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US4163525A Expired / Lapsed US ⏱️ 0.0 years remaining

Device for evacuating blow-back steam in pulp refining apparatus

Assignee: Individual
•
Filing: 1977-12-27
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Granted: 1979-08-07
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Expires: 1997-12-27
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Abstract

Abstract A device for evacuating blow-back steam in a pulp refining apparatus in which lignocellulosic pulp stock is ground in an environment of superatmospheric steam in a grinding space defined between a pair of grinding members which rotate relatively to one another in a closed housing having a feed-in opening into which the pulp stock is advanced by means of a feed screw which rotates within a feed-in passage. A jacket having a perforate wall is arranged about the feed-in passage for receiving the blow-back steam separated from the pulp stock, and which steam is evacuated therefrom through a conduit connected to the jacket. The feed screw rotates in close proximity to the perforate wall to maintain it free of pulp stock particles.

Inventors

  • 👤 Rolf B. Reinhall

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 17:58
CPC Classifications
D; D21; D21D; D21D1/00; D21D1/20; D21D1/30; D21B; D21B1/00; D21B1/04; D21B1/12

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 130 words
In a pulp refining apparatus in which lignocellulosic pulp stock is ground in an environment of superatmospheric steam in a grinding space defined between a pair of grinding members which rotate relatively to one another within a closed housing having a stock inlet opening into which the pulp stock is advanced by means of a feed screw rotating within a feed-in passage connected to the stock inlet opening, the improvement for evacuating blow-back steam escaping through said stock inlet opening, comprising: (a) jacket means having a perforate wall mounted about said feed-in passage for separating and receiving blow-back steam; (b) conduit means for evacuating blow-back steam from said jacket means; (c) said feed screw being effective to maintain said perforate wall free of pulp stock entrained in the blow-back steam.
Claim 2
Dependent Claim 130 words
In a pulp refining apparatus in which lignocellulosic pulp stock is ground in an environment of superatmospheric steam in a grinding space defined between a pair of grinding members which rotate relatively to one another within a closed housing having a stock inlet opening into which the pulp stock is advanced by means of a feed screw rotating within a feed-in passage connected to the stock inlet opening, the improvement for evacuating blow-back steam escaping through said stock inlet opening, comprising: (a) jacket means having a perforate wall mounted about said feed-in passage for separating and receiving blow-back steam; (b) conduit means for evacuating blow-back steam from said jacket means; (c) said feed screw being effective to maintain said perforate wall free of pulp stock entrained in the blow-back steam.
Claim 3
Dependent Claim 20 words
A pulp refining apparatus according to claim 1, in which said jacket means is located adjacent said stock inlet opening.
Claim 4
Dependent Claim 22 words
A pulp refining apparatus according to claim 2, in which said perforate wall extends about only a portion of said feed-in passage.

References Cited (Backward Citations)

FR2183928A1 Cited
US4037792A Cited
US3921918A Cited
US4059237A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-08-06 1983-02-05 1983-08-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-08-06 1987-02-05 1987-08-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-08-06 1991-02-05 1991-08-07 $7700.00 Window Closed / Lapsed

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