Dishwasher Circulation Pump Silent Mode With Soaking Steps

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Solution Overview

Problem

Modern dishwashers operate at noise levels that are disturbing at night, despite acoustic insulation, as the noise from the circulation pump is not sufficiently reduced, and existing methods only prolong washing programs to lower sound levels.

Innovation Solution

Implementing a silent mode by operating the circulation pump at reduced speeds during part of the washing cycle and incorporating soaking steps to maintain cleaning efficiency, where the pump is inactive for periods, allowing cleaning liquid to soak and penetrate soiling effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the circulation pump operates at nominal speed throughout the washing program, then cleaning efficiency is maintained, but noise level remains high (39-40 dB)

Engineering Contradiction:
Improvenoise levelVSAvoidcleaning efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The circulation pump operates intermittently with periodic soaking steps instead of continuous operation. The pump runs during washing steps and stops during soaking steps, creating a periodic action pattern that reduces noise exposure while maintaining cleaning effectiveness through alternating mechanical circulation and chemical soaking processes.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The circulation pump speed is dynamically adjusted between nominal speed during washing steps and zero speed during soaking steps. This dynamic operation allows the system to optimize between cleaning performance and noise reduction by adapting pump activity to the specific requirements of each washing phase.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If the circulation pump operates at reduced speed for noise reduction, then noise level decreases, but cleaning efficiency deteriorates

Engineering Contradiction:
Improvenoise levelVSAvoidcleaning efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The washing program alternates between active washing phases with pump operation and soaking phases with pump inactivity. This periodic structure ensures that reduced-speed operation does not compromise overall cleaning efficiency, as the soaking phases compensate for reduced mechanical action during low-speed periods.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system changes operational parameters by switching between different pump speeds (nominal and reduced) and different program modes (standard and silent). These parameter changes allow optimization of both noise levels and cleaning efficiency for different operating conditions and user requirements.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If soaking steps are added to maintain cleaning efficiency during reduced pump speed, then cleaning performance is preserved, but program duration increases

Engineering Contradiction:
Improvecleaning efficiencyVSAvoidprogram duration
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The soaking steps provide continuous useful action through chemical cleaning processes during periods when mechanical pump action is reduced or stopped. This ensures that cleaning effectiveness is maintained continuously throughout the program, even when the pump is inactive, by relying on the continuous chemical action of the washing solution.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP2181636B1Method for operating a dishwasher
Publication Date: 2016.08.31 ELECTROLUX HOME PROD CORP NV
  • EP2181636B1 patent drawingFigure 1~3

AI summary

A method for operating a dishwasher comprising a washing tub for accommodating articles to be cleaned and a circulation pump for circulating a cleaning liquid within the washing tub, and wherein there is provided for a plurality of washing programs selectable by the user, said washing programs comprising a series of consecutive steps selected from filling, pre-washing, washing, rinsing, soaking, draining and drying steps. In the method suggested herein, the washing programs comprise: (a) a first washing program in which the circulation pump is operated at a nominal speed, and (b) a second washing program in which, for at least part of the program, the circulation pump is operated at a speed which is reduced with respect to the nominal speed, and in which there is provided at least one soaking step during which the circulation pump is inactive.