Radial Cutter Chopper Pump Eliminates Axial Shaft Loading
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional chopper pumps face issues with axial loading due to shearing action, require complex maintenance, and are inefficient in handling suction lift, often necessitating additional cutting devices and filters that can clog and reduce pump performance.
Innovation Solution
A pump design featuring a rotating cutter and stationary cutter aligned parallel to the pump shaft, with the cutting action occurring radially, eliminating axial loading and allowing for easier maintenance and operation without additional cutting devices, and incorporating an adjustable impeller and wear plate clearance for improved efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a traditional chopper pump design with perpendicular cutters is used, then cutting action is achieved, but axial loading increases and maintenance complexity increases
Solution Approach 1:
The patent inverts the traditional cutter orientation from perpendicular to the shaft to parallel with the shaft. This inversion changes the cutting geometry so that cutters engage solids in a radial direction rather than axially, eliminating axial loading on the shaft while maintaining effective cutting action.
Solution Approach 2:
The patent transitions the cutting action from the axial dimension to the radial dimension. By orienting cutters parallel to the shaft and positioning them to engage solids radially, the design moves the harmful axial forces into the radial plane where they do not create axial loading on the pump shaft.
2Object-generated harmful factors
If additional cutting devices and filters are added upstream, then solid cutting capability is improved, but device complexity and clogging risk increase
Solution Approach 1:
The patent merges the cutting function directly into the pump assembly by integrating cutters within the pump housing. This consolidation eliminates the need for separate upstream cutting devices and filters, reducing system complexity while maintaining the ability to handle solids effectively.
Solution Approach 2:
The pump assembly is designed to perform multiple functions: pumping liquid and cutting solids simultaneously. The integrated cutters enable the pump to handle solids directly without requiring additional specialized components, making the system more versatile and simpler overall.
3Object-generated harmful factors
If screens and filters are used upstream, then solid removal is improved, but NPSHA is reduced and pump performance decreases
Solution Approach 1:
The patent extracts the cutting function from upstream components and places it directly within the pump. By removing screens and filters from the suction side and replacing them with integrated cutters, the design eliminates the NPSHA penalty associated with filtering while maintaining solid handling capability.
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 enhances pump efficiency by reducing axial loads, simplifying maintenance, and enabling operation without the need for additional cutting devices, while maintaining performance across various flow rates and solid sizes.
Implementation Method 1
Chopper pumps, referred to as such due to the fact that they cut the solids as they pass through the pump
Implementation Method 2
A rotating impeller with curved vanes is surrounded by a stationary diffuser
Data Source
AI summary
A pump for chopping solid material in a liquid stream having a volute housing, a rotating cutter with at least one blade parallel to a rotational axis of the rotating cutter, an impeller arranged at an outer circumference of the rotating cutter, and a stationary cutter having at least one blade parallel to the rotational axis of the rotating cutter. The stationary cutter is concentric with the rotating cutter, and the stationary cutter, the rotating cutter and the impeller are all at least partially housed within the volute housing. Typically, the rotating cutter has a different number of blades than the stationary cutter. Optionally, the pump, further comprises an inspection cover that is removably attached to the pump, and has an opening large enough to remove the stationary cutter and the rotating cutter from the volute housing.