Patent US4613713A successfully refreshed from Google Patents.
US4613713A
Expired / Lapsed
US
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Method and apparatus for pyrolysis of atactic polypropylene
Assignee: Allstate Financial Corp
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Filing: 1984-05-22
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Granted: 1986-09-23
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Expires: 2004-05-22
Abstract
Abstract This invention relates to an apparatus and a method for pyrolytic decomposition of polymeric materials into lower molecular weight products involving the heat treatment of raw polymeric material within reactive conduits submerged in a fluidized bed furnace operated at pyrolizing temperatures.
Inventors
- 👤 H. Kenneth Staffin
- 👤 R. B. Roaper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:47
CPC Classifications
C; C10; C10G; C10G1/00; C10G1/02; C10G9/00; C10G9/14; C10G9/16
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
130 words
A method for pyrolizing polymeric materials, which comprises: melting the polymeric material prior to passing it thru a reactor and conduit; passing the polymeric material thru the reactor conduit disposed in a fluidized bed thereby exposing the polymeric material to pyrolizing temperatures causing it to decompose into lower molecular weight fragments whereby the fluidized bed heats the polymeric material to pyrolizing temperatures causing it to decompose cleaning carbonaceous deposits from the reactor conduit by exposing the deposits to oxygen at sufficient temperatures to cause combustion of said deposits and contacting surfaces of the reactor conduit with fluidized particles of the fluidized bed to conduct heat away from the surfaces at a rate sufficiently high to permit rapid combustion of the deposits without damage to the surface of the reactor conduit.
Claim 2
Independent Claim
130 words
A method for pyrolizing polymeric materials, which comprises: melting the polymeric material prior to passing it thru a reactor and conduit; passing the polymeric material thru the reactor conduit disposed in a fluidized bed thereby exposing the polymeric material to pyrolizing temperatures causing it to decompose into lower molecular weight fragments whereby the fluidized bed heats the polymeric material to pyrolizing temperatures causing it to decompose cleaning carbonaceous deposits from the reactor conduit by exposing the deposits to oxygen at sufficient temperatures to cause combustion of said deposits and contacting surfaces of the reactor conduit with fluidized particles of the fluidized bed to conduct heat away from the surfaces at a rate sufficiently high to permit rapid combustion of the deposits without damage to the surface of the reactor conduit.
Claim 3
Dependent Claim
24 words
The method of claim 1 further comprising the step of separating the polymeric material fragments by sizes when they emerge from the reactor tube.
Claim 4
Dependent Claim
51 words
The method recited in claim 2 wherein a plurality of reactor conduits are provided and the cleaning step is carried out in at least one reactor conduit while polymeric material is pyrolytically decomposed in at least one other reactor conduit so that the apparatus continuously produces the lower molecular weight fragments.
Claim 5
Dependent Claim
26 words
The method recited in claim 3 further comprising: the step of purging the reactor conduits with an inert gas before exposing carbonaceous deposits therein to oxygen.
Claim 6
Dependent Claim
26 words
The method recited in claim 4 further comprising: the step of purging the reactor conduits with an inert gas after carbonaceous deposits have been combusted therein.
Claim 7
Dependent Claim
12 words
The method recited in claim 4 wherein the inert gas is nitrogen.
Claim 8
Dependent Claim
12 words
The method recited in claim 5 wherein the inert gas is nitrogen.
Claim 9
Independent Claim
23 words
The method recited in claims 3, 4, 5, 6 or 7 wherein the oxygen is contained in air introduced to the reactor conduits.
Claim 10
Dependent Claim
31 words
The method of claim 1 wherein the step of melting the polymeric material further comprises passing polymeric material in a solid state into a preheat tank to melt the polymeric material.
Claim 11
Independent Claim
173 words
A method for pyrolyzing polymeric materials comprising: providing a source of waste polymeric material; preheating the polymeric material to melt it; pumping the melted polymeric material through feed conduit into a heated fluidized bed through at least both a first and second reactor conduit; heating the melted polymeric material in the reactor conduits to decompose it whereby the fluidizing bed heats the polymeric material; separating high molecular weight product from low molecular weight product; cleaning carbonaceous deposits from the reactor conduit by closing a valve in the feed conduit to stop the flow of melted polymeric material to the reactor conduits, introducing a purging gas, downstream of the valve, so that it passes into the reactor conduit to flush out excess polymeric material, introducing oxygen containing gas into the reactor conduit downstream of the valve to cause spontaneous combustion of the carbonaceous residue in the heated portion of the conduit, the fluidized bed conducting a portion of the heat of combustion away from the surfaces of the reactor conduit to prevent damage thereto.
Claim 12
Independent Claim
173 words
A method for pyrolyzing polymeric materials comprising: providing a source of waste polymeric material; preheating the polymeric material to melt it; pumping the melted polymeric material through feed conduit into a heated fluidized bed through at least both a first and second reactor conduit; heating the melted polymeric material in the reactor conduits to decompose it whereby the fluidizing bed heats the polymeric material; separating high molecular weight product from low molecular weight product; cleaning carbonaceous deposits from the reactor conduit by closing a valve in the feed conduit to stop the flow of melted polymeric material to the reactor conduits, introducing a purging gas, downstream of the valve, so that it passes into the reactor conduit to flush out excess polymeric material, introducing oxygen containing gas into the reactor conduit downstream of the valve to cause spontaneous combustion of the carbonaceous residue in the heated portion of the conduit, the fluidized bed conducting a portion of the heat of combustion away from the surfaces of the reactor conduit to prevent damage thereto.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-22 | 1990-03-24 | 1990-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-22 | 1994-03-24 | 1994-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-22 | 1998-03-24 | 1998-09-23 | $7700.00 | Window Closed / Lapsed |