Dishwasher Wash-Zone Control for Alternating Steam and Spray Cleaning

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Dishwashers with steam generation units face inefficiencies when operating spray arms and steam simultaneously, as hot water cools down steam, reducing its cleaning effect, and alternating operation between steam and water cleaning limits available cleaning time.

Innovation Solution

The steam generation unit is operated intermittently when the spray arm in the second washing zone is active, and the steam generation unit is switched off when the spray arm in the first zone is active to maximize cleaning efficiency, with the washing liquor heater activated during steam non-operation to maintain temperature and reduce energy consumption, and pump speed varied to adapt mechanical cleaning based on dish type.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the spray arm and steam generation unit are operated simultaneously, then the cleaning process is continuous, but the hot water from the spray arm cools down the steam and reduces its cleaning effect

Engineering Contradiction:
Improvecleaning continuityVSAvoidsteam cleaning effect
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The control device operates the spray arm and steam generation unit in alternating periodic cycles rather than simultaneously. The spray arm operates for a first period, then the steam generation unit operates for a second period, allowing the steam to maintain its temperature and cleaning effectiveness while still achieving continuous cleaning coverage over time

Inventive Principle:
Principle #19Periodic action

2Manufacturing precision

If the spray arm and steam generation unit are operated alternately, then the steam cleaning effect is maintained, but the available cleaning time is used only alternatively for steam or water cleaning

Engineering Contradiction:
Improvesteam cleaning effectVSAvoidcleaning time utilization
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The dishwasher is divided into different washing zones with the steam generation unit positioned in a specific location. The control device directs steam to specific zones where it is most needed while the spray arm operates in other zones, allowing different parts of the dishwasher to receive different cleaning treatments simultaneously or in optimized sequences

Inventive Principle:
Principle #3Local quality

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 method optimizes the cleaning effect of steam and utilizes available cleaning time effectively, providing an optimal cleaning result by alternating steam and mechanical cleaning cycles and reducing energy consumption.

Implementation Method 1

a steam generating unit with a steam outlet opening... Steam released into this rinsing zone via the steam outlet opening enables an intensive cleaning effect

Methodology Applied
Scientific EffectPhase change (water to steam): Phase Change

Implementation Method 2

a spray arm for cleaning the items to be washed is arranged

Methodology Applied
Scientific EffectFluid spray: Fluid Spray

Implementation Method 3

a washing liquor heater is only actuated when the steam generation unit is not active

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP2865312B1Dishwasher and method for operating a dishwasher
Publication Date: 2015.12.30 MIELE & CO KG
  • EP2865312B1 patent drawingFigure 1
  • EP2865312B1 patent drawingFigure 2
  • EP2865312B1 patent drawingFigure 3a~3d

AI summary

A method for operating a dishwasher (1) comprising at least two superimposed wash zones (10, 20), each in which a spray arm (11, 21) is arranged, further comprising a steam generation unit (30) with a steam outlet opening (31) arranged in one of the wash zones (10), wherein the spray arms (11, 21) in the different wash zones (10, 20) are operated alternatively, wherein the steam generation unit (30) is operated at least intermittently when the spray arm (21) arranged in the second wash zone (20) is active and is not operated when the spray arm (11) arranged in the first wash zone is active. The invention further relates to a dishwasher (1) configured for carrying out the aforementioned method, which has a water diverter that directs the spray arms (11, 21) of the first and second wash zones (10, 20) to the second wash zone (20).the second rinsing zone (10, 20) is optionally hydraulically connected to a circulation pump, wherein a control device (4) is provided which operates the steam generating unit (30) depending on the position of the water diverter.