US4030969A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of dispersing a bleaching agent into a stream of fibrous cellulosic pulp material in a throttling nozzle
Assignee: Valmet AB
•
Filing: 1975-01-20
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Granted: 1977-06-21
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Expires: 1995-01-20
Abstract
Abstract A stream of disintegrated fibrous cellulosic pulp material and steam under pressure is subjected to an instantaneous pressure reduction as said stream and steam pass through a throttling nozzle, in a throttling zone, wherein a liquid solution of a bleaching agent is admixed with said stream and which stream, admixed with bleaching agent, is then passed into an expansion zone ahead of the throttling nozzle resulting in a uniform dispersion of the bleaching agent into the fibers in the stream of fibrous cellulosic pulp material.
Inventors
- 👤 Arne Johan Arthur Asplund
- 👤 Rolf Bertil Reinhall
- 👤 Per Johan Ingemar Ahrel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:37
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/10; D21C9/1026
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
160 words
A method of admixing and dispersing a liquid solution of a bleaching agent into a stream of fibrous cellulosic pulp material comprising: a. disintegrating fibrous cellulosic material in a defibrating zone in an atmosphere of steam above 100° C and at superatmospheric pressure to form a fibrous cellulosic pulp material; b. passing a stream of the fibrous cellulosic pulp material together with the steam under pressure into a throttling zone of reduced pressure; c. subjecting said stream and steam to an instantaneous reduction of pressure by passing said stream and steam through a throttling nozzle in said throttling zone; d. introducing a liquid solution of the bleaching agent into said stream as said stream passes through said nozzle; e. discharging said stream and bleaching solution into an expansion zone ahead of said throttling nozzle to enhance dispersion of the bleaching agent into the fibrous cellulosic pulp material; and then f. passing the fibrous cellulosic pulp material to a collection zone.
Claim 2
Independent Claim
160 words
A method of admixing and dispersing a liquid solution of a bleaching agent into a stream of fibrous cellulosic pulp material comprising: a. disintegrating fibrous cellulosic material in a defibrating zone in an atmosphere of steam above 100° C and at superatmospheric pressure to form a fibrous cellulosic pulp material; b. passing a stream of the fibrous cellulosic pulp material together with the steam under pressure into a throttling zone of reduced pressure; c. subjecting said stream and steam to an instantaneous reduction of pressure by passing said stream and steam through a throttling nozzle in said throttling zone; d. introducing a liquid solution of the bleaching agent into said stream as said stream passes through said nozzle; e. discharging said stream and bleaching solution into an expansion zone ahead of said throttling nozzle to enhance dispersion of the bleaching agent into the fibrous cellulosic pulp material; and then f. passing the fibrous cellulosic pulp material to a collection zone.
Claim 3
Dependent Claim
68 words
The method as claimed in claim 1, wherein a portion of moisture in the stream of fibrous cellulosic pulp material is transformed to vapor upon the stream passing through the throttling nozzle thereby partially drying the pulp material to a higher solids concentration thus permitting chemical action of the bleaching agent with the pulp material without appreciable dilution of the pulp material by water accompanying said pulp material.
References Cited (Backward Citations)
CA496671A
Cited
US2422522A
Cited
US2717195A
Cited
US3388037A
Cited
US3467574A
Cited
US3644170A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-20 | 1980-12-20 | 1981-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-20 | 1984-12-20 | 1985-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-20 | 1988-12-20 | 1989-06-21 | $7700.00 | Window Closed / Lapsed |