Screw Compressor Discharge Muffler Layout for Noise Reduction

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Solution Overview

Problem

Screw compressors experience noise and vibration due to pressure fluctuations of the fluid being compressed, which are not effectively mitigated by existing designs.

Innovation Solution

Incorporating a muffler space in the casing that communicates with the discharge passages to reduce pressure fluctuations, and using an odd number of helical grooves on the screw rotor with two gate rotors to shift and cancel pressure waveforms, thereby reducing noise and vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the fluid is discharged sequentially from the fluid chambers defined by helical grooves, then the compression function is achieved, but the pressure inside the fluid fluctuates significantly causing vibration and noise

Engineering Contradiction:
Improvecompression functionVSAvoidpressure fluctuation, vibration, and noise
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The discharge system is segmented into multiple discharge passages (first discharge passage and second discharge passage) that discharge fluid at different timings. This segmentation of the discharge function reduces the pressure fluctuation by distributing the discharge events over time, preventing simultaneous pressure peaks from all fluid chambers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention utilizes periodic discharge actions through multiple discharge passages with different discharge timings. The first discharge passage discharges when the first fluid chamber communicates with the high-pressure space, while the second discharge passage discharges when the second fluid chamber communicates, creating a periodic discharge pattern that smooths pressure fluctuations.

Inventive Principle:
Principle #19Periodic action

2Object-generated harmful factors

If a muffler space is added to reduce pressure fluctuation, then noise and vibration are reduced, but the device complexity increases

Engineering Contradiction:
Improvenoise and vibrationVSAvoidcasing structure
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The muffler space is merged with the existing high-pressure space, combining two functional spaces into one. The high-pressure space serves both as the discharge destination for the fluid and as the muffler space for reducing pressure fluctuations. This integration avoids adding a separate muffler component, thus reducing device complexity while still achieving noise and vibration reduction.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The high-pressure space is given multiple functions: it serves as both the discharge destination for compressed fluid and as the muffler space for pressure fluctuation reduction. This multi-functionality eliminates the need for a dedicated muffler component, maintaining simplicity while achieving noise control.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution effectively reduces pressure fluctuations and noise generated by the compressor, enhancing operational stability and reducing the risk of vibration in the compressor's main body.

Implementation Method 1

one muffler space (50) disposed in the casing (10), and communicating with the discharge passage (26, 27), thereby reducing a pressure fluctuation of the fluid flowing from the discharge passage (26, 27) to the high-pressure fluid passage (61, 64)

Methodology Applied
Scientific EffectPressure fluctuation reduction: Damping

Data Source

PatentEP3450763B1Screw compressor
Publication Date: 2021.06.02 DAIKIN INDUSTRIES LTD
  • EP3450763B1 patent drawingFigure 1
  • EP3450763B1 patent drawingFigure 2
  • EP3450763B1 patent drawingFigure 3

AI summary

In a casing (10) of a screw compressor, high-pressure fluid passages (61, 64) are formed between the main body (10a) and the cylinder (30). A screw rotor (40) is inserted into the cylinder (30) to define fluid chambers (23). A fluid that has been discharged from the fluid chambers (23) passes through discharge passages (26, 27) to flow into the high-pressure fluid passages (61, 64). The casing (10) is provided with a muffler space (50) communicating with the discharge passages (26, 27). This reduces the pressure fluctuations of the fluid flowing from the discharge passages (26, 27) into the high-pressure fluid passages (61, 64). This can reduce noise of the screw compressor.