Air Purifier Filter Replacement Timing via Differential Pressure

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Solution Overview

Problem

Existing air purifiers struggle to determine the accurate timing for filter replacement, leading to untimely replacements due to reliance on operating time rather than environmental conditions.

Innovation Solution

An air purifier system that includes a differential pressure sensor and a filter replacement time management unit, which uses flow rate/differential pressure correlation graphs to determine the optimal time for filter replacement based on usage states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If filter replacement is determined based on operating time, then the system is simple to operate, but the filter replacement timing is inaccurate and does not reflect actual filter condition

Engineering Contradiction:

Improvefilter replacement determinationVSAvoidfilter replacement timing accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent changes the parameter basis for filter replacement determination from operating time to differential pressure. The differential pressure sensor continuously monitors the pressure difference across the filter, providing a direct measurement of filter clogging status. This parameter change enables accurate detection of actual filter condition rather than relying on estimated time-based schedules.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical/time-based replacement system with a sensor-based measurement system. Instead of using a timer or operating hour counter, the system uses a differential pressure sensor to electronically measure and determine filter status, substituting mechanical time-tracking with electronic pressure sensing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If filter replacement is determined based on operating time, then the device complexity is low, but the reliability of air purification is reduced due to untimely replacement

Engineering Contradiction:

Improvefilter replacement managementVSAvoidair purification effectiveness

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the differential pressure sensor continuously monitors filter condition and provides real-time information to the control unit. When the differential pressure exceeds a threshold indicating filter clogging, the system generates a replacement notification. This closed-loop feedback ensures timely filter replacement and maintains reliable air purification performance.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The filter replacement determination system operates autonomously by automatically sensing differential pressure and generating replacement notifications without user intervention. The air purifier self-monitors its own filter condition and informs the user when maintenance is needed, eliminating the need for manual tracking or estimation.

Inventive Principle:

Principle #25Self-service

3Ease of manufacture

If filter replacement is determined based on operating time, then the system is easy to manufacture, but it fails to account for environmental variations affecting filter lifespan

Engineering Contradiction:

Improvefilter replacement systemVSAvoidenvironmental adaptation

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent changes the determination parameter from fixed operating time to variable differential pressure that naturally reflects environmental conditions. Factors such as dust concentration, air flow rate, and usage intensity all affect differential pressure, enabling the system to adapt to different environments without requiring complex environmental sensors or adjustable parameters.

Inventive Principle:

Principle #35Parameter changes

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 approach allows for timely and accurate filter replacement, ensuring continuous effective air purification by matching measured differential pressure and flow rate to stored correlation graphs, thereby alerting users when filter replacement is necessary.

Implementation Method 1

a differential pressure sensor measuring differential pressure as a pressure difference between a front end of the filter and a rear end of the filter

Methodology Applied

Scientific EffectDifferential pressure measurement: Pressure Drop

Data Source

PatentUS10188976B2Air purifier, method for determining time to replace filter thereof, and device and method for determining filter replacement time pressure differential therefor

Publication Date: 2019.01.29 COWAY CO LTD

AI summary

An air purifier according to the present disclosure includes: a memory for storing a flow rate/pressure differential correlation graph with regard to each filter utilization state; a pressure differential sensor for measuring a pressure differential, which is a difference in pressure between the front and rear ends of the filter; and a filter replacement time management unit for determining the time to replace the filter according to a result of matching a pressure differential of the filter, which is measured by the pressure differential sensor at a preset cycle, and the flow rate of air flowing into the filter during pressure differential measurement with the flow rate/pressure differential correlation graph for each utilization state.