NO860249L - PROCEDURE FOR CELLULOSE TREATMENT. - Google Patents
PROCEDURE FOR CELLULOSE TREATMENT.Info
- Publication number
- NO860249L NO860249L NO860249A NO860249A NO860249L NO 860249 L NO860249 L NO 860249L NO 860249 A NO860249 A NO 860249A NO 860249 A NO860249 A NO 860249A NO 860249 L NO860249 L NO 860249L
- Authority
- NO
- Norway
- Prior art keywords
- foam
- oxygen
- mass
- pulp
- reaction
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims description 14
- 239000001913 cellulose Substances 0.000 title claims description 5
- 229920002678 cellulose Polymers 0.000 title claims description 5
- 239000006260 foam Substances 0.000 claims description 24
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 8
- 229910001882 dioxygen Inorganic materials 0.000 claims description 8
- 239000004088 foaming agent Substances 0.000 claims description 4
- 238000005187 foaming Methods 0.000 claims description 3
- 238000004061 bleaching Methods 0.000 claims description 2
- 239000003795 chemical substances by application Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 23
- 239000001301 oxygen Substances 0.000 description 23
- 229910052760 oxygen Inorganic materials 0.000 description 23
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 15
- 235000011121 sodium hydroxide Nutrition 0.000 description 5
- 238000005406 washing Methods 0.000 description 5
- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 4
- 239000000725 suspension Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- 238000011144 upstream manufacturing Methods 0.000 description 3
- 239000004155 Chlorine dioxide Substances 0.000 description 2
- 235000019398 chlorine dioxide Nutrition 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 241000196324 Embryophyta Species 0.000 description 1
- 235000008331 Pinus X rigitaeda Nutrition 0.000 description 1
- 235000011613 Pinus brutia Nutrition 0.000 description 1
- 241000018646 Pinus brutia Species 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 239000003945 anionic surfactant Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910001902 chlorine oxide Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- LYCAIKOWRPUZTN-UHFFFAOYSA-N ethylene glycol Natural products OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 150000002191 fatty alcohols Chemical class 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- -1 glycol ethers Chemical class 0.000 description 1
- 230000002706 hydrostatic effect Effects 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 239000002736 nonionic surfactant Substances 0.000 description 1
- 238000004076 pulp bleaching Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/147—Bleaching ; Apparatus therefor with oxygen or its allotropic modifications
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Paper (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
Description
Foreliggende oppfinnelse angår en fremgangsmåte for i en prosess for fremstilling av cellulosemasse å gjennomføre et behandlingssteg i hvilket oksygengass inngår som et reak-s j onsmiddel. The present invention relates to a method for, in a process for the production of cellulose pulp, to carry out a treatment step in which oxygen gas is included as a reaction agent.
Ved oksygendelignifisering av cellulosemasse finnes for tiden en tendens til å gå over fra høykonsentrert masse med en massekonsentrasjon på 25 - 30% til middelkonsentrert masse som har en konsentrasjon på 8 - 15%. Grunnen er først og fremst å minske investeringskostnadene. Ved til-setning av oksygen til en slik middelkonsentrert masse opp-står imidlertid problem ettersom de mengder som kreves er betydelig større en hva som kan løses i væsken. In oxygen delignification of cellulose pulp, there is currently a tendency to move from highly concentrated pulp with a pulp concentration of 25 - 30% to medium concentrated pulp with a concentration of 8 - 15%. The reason is primarily to reduce investment costs. When oxygen is added to such a medium-concentrated mass, a problem arises, however, as the amounts required are significantly greater than what can be dissolved in the liquid.
Et første problem er å fordele oksygenet jevnt i massen i form av små bobler for å få en stor kontakflate. A first problem is to distribute the oxygen evenly in the mass in the form of small bubbles to obtain a large contact surface.
Et annet problem er å holde boblene svevende i massesuspensjonen under tilstrekkelig lang tid for å gjennomføre reaksjonen. Another problem is keeping the bubbles suspended in the pulp suspension for a sufficiently long time to carry out the reaction.
Et tredje er å ved behov kunne tilsette større mengder enn 4-5 kg oksygen per tonn masse regnet på tørket masse med ca. 90% tørrsubstans. A third is to be able, if necessary, to add larger quantities than 4-5 kg of oxygen per tonne of pulp calculated on dried pulp with approx. 90% dry matter.
Med de omrørere såkalte miksere som for tiden anvendes for å innblande oksygenet i massen har det vist seg at boblene ikke blir så små som er ønsket hvilket leder til at en hel del oksygen flyter opp gjennom massen til reaksjonskarets topp uten å forbrukes. For ønsket reaksjon kreves derfor et relativt høyt trykk spesielt ved reaksjonens begynnelse. Som følge derav er man henvist til en oppstrøms fremgangsmåte hvor det hydrostatiske trykk ved karets bunn er høyt. Ved en nedstrøms fremgangsmåte kommer nemlig i tillegg for-uten det lave trykket ved reaksjonens begynnelse, i tillegg ulempen med det ovenfor massens i karets topp værende tom-rom gjennom hvilket den tilførte masse faller fritt hvorved en stor del av oksygen unnslipper. With the stirrers, so-called mixers, which are currently used to mix the oxygen into the mass, it has been shown that the bubbles do not become as small as desired, which leads to a whole lot of oxygen flowing up through the mass to the top of the reaction vessel without being consumed. For the desired reaction, a relatively high pressure is therefore required, especially at the beginning of the reaction. As a result, one is referred to an upstream method where the hydrostatic pressure at the bottom of the vessel is high. In a downstream method, in addition to the low pressure at the start of the reaction, there is also the disadvantage of the empty space above the mass in the top of the vessel through which the supplied mass falls freely, whereby a large part of oxygen escapes.
For å løse disse problem har det blitt foreslått en fremgangsmåte for bleking av masse med oksygen hvorved massen med høyt trykk (15 bar) tilføres først skummiddel og der-etter oksygengass. Blandingen omrøres til et skum som får ekspandere ved trykksenking til 3 bar over en ventil. In order to solve these problems, a method has been proposed for bleaching pulp with oxygen, whereby the pulp is fed at high pressure (15 bar) first with a foaming agent and then with oxygen gas. The mixture is stirred into a foam which is allowed to expand when the pressure is reduced to 3 bar via a valve.
Ved skumdannelses bindes oksygen sterkere til massen slik ta ovennevnte ulemper i en viss grad reduseres. Selv denne fremgangsmåten er imidlertid belemret med ulemper. Således er den kraftige trykkforhøyelsen dels energikrevende og dels vanskelig å oppnå med normalt tilgjengelige pumper. Videre leder den raske og kraftige trykksenkningen til at oksygenboblene i skummet har en tendens til å briste hvorved oksygentapet likevel blir betydelig. When foaming occurs, oxygen binds more strongly to the mass, thus reducing the above-mentioned disadvantages to a certain extent. However, even this method is beset with disadvantages. Thus, the strong pressure increase is partly energy-intensive and partly difficult to achieve with normally available pumps. Furthermore, the rapid and strong reduction in pressure leads to the fact that the oxygen bubbles in the foam have a tendency to burst, whereby the loss of oxygen nevertheless becomes significant.
Formålet ved foreliggende oppfinnelse er å fremskaffe en oksygenbehandling av cellulosemasse i hvilken de ovenfor beskrevne problem i forbindelse med den kjente teknikk har blitt eliminert. Dette oppnås ved hjelp av en fremgangsmåte av det i innledningen nevnte slag hvilken ifølge oppfinnelsen utmerker seg i hovedsak derved at oksygengassen via et skummiddel omdannes til et skum og at skummet som inneholder oksygengassen innblandes i massen før behandlingssteget. The purpose of the present invention is to provide an oxygen treatment of cellulose pulp in which the above-described problems in connection with the known technique have been eliminated. This is achieved by means of a method of the type mentioned in the introduction which, according to the invention, is distinguished mainly by the fact that the oxygen gas is converted into a foam via a foaming agent and that the foam containing the oxygen gas is mixed into the mass before the treatment step.
For skumdannelsen anvendes eksempelvis en skumgenerator av det slag som er beskrevet i svensk patent 86586. Som skummiddel anvendes eksempelvis en blanding av nonionaktive og anionaktive tensider, stabiliseringsmiddel (foreksempel fettalkoholer) samt løsningsmiddel (foreksempel glykol-etere). Skummediet blandes med vann eller natronlut eller annen passende væske i et blandingskar og pumpes til skumgeneratoren. Samtidig ledes oksygengass til skumgeneratoren fra en forrådstank hvorved.overtrykket i tanken utnyttes som drivkilde. A foam generator of the type described in Swedish patent 86586 is used, for example, for foaming. As a foaming agent, for example, a mixture of nonionic and anionic surfactants, stabilizers (for example fatty alcohols) and solvents (for example glycol ethers) are used. The foam medium is mixed with water or caustic soda or other suitable liquid in a mixing vessel and pumped to the foam generator. At the same time, oxygen gas is led to the foam generator from a storage tank, whereby the excess pressure in the tank is used as a drive source.
Det i skumgeneratoren dannede skum tillates å ekspandere langsomt gjennom suksessiv trykksenkning i en relativt lang rørledning innen det iblandes i massesuspensjonen hvilket skjer ved hjelp av en foran det aktuelle behandlingsstedet anordnet omrører som inngår i den normale prosessapparatur-en. Gjennom den suksessive trykksenkningen ekspanderes skummet relativt langsomt hvorved boblene ikke brister. The foam formed in the foam generator is allowed to expand slowly through successive pressure reduction in a relatively long pipeline before it is mixed into the mass suspension, which occurs with the help of a stirrer arranged in front of the treatment site in question which is part of the normal process equipment. Through the successive reduction in pressure, the foam expands relatively slowly, whereby the bubbles do not burst.
Den for skumdannelsen krevede energi er ubetydelig og massesuspensjonen behøver ikke settes under trykk. Det er i tillegg lettere å kontrollere skummets egenskaper når det fremstilles i en for formålet konstruert apparatur. The energy required for foam formation is negligible and the mass suspension does not need to be pressurized. It is also easier to control the properties of the foam when it is produced in a purpose-built apparatus.
Ved denne fremgangsmåte kan oksygen fordeles jevnt i massen i form av små bobler slik at en stor kontaktflate erholdes. Det er til og med mulig å tilsette relativt store mengder oksygen og å holde dette svevende i massesuspensjone i tilstrekkelig lang tid for reaksjonen hvorved tapet nedsettes til et minimum. Selv ved reaksjonskar av nedstrøms type hvor massen innmates ved karets øvre ende kan oksygentil-førselen skje uten betydelige tap ettersom oksygen holdes bundet i skumform. Det er derfor i slike tilfeller ikke heller nødvendig å ved siden av reaksjonskaret anordne noe ytterligere reaksjonskar hvor oksygenreaksjonen skjer i oppstrøm så som iblandt tidligere krevet. With this method, oxygen can be distributed evenly in the mass in the form of small bubbles so that a large contact surface is obtained. It is even possible to add relatively large amounts of oxygen and to keep this suspended in mass suspensions for a sufficiently long time for the reaction whereby the loss is reduced to a minimum. Even with reaction vessels of the downstream type where the mass is fed in at the upper end of the vessel, oxygen can be supplied without significant losses as oxygen is kept bound in foam form. It is therefore not necessary in such cases to arrange any further reaction vessels next to the reaction vessel where the oxygen reaction takes place upstream as previously required.
EksempelExample
Sammenligningsforsøk ble utført med dels direkte konven-sjonell oksygengasstilførsel og dels tilførsel av oksygen i skumform ifølge oppfinnelsen. Ved forsøkene ble barrsulf-atmasse bleket med kappatal 33,1 og viskositet 1179 dm^/- kg med en blanding av klor og klordioksyd, nemlig totalt 70 kg aCl per tørket masse hvorav 5,6 kg som klordioksyd. Den således klorblekte masse ekstraheres derpå på tre ulike måter i henhold til nedenforstående. Comparison tests were carried out with partly direct conventional oxygen gas supply and partly supply of oxygen in foam form according to the invention. In the experiments, pine sulfate pulp was bleached with a kappa number of 33.1 and a viscosity of 1179 dm^/- kg with a mixture of chlorine and chlorine dioxide, namely a total of 70 kg of aCl per dried pulp, of which 5.6 kg as chlorine dioxide. The chlorine-bleached mass is then extracted in three different ways according to the following.
1. Kun med NaOH.1. Only with NaOH.
2. Med NaOH+G^, hvor oksygenet tilføres i form av skum.2. With NaOH+G^, where the oxygen is supplied in the form of foam.
3. Med NaOH+G^, hvor oksygenet tilføres som ren gass. 3. With NaOH+G^, where the oxygen is supplied as pure gas.
Samtlige forsøk ble foretatt ved atmosfæretrykk og beting-elser forøvrig fremgår av nedenforstående tabell. All experiments were carried out at atmospheric pressure and conditions otherwise appear from the table below.
Kjemikaliesatser og resultat fremgår av følgende tabell. Chemical rates and results are shown in the following table.
Av tabellen fremgår at oksygentilførsel til ekstraksjons-steget gir en vesentlig kappatalreduksjon og lyshetsøkning. Det fremgår også at effekten er størst i det tilfelle hvor oksygen tilføres i skumform. Resultatet er bemerkelses-verdig med tanke på det lave trykket. The table shows that the supply of oxygen to the extraction step results in a significant reduction in kappa number and increase in lightness. It also appears that the effect is greatest in the case where oxygen is supplied in foam form. The result is remarkable considering the low pressure.
Eksempler på apparaturoppstillinger i masseblekerier er vist i fig. 1-3 hvor 1 er reaksjonskaret, 2 er vaskefilter, 3 er omrører og 4 er pumper. I samtlige tilfeller vis-es kun et behandlingssteg som inngår i en såkalt fiber-linje. Examples of equipment arrangements in pulp bleaching plants are shown in fig. 1-3 where 1 is the reaction vessel, 2 is the washing filter, 3 is the stirrer and 4 is the pump. In all cases, only one processing step is shown which is part of a so-called fiber line.
Fig. 1 viser et reaksjonskar av nedstrøms type med ovenfor dette anordnede filter og omrører. Massen føres fra fore-gående behandlingssteg via vaskefilter og omrører til karets 1 øvre ende. Etter reaksjonen pumpes massen fra karets bunn via et vaskefilter til etterfølgende behandlingssteg. Fig. 1 shows a downstream type reaction vessel with a filter and stirrer arranged above it. The mass is fed from the previous treatment step via washing filter and agitator to the upper end of the vessel 1. After the reaction, the mass is pumped from the bottom of the vessel via a washing filter to subsequent processing steps.
I fig. 2 er vaskefilter og omrører anordnet ved siden av karet 1 som selv i dette tilfelle er av nedstrøms type. Massen føres fra omrører 3 via pumpen 4 og en rørledning 5 til reaksjonskarets øvre ende. In fig. 2, the washing filter and agitator are arranged next to the vessel 1, which even in this case is of the downstream type. The mass is fed from stirrer 3 via pump 4 and a pipeline 5 to the upper end of the reaction vessel.
Fig. 3 viser et reaksjonskar av oppstrøms type mens appa-ratene forøvrig er anordnet som i fig. 2. Massen mates fra pumpen 4 til karets 1 bunn og føres ut ved dets øvre ende. Fig. 3 shows a reaction vessel of the upstream type, while the apparatus is otherwise arranged as in fig. 2. The mass is fed from the pump 4 to the bottom of the vessel 1 and discharged at its upper end.
I alle de viste tilfeller tilsettes NaOH til massen i forbindelse med utmatningen fra vaskefilteret hvoretter oksygen i skumform tilføres omrøreren 3 fra en ikke vist skumgenerator. In all the cases shown, NaOH is added to the mass in connection with the output from the washing filter, after which oxygen in foam form is supplied to the stirrer 3 from a foam generator not shown.
Claims (2)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE8500342A SE452896B (en) | 1985-01-24 | 1985-01-24 | METHOD OF TREATING CELLULOSAMASSOR |
Publications (1)
Publication Number | Publication Date |
---|---|
NO860249L true NO860249L (en) | 1986-07-25 |
Family
ID=20358888
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
NO860249A NO860249L (en) | 1985-01-24 | 1986-01-23 | PROCEDURE FOR CELLULOSE TREATMENT. |
Country Status (8)
Country | Link |
---|---|
JP (1) | JPS61201094A (en) |
BR (1) | BR8600268A (en) |
CH (1) | CH668788A5 (en) |
DE (1) | DE3601808A1 (en) |
FI (1) | FI78326C (en) |
FR (1) | FR2576331B1 (en) |
NO (1) | NO860249L (en) |
SE (1) | SE452896B (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE460202B (en) * | 1987-03-13 | 1989-09-18 | Aga Ab | SEATED AS TREATMENT OF A MATERIAL WITH A GAS IN A SCIENCE |
CN110670400B (en) * | 2019-09-25 | 2020-11-27 | 刘澄 | Be used for vertical cauldron that boils of sanitary towel chinese mugwort fine hair chip |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE126265C (en) * | ||||
SE390549C (en) * | 1973-12-20 | 1985-10-17 | Ahlstroem Oy | SET TO BLOW CELLULOSIC MATERIAL WITH ACID OR FREE ACID CONTAINING GAS IN ALKALIC ENVIRONMENT |
JPS5249306A (en) * | 1975-10-20 | 1977-04-20 | Toyo Pulp Co Ltd | Process for bleaching pulp under normal pressure with air bubble |
JPS5299302A (en) * | 1976-02-13 | 1977-08-20 | Toyo Pulp Co Ltd | Process for separating lignin from cellulose fiber |
SE462919B (en) * | 1979-05-11 | 1990-09-17 | Sunds Defibrator Ind Ab | PROCEDURE TO PERFORM ALKALIE EXTRACTION OF CELLULOSAMASS IN THE PRESENCE OF ACID |
-
1985
- 1985-01-24 SE SE8500342A patent/SE452896B/en not_active IP Right Cessation
-
1986
- 1986-01-21 CH CH218/86A patent/CH668788A5/en not_active IP Right Cessation
- 1986-01-22 DE DE19863601808 patent/DE3601808A1/en active Granted
- 1986-01-23 BR BR8600268A patent/BR8600268A/en unknown
- 1986-01-23 NO NO860249A patent/NO860249L/en unknown
- 1986-01-23 FI FI860328A patent/FI78326C/en not_active IP Right Cessation
- 1986-01-23 JP JP61012930A patent/JPS61201094A/en active Pending
- 1986-01-24 FR FR8601014A patent/FR2576331B1/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
DE3601808A1 (en) | 1986-07-24 |
FI78326B (en) | 1989-03-31 |
CH668788A5 (en) | 1989-01-31 |
JPS61201094A (en) | 1986-09-05 |
FR2576331A1 (en) | 1986-07-25 |
SE452896B (en) | 1987-12-21 |
SE8500342L (en) | 1986-07-25 |
FI860328A0 (en) | 1986-01-23 |
BR8600268A (en) | 1986-10-07 |
DE3601808C2 (en) | 1988-12-08 |
SE8500342D0 (en) | 1985-01-24 |
FI860328A (en) | 1986-07-25 |
FR2576331B1 (en) | 1988-06-17 |
FI78326C (en) | 1989-07-10 |
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