Discharge pump for household appliance provided with a filter for microplastics and related control method
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Solution Overview
Problem
Mechanical filters for microplastics in household appliances suffer from increasing hydraulic resistance over time, leading to reduced water flow rates and misdiagnosis of clogging, necessitating premature filter replacement or cleaning, and conflicting with control electronics.
Innovation Solution
A variable speed discharge pump with a control method that adjusts its rotational speed over time to maintain a constant flow rate by compensating for filter clogging, using electric parameters to monitor and signal when the filter needs replacement or cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical filter is used to capture microplastics in the drain line, then microplastic collection efficiency is improved, but hydraulic resistance increases progressively over time reducing water flow rate
Solution Approach 1:
The discharge pump operates with variable rotational speed that changes dynamically over time. The control unit increases the pump speed progressively to compensate for the increasing hydraulic resistance of the filter, thereby maintaining constant water flow rate throughout the filter's service life until replacement is needed.
2Device complexity
If the discharge pump operates at constant speed, then device complexity is reduced, but water flow rate decreases over time as the filter clogs
Solution Approach 1:
The discharge pump transitions from constant speed operation to variable speed operation. The control unit manages the motor's rotational speed dynamically, increasing it over time to compensate for filter clogging and maintain constant water flow rate, thereby resolving the contradiction between simplicity and productivity.
3Productivity
If the filter is replaced or cleaned before complete saturation to maintain flow rate, then water flow rate is preserved, but filter life cycle is reduced and replacement frequency increases
Solution Approach 1:
By dynamically adjusting the pump speed to compensate for increasing filter resistance, the system maintains constant water flow rate throughout the entire filter service life. This allows the filter to be used until complete saturation without premature replacement, maximizing filter life cycle while preserving productivity.
4Productivity
If pump speed is increased to compensate for filter clogging, then water flow rate is maintained, but energy consumption increases
Solution Approach 1:
The system maintains continuous constant water flow rate through the filter by progressively increasing pump speed. This ensures uninterrupted drainage performance throughout the filter's service life, accepting increased energy consumption as the necessary trade-off to maintain continuous productive operation without flow rate degradation.
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
Extends the life cycle of the filter by maintaining consistent flow rates and preventing misdiagnosis, ensuring optimal filter performance and reducing unnecessary maintenance.
Implementation Method 1
These mechanical filters have an increasing hydraulic resistance over their life, since they are progressively saturated by the collected particles
Implementation Method 2
mechanical filters placed on the drain line of a washing machine, in order to incorporate microplastic particles before the water is released into the drain
Data Source
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AI summary
Control method for a variable speed discharge pump of a large household appliance for washing and/or drying clothes, wherein a filter for collecting microplastics is placed downstream of said discharge pump, said control method comprising the following steps: - operating the discharge pump at an initial rotational speed to which an initial flow rate through the filter (100) corresponds; - increasing the rotational speed of the discharge pump over time until the filter is replaced or cleaned, in order to compensate for the decrease in the flow rate due to the progressive clogging of the filter (600).