US4506834A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for dispersing material
Assignee: Valmet AB
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Filing: 1983-11-07
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Granted: 1985-03-26
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Expires: 2003-11-07
Abstract
Abstract The invention relates to a method and a device for dispersing fibrous material. The fibrous material is accelerated and expanded together with a flowing medium in a nozzle (10). The nozzle (10) includes a converging and a diverging section and, thus, is a so-called de Lavel nozzle.
Inventors
- 👤 Bo R. Ek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:27
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/18; D21C9/185; F; F26; F26B; F26B17/00; F26B17/10; F26B17/101; F26B17/103
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
105 words
A method of increasing fiber separation in the flash drying of paper pulp comprising feeding a fibrous material into a nozzle having a converging inlet for a flowing medium, a feed inlet gap for the fibrous material and a diverging outlet, the feed inlet gap for the fibrous material opening into the nozzle adjacent but not upstream of the smallest cross-section of the nozzle, expanding the fibrous material together with the flowing medium in the diverging section of the nozzle to isentropic supersonic and sub-sonic flow; and supplying the expanded fibrous material and flowing medium to a flash dryer wherein the fibrous material is dried.
Claim 2
Independent Claim
105 words
A method of increasing fiber separation in the flash drying of paper pulp comprising feeding a fibrous material into a nozzle having a converging inlet for a flowing medium, a feed inlet gap for the fibrous material and a diverging outlet, the feed inlet gap for the fibrous material opening into the nozzle adjacent but not upstream of the smallest cross-section of the nozzle, expanding the fibrous material together with the flowing medium in the diverging section of the nozzle to isentropic supersonic and sub-sonic flow; and supplying the expanded fibrous material and flowing medium to a flash dryer wherein the fibrous material is dried.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein the flowing medium is expanded so that at least somewhere in the nozzle sonic speed is obtained.
Claim 4
Dependent Claim
11 words
The method of claim 1 wherein the flowing medium is steam.
Claim 5
Dependent Claim
15 words
The method of claim 3 wherein the steam has a pressure of 3.2 atmosphere gauge.
Claim 6
Dependent Claim
26 words
The method of claim 1 wherein the nozzle has a rectangular cross-section and a total pressure drop of 0.3 atmosphere gauge is applied over the nozzle.
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) | 1988-03-25 | 1988-09-24 | 1989-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-25 | 1992-09-24 | 1993-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-25 | 1996-09-24 | 1997-03-26 | $7700.00 | Window Closed / Lapsed |