A method to indicate filter replacement in a refrigerant recovery and recharge device and a refrigerant recovery and recharge device

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Solution Overview

Problem

Conventional refrigerant recovery and recharge devices lack an efficient method to determine when a filter needs replacement, often leading to premature replacement or reduced filter effectiveness, which increases operational costs and can damage device components.

Innovation Solution

A method and device that utilize a fuse system, where the controller monitors refrigerant flow through a load cell and sends a signal to a fuse blow circuit to indicate when the filter should be replaced, providing visual and audio warnings, and halting operations until a new filter is installed, ensuring the filter is functional and effective.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If filter replacement is based on fixed schedules or random replacement, then filter effectiveness cannot be ensured, but operational costs increase due to premature replacement

Engineering Contradiction:
Improvefilter effectivenessVSAvoidoperational costs
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The system implements feedback by continuously monitoring refrigerant flow through the filter using a load cell and controller. When the filter becomes saturated and causes excessive pressure drop, the system detects this change and provides feedback signals (visual and audio) to indicate filter replacement is needed, replacing fixed-schedule maintenance with condition-based maintenance.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The filter replacement indication system enables the equipment to self-monitor its own filter condition and automatically signal when maintenance is needed, eliminating the need for external monitoring or guesswork about filter status.

Inventive Principle:
Principle #25Self-service

2Reliability

If filter is replaced before saturation, then operational costs increase, but filter effectiveness is maintained

Engineering Contradiction:
Improvefilter effectivenessVSAvoidoperational costs
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The system provides real-time feedback on filter condition through load cell monitoring of refrigerant flow. This allows operators to replace the filter at the precise moment when it becomes saturated, avoiding both premature replacement and operation with a saturated filter.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system monitors changes in refrigerant flow parameters (pressure drop across the filter) to detect filter saturation. By tracking these parameter changes, the system determines the optimal replacement timing based on actual filter condition rather than fixed schedules.

Inventive Principle:
Principle #35Parameter changes

3Loss of substance

If filter is not replaced when saturated, then operational costs decrease, but device components may be damaged

Engineering Contradiction:
Improveoperational costsVSAvoidcomponent damage risk
Core Design Contradiction:
Loss of substanceVSObject-affected harmful factors

Solution Approach 1:

The monitoring system provides continuous feedback on filter condition and automatically alerts operators when saturation occurs. This prevents operation with saturated filters that could allow particulate matter to reach and damage downstream components like compressors and valves.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system takes preliminary action by detecting filter saturation before it can cause damage to other components. The visual and audio warnings provide advance notice, allowing operators to replace the filter before particulate matter accumulates to damaging levels.

Inventive Principle:
Principle #9Preliminary anti-action

4Measurement precision

If volumetric flow measurement is used to monitor refrigerant through filter, then filter replacement timing can be determined, but system complexity increases

Engineering Contradiction:
Improverefrigerant flow measurementVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system replaces complex volumetric flow measurement mechanisms with a simpler load cell-based weight measurement system. By measuring the weight of refrigerant collected in the storage tank over time, the system calculates volumetric flow without requiring direct flow sensors in the filter line, reducing system complexity.

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

Solution Approach 2:

The load cell acts as an intermediary measurement device, indirectly measuring refrigerant flow through weight accumulation rather than directly measuring flow through the filter. This intermediary approach simplifies the measurement system while maintaining accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution ensures filters are replaced only when necessary, preventing damage to device components and reducing operational costs by accurately monitoring refrigerant flow and indicating filter saturation, thus maintaining the effectiveness of the refrigerant recovery and recharge process.

Implementation Method 1

A refrigerant pump, such as a refrigerant compressor, pumps refrigerant through the filter/drier unit during recovery of refrigerant from equipment under service and/or in a separate refrigerant purification cycle. A flow meter is coupled to the filer/drier unit for measuring volumetric flow of refrigerant passing through the filter/drier unit.

Methodology Applied
Scientific EffectWeight measurement:

Implementation Method 2

The controller is adapted to send a signal to a fuse blow circuit. The fuse blow circuit renders the fuse inoperative when the signal is received from the controller. When the fuse is rendered inoperative an audio and/or visual indication indicating that the filter should be replaced is provided in the refrigerant recharge and recovery device.

Methodology Applied
Scientific EffectElectrical signal indication:

Data Source

PatentEP2635361B1A method to indicate filter replacement in a refrigerant recovery and recharge device and a refrigerant recovery and recharge device
Publication Date: 2019.06.05 MAHLE INT GMBH
  • EP2635361B1 patent drawingFigure 1
  • EP2635361B1 patent drawingFigure 2

AI summary

A method to indicate filter replacement in a refrigerant recovery and recharge device (10) and a refrigerant recovery and recharge device (10) is disclosed. The device (10) is adapted to be connected to a refrigeration equipment (12). The device (10) comprising a filter (16) adapted to filter said refrigerant and removal contaminants in said recovered refrigerant. The filter (16) comprising a fuse (26) adapted to indicate when the filter (16) should be replaced.