttagas intermittent. The combined, fine-grained starches containing the liquid fractions from the fractionation concentrator and purification centrifuge are centrifugally separated in another centrifugal concentrator G with a higher separation effect than the separator A. The resulting concentrate of fine-grained starch, fibers a significant part of which can be: separated by sieving. The collected concentrate is taken out at H and then purified in the apparatus J with water from K, after which the starch is taken out at L, while starch-containing water is passed through line N back to the centrifuge G for all is subjected to new centrifugation together with the fraction from line B. Fran the centrifuge G emits the water at M. The sewage from the cleaner J is then circulated through the highly efficient separator G. The cleaner j can be trained in different ways. It can e.g. consists of a container with inclined plane-parallel plates or concentric plates in the form of truncated cones, which on the edge sat facilitate the sedimentation of the starch from the concentrate coming from H. They also facilitate the descent of the starch towards the outlet L and this sliding can take place upstream of water from K. According to a simpler embodiment, the cleaner can consist of a rectangular barn with. inlet H I Or concentrate in one .and outlet N in the other. During the passage through 'One settles starch, which during supply .ay water frail K can be taken intermittently.

Det liar visat sig, att denna metod att forst avskilja den grovkorniga starkelsen och sedan underkasta den finkorniga starkelsen upprepad centrifugalsep.arering ger synnerligen goda utbyten .av starkelse. Vid hittills Um& metoder har det alltid varit synnerligen s-vart eller .omojligt att tillvarataga just de sista res- terna av starkelsen. Uppfinningen innebar salunda i detta avseende ett :avsevart tekniskt framsteg. It has been found that this method of first separating the coarse-grained starch and then subjecting the fine-grained starch to repeated centrifugal separation gives extremely good yields of starch. In the case of Um & methods so far, it has always been extremely difficult or impossible to utilize the last remnants of the starch. The invention thus entailed in this respect a: considerable technical progress.

Genom det salunda beskrivna forfaringssattet uppnas att storsta mojliga mangd starkelse kan utvinnas utan att alltf Or skrymmande reningsanlaggningar behova vidtagas. Genom att 0,1-2 % av starkelsen far bortga riled fororeningarna IrOn centrifugen A, uppnas .att all den ovriga starkelsemangden, namligen 98-99,9 % av starkelsen, avskilj es i ren form utan att vara blandad med na.gra namnvarda fororeningar och salunda Nit kunna tiilvaratagas i renaren C. Enligt uppfinningen har det genom manga forsok faststallts, att gransen for fororeningarnas .avskiljning just ligger -vid detta -varde, namligen om separeringseffekten i den forsta centrifugen A icke drives langre an att cirka 00-2av star- kelsen far medfolja fororeningarna. Om man driver separeringseffekten i den forsta centrifugen A langre, erhalles visserligen annu mera starkelse i den storsta fraktionen till renaren C, men samtidigt medfOlja i denna fraktion a.ven en relativt stor mangd fOroreningar, -varf or huvudfraktionen skulk bli relativt oren. Detta undvikes, em man nojer sig med att i den forsta centrifugen A endast uttaga 9899, % starkelse, ,och att lata resten (0,1-2 %) av starkelsen medfolja fororeningarna for att separeras fran dessa i en eller flera ytterligare centrifuger G, som da naturlighis maste arbeta med hOgre separeringseffekt an den forstnamnda centrifugen A. The procedure described below achieves that the greatest possible amount of starch can be extracted without the need for excessive bulking treatment plants. By removing 0.1-2% of the starch due to the impurities IrOn centrifuge A, it is achieved that all the other starch composition, namely 98-99.9% of the starch, is separated in pure form without being mixed with any nominal values. According to the invention, it has been established through many experiments that the limit for the separation of the contaminants lies precisely at this value, namely if the separation effect in the first centrifuge A is no longer driven by about 00-2of starch may accompany the contaminants. If you drive the separation effect in the first centrifuge A longer, it is true that even more strength is obtained in the largest fraction to the cleaner C, but at the same time a relatively large amount of impurities, laps or the main fraction would also be included in this fraction. This is avoided if one is content to take in the first centrifuge A only 9899,% starch,, and to let the rest (0.1-2%) of the starch accompany the impurities to be separated from them in one or more additional centrifuges G , which then naturally must work with a higher separation effect than the first-mentioned centrifuge A.

Den mindre .starkelsefraktionens (0,1-2 %) skiljande i centrifugen G fran de medf6ljande fororeningarna, som kunna uppga till reIativt star mangd, erbjuder naturligtvis en hel del svarigheter, forst .och framst beroende pa att starkelsens koncentration i denna Iraktion dr synnerligen liten, da ju aven hela vatskefasen fran den forsta centrifugen A medfoljer. Sarskilda atgarder vidtagas (tailor f Or .att i den eller de senare eentritugerna G Oka starkelsens koncentration, namligen genom att avloppsvatskan fran sistnamnda centrifug (eller centrifuger) G- aterfores genom ledningen N till denna (eller dessa centrifuger G) for .att underkastas ytterligare centrifugering, innan det slutligen ,erhallna starkelsekoncentratet fran denna mindre fraktion till slut uttages ur renaren J. Om sistnamnda centrifug eller centrifuger G exempelvis .arbeta med en avskiljningseffekt av 1: 10 ('vilket innebar, att man av 1 000 liter till G till-ford avloppsvatska jamte fororeningar saint 00.-2 % starkelse fran avskiljningen .av huvudfraktionen i centrifugen A erhaller 100 liter .starkelsekoncentrat fran centrifugen G), kan man salunda genom att aterfora detta starkelsekoncentrat genom ledningen N till centrifugen G erhalla en ytterligare koncentrering av starkelsen till ett koncentrat av endast 10 liter, som slutligen renas 1 renaren J. — —3 Renaren J kan utgoras ay en behallare, genom vilken koncentratet fran centrifugen G ledes. Under passagen genom renaren sedimenteras en del av ,starkelsen, och denna kan sedan periodiskt eller kontinuerligt tvattas och uttogas. Den frau behallaren avgaende, nagot starkelsehaltiga vatskan aterfores genom ledningen N till centrifugen G. The difference of the smaller starch fraction (0.1-2%) in the centrifuge G from the accompanying impurities, which can amount to a relatively large amount, naturally offers a lot of similarities, first and foremost due to the fact that the concentration of starch in this reaction is particularly small, as the whole liquid phase from the first centrifuge A also follows. Separate measures are taken (tailor f Or .att in the one or the other centrifuges G Increase the concentration of the starch, namely by returning the effluent from the latter centrifuge (or centrifuges) G through the line N to this (or these centrifuges G) to. centrifugation, before the finally obtained starch concentrate from this smaller fraction is finally taken out of the purifier J. If the latter centrifuge or centrifuges G, for example, work with a separation effect of 1:10 ('which meant that from 1,000 liters to G ford wastewater and contaminants saint 00.-2% starch from the separation .of the main fraction in centrifuge A receives 100 liters. starch concentrate from centrifuge G), one can thus by returning this starch concentrate through line N to centrifuge G obtain a further concentration of the starch to a concentrate of only 10 liters, which is finally purified 1 the purifier J. - —3 the purifier J can be as ay a container through which the concentrate from the centrifuge G is passed. During the passage through the cleaner, part of the starch is sedimented, and this can then be washed and taken out periodically or continuously. The frau container, which is slightly starchy, is returned through the line N to the centrifuge G.

Det Or forst genom denna langt gaende koncentrering av den mindre starkelsefraktionen, som man Over huvud taget kan atervinna starkelsen i denna genom efterfoljande rening i relativt hog koncentration i renaren J, utan att dennas dimensioner behova bli onormalt stora. Det lases, att detta problem intimt sammanhanger med att den mindre starkelsefraktionen enligt .uppfinningen Or Men, (t. ,ex. 0,12 %). Hittills liar det icke ansetts lanan- de att forsoka tillvarataga starkelsen i sa lag koncentration, men det liar lyckats enligt uppfinningen tack vare anordnandet av returledningen N. It is only through this far-reaching concentration of the smaller starch fraction that one can at all regain the strength in it by subsequent purification in a relatively high concentration in the purifier J, without its dimensions having to become abnormally large. It is read that this problem is intimately related to the smaller starch fraction of the invention Or Men, (e.g., 0.12%). Until now, it has not been considered successful to try to utilize the starch in such a concentration, but it has succeeded according to the invention thanks to the arrangement of the return line N.

Claims

Patent claim:

1. Procedure for the purification of starch slurried in contaminants from contaminants, Unsubscribed therefrom, all the starch sludge by fractional concentration in centrifuge is divided into fractions of different starch grain sizes tl. vs partly in a main fraction of coarse-grained starch concentrate, which is purified and washed, and partly in one or more smaller fractions of relatively fine-grained starch, which accompanies the liquid phase from the fractionated concentration and is subjected to concentration in a (or Hera) centrifugal sept, working with higher separation effect to the former centrifuge, and finally purified or washed, the effluent from the purification or washing of the main fraction together with the effluent and the accompanying starch. u gals ep ar atorern a.

Procedure according to claim 1, characterized in that 0.1-2 of the starch dilates to give off with the rolling phase after the fractional concentration.

3. Procedure according to any one of claims 1-2, characterized in that the main fraction of the starch slurry suspended during the purification is filtered and, if necessary, stirred for all free from coarse contaminants, after which the purification takes place in a centrifuge with a tat drum. Stockholm 1949. Enna Bokix. P. A. Norstedt & Sillier 490089