Vacuum Pump Startup Sequence for By-Product Suppression

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Solution Overview

Problem

The introduction of inert gas into vacuum pump apparatuses to suppress by-product formation leads to increased power consumption and potential stagnation of rotational speed, resulting in prolonged startup times and failure to reach rated rotational speed.

Innovation Solution

A vacuum exhaust method and system that gradually increase the rotational speed of the vacuum pump apparatus to a stable speed before introducing inert gas, utilizing a bypass line for initial inert gas introduction at a low flow rate and subsequent higher flow rate introduction once stable speed is reached.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If inert gas is introduced into the vacuum pump apparatus to suppress by-product formation, then by-product formation is suppressed, but power consumption increases and rotational speed stagnates

Engineering Contradiction:
Improveby-product formationVSAvoidpower consumption
Core Design Contradiction:
Object-generated harmful factorsVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by increasing the rotational speed to a stable speed before introducing inert gas. This preliminary speed increase ensures the pump is already operating efficiently when the inert gas is introduced, preventing rotational speed stagnation and reducing the overall amount of inert gas needed, thereby suppressing by-product formation without excessive power consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the parameter of inert gas flow rate dynamically. It introduces inert gas at a first flow rate (including zero) during the speed increase phase, then switches to a second flow rate (larger than the first) after stable speed is reached. This parameter change optimizes both by-product suppression and power consumption by matching inert gas introduction to the pump's operational state.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If inert gas is introduced into the vacuum pump apparatus to suppress by-product formation, then by-product formation is suppressed, but startup time increases

Engineering Contradiction:
Improveby-product formationVSAvoidstartup time
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The patent performs the speed increase to stable speed as a preliminary action before inert gas introduction. This sequencing allows the pump to reach optimal operating conditions quickly without the drag of continuous inert gas introduction during startup, thereby reducing startup time while still achieving by-product suppression once the pump is running.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses periodic action by introducing inert gas in two distinct phases: first at a low flow rate (including zero) during startup, then at a higher flow rate after stable speed is reached. This periodic introduction pattern minimizes the time inert gas interferes with startup while ensuring by-product suppression during steady operation.

Inventive Principle:
Principle #19Periodic action

3Object-generated harmful factors

If inert gas is introduced into the vacuum pump apparatus to suppress by-product formation, then by-product formation is suppressed, but rotational speed fails to reach rated speed

Engineering Contradiction:
Improveby-product formationVSAvoidrotational speed
Core Design Contradiction:
Object-generated harmful factorsVSSpeed

Solution Approach 1:

The patent applies preliminary action by ensuring the rotational speed reaches a stable speed (preferably rated speed) before significant inert gas introduction occurs. This preliminary speed establishment prevents the inert gas from interfering with the acceleration process, allowing the pump to reach and maintain rated rotational speed while still achieving by-product suppression.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the inert gas flow rate parameter based on operational phase: using a first flow rate (including zero) during acceleration to minimize resistance to speed increase, then switching to a second flow rate (larger than the first) after stable speed is reached to suppress by-products without impeding rotational speed achievement.

Inventive Principle:
Principle #35Parameter changes

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 effectively suppresses by-product formation while minimizing power consumption, ensuring rapid startup and achieving rated rotational speed without unnecessary inert gas usage.

Implementation Method 1

a vacuum pump apparatus for exhausting a gas in a vacuum chamber

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

a method of introducing an inert gas into the vacuum pump apparatus to dilute a concentration of the gas

Methodology Applied
Scientific EffectGas mixing and dilution: Diffusion

Implementation Method 3

a gas heating step of heating the inert gas through an inert gas supply line connected to the vacuum pump apparatus

Methodology Applied
Scientific EffectGas heating: Heating

Data Source

PatentEP4050216B1Vacuum exhaust method and vacuum exhaust system
Publication Date: 2025.01.22 EBARA CORP
  • EP4050216B1 patent drawingFigure 1
  • EP4050216B1 patent drawingFigure 2
  • EP4050216B1 patent drawingFigure 3

AI summary

A vacuum exhaust method capable of solving problems associated with an introduction of an inert gas while suppressing a formation of a by-product is disclosed. The vacuum exhaust method includes: an increasing step of increasing a rotational speed of the vacuum pump apparatus to a predetermined stable speed after starting the vacuum pump apparatus; and a gas introduction step of introducing an inert gas into the vacuum pump apparatus after the rotational speed of the vacuum pump apparatus reaches the stable speed.