Automatic Fan Inlet Damper Prevents Backflow
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Solution Overview
Problem
Centrifugal fans in air delivery systems experience backflow when one fan becomes inoperative, leading to reduced pressure and potential noise issues, with conventional solutions often requiring complex mechanical linkages or external attachments that impair performance.
Innovation Solution
An automatic closure damper system that reconfigures based on air pressure differentials, engaging or disengaging with rotatable components to prevent backflow without complex linkages or external supports, maintaining performance and reducing noise by minimizing turbulence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional dampers are placed at the fan inlet to prevent backflow, then backflow prevention is achieved, but fan performance is reduced and noise increases due to flow disturbances
Solution Approach 1:
The damper is designed to be dynamically positioned based on fan operation status. During normal operation, the damper is positioned away from the inlet to minimize flow disturbance. When the fan stops, the damper automatically moves to block the inlet, preventing backflow. This dynamic positioning resolves the contradiction by adapting the damper position to operational conditions.
Solution Approach 2:
The damper is positioned in advance to be out of the airflow path before the fan starts operating, preventing flow disturbances and performance reduction. When the fan stops, the damper is preliminarily positioned to block the inlet, ready to prevent backflow immediately. This preliminary action ensures optimal performance during operation while maintaining backflow prevention capability.
2Reliability
If conventional dampers with mechanical linkages are used to prevent backflow, then backflow prevention is achieved, but device complexity increases and installation becomes more difficult
Solution Approach 1:
The damper system is designed to automatically position itself based on the fan's operation status without requiring external mechanical linkages or actuators. The damper's own movement and the airflow dynamics provide the mechanism for positioning, eliminating the need for complex mechanical linkages and reducing device complexity while maintaining backflow prevention reliability.
Solution Approach 2:
The complex mechanical linkages, external supports, and actuators are completely removed from the system. The invention extracts these unnecessary components and replaces them with a simplified damper design that uses the fan's operational state and airflow to automatically control damper position, achieving backflow prevention without added complexity.
3Reliability
If dampers are positioned at the fan inlet during operation, then backflow prevention is ensured, but turbulence increases and noise is amplified
Solution Approach 1:
The damper dynamically adjusts its position based on fan operation. During operation, the damper is positioned away from the inlet to eliminate flow disturbance, turbulence, and noise. When the fan stops, the damper moves to block the inlet to prevent backflow. This dynamic behavior resolves the contradiction by ensuring backflow prevention only when necessary, eliminating harmful effects during operation.
Solution Approach 2:
The damper alternates between two positions: open during fan operation to minimize turbulence and noise, and closed when the fan stops to prevent backflow. This periodic action between open and closed states ensures that backflow prevention is achieved only when needed, while eliminating harmful turbulence and noise during operation.
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
Effectively prevents backflow through inoperative centrifugal fans while maintaining normal operation performance and reducing noise by using air pressure to control the damper's configuration, ensuring balanced rotation and efficient airflow.
Implementation Method 1
the closure damper is reconfigurable from a closed configuration to an open configuration in response to air flow through the fan at the start of normal operation
Implementation Method 2
a clutch that causes the damper to be engaged with rotatable componentry at certain times (such as when the damper is in open configuration)
Data Source
AI summary
Embodiments of the inventive technology may include an automatically reconfigurable flow blocking damper to prevent back flow; applications include, e.g., centrifugal fans that may at times be susceptible to such back flow, such as centrifugal fans established in an array and discharging to a common space. A clutch may effect damper engagement with rotatable componentry such that the damper is engaged with rotatable componentry when the damper is in open configuration, and effect damper disengagement from rotatable componentry such that the damper is disengaged from rotatable componentry when the damper is in closed configuration. The clutch may, in particular embodiments, act to prevent rotational imbalance problems otherwise observed when the damper is engaged to and rotates with rotatable componentry.