Continuous Dishwasher Self-Cleaning With Recirculated Wash Liquid

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Solution Overview

Problem

Conventional automatic cleaning machines, such as tunnel-type dishwashers, face inefficiencies in water and energy consumption during end-of-cycle cleaning, relying on manual processes that are ergonomically challenging, time-consuming, and dependent on subjective quality, with limited cleaning effectiveness due to the use of fresh water without cleaning agents.

Innovation Solution

The implementation of a conveyor dishwasher with filter devices in each storage tank and additional pumps between zones allows for controlled recirculation and filtration of cleaning fluid, enabling automated cleaning by gradating water quality for targeted use in progressively cleaner zones, reducing water and energy consumption, and ensuring thorough cleaning with heated washing liquid and detergent.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual cleaning processes are used with fresh water, then cleaning of internal surfaces can be performed, but water consumption and energy consumption increase significantly

Engineering Contradiction:
Improvemanual cleaning operationVSAvoidwater consumption
Core Design Contradiction:
Ease of operationVSLoss of substance

Solution Approach 1:

The dishwasher cleaning system performs self-cleaning automatically using its own recirculated washing liquid and filtration system, eliminating the need for manual intervention and external water resources. The system serves itself by utilizing its existing resources (washing liquid, pumps, filters) to clean its own components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system recovers and reuses washing liquid that would otherwise be discarded, by filtering and recirculating it through the cleaning process. The filtration system captures dirt particles from the washing liquid, allowing the liquid to be reused multiple times, thereby reducing overall water consumption.

Inventive Principle:
Principle #34Discarding and recovering

2Ease of operation

If manual cleaning processes are used, then cleaning can be performed, but the process is time-consuming and ergonomically challenging

Engineering Contradiction:
Improvemanual cleaning operationVSAvoidcleaning time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The dishwasher cleaning system performs self-cleaning automatically using its own recirculated washing liquid and filtration system, eliminating the need for manual intervention and external water resources. The system serves itself by utilizing its existing resources (washing liquid, pumps, filters) to clean its own components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The cleaning process operates in periodic cycles, with the pump system alternating between washing operations and cleaning operations. During designated cleaning cycles, the system automatically directs washing liquid through filtration and recirculation to clean internal surfaces, performing maintenance tasks periodically without continuous manual intervention.

Inventive Principle:
Principle #19Periodic action

3Reliability

If fresh water without cleaning agents is used for cleaning, then water resources are consumed, but cleaning effectiveness is limited

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidwater consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The system recovers and reuses washing liquid that would otherwise be discarded, by filtering and recirculating it through the cleaning process. The filtration system captures dirt particles from the washing liquid, allowing the liquid to be reused multiple times, thereby reducing overall water consumption.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The system changes the parameters of the washing liquid by adding cleaning agents and adjusting temperature, transforming it into an effective cleaning solution. The heating element raises the temperature of the washing liquid to enhance its cleaning capability, while detergents are dosed to improve removal of food residues and grease.

Inventive Principle:
Principle #35Parameter changes

4Loss of substance

If the cleaning process is automated with recirculation and filtration, then resource consumption is reduced, but device complexity increases

Engineering Contradiction:
Improvewater consumptionVSAvoidcleaning system structure
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The pump system and filtration system serve multiple functions: they are used during normal washing operations to circulate washing liquid, and during cleaning operations to direct filtered liquid for self-cleaning. The same components perform both washing and cleaning tasks, reducing the need for separate dedicated systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The cleaning system is divided into functional segments: a recirculation system with pumps, a filtration system with separable filters, and a control system. This segmentation allows each component to be optimized for its specific function while maintaining overall system efficiency and ease of maintenance.

Inventive Principle:
Principle #1Segmentation

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 achieves efficient, automated, and ergonomic self-cleaning of conveyor dishwashers with significantly reduced resource usage, ensuring consistently high-quality cleaning of all internal surfaces with minimal material and time expenditure.

Implementation Method 1

rinsing liquid is sucked in by a pump from the storage tank associated with this treatment zone and sprayed over the items to be cleaned through suitably designed nozzles

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 2

the heated washing liquid is drawn in by a further circulating pump from the storage tank assigned to the cleaning zone and sprayed over the wash items by means of suitably positioned and oriented nozzles

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 3

DE 10 2005 008987 B3 discloses a dishwasher which, in contrast to the embodiment described above, has a filter device in each treatment zone, with which the cleaning fluid located in the respective storage tank is continuously filtered

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 4

In the at least one cleaning zone, which adjoins the pre-cleaning zone, dirt particles still adhering to the items to be cleaned are removed by means of a typically alkaline rinsing liquid. For this purpose, the heated washing liquid is drawn in by a further circulating pump

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP2252191B1Method for self-cleaning of a continuous dishwasher and corresponding dishwasher
Publication Date: 2013.01.23 MEIKO MASCHINENBAU GMBH & CO KG
  • EP2252191B1 patent drawingFigure 1
  • EP2252191B1 patent drawingFigure 2a
  • EP2252191B1 patent drawingFigure 2b

AI summary

The invention relates to a method for the automatic self-cleaning of a continuous dishwasher for items to be cleaned, comprising at least one washing zone (2, 3), at least one clear rinsing zone (4, 5) and a transport device (7). Items to be cleaned are transported via the transport device (7) in the transport direction (8). The continuous dishwasher comprises at least one fine filter with a backwash apparatus (16) on at least one storage tank (13) and at least one device (18) for emptying each of the storage tanks (13). The continuous dishwasher automatically carries out a self-cleaning cycle, during which cleaning liquid (22) located in each of the storage tanks (13) is successively used several times in the different zones (2, 3, 4 and 5) for cleaning. The cleaning liquid (22) is circulated by means of circulating pumps (14) in the respective storage tanks (13) and is fed to spraying systems (9, 10, 11) that are already present in the associated zones (2, 3, 4 or 5), or to separate nozzles or nozzle heads for wetting the inside of the surfaces delimiting the respective zone (2, 3, 4 and 5).