Dry Vacuum Pump with Ejector for Energy Reduction
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Solution Overview
Problem
Dry primary vacuum pumps in semiconductor manufacturing consume a significant amount of electrical energy, particularly during the initial pumping stage and when maintaining vacuum pressure, which is not efficiently reduced by existing optimization methods.
Innovation Solution
A method involving a dry primary vacuum pump assisted by a multistage ejector that uses compressed fluid to reduce pressure without electrical energy consumption, activated only when specific pressure and power thresholds are met, allowing for a short operational period and maintaining low energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pumping speed of the vacuum pump is increased to handle large gas flows, then the pumping capacity is improved, but the electrical energy consumption increases
Solution Approach 1:
The pumping system is divided into two independent pumping stages: a first vacuum pump for rough pumping and a second vacuum pump for fine pumping. This segmentation allows each pump to operate at optimized speeds for its specific function, reducing overall energy consumption while maintaining high pumping capacity.
Solution Approach 2:
The system operates the first vacuum pump at high speed only during the initial rough pumping phase when gas flow is large, then switches to the second vacuum pump for the maintenance phase. This periodic operation pattern reduces energy consumption by avoiding continuous high-speed operation.
2Use of energy by moving object
If the dimensioning of the last compression stage is reduced to decrease electrical power consumption, then energy efficiency is improved, but the pumping speed and capacity are reduced
Solution Approach 1:
The compression process is segmented into two stages with different dimensional configurations. The first stage uses a larger compression ratio with reduced dimensions optimized for high-power consumption periods, while the second stage uses a smaller compression ratio with larger dimensions optimized for low-power consumption periods, allowing each stage to be dimensioned for its specific operational requirements.
3Stability of the object's composition
If the vacuum pump operates continuously to maintain vacuum pressure, then vacuum stability is improved, but electrical energy consumption increases
Solution Approach 1:
The system uses periodic action by switching between two pumping modes: active pumping when vacuum pressure deviates from the setpoint, and idle state when the setpoint is maintained. This reduces energy consumption while maintaining vacuum stability through controlled intermittent operation rather than continuous running.
Solution Approach 2:
The control system automatically monitors vacuum pressure and activates the vacuum pump only when needed to restore the setpoint pressure, allowing the system to serve itself by detecting and correcting deviations without continuous operation, thereby reducing energy consumption while maintaining stability.
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 approach significantly reduces electrical energy consumption by the vacuum pump by up to 50% in a short time, with the ejector's operation requiring minimal compressed fluid, achieving energy savings without increasing maintenance or wear.
Implementation Method 1
a multistage ejector that uses compressed fluid to reduce pressure without electrical energy consumption
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The pumping device comprises: a dry rough vacuum pump provided with a gas inlet opening connected to a vacuum chamber and moreover has a gas outlet opening leading into a pipe; a delivery check valve placed in the pipe at the outlet of the dry rough vacuum pump; and an ejector mounted in parallel relative to the delivery check valve. The pumping method includes the following steps: pumping the gases, contained in the vacuum chamber, by means of the dry rough vacuum pump through the gas inlet opening; connecting the gas outlet opening of the dry rough vacuum pump to an ejector; measuring the electrical power used by the dry rough vacuum pump and the pressure of the gases in the pipe at the outlet of the dry rough vacuum pump; setting in motion the ejector, after a time delay, when the pressure of the gases at the outlet of the dry rough vacuum pump has exceeded a rising edge set value and when the electrical power used by the dry rough vacuum pump exceeds a rising edge set value; stopping the ejector when the electrical power used by the dry rough vacuum pump exceeds a falling edge set value and when the pressure of the gases in the pipe at the outlet of the dry rough vacuum pump exceeds a falling edge set value.