Air Wall Blower Slit Geometry for Uniform Thermal Separation
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Solution Overview
Problem
Existing blower devices for thermal separation of air between two spaces suffer from irregular air streams due to parabolic velocity profiles, turbulence, and asymmetrical airflow distribution, leading to inefficient separation and increased energy losses.
Innovation Solution
A blower device with a prismatic air feed and blower slit, featuring smooth parallel surfaces, adjustable airflow resistance, and a multi-stage pressure system, which reduces turbulence and maintains a uniform airflow pattern, ensuring a consistent and laminar air stream for effective thermal separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If transverse connecting plates are arranged in the air outflow slit to direct the air stream, then the air stream direction is controlled, but the parabolic velocity profile creates irregular air stream and enhances divergence
Solution Approach 1:
The invention removes the transverse connecting plates from the air outflow slit, extracting the source of turbulence and parabolic velocity profile. This allows the air stream to exit smoothly without the disruptive elements that caused irregular flow patterns and divergence.
Solution Approach 2:
Instead of using plates to force air flow direction, the invention inverts the approach by using a carefully designed slit geometry with specific length-to-width ratio (10:1 to 40:1) and rounded edges to naturally guide the air stream in the desired direction while maintaining laminar flow.
2Device complexity
If the air outflow slit surfaces are made short, then the device size is reduced, but the turbulent character is insufficiently converted to laminar airflow
Solution Approach 1:
The invention changes the critical parameter of slit length to a specific range (10-30 cm preferably) that is sufficient to convert turbulent flow to laminar flow while maintaining compact dimensions. This optimal length parameter ensures proper flow transition without excessive device size.
Solution Approach 2:
The invention applies curvature by providing rounded edges at the air outflow slit ends, which smooths the airflow transition and prevents flow separation that would occur with sharp edges. This curvature ensures laminar flow conversion while maintaining a compact slit design.
3Ease of operation
If a control valve is placed at the end of the air outflow slit, then airflow control is achieved, but turbulence is enhanced in the air wall
Solution Approach 1:
The invention removes the control valve from the air outflow slit area, extracting the source of turbulence it introduces. Airflow control is instead achieved through the overall system design including fan speed control and slit geometry, avoiding local disruptions to the air wall smoothness.
4Ease of manufacture
If asymmetric embodiment of the air distributing box is used, then manufacturing is simplified, but a bending air wall is created relative to the axis
Solution Approach 1:
The invention intentionally introduces asymmetry in the form of rounded edges at the slit ends, which compensates for any asymmetry in the air distributing box. This controlled asymmetry in the outlet geometry ensures symmetric laminar flow emergence and a straight air wall, while the bulk of the distributing box can remain asymmetrically designed for manufacturing ease.
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 significantly reduces turbulence and enhances the uniformity of the air stream, improving thermal separation efficiency and reducing energy losses, while allowing for adjustable airflow to manage varying wind conditions and maintain a smooth air wall.
Implementation Method 1
the air stream is affected considerably less by factors reducing the smoothness of the main flow and forms a better separation between the two spaces
Implementation Method 2
the turbulence of the air stream flowing out of the outflow slit is greatly reduced, so that the air stream is affected considerably less by factors reducing the smoothness of the main flow
Data Source
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AI summary
The invention relates to a blower unit for generating an air wall for thermal separation of the air in a first relatively cold space from the air in a second relatively warm space, for instance the surrounding area, which spaces are mutually connected by a passage opening, the blower unit comprising: an elongate blower unit positioned on one side of the passage opening and comprising fan means and a blower slit for generating a flat air stream directed toward the opposite side of the passage opening. The unit has the special feature that the speed of the air in the air blower slit amounts to at least 15 m/s; the width of the blower slit lies in the range of 5-40 mm; the length of the blower slit in the direction of the air stream lies in the range of 5-100 cm; the cavity has a prismatic form; connecting to which cavity on one side is at least one air feed, extending substantially over the whole longitudinal dimension of the cavity, and on the other side the blower slit; in the upstream zone of which cavity an airflow resistance is present; and the zone of which cavity downstream of the airflow resistance has a form narrowing in the flow direction.