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US3884766A Expired / Lapsed US ⏱️ 0.0 years remaining

Recovery of alkenyl-aromatic monomers by falling strand devolatilization

Assignee: Monsanto Co
•
Filing: 1973-03-09
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Granted: 1975-05-20
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Expires: 1993-03-09
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Abstract

Abstract Disclosed is an apparatus adapted for the continuous on-line recovery of alkenylaromatic monomer from a polymer-monomer melt and for the removal of alkenylaromatic oligomers and high boiling organic compounds from the thus-recovered monomer. The apparatus comprises in combination a two-stage falling strand devolatilization unit, a perforated sieve tray liquid-vapor contacting and separation unit receiving a vapor stream from the first stage of the volatilization unit and a direct liquid contact condensing unit receiving a vapor stream from the second stage of the falling strand devolatilization unit.

Inventors

  • 👤 Wallace G Bir
  • 👤 Joseph Novack

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 16:46
CPC Classifications
C; C08; C08F; C08F6/00; C08F6/26; B; B01; B01D; B01D3/00; B01D3/06; C08F6/001; C08F6/003

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 284 words
AN APPARATUS FOR THE CONTINUOUS ON-LINE RECOVERY OF ALKENYLAROMATIC MONOMER FROM A STREAM CONTAINING ALKENYLAROMATIC MONOMER, ALKENYLAROMATIC HIGHER POLYMER, ALKENYLAROMATIC OLIGOMER, HIGH BOILING ORGANIC COMPOUNDS AND INERT HYDROCARBONS, AND FOR REDUCING THE CONCENTRATION OF ALKENYLAROMATIC OLIGOMERS AND HIGH BOILING ORGANIC COMPOUNDS IN SAID RECOVERED ALKENLAROMATIC MONOMER, SAID APPARATUS COMPRISING IN COMBINATION A. A TWO-STAGE FALLING STRAND DEVOLATIZING MEANS FOR AN ALKENYLAROMATIC POLYMER-MONOMER MELT, COMPRISING A HEATING MEANS FOR SAID MELT MOUNTED INTEGRALLY ABOVE FIRST AND SECOND FLASH VAPORATIZION CHAMBERS POSITIONED RESPECTIVELY IN CONTIGUOUS DECENDING VERTICAL RELATIONSHIP AND COMMUNICATING WITH ONE ANOTHER, MEANS FOR PRODUCING A FIFFERENT VACUUM WITHIN EACH OF SAID FLASH VAPORIZATION CHAMBERS AND MEANS FOR MAINTAINING AN ELEVATED TEMPERATURE IN SAID CHAMBERS; B. A FIRST CONTACTING AND SEPARATION MEANS FOR BRINGING INTO DIRECT AND INIMATE CONTACT A VAPOR STREAM FFROM THE SAID FIRST FLASH VAPORIZATION CHAMBER OF SAID VOLATILIZING MEANS AND A LIQUID STREAM AND FOR THEREAFTER SEPARATING SAID VAPOR STREAM FROM SAID LIQUID STREAM, COMPRISING AN ENCLOSED VESSEL HAVING A PLURALITY OF PERFORATED SIEVE TRAYS CARRING SAID LIQUID STREAM AMD PERMITTING DIRECT AND INTIMATE CONTACT WITH SAID VAPOR STREAM PASSING UPWARDLY THROUGH SAID PERFORATIONS IN SAID TRAYS AND THE LIQUID STREAM CARRIED THEREBY, AND A SEPARATION ZONE FOR SEPARATING SAID VAPOR STREAM FROM SAID LIQUID STREAM; C. A SECOND CONTACTING MEANS FOR BRINGING INTO DIRECT AND INTIMATE CONTACT A VAPOR STREAM FROM SAID SECOMD FLASH VAPORIZATION CHAMBER OF THE DEVOLATIZING MEANS AND A COOLED LIQUID STREAM FROM SUFFICIENTLY TO CONDENSE SUBSTANTIALLY ALL OF SAID VAPOR STREAM; D. CONDUIT MEANS ESTABLISHING COMMUNICATION BETWEEN SAID FIRST FLASH VAPORIZATION CHAMBER AND SAID FIRST CONTACTING AND SEPARATION MEANS; AND E. CONDUIT MEANS ESTABLISHING COMMUNICATION BETWEEN SAID SECOND FLASH VAPORIZATION CHAMBER AND SAID SECOND CONTACTING MEANS.
Claim 2
Independent Claim 284 words
AN APPARATUS FOR THE CONTINUOUS ON-LINE RECOVERY OF ALKENYLAROMATIC MONOMER FROM A STREAM CONTAINING ALKENYLAROMATIC MONOMER, ALKENYLAROMATIC HIGHER POLYMER, ALKENYLAROMATIC OLIGOMER, HIGH BOILING ORGANIC COMPOUNDS AND INERT HYDROCARBONS, AND FOR REDUCING THE CONCENTRATION OF ALKENYLAROMATIC OLIGOMERS AND HIGH BOILING ORGANIC COMPOUNDS IN SAID RECOVERED ALKENLAROMATIC MONOMER, SAID APPARATUS COMPRISING IN COMBINATION A. A TWO-STAGE FALLING STRAND DEVOLATIZING MEANS FOR AN ALKENYLAROMATIC POLYMER-MONOMER MELT, COMPRISING A HEATING MEANS FOR SAID MELT MOUNTED INTEGRALLY ABOVE FIRST AND SECOND FLASH VAPORATIZION CHAMBERS POSITIONED RESPECTIVELY IN CONTIGUOUS DECENDING VERTICAL RELATIONSHIP AND COMMUNICATING WITH ONE ANOTHER, MEANS FOR PRODUCING A FIFFERENT VACUUM WITHIN EACH OF SAID FLASH VAPORIZATION CHAMBERS AND MEANS FOR MAINTAINING AN ELEVATED TEMPERATURE IN SAID CHAMBERS; B. A FIRST CONTACTING AND SEPARATION MEANS FOR BRINGING INTO DIRECT AND INIMATE CONTACT A VAPOR STREAM FFROM THE SAID FIRST FLASH VAPORIZATION CHAMBER OF SAID VOLATILIZING MEANS AND A LIQUID STREAM AND FOR THEREAFTER SEPARATING SAID VAPOR STREAM FROM SAID LIQUID STREAM, COMPRISING AN ENCLOSED VESSEL HAVING A PLURALITY OF PERFORATED SIEVE TRAYS CARRING SAID LIQUID STREAM AMD PERMITTING DIRECT AND INTIMATE CONTACT WITH SAID VAPOR STREAM PASSING UPWARDLY THROUGH SAID PERFORATIONS IN SAID TRAYS AND THE LIQUID STREAM CARRIED THEREBY, AND A SEPARATION ZONE FOR SEPARATING SAID VAPOR STREAM FROM SAID LIQUID STREAM; C. A SECOND CONTACTING MEANS FOR BRINGING INTO DIRECT AND INTIMATE CONTACT A VAPOR STREAM FROM SAID SECOMD FLASH VAPORIZATION CHAMBER OF THE DEVOLATIZING MEANS AND A COOLED LIQUID STREAM FROM SUFFICIENTLY TO CONDENSE SUBSTANTIALLY ALL OF SAID VAPOR STREAM; D. CONDUIT MEANS ESTABLISHING COMMUNICATION BETWEEN SAID FIRST FLASH VAPORIZATION CHAMBER AND SAID FIRST CONTACTING AND SEPARATION MEANS; AND E. CONDUIT MEANS ESTABLISHING COMMUNICATION BETWEEN SAID SECOND FLASH VAPORIZATION CHAMBER AND SAID SECOND CONTACTING MEANS.
Claim 3
Dependent Claim 47 words
The apparatus as defined by claim 1, further comprising discharge means in said second contacting means for removal of said cooled liquid stream and said condensed vapor stream and conduit means operatively connecting said discharge means with said liquid stream in the first contacting and separation means.
Claim 4
Dependent Claim 164 words
The apparatus as defined by claim 1, wherein said first contacting and separation means comprises a vessel having (1) a vapor stream inlet means near its lower end, (2) a vapor stream outlet near its upper end, (3) a liquid stream inlet means near its upper end, (4) a liquid stream outlet means near its lower end, (5) a plurality of perforated sieve trays positioned within said vessel in a manner permitting said liquid stream to successively traverse each tray in descending order as said liquid stream flows from its said inlet means to its said outlet means, said trays permitting the vapor stream to pass from its said inlet means to its said outlet means only by passing through said perforations in the trays, (6) a separation zone near its upper end for separating said vapor stream from said liquid stream, and (7) means to recirculate exteriorly of said vessel the liquid stream from its said outlet means to its said inlet means.
Claim 5
Dependent Claim 36 words
The apparatus as defined by claim 3, further comprising a refrigeration means and a bypass means in parallel therewith in said recirculating means and valve means selectively permitting complete or partial bypass of said refrigeration means.
Claim 6
Dependent Claim 20 words
The apparatus as defined by claim 1, wherein said first contacting and separating means contains three of said sieve trays.
Claim 7
Dependent Claim 104 words
The apparatus as defined by claim 1, wherein said second contacting means comprises an enclosed vessel having (1) a vapor stream inlet near its upper end, (2) a vapor stream outlet near its lower end, (3) a liquid stream outlet means near its lower end, (4) a plurality of spraying head members positioned in vertically spaced relationship within said vessel in such a manner as to assure intimate contact of a cooled liquid sprayed therefrom with said vapor stream as it passes from its said inlet means to its said outlet means, and (5) means to supply a cooled liquid to said spraying heads.
Claim 8
Dependent Claim 65 words
The apparatus as defined in claim 6, further comprising a collection means at the lower end of said vessel for collecting said cooled liquid stream and said condensed vapor stream and recycle loop means for recirculating exteriorly of said vessel at least a portion of said cooled liquid stream and condensed vapor stream collected By said means, said recycle loop means containing refrigeration means therein.
Claim 9
Dependent Claim 47 words
The apparatus as defined in claim 6, wherein said vapor stream outlet means comprises an L-shaped conduit member containing in its upstanding leg portion at least one spraying head member for said cooled liquid stream and means to supply a cooled liquid to said cooled spraying heads.

References Cited (Backward Citations)

US2813137A Cited
US3201365A Cited
US3450183A Cited
US3719720A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-05-19 1978-11-18 1979-05-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-05-19 1982-11-18 1983-05-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-05-19 1986-11-18 1987-05-20 $7700.00 Window Closed / Lapsed

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