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US3970513A Expired / Lapsed US ⏱️ 0.0 years remaining

Steam supplying structure for opposing build-up of matter in headboxes

Assignee: Valmet Technologies Oy
•
Filing: 1975-04-09
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Granted: 1976-07-20
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Expires: 1995-04-09
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Abstract

Abstract A structure for keeping clean the interior of the headbox of a paper machine as well as contributing to the homogeneity of the stock flowing through the headbox. At a location in the headbox where there is a tendency for accumulation or build-up of matter such as fibers, fillers, slime, or the like, steam is introduced such as by supplying steam to the interior of a hollow body having a wall provided with passages through which the steam can escape to the exterior of the hollow body into the stock in the headbox.

Inventors

  • 👤 Antti Lehtinen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 10:29
CPC Classifications
D; D21; D21F; D21F1/00; D21F1/02; D21F1/026

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 231 words
In a paper machine, a headbox having in its interior a location where there is a tendency for accumulation and build-up of matter such as fibers, fillers, slime and the like, and means situated in the region of said location for introducing steam into stock flowing through the headbox so as to oppose the tendency of said matter to accumulate and build-up at said location, said means including at the region of said location a plurality of hollow bodies each having a wall surrounding a hollow interior space and formed at least in part with passages through which steam can flow from the interior space to the exterior of each hollow body, and steam-supply means communicating with the hollow interior of each body for supplying thereto steam to flow through said passages to the exterior of each body into stock situated at the exterior of said body, said headbox having in its interior a plurality of flow-equalizing lamellae which define between themselves spaces through which the stock flows, and said lamellae respectively having leading edge regions toward which the stock flows and trailing edge regions away from which the stock flows, and said plurality of hollow bodies, respectively being connected with said lamellae and extending along one of said edge regions thereof for introducing steam into the stock at the region of said one of said edge regions of said lamellae.
Claim 2
Dependent Claim 231 words
In a paper machine, a headbox having in its interior a location where there is a tendency for accumulation and build-up of matter such as fibers, fillers, slime and the like, and means situated in the region of said location for introducing steam into stock flowing through the headbox so as to oppose the tendency of said matter to accumulate and build-up at said location, said means including at the region of said location a plurality of hollow bodies each having a wall surrounding a hollow interior space and formed at least in part with passages through which steam can flow from the interior space to the exterior of each hollow body, and steam-supply means communicating with the hollow interior of each body for supplying thereto steam to flow through said passages to the exterior of each body into stock situated at the exterior of said body, said headbox having in its interior a plurality of flow-equalizing lamellae which define between themselves spaces through which the stock flows, and said lamellae respectively having leading edge regions toward which the stock flows and trailing edge regions away from which the stock flows, and said plurality of hollow bodies, respectively being connected with said lamellae and extending along one of said edge regions thereof for introducing steam into the stock at the region of said one of said edge regions of said lamellae.
Claim 3
Dependent Claim 52 words
The combination of claim 1 and wherein the wall of at least one of said hollow bodies has at least in part a sintered construction which provides between particles of said sintered construction which are sintered together said passages through which steam flows from the interior to the exterior of said body.
Claim 4
Dependent Claim 18 words
The combination of claim 1 and wherein said bodies extend along said leading edge regions of said lamellae.

References Cited (Backward Citations)

US2736247A Cited
GB419369A Cited
US3005746A Cited
US3122470A Cited
US3791918A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-07-20 1980-01-19 1980-07-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-07-20 1984-01-19 1984-07-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-07-20 1988-01-19 1988-07-20 $7700.00 Window Closed / Lapsed

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