Pump Assembly Outer Gap Filtration Design
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Solution Overview
Problem
Existing fire-fighting pumps are bulky and require frequent maintenance due to sensitivity to contamination, which affects the high-pressure stage's reliability and necessitates additional filtration systems that can clog and require regular cleaning.
Innovation Solution
A combined fire pump design featuring an outer gap between the impeller and the pump housing that acts as a filter, preventing large particles from reaching the high-pressure stage and eliminating the need for external filters, allowing for a compact and maintenance-free operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional strainers or filters are installed in the connecting line between the low-pressure stage and high-pressure stage, then the high-pressure stage is protected against contamination, but the overall design becomes larger and bulkier
Solution Approach 1:
The patent merges the filtration function with the pump housing structure by forming the constriction directly in the housing wall between the low-pressure and high-pressure stages. This integration eliminates the need for separate external filters while maintaining contamination protection, thereby reducing overall system size.
Solution Approach 2:
The housing wall serves multiple functions: it provides structural support, contains the liquid flow, and simultaneously acts as a filter through the integrated constriction. This multi-functionality eliminates the need for dedicated filtration components, reducing system complexity and size.
2Reliability
If conventional cylindrical filters with through holes are used, then filtration is provided, but they are prone to clogging and require frequent cleaning interruptions
Solution Approach 1:
The constriction design allows the pump to protect itself from contamination without requiring external filtration systems that need maintenance. The geometric constraint passively prevents particle ingress based on size, providing self-service protection that eliminates frequent cleaning interruptions.
3Ease of repair
If a slotted filter with helical support structure is used, then it is easier to clean by flushing, but it still accumulates solids and dirt requiring regular maintenance
Solution Approach 1:
The patent extracts the filtration function from complex filter structures and implements it through a simple geometric constriction in the housing wall. This minimalistic approach eliminates the need for slotted filters, helical supports, and associated cleaning mechanisms, achieving contamination protection without maintenance requirements.
4Reliability
If the outer gap cross-section is made small to retain particles, then the high-pressure stage is protected, but the flow rate may be reduced
Solution Approach 1:
The constriction creates a localized particle retention zone with specific dimensional characteristics that filter based on particle size while maintaining overall system flow capacity. The local geometric constraint achieves protection without globally restricting fluid flow through the pump system.
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 design effectively prevents contamination from reaching the high-pressure stage, ensuring continuous operation and reducing the pump's size and maintenance requirements while maintaining high delivery pressure.
Implementation Method 1
at least one first cross-sectional constriction is formed between at least one fixed inner wall of the first pump housing cavity and the first impeller, forming at least one outer gap for fluid passage
Data Source
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Figure 3
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AI summary
The invention relates to a pump assembly comprising a first liquid pump unit which has a first impeller that can be rotated in a first pump housing cavity and comprising a second liquid pump unit which is arranged downstream of the first liquid pump unit in the liquid pumping direction of the pump assembly, which generates a second liquid pressure that is higher than the first liquid pressure, and which has a second impeller that rotates in a second pump housing cavity, wherein a pressure outlet of the first liquid pump unit is connected to the second liquid pump unit via at least one connection. The aim of the invention is to provide such a pump assembly which has a compact design and in which the second liquid pump unit is reliably protected from the penetration of dirt. According to the invention, this is achieved in that at least one outer gap is formed between the inner wall and the first impeller between at least one stationary inner wall of the first pump housing cavity and the first impeller. The connection is provided by at least one connection channel which is provided downstream of the outer gap in the liquid pumping direction and runs between the first pump housing cavity and the second pump housing cavity.