Vacuum Pump Exhaust Negative Pressure to Limit By-Product Buildup
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Solution Overview
Problem
Dry vacuum pumps in semiconductor manufacturing facilities face frequent damage and reduced effectiveness due to by-product accumulation, leading to high maintenance and replacement costs, especially in large facilities with many pumps.
Innovation Solution
An abatement system incorporating a liquid-ring pump maintains a negative pressure in the exhaust line, reducing gas precipitation and by-product accumulation by recycling liquid through a burn chamber and recirculation tank, thereby extending the life of both the vacuum and liquid-ring pumps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dry vacuum pumps are used to exhaust process gas from process chambers, then vacuum conditions are achieved for manufacturing processes, but by-product accumulation damages the pumps and reduces their effectiveness
Solution Approach 1:
A liquid-ring pump is introduced as an intermediary device between the process vacuum pump and the exhaust system. The liquid-ring pump captures by-products before they can damage the process vacuum pump, maintaining its effectiveness while allowing continuous operation.
Solution Approach 2:
The system converts the harmful by-products into a beneficial liquid form that can be easily removed and disposed of. The by-products that would normally damage the pump are transformed into a liquid slurry that can be drained away, turning a harmful accumulation into a manageable waste stream.
2Productivity
If vacuum pumps operate continuously in large facilities, then manufacturing productivity is maintained, but maintenance and replacement costs become very costly
Solution Approach 1:
The liquid-ring pump serves as a protective intermediary that absorbs the brunt of by-product accumulation, allowing the process vacuum pump to operate continuously without suffering the same damage. This extends pump life and reduces replacement costs while maintaining manufacturing productivity.
Solution Approach 2:
The system provides beforehand protection by capturing by-products before they can accumulate to damaging levels in the process vacuum pump. The liquid-ring pump acts as a cushioning element that prevents harmful accumulation, enabling longer continuous operation.
3Reliability
If exhaust line pressure is not maintained negatively, then gas precipitation occurs in the vacuum pump, but maintaining negative pressure requires additional system complexity
Solution Approach 1:
The liquid-ring pump maintains negative pressure in the exhaust line as an intermediary function, preventing gas precipitation without requiring complex control systems. The liquid seal naturally maintains the pressure differential, simplifying the overall system design.
Solution Approach 2:
The system uses hydraulic principles with the liquid-ring pump to maintain negative pressure in the exhaust line. The liquid seal creates a pressure differential that prevents gas precipitation, using fluid mechanics rather than complex mechanical or electronic control systems.
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 solution significantly increases the operational life of vacuum pumps by minimizing by-product accumulation and damage, reducing maintenance and replacement costs in manufacturing facilities.
Implementation Method 1
maintains an exhaust line at a negative pressure during operation of a vacuum pump
Implementation Method 2
reduces precipitation of gases in the vacuum pump thereby reducing by-product accumulation
Implementation Method 3
Liquid is recycled through the liquid-ring pump thereby reducing accumulation of precipitated gas and by-product
Implementation Method 4
The liquid-ring pump includes a separator that outputs the gas portion to the burn chamber and liquid portion to the tank
Data Source
AI summary
An abatement system with liquid-ring pump maintains an exhaust line at a negative pressure during operation of a vacuum pump. The vacuum pump operates to exhaust process gas and by-products from a process chamber through a foreline. The vacuum pump exhausts the process gas to the abatement system with liquid-ring pump through the exhaust line. The overall life of the vacuum pump is increased significantly because the exhaust line is maintained at a negative pressure which reduces precipitation of gases in the vacuum pump thereby reducing by-product accumulation and damage to the vacuum pump. The liquid-ring pump receives the exhaust process gas from the vacuum pump and outputs gas to a burn chamber and liquid to a recirculation tank. Liquid is recycled through the liquid-ring pump thereby reducing accumulation of precipitated gas and by-product. The overall life of the liquid-ring pump and vacuum pump are increased.