Heating circulation type drying module of dishwasher

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Solution Overview

Problem

Conventional dishwashers consume excessive power for drying due to the heating of water in the rinsing course, and they lack efficient control over air temperature and circulation patterns for uniform drying.

Innovation Solution

A dishwasher design that uses only hot air for drying, with adjustable temperature and airflow rate, and a control method that opens and closes the door based on humidity levels to optimize air circulation and reduce power consumption, featuring PTC heaters and a fan with adjustable RPM to enhance drying performance and reduce dehumidification power usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If water is heated in the rinsing course to evaporate moisture from dishes, then drying performance is improved, but power consumption increases significantly

Engineering Contradiction:
Improvedrying performanceVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The invention extracts the water heating step from the drying process, separating the rinsing function from the drying function. Instead of heating water for drying purposes, the system uses only air heating through heaters (611, 612) positioned in the exhaust duct, thereby eliminating the energy-intensive water heating step while maintaining effective moisture evaporation from dishes.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the physical parameters of the drying process by controlling air temperature through independent heater regulation and adjusting air circulation patterns via fan speed control. This allows optimization of drying efficiency using air alone, replacing the conventional approach that relies on heated water, thus reducing energy consumption while maintaining or improving drying performance.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If air temperature and circulation are fixed, then the drying process is simple to control, but drying uniformity across different regions inside the tub deteriorates

Engineering Contradiction:
Improvecontrol simplicityVSAvoiddrying uniformity
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The invention introduces dynamic control elements that allow adjustment of drying parameters during operation. The fan speed can be varied to change air circulation patterns, and the heaters can be independently controlled to adjust temperature distribution. This dynamic adaptability enables uniform drying across different tub regions while maintaining relatively simple control architecture through automated sensing and regulation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention applies local quality control by positioning multiple heaters (611, 612) at different locations within the exhaust duct and enabling independent control of each heater. This allows differential temperature regulation in different zones of the drying chamber, ensuring uniform drying performance across various regions while keeping the overall control system manageable through localized adjustment capabilities.

Inventive Principle:
Principle #3Local quality

3Reliability

If moist air is retained inside the tub during drying, then the drying environment is maintained, but additional power is consumed for dehumidification

Engineering Contradiction:
Improvedrying environment stabilityVSAvoiddehumidification power
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The invention converts the harmful effect of moisture accumulation into a beneficial outcome by using the moist air as part of the drying cycle. The air circulation system draws moist air from the tub, passes it through heaters for moisture evaporation enhancement, and redistributes it. This approach eliminates the need for separate dehumidification systems, reducing additional power consumption while maintaining effective drying conditions through continuous air movement and controlled heating.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 reduces energy consumption by 20-30% compared to conventional methods, improves drying efficiency by adjusting air temperature and circulation, and prevents additional power use for dehumidification by discharging moist air outside.

Implementation Method 1

at least two heaters provided inside the exhaust duct for heating the air

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a fan for supplying the air to the heaters

Methodology Applied
Scientific EffectForced convection: Forced Convection

Implementation Method 3

evaporating water on the surface of dishes by heating only air

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3307133B1Heating circulation type drying module of dishwasher
Publication Date: 2023.05.03 LG ELECTRONICS INC
  • EP3307133B1 patent drawingFigure 1
  • EP3307133B1 patent drawingFigure 2
  • EP3307133B1 patent drawingFigure 3~4

AI summary

Disclosed is a heating circulation type drying module of a dishwasher using a fan module and PTC heaters. The dishwasher includes a cabinet defining the external appearance, a tub provided in the cabinet, a door for opening or closing the tub, a flow-path unit for circulating air inside the tub through a suction port and an exhaust port, which communicate with the tub, a suction duct for communicating with the suction port, an exhaust duct for communicating with the suction duct and the exhaust port, at least two heaters provided inside the exhaust duct for heating the air, and a fan for supplying the air to the heaters. The dishwasher may achieve improved drying performance via adjustment in the temperature of air to be discharged, and may reduce power consumption via omission of a rinsing water heating course.