Vacuum Pump System with Flow Constrictions for Load Balancing

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Solution Overview

Problem

Existing pump systems for multi-chamber vacuum systems face challenges in efficiently distributing gas loads across multiple pumps while maintaining desired vacuum pressures, leading to high energy and cooling requirements, and are costly due to the need for specialized pumps and complex adjustments.

Innovation Solution

A pump system utilizing at least four vacuum pumps, with two turbomolecular pumps and two backing pumps, where all turbomolecular pumps are identical and assisted by backing pumps, and featuring cross-sectional constrictions in connecting lines to regulate gas flow, allowing for even load distribution and cost savings by using similar pumps across the system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If large backing pumps are used to handle high gas loads at low pressure, then the desired vacuum pressure is maintained, but energy consumption and cooling requirements increase significantly

Engineering Contradiction:
Improvevacuum pressure maintenanceVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system divides the vacuum pumping task into multiple independent pump units, each handling a portion of the total gas load. Instead of using one large backing pump, the invention employs several smaller backing pumps working in parallel, each supporting a turbomolecular pump. This segmentation reduces the gas friction and mechanical losses in each pump, thereby lowering energy consumption while maintaining the required vacuum pressure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses multiple pumps providing more pumping capacity than strictly necessary for each individual chamber, allowing for flexible load distribution. The cross-sectional constrictions regulate the gas flow to each pump, enabling partial utilization of each pump's capacity while collectively handling the total gas load efficiently, thus reducing overall energy consumption.

Inventive Principle:
Principle #16Partial or excessive action

2Volume of stationary object

If multiple small pumps are used instead of one large pump, then installation space and cooling requirements are reduced, but load distribution and efficiency optimization become difficult

Engineering Contradiction:
Improveinstallation spaceVSAvoidload distribution
Core Design Contradiction:
Volume of stationary objectVSEase of operation

Solution Approach 1:

The invention introduces cross-sectional constrictions as intermediary elements in the connecting lines between backing pumps and chambers. These constrictions act as flow regulators that automatically balance the gas load distribution among multiple backing pumps. By controlling the gas flow through each constriction, the system achieves even load distribution across all pumps, optimizing their efficiency while maintaining compact installation space.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system incorporates measurement devices for vacuum pressure and gas flow rate at various points, providing feedback on the actual operating conditions. This feedback enables automatic adjustment of the cross-sectional constrictions to maintain optimal load distribution among pumps, ensuring each pump operates at its most efficient point regardless of varying gas loads from different chambers.

Inventive Principle:
Principle #23Feedback

3Reliability

If specialized pumps with intermediate connections are used to adjust gas loads, then vacuum pressure control is improved, but system complexity and cost increase

Engineering Contradiction:
Improvevacuum pressure controlVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention changes the physical parameter of the connecting lines by introducing cross-sectional constrictions with specific flow resistance characteristics. Instead of using complex specialized pumps with variable intermediate connections, the system uses simple constrictions that passively regulate gas flow based on pressure differences. This approach achieves effective vacuum pressure control while significantly reducing system complexity and cost.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system applies different local qualities to different connecting lines by adjusting the cross-sectional area of constrictions in each line according to the specific gas load characteristics of connected chambers. This localized optimization allows each pump to handle its designated load efficiently without requiring complex global control mechanisms, thereby simplifying the overall system while maintaining precise vacuum pressure control.

Inventive Principle:
Principle #3Local quality

4Ease of manufacture

If identical pumps are used across the system, then cost and manufacturing simplicity are improved, but adapting to varying gas loads and pressure requirements becomes challenging

Engineering Contradiction:
Improvepump standardizationVSAvoidgas load adaptation
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The cross-sectional constrictions serve as intermediary elements that adapt the output of identical pumps to varying chamber requirements. By adjusting the constriction size in each connecting line, the system can match the gas flow from standardized pumps to the specific gas load and pressure requirements of different chambers, thereby maintaining both manufacturing simplicity and system adaptability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system introduces dynamic adjustment capability through controllable cross-sectional constrictions that can modify gas flow resistance in real-time. This allows identical pumps to dynamically adapt to varying gas loads and pressure requirements by changing the flow characteristics in their connecting lines, rather than requiring each pump to be statically optimized for specific conditions.

Inventive Principle:
Principle #15Dynamics

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 enables efficient gas load distribution across similar pumps, reducing energy consumption, cooling requirements, and costs by allowing for the use of identical pumps, while maintaining consistent vacuum pressures and improving system robustness to pressure fluctuations.

Implementation Method 1

at least one cross-sectional constriction for regulating a gas flow is provided in at least one connecting line between the at least two backing pumps

Methodology Applied
Scientific EffectFlow resistance: Drag

Data Source

PatentEP2644900B1Pump system for evacuating of gas from a plurality of chambers and method for controlling the pump system
Publication Date: 2017.12.27 PFEIFFER VACUUM GMBH
  • EP2644900B1 patent drawingFigure 1~2
  • EP2644900B1 patent drawingFigure 3
  • EP2644900B1 patent drawingFigure 4

AI summary

The pumping system comprises turbomolecular pump (3,4) and two fore-vacuum pumps (5,6). A connection conduit (8) is extended between the two fore-vacuum pumps. A cross-section constriction portion (9) is provided for reducing and regulating of flow of gas. The cross-section constriction portion is formed as one of throttle orifice, throttle valve, and gas flow controller. A regular or switched valve is provided in cross-section constriction portion. An independent claim is included for method for controlling pumping system.