Rotatable Damper Blade Assembly for Fire-Safe Ductwork Sealing

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Solution Overview

Problem

Existing fire and smoke dampers in air handling systems face challenges in sealing off ductwork during intense heat conditions while maintaining airflow integrity, often resulting in inefficient airflow resistance under normal conditions due to complex and dirty environments.

Innovation Solution

A dynamic damper apparatus with a rotatable damper blade assembly, where the blade is larger than the opening and can move between open and closed positions, utilizing a thermally separable linkage and biasing springs to seal effectively during high temperatures, and a sealing material for enhanced closure, minimizing airflow obstruction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex rigid heavy-duty components with precise alignments are used to seal ductwork during fire conditions, then fire and smoke rating is maintained, but airflow energy losses increase during normal operations

Engineering Contradiction:

Improvefire and smoke ratingVSAvoidairflow energy losses

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The damper blade is divided into a stationary portion attached to the duct and a movable portion that rotates independently. This segmentation allows the movable portion to be lightweight and simple while the stationary portion provides the sealing surface, resolving the contradiction between fire rating reliability and airflow energy efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs a simple flat damper blade that acts as a thin sealing surface rather than a complex rigid structure. The blade rotates on a pivot to seal against the stationary portion, providing effective fire containment without the need for heavy-duty components that would obstruct airflow during normal operations.

Inventive Principle:

Principle #30Flexible shells and thin films

2Reliability

If complex arrangements with tight tolerances are used to seal ductwork, then sealing effectiveness during fire is improved, but device complexity increases

Engineering Contradiction:

Improvesealing effectivenessVSAvoidarrangement complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

By separating the damper into stationary and movable portions with a simple pivot connection, the design achieves effective sealing without complex arrangements. The stationary portion provides a fixed sealing surface while the movable portion simply rotates into place, eliminating the need for tight tolerances and complex alignment mechanisms.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of using a complex mechanism to create the sealing surface, the patent inverts the approach by using a simple flat blade that seals against a stationary structure. This inversion simplifies the overall device complexity while maintaining sealing effectiveness through the basic rotational motion of the blade.

Inventive Principle:

Principle #13The other way round (Inversion)

3Loss of energy

If a simple flat damper blade is used to seal the opening, then airflow obstruction is minimized, but sealing reliability under intense heat conditions deteriorates

Engineering Contradiction:

Improveairflow obstructionVSAvoidsealing reliability under heat

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The segmented design with a stationary portion provides structural stability and sealing reliability under heat conditions, while the simple movable blade minimizes airflow obstruction. The stationary portion remains fixed and stable during fire conditions, ensuring reliable sealing even with a simple blade design.

Inventive Principle:

Principle #1Segmentation

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 reliable sealing during fire conditions without significant airflow energy losses under normal conditions, ensuring effective smoke and fire containment while maintaining efficient airflow operation.

Implementation Method 1

selectively releasing the damper blade from the open position in relation to a temperature of the airflow

Methodology Applied

Scientific EffectThermal separation: Melting

Implementation Method 2

urging the damper blade to a closed position where the flat area engages against the through opening

Methodology Applied

Scientific EffectElastic potential energy storage: Spring

Data Source

PatentUS12186602B1Dynamic damper in the ductwork of an air handling system

Publication Date: 2025.01.07 METAL FAB INC

AI summary

Apparatus contemplating a damper apparatus for controlling airflow through a ductwork in an air handling system. The damper has a stationary plenum having a collar defining a through opening. A damper blade assembly has a rigid damper blade defining a substantially flat area sized larger than a cross-sectional area of the through opening. The damper blade is selectively positionable between an open position in which the flat area is retained parallel to the collar and thereby clearingly disengages the plenum to open the through opening an thereby permit the airflow to pass through the plenum, and a closed position in which the flat area is perpendicular to the collar and engages against the collar to close the through opening and thereby prevent the airflow from passing through the plenum.