Passive Backflow Restriction for Compressor Reverse-Rotation Protection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing compressor devices face the risk of mechanical damage and safety hazards due to reverse rotation caused by backflow of compressed air when non-return valves fail, which is exacerbated by the need for actively controlled components that increase costs and complexity.

Innovation Solution

Incorporating a passive element, such as a restriction or sonic nozzle, in the gas flow channel to limit the backflow rate and prevent excessive reverse rotation, ensuring the compressor operates within safe speed limits without moving parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If actively controlled components (release valve, inlet throttle, inlet vanes) are used to limit reverse rotation speed, then the compressor is protected from damage, but the device complexity and cost increase due to active control requirements and safety standards

Engineering Contradiction:
Improvecompressor protectionVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces actively controlled mechanical components (release valves, inlet throttles, inlet vanes) with a passive mechanical element that automatically limits reverse rotation speed through its inherent mechanical properties, eliminating the need for active control systems and reducing device complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The passive element automatically limits reverse rotation speed without requiring external control signals or active management, making the system self-regulating during reverse flow conditions and eliminating dependency on complex control systems

Inventive Principle:
Principle #25Self-service

2Object-affected harmful factors

If the compressor is designed to withstand high reverse speeds, then safety is improved, but the compressor becomes more expensive and heavier

Engineering Contradiction:
Improvesafety against reverse rotationVSAvoidcompressor weight
Core Design Contradiction:
Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The passive element is pre-configured to automatically counteract reverse rotation by limiting the backflow rate before dangerous reverse speeds can be reached, preventing the harmful effect rather than merely withstanding it, thereby allowing lighter compressor construction

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If actively controlled components are used to limit reverse rotation, then compressor damage is prevented, but the ease of operation deteriorates due to strict safety standards and active control requirements

Engineering Contradiction:
Improvecompressor protectionVSAvoidoperation simplicity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces actively controlled mechanical components with a passive mechanical element that automatically limits reverse rotation speed through its inherent mechanical properties, eliminating the need for active control systems and reducing device complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 passive element effectively restricts reverse rotation speed, protecting the compressor from damage and reducing the risk of failure while simplifying construction and lowering safety requirements.

Implementation Method 1

a passive element (15) is provided in the channel (6) which, in the event of backflow of the compressed gas from the pressure vessel to the inlet (4), restricts a backflow rate through the compressor (3) such that a reverse turning speed of the compressor (3) is limited to a maximum allowed reverse speed

Methodology Applied
Scientific EffectFlow resistance: Drag

Data Source

PatentEP3214313B2Compressor device
Publication Date: 2025.11.05 ATLAS COPCO AIRPOWER NV
  • EP3214313B2 patent drawingFigure 1~2
  • EP3214313B2 patent drawingFigure 3~4
  • EP3214313B2 patent drawingFigure 5~6

AI summary

Compressor device with at least one compressor (3) with an inlet (4) and an outlet (5) and a channel (6) for channelling the gas flow drawn in by the compressor and the gas flow compressed by the compressor to a consumer, characterised in that the compressor device (1) is provided with a passive element (15) that limits the backflow of the compressed gas from the consumer (7) to the inlet (4) to a set maximum flow.