Vacuum Line Pressure Control With Diluent Gas for Explosion Risk
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Solution Overview
Problem
Existing methods for managing flammable and explosive gases in vacuum lines used in semiconductor, flat panel display, and photovoltaic manufacturing are costly, energy-intensive, and generate harmful pollutants like nitrogen oxides, while also facing limitations in handling increasingly unstable precursors and condensable species, leading to safety risks and equipment damage.
Innovation Solution
A vacuum line system with an auxiliary pumping device and diluent gas injection, controlled by a pressure sensor and control unit, maintains optimal pressure levels to minimize diluent gas use, prevent deposits, and manage flammability, using a combination of Venturi gas jet pumps, water jet pumps, and bypass systems to ensure safety and reduce energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a significant supply of nitrogen is continuously injected into the vacuum line to dilute flammable gases, then the safety against explosions is improved, but the gas consumption and energy consumption increase significantly
Solution Approach 1:
The patent implements periodic monitoring of gas composition and conditional injection of nitrogen only when flammable gas concentrations approach dangerous levels, rather than continuous injection. The control unit activates the nitrogen injection device selectively based on sensor readings, transforming the continuous action into a periodic, demand-driven action that maintains safety while reducing energy and gas consumption.
Solution Approach 2:
The patent employs a feedback control system where sensors continuously monitor the composition of gases in the vacuum line and provide real-time data to a control unit. Based on this feedback, the control unit dynamically adjusts the nitrogen injection rate to maintain safe gas concentrations, replacing the open-loop continuous injection with a closed-loop controlled system that optimizes resource usage while ensuring safety.
2Reliability
If a significant supply of nitrogen is continuously injected into the vacuum line to dilute flammable gases, then the safety against explosions is improved, but the cost of gas consumption increases
Solution Approach 1:
The patent implements periodic monitoring of gas composition and conditional injection of nitrogen only when flammable gas concentrations approach dangerous levels, rather than continuous injection. The control unit activates the nitrogen injection device selectively based on sensor readings, transforming the continuous action into a periodic, demand-driven action that maintains safety while reducing nitrogen consumption and associated costs.
Solution Approach 2:
The patent employs a feedback control system where sensors continuously monitor the composition of gases in the vacuum line and provide real-time data to a control unit. Based on this feedback, the control unit dynamically adjusts the nitrogen injection rate to maintain safe gas concentrations, replacing the open-loop continuous injection with a closed-loop controlled system that optimizes nitrogen usage and reduces operational costs.
3Reliability
If a significant supply of nitrogen is continuously injected into the vacuum line to dilute flammable gases, then the safety against explosions is improved, but the formation of nitrogen oxides increases
Solution Approach 1:
The patent implements periodic monitoring of gas composition and conditional injection of nitrogen only when flammable gas concentrations approach dangerous levels, rather than continuous injection. By reducing the total amount of nitrogen introduced into the system, the subsequent formation of nitrogen oxides during gas treatment is minimized, reducing harmful emissions while maintaining safety through targeted intervention.
Solution Approach 2:
The patent employs a feedback control system where sensors continuously monitor the composition of gases in the vacuum line and provide real-time data to a control unit. Based on this feedback, the control unit dynamically adjusts the nitrogen injection rate to maintain safe gas concentrations, replacing the open-loop continuous injection with a closed-loop controlled system that reduces total nitrogen consumption and consequently reduces nitrogen oxide formation.
4Productivity
If the vacuum pump pumping capacity is increased to handle higher gas flows, then the ability to manage extreme operating conditions is improved, but the cost of overrating the equipment increases
Solution Approach 1:
The patent transforms the static, fixed pumping capacity requirement into a dynamic system that adapts to actual process needs. By using conditional nitrogen injection based on real-time gas composition monitoring, the system only increases total gas flow when necessary, allowing the use of appropriately sized pumping equipment rather than oversized equipment designed for worst-case continuous scenarios.
Solution Approach 2:
The patent employs a feedback control system that monitors gas composition and dynamically adjusts nitrogen injection rates. This allows the gas treatment system to handle variable flow conditions efficiently, matching the pumping capacity requirements to actual process demands rather than requiring constant operation at maximum capacity, thereby avoiding equipment overrating and associated costs.
5Stability of the object's composition
If the temperature of the pipes and vacuum pumps is lowered to prevent thermal decomposition, then the chemical reactions are minimized, but the risk of deposition by condensation increases
Solution Approach 1:
The patent changes the approach from temperature control to composition control. Instead of adjusting temperature to manage chemical reactions, the system uses conditional nitrogen injection to dilute flammable gases and control the chemical environment. This allows maintaining temperatures that prevent condensation while still managing thermal decomposition risks through inerting the atmosphere rather than cooling the system.
Solution Approach 2:
The patent creates an inert atmosphere by injecting nitrogen into the vacuum line, replacing the need for temperature-based chemical control. The nitrogen dilution reduces the concentration of reactive gases, minimizing thermal decomposition and chemical reactions without requiring temperature reduction, thereby avoiding condensation issues while still preventing unwanted chemical reactions through atmospheric inerting.
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 system effectively reduces the risk of explosions, minimizes deposits, lowers energy and gas consumption, and prevents the formation of nitrogen oxides, enhancing the reliability and longevity of vacuum line components while maintaining safe operating conditions.
Implementation Method 1
at least one auxiliary pumping device configured to lower the pressure in the discharge pipe
Implementation Method 2
a diluent gas injection device configured to inject a diluent gas into the stream of the pumped gases... such that the concentration of flammable gases is less than the lower explosive limit
Implementation Method 3
a pressure sensor configured to measure the pressure prevailing in the discharge pipe
Implementation Method 4
a control unit configured to control the auxiliary pumping device and the diluent gas injection device according to a first operating mode... or according to a second operating mode
Data Source
AI summary
A vacuum line and method for controlling a vacuum line in which an auxiliary pumping device and a diluent gas injection device are controlled according to a first operating mode in which the pressure prevailing in the discharge pipe is maintained at less than or equal to 20,000 Pa or according to a second operating mode in which the pressure prevailing in the discharge pipe is greater than 20,000 Pa, and the injection of a diluent gas into the stream of the pumped gases is controlled, downstream of an intake of the rough pumping device, such as into the discharge pipe and/or into the rough pumping device and/or into the auxiliary pumping device by the diluent gas injection device in the second operating mode. This reduces the potential for explosion in the vacuum line via injection of diluent gas to lower flammable gas concentration.