Helical Lobe Compressor Noise Reduction via Gas Injection

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Solution Overview

Problem

Traditional volumetric compressors used in suction and compression systems for waste material collection generate excessive noise due to pressure oscillations and pulsations, which affect durability and reliability, especially in mobile urban applications.

Innovation Solution

A volumetric compressor design featuring helical lobe rotors and lateral gas injection, where the gas is injected through headers with specific openings and channels to reduce noise and vibrations, combined with inner passages for efficient cooling of mechanical components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If traditional volumetric compressors with straight lobe rotors are used, then compression function is achieved, but excessive noise and vibrations are generated

Engineering Contradiction:
Improvenoise and vibrationsVSAvoiddurability and reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies curvature by transitioning from straight lobe rotors to helical lobe rotors. The helical configuration replaces linear geometric forms with curved, spiral forms that wrap around the rotor axis. This curvature modifies the compression chamber geometry and gas flow paths, resulting in smoother pressure transitions and reduced pulsations that generate noise and vibrations, thereby improving reliability while maintaining compression function.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent changes the geometric parameters of the rotor lobes from straight to helical configurations. This parameter modification alters the compression process characteristics, creating more gradual pressure changes and reducing the intensity of pressure oscillations. The helical angle and lobe profile parameters are optimized to minimize harmful vibrations and noise while preserving the compression ratio and flow rate.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If gas injection is used to lower exhaust temperature, then temperature control is improved, but device complexity increases

Engineering Contradiction:
Improveexhaust temperatureVSAvoidinjection system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges the gas injection function with the existing rotor and chamber structure. The injection openings are integrated into the rotor design, and the injection process is combined with the compression cycle rather than being a separate operation. This integration allows temperature control to be achieved through the existing mechanical components, reducing the need for additional complex temperature management systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The compression chamber and rotor structure serve dual functions: they perform compression while also acting as the injection system for temperature control. The same components that compress the gas also provide the pathways for injection gas to enter and mix with the compressed gas, thereby lowering exhaust temperature. This self-service approach eliminates the need for separate temperature control apparatus.

Inventive Principle:
Principle #25Self-service

3Object-affected harmful factors

If helical lobe rotors with lateral gas injection are implemented, then noise and vibrations are reduced, but manufacturing complexity increases

Engineering Contradiction:
Improvenoise and vibrationsVSAvoidmanufacturing complexity
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent segments the rotor structure into distinct functional zones: the helical lobe sections for compression, the injection opening sections for gas introduction, and the chamber sections for mixing. This segmentation allows each component to be manufactured separately using optimized processes and then assembled, reducing overall manufacturing complexity despite the advanced helical geometry. The modular approach facilitates precision manufacturing of complex helical forms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by providing injection openings only at specific locations on the rotor lobes where they are most effective for temperature control and noise reduction. The helical configuration is applied selectively to the compression surfaces, while other portions of the rotor maintain simpler geometries. This localized application of complex features minimizes manufacturing difficulty while achieving the desired noise and vibration reduction benefits.

Inventive Principle:
Principle #3Local quality

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 design significantly reduces noise and vibrations, enhancing the durability and reliability of the compressor, while maintaining a compact and cost-effective structure, thus improving its versatility and operational performance.

Implementation Method 1

a volumetric compressor design featuring helical lobe rotors... The synchronized motion of the rotors creates, with the body of the chamber, suction volumes containing an air volume at suction pressure

Methodology Applied
Scientific EffectVolumetric compression: Compression

Implementation Method 2

the temperature (Ts) of the gas in the exhaust section 4 is higher than the temperature (Ta) in the suction section 3... In order to contain/lower the end of compression temperature, it is known to introduce gas into the chamber through openings

Methodology Applied
Scientific EffectGas injection cooling: Cooling

Data Source

PatentEP3332123B1Volumetric lobe compressor for equipment collecting waste material
Publication Date: 2021.01.20 JUROP
  • EP3332123B1 patent drawingFigure 1~3
  • EP3332123B1 patent drawingFigure 4~6
  • EP3332123B1 patent drawingFigure 7~8

AI summary

Volumetric compressor (1) for collection and/or treatment equipment of material in liquid, solid, dusty or muddy form. The compressor (1) comprises an operative chamber (50), defining a suction section and an exhaust section of a first fluid, a first header (61) and a second header (62), which delimit said chamber (50) on opposite parts along a longitudinal axis (101). The compressor further comprises at least two rotors (80', 80") with lobes (81', 81 ") housed in the chamber (50), each rotor (80', 80") rotating about a rotation axis (108', 108") substantially parallel to said longitudinal axis (101). The lobes of each rotor develop according to a helical profile. Furthermore, each of the headers (61,62) defines at least one injection opening (71', 71 ",72',72") communicating with a feeding device (150) of a second fluid.