Patent US2938860A successfully refreshed from Google Patents.
US2938860A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radioactive analysis of cracking catalysts
Assignee: Shell USA Inc
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Filing: 1956-03-16
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Granted: 1960-05-31
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Expires: 1976-03-16
Abstract
No abstract record available.
Inventors
- 👤 Vincent P Guinn
- 👤 Charles P Brewer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:51
CPC Classifications
G; G21; G21H; G21H5/00; G21H5/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
132 words
A METHOD FOR SIMULTANEOUSLY MEASURING THE RATES OF DEACTIVATION BY SURFACE AREA LOSS OF A PLURALITY OF DIFFERENT CRACKING CATALYSTS, COMPRISING THE STEPS OF TAGGING A PREDETERMINED AMOUNT OF EACH OF SAID CATALYST WITH A DIFFERENT ISOTOPE, SAID ISOTOPES EACH EMITTING GAMMA RAYS OF DIFFERENT ENERGY DISTINGUISHABLE FROM THAT OF THE OTHER ISOTOPES, INJECTING THE TAGGED CATALYSTS INTO A CRACKING UNIT, LETTING THE TAGGED CATALYST CIRCULATE THROUGH THE CRACKING UNIT IN ADMIXTURE WITH THE EQUILIBRIUM CATALYST PRESENT THEREIN FOR A DESIRED PERIOD OF TIME, WITHDRAWING SAMPLES OF CATALYST FROM THE UNIT, FRACTIONATING SAID SAMPLES INTO A PLURALITY OF FRACTIONS OF KNOWN DIFFERENT SURFACE AREAS, AND MEASURING THE RADIOACTIVITY OF SAID FRACTIONS BY SEPARATELY COUNTING THE PULSES DUE TO EACH OF THE GAMMA RAYS OF DIFFERENT ENERGY EMITTED BY THE DIFFERENT TAGGING ISOTOPES.
Claim 2
Independent Claim
132 words
A METHOD FOR SIMULTANEOUSLY MEASURING THE RATES OF DEACTIVATION BY SURFACE AREA LOSS OF A PLURALITY OF DIFFERENT CRACKING CATALYSTS, COMPRISING THE STEPS OF TAGGING A PREDETERMINED AMOUNT OF EACH OF SAID CATALYST WITH A DIFFERENT ISOTOPE, SAID ISOTOPES EACH EMITTING GAMMA RAYS OF DIFFERENT ENERGY DISTINGUISHABLE FROM THAT OF THE OTHER ISOTOPES, INJECTING THE TAGGED CATALYSTS INTO A CRACKING UNIT, LETTING THE TAGGED CATALYST CIRCULATE THROUGH THE CRACKING UNIT IN ADMIXTURE WITH THE EQUILIBRIUM CATALYST PRESENT THEREIN FOR A DESIRED PERIOD OF TIME, WITHDRAWING SAMPLES OF CATALYST FROM THE UNIT, FRACTIONATING SAID SAMPLES INTO A PLURALITY OF FRACTIONS OF KNOWN DIFFERENT SURFACE AREAS, AND MEASURING THE RADIOACTIVITY OF SAID FRACTIONS BY SEPARATELY COUNTING THE PULSES DUE TO EACH OF THE GAMMA RAYS OF DIFFERENT ENERGY EMITTED BY THE DIFFERENT TAGGING ISOTOPES.
References Cited (Backward Citations)
US2631968A
Cited
US2567207A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-05-31 | 1963-11-30 | 1964-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-05-31 | 1967-11-30 | 1968-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-05-31 | 1971-11-30 | 1972-05-31 | $7700.00 | Window Closed / Lapsed |