Hood Suction Device with Self-Closing Flap Collar to Prevent Backflow
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Solution Overview
Problem
Existing hood suction devices are passive when off, leading to backflows and exposure to external disturbances like dust and insects, which can foul and obstruct the impeller, reducing their reliability and ease of assembly/installation.
Innovation Solution
A self-closing collar mechanism with semicircular flaps hinged diametrically on the collar, lifted by airflow to prevent backflow and external contamination, featuring counterweights and abutment elements for efficient closure and assembly, reducing noise and vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the suction device is left open when idle, then assembly and installation are simple, but backflow and external contamination occur
Solution Approach 1:
The collar is designed to be dynamic rather than static, automatically opening when airflow is detected and closing when idle. This dynamic behavior allows the collar to provide protection during idle periods while permitting airflow during operation, resolving the contradiction between simplicity and protection.
Solution Approach 2:
The collar operates autonomously using the airflow itself as the actuating force. The airflow detected by the impeller automatically opens the collar, and the cessation of airflow automatically closes it, eliminating the need for external control mechanisms or additional energy input.
2Reliability
If the collar is kept closed to prevent backflow, then protection from contamination improves, but assembly and installation become more complex
Solution Approach 1:
The collar mechanism utilizes pneumatic principles by employing airflow detection to actuate the opening and closing motion. The air current detected by the impeller serves as the actuating force, eliminating the need for complex mechanical actuators, motors, or control systems.
Solution Approach 2:
The control function is extracted from the main suction mechanism and integrated into the collar itself. The collar uses the airflow field already present in the system to actuate itself, removing the need for separate control mechanisms and reducing overall device complexity.
3Productivity
If the suction device operates continuously, then fume extraction is maintained, but energy consumption increases
Solution Approach 1:
The collar operates in a periodic manner, opening only during the brief periods when airflow is present and closing during extended idle periods. This periodic operation allows the suction device to maintain extraction capability when needed while minimizing energy consumption during non-operational periods.
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 effectively prevents backflow and external contamination, enhancing the reliability and simplicity of the suction device, ensuring it remains functional and easier to assemble/install, while reducing noise and vibration.
Implementation Method 1
a suction device (103) for a hood (101), comprising a motor (not shown) and an impeller (not shown) driven by the motor and configured to draw an airflow and direct it into an outflow collar (203)
Implementation Method 2
the flaps (204, 205) are lifted, preferably in a symmetrical manner, when hit by the air flow
Implementation Method 3
each one of the flaps (204, 205) comprises a closing counterweight (403, 404) adapted to foster the closing of the flap by gravity for obstructing the collar (203) when the impeller (not shown) is idle
Data Source
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AI summary
The present invention relates to a suction device (103) for a hood (101), comprising a motor, and further comprising an impeller driven by the motor and configured to draw an air flow and direct it into an outflow collar (203); the suction device (103) further comprises at least one flap (204, 205) connected to the collar (203) and hinged (301) on one side only, the at least one flap (204, 205) being configured to close the collar (203) when the impeller is idle, and to be lifted by the air flow so as to clear the collar (203) when the impeller is rotating.