Patent US2681871A successfully refreshed from Google Patents.
← Back to Patent Explorer
US2681871A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for hydrolyzing cellulosic materials

Assignee: United States Steel Corp
•
Filing: 1951-02-16
•
Granted: 1954-06-22
•
Expires: 1971-02-16
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

No abstract record available.

Inventors

  • 👤 Lewis C Wallace

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 22:43
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/02; C07D307/34; C07D307/38; C07D307/40; C07D307/46; C07D307/48; C07D307/50

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 155 words
APPARATUS FOR HYDROLYZING CELLULOSIC MATERIALS COMPRISING A VERTICALLY EXTENDING REACTION CHAMBER HAVING DOWNWARDLY FLARING SIDE WALLS AT THE UPPER PORTION THEREOF, THE UPPER PORTION OF SAID SIDE WALLS FORMING A CONE-SHAPED TOP AND THE LOWER PORTION OF SAID SIDE WALLS FORMING AN INVERTED CONE SHAPED BOTTOM, A FILTER SCREEN ADJACENT THE TOP OF THE REACTION CHAMBER SECURED TO THE INNER SURFACE OF SAID SIDE WALLS AND SPACED FROM SAID UPPER PORTION DEFINING THEREBETWEEN A SECOND CHAMBER, A VAPOR OFF-TAKE CONDUIT COMMUNICATING WITH SAID SECOND CHAMBER ADJACENT THE TOP THEREOF, A SUGAR LIQUOR DISCHARGE CONDUIT COMMUNICATING WITH SAID SECOND CHAMBER ADJACENT THE BOTTOM THEREOF, MEANS TO INTRODUCE CELLULOSIC MATERIAL CONTINUOUSLY UNDER PRESSURE ADJACENT THE TOP OF THE REACTION CHAMBER, MEANS TO INTRODUCE CONTINUOUSLY A HYDROLYZING SOLUTION AND STEAM ADJACENT THE BOTTOM OF THE REACTION CHAMBER IN COUNTER-CURRENT FLOW TO SAID CELLULOSIC MATERIAL, AND MEANS TO REMOVE LIGNIN SUBSTANTIALLY CONTINUOUSLY ADJACENT THE BOTTOM OF THE REACTION CHAMBER.
Claim 2
Independent Claim 148 words
THE METHOD OF HYDROLYZING CELLULOSIC MATERIALS COMPRISING INTRODUCING CONTINUOUSLY CELLULOSIC MATERIALS AT THE UPPER END OF A DOWNWARDLY MOVING COLUMN THEREOF WHILE MAINTAINING SAID COLUMN UNDER SUPERATMOSPHERIC PRESSURE, INTRODUCING CONTINUOUSLY A HYDROLYZING SOLUTION AND STEAM AT THE LOWER END OF SAID COLUMN COUNTER TO THE DIRECTION OF MOVEMENT OF THE CELLULOSIC MATERIALS, EXPANDING THE VOLUME OF THE CELLULOSIC MATERIALS WHILE PASSING THE SAME COUNTER TO THE DIRECTION OF MOVEMENT OF THE HYDROLYZING SOLUTION THUS CAUSING THE CELLULOSIC MATERIALS TO IMBIBE THE HYDROLYZING SOLUTION AND FORM LIGNIN, SUGAR SOLUTION AND VOLATILE MATERIALS, REMOVING CONTINUOUSLY THE VOLATILE MATERIALS AND THE SUGAR SOLUTION FROM THE COLUMN ADJACENT THE POINT OF INTRODUCTION OF THE CELLULOSIC MATERIALS, INTERMITTENTLY RELEASING THE PRESSURE ON THE COLUMN AT THE LOWER END THEREOF AND IMMEDIATELY FOLLOWING SAID RELEASE OF PRESSURE REMOVING FROM THE LOWER END A QUANTITY OF LIGNIN THEREBY CAUSING SAID COLUMN TO MOVE ABRUPTLY DOWNWARD.

References Cited (Backward Citations)

US1677406A Cited
GB367916A Cited
US2088977A Cited
US2086701A Cited
US2108567A Cited
US2198785A Cited
US2426677A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1957-06-21 1957-12-21 1958-06-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1961-06-21 1961-12-21 1962-06-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1965-06-21 1965-12-21 1966-06-22 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag