Gravity-Closed Fan Check Valve for Backflow and Motor Overload
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Solution Overview
Problem
Ventilation systems in structures like grain bins face issues with backpressure from operating fans causing non-operating fans to reverse direction, leading to motor overload and potential clogging, and there is a need for minimizing moving components that can inhibit smooth operation while allowing for retrofitting without additional space or hardware.
Innovation Solution
An air check valve system with a ring, flanges, and pivot-mounted damper plates that automatically close under gravity when the fan is deactivated and open with airflow, minimizing backflow and air leakage, and can be easily mounted between a fan and transition duct without requiring additional space or hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple fans are used in a ventilation system, then air circulation is improved, but backpressure causes non-operating fans to reverse direction leading to motor overload
Solution Approach 1:
The damper plate is extracted as a separate movable component that can be independently controlled to block backflow air paths, allowing the fan to operate without being affected by backpressure from other fans in the system
Solution Approach 2:
The damper plate acts as an intermediary element between the fan and the air passage, mediating the airflow to prevent harmful backflow while maintaining normal ventilation function
2Reliability
If check valve components are added to prevent backflow, then motor overload is prevented, but device complexity increases
Solution Approach 1:
The damper plate is designed to automatically open and close based on airflow pressure differential, eliminating the need for external actuators, sensors, or control systems while still providing reliable backflow prevention
Solution Approach 2:
The system utilizes changes in airflow pressure parameters to automatically control the damper plate position, converting pressure differential into mechanical motion without additional control mechanisms
3Reliability
If retrofitting is performed on existing ventilation systems, then system reliability is improved, but additional space and mounting hardware are required
Solution Approach 1:
The damper plate assembly is nested within the existing fan housing structure, utilizing the available internal space without requiring external mounting areas or additional structural modifications
Solution Approach 2:
The mounting flange serves multiple functions: it provides structural support for the damper plate, enables attachment to the fan housing, and maintains the air passage, eliminating the need for separate mounting hardware
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 air check valve system prevents motor overload by reducing backflow and air leakage, ensures smooth operation, and allows for efficient airflow management without additional power or hardware, enhancing the reliability and efficiency of ventilation systems.
Implementation Method 1
the first and second damper plates are influenced by gravity to locate at the closed position when the fan is in a deactivated state
Implementation Method 2
air flow generated by the fan in an activated state urges the damper plates into the open position
Data Source
AI summary
An air check valve system configured to be mounted for fluid communication with a fan can include a ring having a generally circular inner diameter that defines an air passage through a plane of the ring. A first and a second flange can extend from the ring. A rod can have a first end mounted to the first flange and a second end mounted to the second flange. The rod can define a pivot axis. A first and a second damper plate can be mounted to the rod for rotation around the pivot axis between an open and a closed position.