Gas Abatement Device with Liquid Ring Pump for Effluent Treatment
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Solution Overview
Problem
Conventional abatement devices for treating effluent gas streams from semiconductor and flat panel display manufacturing processes face high power requirements due to the need for inert purge gases, which increase energy consumption and costs, especially when dealing with effluent streams containing high percentages of purge gas.
Innovation Solution
The use of a sub-atmospheric pressure abatement device combined with a pump, such as a multi-rotor screw mechanism or liquid ring pump, that converts harmful components into liquid-soluble compounds, reducing the need for purge gases and lowering energy demands by utilizing reactive species like H+ and OH− ions from water vapor to facilitate efficient destruction of PFCs at ambient temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If inert purge gas is injected into the backing pump to reduce by-product contamination, then the reliability of the pumping mechanism is improved, but the power requirement of the abatement device increases significantly
Solution Approach 1:
The invention extracts and removes the inert purge gas from the effluent stream before it enters the abatement device. A separate purge gas removal system is implemented that diverts the purge gas away from the main effluent stream, allowing the abatement device to process only the actual waste gases (PFCs and by-products). This extraction approach maintains pump reliability by still providing purge gas where needed while dramatically reducing the energy burden on the abatement device by eliminating the need to treat 70-90% inert gas.
Solution Approach 2:
The effluent stream is segmented into two separate paths: one for the actual waste gases containing PFCs and by-products, and another for the inert purge gas. The purge gas is routed through a separate removal system that prevents it from mixing with the waste stream entering the abatement device. This segmentation allows the abatement device to focus only on treating the harmful components rather than processing the entire mixed stream, thereby reducing power consumption while maintaining system reliability.
2Manufacturing precision
If purge gas flow rate is increased to maintain close tolerances in the backing pump, then the manufacturing precision of the pumping mechanism is improved, but the productivity of the abatement process decreases
Solution Approach 1:
The inert purge gas is extracted and removed from the effluent stream before abatement treatment. This allows the backing pump to maintain its required close tolerances and receive adequate purge gas flow without forcing the abatement device to process the same volume of inert gas. The extraction of purge gas from the treatment path effectively decouples the pump's operational requirements from the abatement device's processing load, maintaining manufacturing precision while improving abatement productivity.
3Object-affected harmful factors
If conventional abatement methods are used to treat effluent streams with high purge gas content, then the harmful PFC components are converted into less harmful compounds, but the energy consumption increases significantly
Solution Approach 1:
The inert purge gas is extracted and removed from the effluent stream before it enters the abatement device. This extraction ensures that only the actual harmful PFC components and their by-products are subjected to abatement treatment, eliminating the wasteful energy consumption associated with processing 70-90% inert gas. The harmful factors are still effectively addressed through targeted abatement while energy loss is minimized by excluding the inert portion from the treatment process.
Solution Approach 2:
Instead of applying abatement treatment to the entire effluent stream including the excessive inert purge gas, the invention applies partial action by treating only the necessary portion containing PFCs and by-products. The purge gas is removed and excluded from the abatement process, allowing the system to achieve sufficient treatment of harmful components without the excessive energy consumption that would result from processing the full stream volume.
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
This configuration significantly reduces energy consumption and costs by converting harmful gases into soluble forms, allowing for efficient treatment of effluent streams with reduced power requirements and eliminating the need for purge gases, thereby enhancing the environmental sustainability of the process.
Implementation Method 1
an abatement device for converting a component of the effluent stream into a liquid-soluble component
Implementation Method 2
a pump for at least partially evacuating the abatement device
Implementation Method 3
means for conveying a liquid to the pump
Implementation Method 4
an outlet for exhausting a solution comprising the liquid and the liquid-soluble component of the gas stream
Data Source
AI summary
System for treating an effluent fluid stream from a process tool including a vacuum pump (16) for drawing an effluent stream from the process tool chamber, an abatement device (12) for treating the effluent stream and a liquid ring pump (14) for at least partially evacuating the abatement device (12). During use, the abatement device (12) converts one or more components of the effluent stream, for example F2 or a PFC, into one or more liquid-soluble a compounds, for example HF, that are less harmful to the environment. The liquid ring pump (14) receives the effluent stream and a liquid, and exhausts a solution of the liquid and the liquid-soluble component of the effluent stream. The liquid ring pump (14) thus operates as both a wet scrubber and an atmospheric vacuum pumping stage.