Inertial Filtration for Motor Compressor Cooling Gas

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Solution Overview

Problem

Current filtration systems for integrated motor compressor units require frequent maintenance and energy-intensive filters to remove particles larger than 3 microns from cooling gas, leading to increased costs and potential bearing failure due to inadequate particle removal.

Innovation Solution

A filtration device with an inner cartridge and outer housing that creates a duct with a particle trap, utilizing second outlets angled between 135° and 170° to divide the gas flow and create turbulence, trapping larger particles before they reach the active magnetic bearings, and optionally includes filters and a container for particle collection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a filter sized for 100% of the gas flow is used to remove particles from cooling gas, then particle removal effectiveness is improved, but device size, cost, and energy consumption increase

Engineering Contradiction:
Improveparticle removal effectivenessVSAvoidfilter size
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cooling gas flow is divided into two separate streams: a first stream (about 10% of total flow) is directed through the filtration device for particle removal, while a second stream bypasses the filter. This segmentation allows effective particle removal using a smaller filter that only needs to handle a portion of the total gas flow, thereby reducing device size and cost while maintaining reliability.

Inventive Principle:
Principle #1Segmentation

2Reliability

If a filter sized for 100% of the gas flow is used to remove particles from cooling gas, then particle removal effectiveness is improved, but energy consumption increases

Engineering Contradiction:
Improveparticle removal effectivenessVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The cooling gas flow is divided into two separate streams: a first stream (about 10% of total flow) is directed through the filtration device for particle removal, while a second stream bypasses the filter. This segmentation allows effective particle removal using a smaller filter that only needs to handle a portion of the total gas flow, thereby reducing device size and cost while maintaining reliability.

Inventive Principle:
Principle #1Segmentation

3Reliability

If filters are placed in the cooling loop, then particle removal is achieved, but maintenance requirements increase due to filter dirt accumulation

Engineering Contradiction:
Improveparticle removalVSAvoidmaintenance frequency
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The cooling gas flow is divided into two separate streams: a first stream (about 10% of total flow) is directed through the filtration device for particle removal, while a second stream bypasses the filter. This segmentation allows effective particle removal using a smaller filter that only needs to handle a portion of the total gas flow, thereby reducing device size and cost while maintaining reliability.

Inventive Principle:
Principle #1Segmentation

4Reliability

If filters are placed centrally in the motor, then comprehensive filtration is achieved, but device complexity and space requirements increase

Engineering Contradiction:
Improvefiltration coverageVSAvoidfilter placement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The filtration device is extracted from the central motor location and positioned at a different location in the cooling loop. The device includes an outer housing with a cylindrical inner wall and an inner cartridge with filtering elements arranged in a specific pattern. This extraction allows the filter to be positioned where it can effectively treat the first cooling gas stream without interfering with the second stream, thereby simplifying the overall system architecture and reducing device complexity.

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

Reduces the need for additional filters, minimizes maintenance, and effectively prevents premature wear or failure of active magnetic bearings by efficiently trapping particles larger than 3 microns, thereby enhancing the reliability and longevity of the IMC unit.

Implementation Method 1

second outlets (8a, 8b) arranged in the inner cartridge (2) at an angle between 135° and 170° with respect to the downstream direction of the cooling gas flow from the inlet (6), the second outlets (8a, 8b) dividing the cooling gas flow into two streams flowing in opposite directions in the duct (5), the streams meeting above the first outlet (7) and creating a turbulent zone in which the larger particles are trapped

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 2

the largest undesirable particles cannot enter the second outlet and are therefore caused to fall toward the first outlet

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3880974B1Inertial filter for an integrated motor compressor unit
Publication Date: 2023.08.23 THERMODYN
  • EP3880974B1 patent drawingFigure 1
  • EP3880974B1 patent drawingFigure 2
  • EP3880974B1 patent drawingFigure 3

AI summary

The present filtration device (1) is used to filter a cooling gas in an integrated compressor unit. A gas is circulated in two directions between two concentric cylindrical walls (W0, W1) forming a duct (5). The walls (W0, W1) are part of a removable inner cartridge (2) and the motor housing of the integrated motor compressor unit, on which the cartridge (2) is mounted. The gas enters the duct (5) through an inlet (6), divides into two streams flowing downwards and meets again from two opposite directions at the bottom of the duct (5). It creates a turbulent zone in front of a first outlet (7), where some of the larger particles are trapped and eventually fall into the first outlet (7) under the effect of gravity. The filtered particles fill the duct (5) and pass through upper second outlets (8a, 8b) which are provided at an intermediate location in the duct (5). The filtered gas passes through the second outlets (8a, 8b) and reaches an inner passage (4) leading to bearings that require cooling.