Wastewater Pump Blockage Detection via Motor Current Slope and Curvature
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Solution Overview
Problem
Current methods for detecting and clearing blockages in wastewater pumps are not effective in timely and reliable fashion, often leading to damage due to undetected clogging or incorrect detection of mechanical resistance.
Innovation Solution
A method that uses the slope and curvature of electrical operating values to detect impending blockages, allowing for early recognition and targeted unblocking routines based on the type and location of the blockage, by reversing the motor's direction of rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current detection methods based on power or torque time signals are used, then the detection system is simple to implement, but the blockage detection is not timely and reliable, leading to pump damage
Solution Approach 1:
The system performs preliminary analysis by calculating gradient and curvature of electrical operating values before a blockage fully develops. This early detection approach allows the system to identify impending blockages based on changing trends in electrical parameters, enabling preventive action before damage occurs.
Solution Approach 2:
The patent replaces traditional mechanical or power-based detection methods with an electrical parameter analysis system. By monitoring gradient and curvature of electrical operating values (current, power, torque), the system achieves more reliable blockage detection without requiring additional mechanical sensors or complex mechanical detection mechanisms.
2Productivity
If the motor operates continuously in one direction to maintain pumping efficiency, then productivity is maintained, but blockages cannot be cleared and mechanical resistance increases
Solution Approach 1:
The system implements periodic reverse operation of the motor to clear blockages. When blockage is detected through gradient and curvature analysis, the motor reverses direction for a predetermined time period to dislodge contaminants, then returns to normal pumping operation. This periodic reversal prevents permanent blockage accumulation while maintaining overall pumping productivity.
Solution Approach 2:
The patent uses reverse rotation of the motor to clear blockages that develop during forward pumping operation. By inverting the rotation direction, the impeller moves in the opposite direction, dislodging contaminants that have accumulated on the impeller or pump housing, thereby restoring reliable operation without requiring pump disassembly.
3Reliability
If mechanical resistance increase is detected to trigger unblocking routines, then blockages can be cleared, but false positive detections occur when the impeller simply becomes stiffer
Solution Approach 1:
The system uses gradient and curvature calculations of electrical operating values as feedback mechanisms to distinguish between actual blockages and normal impeller stiffening. By analyzing the rate of change and acceleration of electrical parameters, the system can identify the specific pattern characteristic of blockage development versus the gradual stiffening that occurs during normal operation, reducing false positive detections.
Data Source
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AI summary
The invention relates to a method for detecting and/or classifying blockages in a wastewater pump (1) comprising a pump housing (2), a shaft (4) arranged in the pump housing (2), an impeller (6) mounted on the shaft (4), and a motor (5) driving the shaft (4), comprising the steps of: during the pumping of wastewater with the wastewater pump (1), by operating the motor (5) in a first direction of rotation, detecting at least one slope and/or curvature of a time-dependent characteristic of the electrical wastewater operating values of the rotating motor (5), if the slope and/or curvature of the time-dependent characteristic of the wastewater operating values exceeds a blockage threshold, and clearing the blockage by operating the motor (5) in at least one second direction of rotation opposite to the first direction of rotation.