Dishwasher Circulation Pump Pulsing for Stable Spray Pressure

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Solution Overview

Problem

Existing dishwashing machine methods fail to achieve improved cleaning performance while maintaining or reducing water and energy consumption.

Innovation Solution

The method involves a circulating pump that operates at a nominal speed during normal sections and increases to a higher impulse speed during pulse sections, with continuous operation and specific speed changes to ensure stable and prolonged washing pressure, allowing for a longer duration of pulsed operation sections to effectively clean items.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the circulating pump is operated at a higher speed during pulse sections, then cleaning performance is improved through increased washing pressure, but the duration of stable operation is reduced due to brief pressure peaks

Engineering Contradiction:
Improvewashing pressureVSAvoidduration of pressure peak
Core Design Contradiction:
PowerVSDuration of action of moving object

Solution Approach 1:

The circulating pump operates in periodic impulse sections with alternating high and low speeds, creating rhythmic pressure variations that enhance cleaning effectiveness while maintaining stable overall operation through controlled cycles

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The pump speed is dynamically adjusted between different operational states (high speed during impulse sections, low speed during intervals) rather than maintaining a constant speed, allowing optimization of both cleaning power and operational stability

Inventive Principle:
Principle #15Dynamics

2Power

If the circulating pump is switched off during pulse sections to create pressure peaks, then washing pressure is increased, but water consumption increases due to repeated switching

Engineering Contradiction:
Improvewashing pressureVSAvoidwater consumption
Core Design Contradiction:
PowerVSLoss of substance

Solution Approach 1:

The circulating pump maintains continuous operation throughout the washing cycle without complete shutdowns, ensuring uninterrupted water flow and pressure while still creating the necessary pressure variations for effective cleaning

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The pump operates in periodic impulse sections with alternating high and low speeds rather than complete on/off switching, maintaining continuous water circulation while creating pressure peaks for enhanced cleaning

Inventive Principle:
Principle #19Periodic action

3Stability of the object's composition

If the circulating pump operates at rated speed continuously, then stable washing pressure is maintained, but cleaning performance is reduced due to lack of pressure variation

Engineering Contradiction:
Improvewashing pressure stabilityVSAvoidcleaning performance
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The pump alternates between high-speed impulse sections and low-speed intervals, creating periodic pressure variations that enhance cleaning effectiveness while maintaining overall operational stability through controlled cycling

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The pump speed is dynamically modulated between different operational states rather than remaining constant, allowing the system to achieve both stability and variable pressure conditions needed for optimal cleaning performance

Inventive Principle:
Principle #15Dynamics

4Duration of action of moving object

If the pulse operation section duration is increased to improve cleaning, then spray arm completes full revolution, but pump supply stability may be compromised

Engineering Contradiction:
Improvepulse operation durationVSAvoidpump supply stability
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The pump speed is dynamically adjusted based on operational phase, maintaining high speed during impulse sections for adequate spray arm rotation while transitioning to low speed during intervals to ensure stable water supply and prevent pressure collapse

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses periodic impulse sections with carefully controlled duration and frequency, alternating between high-speed cleaning phases and low-speed supply stabilization phases to balance spray arm rotation requirements with pump supply stability

Inventive Principle:
Principle #19Periodic action

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

This approach enhances cleaning performance by ensuring all items are reached with a powerful and homogeneous spray jet, reducing water consumption, and improving energy efficiency while minimizing acoustic noise and microfilter clogging.

Implementation Method 1

a circulating pump (1) conveys washing liquid to at least one rotating spray arm (2, 3)

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 2

the circulating pump is operated at a speed that is higher than the nominal speed

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 3

at least one rotating spray arm (2, 3) by means of which the washing liquid is applied to the items to be washed

Methodology Applied
Scientific EffectRotation:

Implementation Method 4

the spray arm in the program section is rotated at least approximately once completely around its axis of rotation

Methodology Applied
Scientific EffectSpray: Spray

Data Source

PatentEP2798993B1Device for performing a flushing programme
Publication Date: 2016.11.16 MIELE & CO KG
  • EP2798993B1 patent drawingFigure 1
  • EP2798993B1 patent drawingFigure 2
  • EP2798993B1 patent drawingFigure 3

AI summary

The invention relates to a method for carrying out a washing program in a dishwasher, in which a circulation pump delivers washing fluid to a rotating spray arm, by means of which the items to be cleaned are sprayed with the washing fluid. The washing program includes a pulse washing phase (1) in which normal operating sections (2), in which the circulation pump is operated at a rated speed (UN), alternate several times with pulse operating sections (3), in which the circulation pump is operated at a speed (UI) increased compared to the rated speed (UN). The invention is characterized in that, following a normal operating section (2), the speed of the circulation pump is first reduced to a speed (UA) lower than the rated speed (UN) before being increased to the increased speed (UI) of the pulse operating section (3).