Reciprocating Compressor Valve Assembly in Hollow Chamber

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Solution Overview

Problem

Prior art reciprocating compressor cylinder designs face issues with high mechanical stresses at valve seats due to differential pressures, leading to structural failures and limited pressure capabilities, as thick valve seats provide only partial stress reduction and are prone to overstress from variable pressure conditions and over-torque during operation.

Innovation Solution

The valve assembly is relocated to an axially-stacked arrangement within a hollow chamber of the cylinder block, spaced apart from the cylinder wall, with axial compression and perimeter fluid seals, eliminating mechanical interference and allowing for independent anchoring, thus distributing pressure forces across individual components without relying on cylinder wall features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If valves are positioned on valve seats constructed in the cylinder wall, then the compressor can operate, but high mechanical stresses concentrate at the valve seats leading to structural failure

Engineering Contradiction:
Improvestructural reliabilityVSAvoidmechanical stress at valve seat
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The valve assembly is extracted from the cylinder wall and relocated to a separate hollow chamber. The valves are no longer positioned on valve seats constructed in the cylinder wall, but rather on valve seats formed in the hollow chamber structure. This extraction eliminates the stress concentration problem at the cylinder wall valve seats while maintaining valve function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The valve assembly is moved from a two-dimensional surface mounting on the cylinder wall to a three-dimensional hollow chamber structure. This dimensional change allows the valve assembly to be self-contained and independently supported, distributing forces throughout the chamber structure rather than concentrating them at the cylinder wall interface.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Stress or pressure

If thick valve seats are used to reduce stress concentration, then some stress reduction is achieved, but the valve seats remain prone to overstress from variable pressure conditions and over-torque

Engineering Contradiction:
Improvestress distributionVSAvoidresistance to overstress
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The valve assembly is segmented into a separate, self-contained unit within the hollow chamber. This segmentation allows the valve assembly to be independently designed and anchored, with forces distributed through the chamber structure rather than concentrated in a single thick valve seat. The modular design enables each component to be optimized for its specific function without compromising overall reliability.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If valves are mounted in the cylinder head with valve seats constructed in the body, then the design is compact, but maintainability and durability are reduced

Engineering Contradiction:
Improvestructural integrationVSAvoidmaintainability
Core Design Contradiction:
Device complexityVSEase of repair

Solution Approach 1:

The valve assembly is extracted as a separate, self-contained unit within the hollow chamber. This extraction makes the valve assembly independently accessible and replaceable, significantly improving maintainability. The hollow chamber design allows the valve assembly to be removed and replaced without compromising the integrity of the cylinder structure.

Inventive Principle:
Principle #2Taking out (Extraction)

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 design effectively reduces mechanical stresses and allows for higher pressure capabilities by distributing force across individual components, enhancing the reliability and maintainability of reciprocating compressor cylinders, enabling reliable operation at higher pressures without structural failures.

Implementation Method 1

a spring-loaded one-way valve designed to open for flow when the pressure differential in the direction of flow provides a force that exceeds the spring tension

Methodology Applied
Scientific EffectSpring tension: Spring

Implementation Method 2

when the pressure differential in the direction of flow provides a force that exceeds the spring tension

Methodology Applied
Scientific EffectPressure differential force: Pressure Increase

Data Source

PatentEP3768973B1Reciprocating compressor with improved valve cylinder assembly
Publication Date: 2022.08.24 DRESSER RAND CO
  • EP3768973B1 patent drawingFigure 1
  • EP3768973B1 patent drawingFigure 2
  • EP3768973B1 patent drawingFigure 3

AI summary

A reciprocating compressor (10) with an improved valve assembly (20) is disclosed. Compressor (10) includes a cylinder block (12) having a cylinder that defines a cylindrical bore (14) extending longitudinally along a bore axis (16). Cylinder block (12) includes a hollow chamber (15) extending longitudinally along a chamber axis (18), which is non-intersecting relative to the bore axis (16). Valve assembly (20) is disposed in hollow chamber (15). Valve assembly is made up of an axially-stacked arrangement of components extending along chamber axis (18). The axially-stacked arrangement of components is spaced apart from a wall (22) that forms a perimeter of the cylinder and is thus free from mechanical interference with the perimeter of the cylinder.