Patent US3815386A successfully refreshed from Google Patents.
US3815386A
Expired / Lapsed
US
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Device for bleaching of cellulosic pulp
Assignee: Metso Fiber Karlstad AB
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Filing: 1972-01-31
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Granted: 1974-06-11
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Expires: 1992-01-31
Abstract
Abstract For the bleaching of cellulosic pulp the pulp is fed continuously through a standing cylindrical vessel provided with concentric strainer bodies for withdrawal of liquid from the pulp and with nozzles moved in circular paths between the strainer bodies for supply of bleaching liquid. Bleaching liquid passes from said nozzles horizontally through the vertically moving pulp column towards the strainer bodies where liquid is withdrawn from the pulp. In order to equalize the action and the bleaching chemicals upon the pulp, at one level of the vessel bleaching liquid is forced through the pulp in one radial direction and at another level bleaching liquid is forced through the pulp column in the opposite radial direction.
Inventors
- 👤 J Gullichsen
- 👤 R Ekholm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:01
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/75; G03G15/757; B; B01; B01F; B01F23/00; B01F23/40; B01F23/43; B01F23/431; D; D21; D21C; D21C9/00; D21C9/10; D21C9/1026; D21C9/1031; F; F16; F16D; F16D1/00; F16D1/10; F16D1/101; Y; Y10; Y10S; Y10S464/00; Y10S464/901; Y10T; Y10T403/00; Y10T403/70; Y10T403/7005; Y10T403/7007
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
103 words
Device for bleaching cellulosic pulp, comprising an upright cylindrical vessel in which cellulosic pulp is advanced continuously or intermittently in the axial direction, outlet orifices in said vessel for the supply of bleaching liquid into the vessel, and strainers placed at approximately the same level as said orifices and serving for withdrawal of liquid displaced by the bleaching liquid supplied, wherein outlet orifices situated at different levels and strainers pertaining thereto are offset axially relatively to each other so that at two such successivel levels the strainers at one level are located on essentially vertical lines from the orifices at the other level.
Claim 2
Dependent Claim
103 words
Device for bleaching cellulosic pulp, comprising an upright cylindrical vessel in which cellulosic pulp is advanced continuously or intermittently in the axial direction, outlet orifices in said vessel for the supply of bleaching liquid into the vessel, and strainers placed at approximately the same level as said orifices and serving for withdrawal of liquid displaced by the bleaching liquid supplied, wherein outlet orifices situated at different levels and strainers pertaining thereto are offset axially relatively to each other so that at two such successivel levels the strainers at one level are located on essentially vertical lines from the orifices at the other level.
Claim 3
Dependent Claim
54 words
A device as claimed in claim 1, wherein the strainers have cylindrical strainer faces and the outlet orifices move in circular paths concentric to the strainer faces and to the axis of the vessel so that the vertically flowing pulp is penetrated successively by essentially horizontal currents of bleaching liquid flowing in opposite directions.
Claim 4
Dependent Claim
92 words
Device as claimed in claim 1, comprising two strainer body sets of different levels, each set comprising a plurality of concentric strainer bodies located at the same level and having cylindrical strainer faces, the cylindrical strainer faces of one set being offset in the radial direction relatively to the strainer faces of the other set, the outlet orifices for supply of bleaching liquid to each set being arranged to move in concentric paths, the radii of which are different from the radii of the outlet orifices pertaining to the other strainer set.
Claim 5
Dependent Claim
83 words
Device as claimed in claim 3, wherein the strainer bodies of the two sets are all attached to radially extending carrying arms situated at a level between the strainer sets, the outlet orifices for bleaching liquid moveable between the strainer bodies being located on the upper and lower ends, respectively, of vertical tubes conNected to horizontal tubes placed below the lower and above the upper of said two strainer body sets and attached to a rotary core in the center of the vessel.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |