PAPR Heating Module with Active Control for Comfortable Air Delivery

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Solution Overview

Problem

Powered air purifying respirators (PAPRs) often deliver cool air that can be uncomfortable and may cause fogging or increased sickness, due to the temperature and velocity of the ambient air, which existing systems fail to adequately address.

Innovation Solution

Incorporating an electronically controlled active heating element downstream of the filter in the PAPR, with a control system that varies power to the heating element and disables it when overheating is detected, along with a self-contained heating module that communicates with the PAPR to ensure safe and comfortable air delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If ambient air is drawn through the filter and delivered directly to the wearer's face, then the PAPR provides a clean supply of air with little effort, but the air flow feels cold or uncomfortable due to temperature and velocity

Engineering Contradiction:
Improvecomfort of air flowVSAvoidtemperature of delivered air
Core Design Contradiction:
Ease of operationVSTemperature

Solution Approach 1:

The PAPR system is divided into separate functional modules: filtration system, heating element, fan system, and control system. This segmentation allows independent optimization of each component, enabling the heating element to specifically address air temperature without affecting other functions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heating element pre-heats the filtered air before it reaches the wearer's face. This preliminary action of heating prevents the discomfort caused by cold air flow, while the control system ensures this happens in advance of the air delivery.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If a heating element is added to warm the air, then comfort and fog prevention are improved, but the system complexity and overheating risk increase

Engineering Contradiction:
Improvecomfort of air flowVSAvoidcomplexity of heating control system
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The control system continuously monitors temperature and fan operation status, and adjusts heating element operation accordingly. This feedback mechanism automates the complex control logic, preventing overheating while maintaining comfort without requiring complex manual control systems.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system monitors its own operational state (fan rotation, temperature levels) and automatically adjusts heating element operation. This self-service capability simplifies the control architecture by eliminating the need for complex external control systems.

Inventive Principle:
Principle #25Self-service

3Temperature

If the heating element operates continuously to maintain warm air supply, then comfort is improved, but the risk of overheating and safety hazards increases

Engineering Contradiction:
Improvetemperature of delivered airVSAvoidsafety of heating system
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The control system implements preliminary protective actions by monitoring temperature and fan status before overheating can occur. It disables the heating element in advance when potential overheating conditions are detected, preventing safety hazards before they materialize.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The control system provides a safety buffer by continuously monitoring operational parameters and disabling the heating element before dangerous temperature levels are reached. This beforehand cushioning prevents thermal runaway and ensures system safety.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 provides a comfortable supply of warm air to the wearer, preventing overheating and fogging, while ensuring safety through precise control of the heating system, thereby enhancing the usability of PAPRs in various environmental conditions.

Implementation Method 1

an electronically controlled active heating element

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a fan and a filter, and the fan draws air from a user's environment and through the filter

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Data Source

PatentEP3060284B1Heating for powered air unit
Publication Date: 2024.03.13 3M INNOVATIVE PROPERTIES CO
  • EP3060284B1 patent drawingFigure 1~2
  • EP3060284B1 patent drawingFigure 3~4
  • EP3060284B1 patent drawingFigure 5

AI summary

A powered air purifying respirator (PAPR) with an active heating system. The PAPR includes a powered air component designed to be carried by a user of the PAPR, the powered air component including a fan and a filter, wherein the fan draws air from a user's environment through the filter. The PAPR further includes an electronically controlled active heating element and a control system. The control system varies the power provided to the heating element and further disables the heating element when potential overheating of the heating element is detected. The present invention further includes a heating module for use with a PAPR. The heating module includes an electronically controlled active heating element. The heating element is disabled when the fan in the PAPR is not rotating.