US3734400A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of dry thermoplastic synthetic resin powders from liquefied gas suspensions
Assignee: Huels AG
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Filing: 1971-12-15
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Granted: 1973-05-22
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Expires: 1991-12-15
Abstract
Abstract A process and apparatus for obtaining dry thermoplastic synthetic resin powders from suspensions of powdery polymers in liquefied gases by centrifuging such a suspension to remove a majority of the liquefied gas, drying the resultant moist powder with a superheated gaseous current of the liquefied gas, and introducing the gaseous entrained powder into a first cyclone to obtain a dry thermoplastic synthetic resin powder as the bottoms product. The top of the first cyclone is connected to a second cyclone which separates the incoming mixture into a light phase and a heavy phase. The light phase is heated and then recycled as the super-heated gaseous current of liquefied gas to dry the previously noted moist powder. The heavy phase is condensed and recycled back to the incoming suspension to form a closed system. The amount of heavy phase is dependent upon the superatmospheric pressure of the system as regulated by a valve adjacently connected to the bottom of the second cyclone.
Inventors
- 👤 K Pfeiffer
- 👤 J Dietrich
- 👤 K Schonberg
- 👤 G Beckmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:55
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; B; B29; B29B; B29B9/00; Y; Y10; Y10S; Y10S494/00; Y10S494/90
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
124 words
A process for obtaining a dry thermoplastic synthetic resin powder from suspensions of powdery polymers in liquefied gases, which comprises separating said suspension under superatmospheric pressure into a liquefied gas and a powder moist with said liquefied gas, contacting said powder moist with said liquefied gas with a superheated gaseous phase of said liquefied gas to entrain said powder therein, separating said powder from the gaseous phase to obtain the dry thermoplastic synthetic resin powder, condensing the gaseous phase separated from said powder to a proportion equal to that of the liquefied gas moistening said powder after the initial separating step, reintroducing the condensed portion into the original suspension, and heating and returning the uncondensed portion to said powder moist with said liquefied gas.
Claim 2
Dependent Claim
124 words
A process for obtaining a dry thermoplastic synthetic resin powder from suspensions of powdery polymers in liquefied gases, which comprises separating said suspension under superatmospheric pressure into a liquefied gas and a powder moist with said liquefied gas, contacting said powder moist with said liquefied gas with a superheated gaseous phase of said liquefied gas to entrain said powder therein, separating said powder from the gaseous phase to obtain the dry thermoplastic synthetic resin powder, condensing the gaseous phase separated from said powder to a proportion equal to that of the liquefied gas moistening said powder after the initial separating step, reintroducing the condensed portion into the original suspension, and heating and returning the uncondensed portion to said powder moist with said liquefied gas.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein said superatmospheric pressure is from about 0.5 to about 15 atmospheres gauge.
Claim 4
Dependent Claim
14 words
The process of claim 2 wherein the initial separation step comprises a centrifuging operation.
Claim 5
Dependent Claim
18 words
The process of claim 3 wherein ammonia is fed to said super-heated gaseous phase of said liquefied gas.
Claim 6
Dependent Claim
22 words
The process of claim 1 wherein the step of separating said powder from the gaseous phase is achieved by a cyclone operation.
Claim 7
Dependent Claim
50 words
The process of claim 1 wherein said powder is cyclonically separated from the gaseous phase as a bottoms product and the gaseous phase is subjected to a fuRther cyclonic separation, the bottoms product of which is subjected to the condensation step and the overhead of which forms said uncondensed portion.
Claim 8
Independent Claim
219 words
An apparatus for obtaining dry thermoplastic synthetic resin powders from suspensions of powdery polymers in liquefied gases which comprises centrifuge means, including a filtrate draw-off pipe and a powder discharge pipe, for separating said suspension into a liquefied gas filtrate exiting through said filtrate draw-off pipe and a powder moist with said liquefied gas exiting through said powder discharge pipe, drying means connected to said powder discharge pipe of said centrifuge means for drying said powder moist with said liquefied gas by employing a gaseous current of said liquefied gas, first cyclone means, having gas and solids outlets, connected to said drying means for separating the mixture issuing therefrom into said dry thermoplastic synthetic resin powder exiting through said solids outlet and a gaseous phase exiting through said gas outlet, second cyclone means, having gas and solid outlets, connected to said gas outlet of said first cyclone means for separating said gaseous phase into a heavy phase exiting through said solids outlet and a light phase exiting through said gas outlet, said gas outlet being connected to said drying means to supply said light phase to said drying means as a gaseous current of said liquefied gas, and condensing means connected between said solids outlet of said second cyclone means and said centrifuge means for condensing said heavy phase.
Claim 9
Independent Claim
219 words
An apparatus for obtaining dry thermoplastic synthetic resin powders from suspensions of powdery polymers in liquefied gases which comprises centrifuge means, including a filtrate draw-off pipe and a powder discharge pipe, for separating said suspension into a liquefied gas filtrate exiting through said filtrate draw-off pipe and a powder moist with said liquefied gas exiting through said powder discharge pipe, drying means connected to said powder discharge pipe of said centrifuge means for drying said powder moist with said liquefied gas by employing a gaseous current of said liquefied gas, first cyclone means, having gas and solids outlets, connected to said drying means for separating the mixture issuing therefrom into said dry thermoplastic synthetic resin powder exiting through said solids outlet and a gaseous phase exiting through said gas outlet, second cyclone means, having gas and solid outlets, connected to said gas outlet of said first cyclone means for separating said gaseous phase into a heavy phase exiting through said solids outlet and a light phase exiting through said gas outlet, said gas outlet being connected to said drying means to supply said light phase to said drying means as a gaseous current of said liquefied gas, and condensing means connected between said solids outlet of said second cyclone means and said centrifuge means for condensing said heavy phase.
Claim 10
Dependent Claim
20 words
The apparatus of claim 7 further comprising a filtrate vessel connected to said filtrate draw-off pipe of said centrifuge means.
Claim 11
Dependent Claim
30 words
The apparatus of claim 7 further comprising a pressure lock connected at one end to said solids outlet of said first cyclone means, the other end communicating with the atmosphere.
Claim 12
Dependent Claim
25 words
The apparatus of claim 7 further comprising a pressure control valve connected between said solids outlet of said second cyclone means and said condensing means.
Claim 13
Dependent Claim
23 words
The apparatus of claim 7 further comprising a condensate tank and a pump serially connected between said condensing means and said centrifuge means.
Claim 14
Dependent Claim
23 words
The apparatus of claim 7 further comprising a heating element and a fan serially disposed between said gas outlet and said drying means.
Claim 15
Dependent Claim
14 words
The apparatus of claim 7 wherein said drying means is a gas convection dryer.
Claim 16
Dependent Claim
12 words
The apparatus of claim 13 wherein said dryer is a current dryer.
Claim 17
Dependent Claim
93 words
The apparatus of claim 7 further comprising a filtrate vessel connected to said filtrate draw-off pipe of said centrifuge means, a pressure lock connected at one end to said solids outlet of said first cyclone means, the other end communicating with the atmosphere, a pressure control valve connected between said solids outlet of said second cyclone means and said condensing means, a condensate tank and a pump serially connected between said condensing means and said centrifuge means, a heating element and a fan serially disposed between said gas outlet and said drying means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |