Vacuum Separator for Polymer Melt Degassing Gas Purification
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Solution Overview
Problem
Current methods for purifying gases from polymer melt degassing, particularly in continuous production of stretched polymer films, are inefficient in removing sublimable, non-sublimable, and condensible gases, leading to residual impurities and increased energy consumption due to the need for multiple vacuum pumps and frequent maintenance.
Innovation Solution
A method and device utilizing a vacuum separator with a cooling arrangement that freezes out impurities at temperatures below their triple point, combined with a heating arrangement to liquefy and remove them, significantly reducing gas volume and energy consumption by efficiently separating and removing sublimable, non-sublimable, and condensible gases through freezing and subsequent heating, and using a mechanical purifying device for efficient scraping and removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional cooling methods are used to separate gases from polymer melt degassing, then separation efficiency is limited, but energy consumption increases due to the need for multiple vacuum pumps and frequent maintenance
Solution Approach 1:
The patent applies phase transition by cooling the exhaust gas to freeze out condensible substances. The cooling arrangement reduces the temperature of the exhaust gas below the triple point of target impurities, causing them to transition from gas phase to solid phase and deposit on the cooling surfaces. This phase transition mechanism achieves high separation efficiency (removing over 90% of disruptive substances) while reducing the gas volume by up to 95%, thereby minimizing the need for multiple vacuum pumps and reducing energy consumption.
2Manufacturing precision
If the exhaust gas is cooled to freeze out impurities, then separation efficiency improves, but the removed substances require additional heating and removal steps
Solution Approach 1:
The patent merges the cooling arrangement and heating arrangement into a single integrated vacuum separator device. The cooling arrangement freezes out impurities on its surfaces, and the heating arrangement subsequently heats these frozen substances to melt them for removal. This combination of opposing thermal processes within one device simplifies the overall system by eliminating the need for separate freezing and melting equipment, while maintaining high separation efficiency.
3Productivity
If multiple vacuum pumps are used to handle large gas volumes, then gas purification capacity increases, but maintenance frequency and operational complexity increase
Solution Approach 1:
The patent uses phase transition (freezing out) to condense and remove the majority of gas volume reductions. By cooling the exhaust gas below the triple point of target impurities, over 95% of the gas volume is reduced through freezing and deposition on cooling surfaces. This dramatically reduces the volume of gas that needs to be handled by vacuum pumps, allowing a single vacuum pump to suffice instead of multiple pumps, thereby reducing maintenance frequency and operational complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method achieves a separation efficiency of over 90% of disruptive substances, reducing the gas volume by up to 95% and extending the service life of vacuum pumps by minimizing maintenance needs, while ensuring a continuous and energy-efficient purification process.
Implementation Method 1
the exhaust gas is cooled with liquid water, or the condensed substances are heated and subsequently removed via a removal point
Implementation Method 2
condensible, separable by freezing, and/or re-sublimable substances are separated from the supplied and to-be-purified gas by means of a cooling arrangement
Implementation Method 3
the substances separated by means of the cooling arrangement are at least partially liquefied or softened by means of a heating arrangement and removed from the vacuum separator
Data Source
AI summary
A method and a device for the purification of gases from the degassing of polymer melts—in particular, for the continuous further processing to form stretched polymer films. In this case, the gas to be purified is fed from a vacuum zone of a plasticizing unit, via at least one vacuum or degassing line, to a vacuum separator with a gas inlet and a gas outlet in which condensible, separable by freezing, and/or re-sublimable substances are separated from the supplied and purified gas by means of a cooling arrangement, and the separated substances are removed from the vacuum separator. By means of a heating arrangement, the substances separated by means of the cooling arrangement are at least partially liquefied or softened in the vacuum separator and removed from the vacuum separator in particular by suction.