Centrifugal Blower Volute Diffuser for Uniform Pressure Drop
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Solution Overview
Problem
Conventional blower vacuum appliances experience inefficiencies due to non-constant pressure distribution at the impeller outlet, leading to reduced airflow and performance, especially in battery-powered devices where power consumption and run time are concerns.
Innovation Solution
Incorporating a diffuser with a constant radial width annular channel between the centrifugal impeller and the volute outlet, which maintains a uniform pressure drop around the impeller circumference, along with a vaneless diffuser and expanding volute outlet region to minimize losses and enhance airflow efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional volute arrangement is used without a diffuser, then the device complexity is reduced, but the pressure distribution at the impeller outlet becomes non-constant, reducing impeller efficiency and airflow
Solution Approach 1:
A diffuser is introduced as an intermediary component between the impeller and the volute outlet region. The diffuser has a substantially constant radial width and acts as a mediator to distribute the pressure created by the impeller more evenly around the circumference, improving the pressure distribution at the volute inlet without significantly increasing overall device complexity
Solution Approach 2:
The diffuser changes the radial width parameter of the volute inlet region from variable (in conventional designs) to substantially constant. This parameter change ensures that the pressure distribution around the impeller outlet is more uniform, thereby improving impeller efficiency and airflow productivity
2Volume of moving object
If the impeller is positioned closer to the volute walls to reduce size, then the device dimensions are reduced, but the pressure distribution becomes non-constant, reducing impeller efficiency
Solution Approach 1:
The diffuser serves as a buffer zone or intermediary space between the impeller and the volute walls. Even though the impeller may be positioned relatively close to the walls to minimize volute size, the diffuser ensures that the pressure distribution remains substantially constant by its constant radial width design, preventing direct adverse interactions between the impeller and volute walls
3Weight of moving object
If battery power is used to reduce weight and increase portability, then the weight is reduced, but the power consumption limits the run time and available power for high flow rates
Solution Approach 1:
The diffuser with constant radial width optimizes the aerodynamic parameters of the volute inlet, reducing losses and improving the efficiency of the impeller. This allows the battery-powered appliance to achieve greater airflow per unit of power, effectively reducing the power consumption requirement for a given performance level and thereby extending run time
Solution Approach 2:
The patent converts the limitation of battery power (limited energy availability) into a benefit by optimizing the airflow path to minimize losses. The diffuser ensures that the limited battery power is used more efficiently, converting what would be energy waste into useful airflow, thereby achieving high performance despite power constraints
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
This configuration improves the impeller's efficiency, allowing for greater airflow per unit of power without increasing power consumption, resulting in stronger performance and longer operating times for battery-powered appliances.
Implementation Method 1
a centrifugal impeller located within the volute and rotatable by a motor to generate a flow of fluid between the fluid inlet and the fluid outlet
Implementation Method 2
the diffuser comprising an annular channel surrounding the centrifugal impeller and having substantially constant radial width such that the impeller is radially spaced from the volute walls by at least the width of the diffuser
Data Source
Figure 1~2
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AI summary
There is provided a debris blowing and/or vacuum appliance (10; 30). The appliance (10; 30) comprises a body (12; 32) including a fluid inlet (20; 46), a fluid outlet (28; 42) for exhausting fluid externally of the body (12; 32), a volute (100) located in a flowpath between the fluid inlet (20; 46) and the fluid outlet (28; 42) and a centrifugal impeller (200) located within the volute (100) and rotatable by a motor (204) to generate a flow of fluid between the fluid inlet (20; 46) and the fluid outlet (28; 42), the volute (100) comprising volute walls (122) delimiting a volute outlet region (128) in communication with the fluid outlet (28; 42) and a diffuser (114) located immediately downstream of the centrifugal impeller (200) between the centrifugal impeller (200) and the volute outlet region (128). The diffuser (114) comprises an annular channel surrounding the centrifugal impeller (200) and has substantially constant radial width such that the impeller (200) is radially spaced from the volute walls (122) by at least the width of the diffuser (114). By providing such an arrangement, the efficiency of the impeller can be improved. Therefore, an appliance having improved performance for blowing and/or vacuuming dirt and debris can be provided without, for example, increasing power consumption. This is of relevance to battery powered appliances, where improved efficiency may provide stronger performance and a longer operating run time for a given battery size and charge.