Dishwasher having condensing duct and return duct
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Solution Overview
Problem
Existing dishwasher drying modules, particularly closed-circulation types, face challenges in cost, size, and performance due to complex configurations and water interference issues, which affect drying efficiency and durability.
Innovation Solution
A compact dishwasher design with a closed-circulation drying system that includes a tub with strategically positioned inlet and outlet ports, a condensing duct, and a return duct, along with a fan and heater placement that minimizes water contact and vaporization, enhancing drying performance and preventing backflow while maintaining a small size and low manufacturing cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a closed-circulation drying module is used to improve drying performance, then drying efficiency is improved, but manufacturing cost and installation space increase
Solution Approach 1:
The patent combines the condensing duct and return duct into a single integrated duct structure. The duct serves dual functions: condensing moisture from the air stream and returning the dried air to the washing chamber. This merging eliminates the need for separate condensing and return ducts, reducing manufacturing cost and installation space while maintaining closed-circulation drying efficiency
Solution Approach 2:
The integrated duct is designed to perform multiple functions simultaneously: it acts as both a condensing duct (removing moisture from air) and a return duct (delivering dried air back to the chamber). This multi-functionality reduces the overall number of components needed in the drying module, simplifying the system while preserving the high drying performance of closed-circulation design
2Productivity
If the fan size is increased to improve air flow and drying performance, then drying efficiency is improved, but the fan becomes more susceptible to water contact and breakdown
Solution Approach 1:
The patent extracts the fan from the water-prone environment by positioning it in the integrated duct away from the washing chamber. The fan is located in the return air stream path, separated from direct water contact zones. This extraction allows the use of a larger, more effective fan for improved air circulation while protecting it from water damage that would occur if positioned near the washing targets
3Productivity
If the heater size is increased to improve air heating capacity, then drying performance is improved, but water vaporization increases when water is present at the heater periphery
Solution Approach 1:
The heater is extracted from direct contact with water by positioning it within the integrated duct structure, where it heats the return air stream away from the washing chamber. This extraction prevents water from reaching the heater periphery, eliminating the harmful vaporization effect while maintaining the heater's ability to warm the air for improved drying performance
Solution Approach 2:
The integrated duct structure acts as an intermediary barrier between the heater and water. The heater is positioned to heat air within the duct, and the duct itself prevents water from contacting the heater. This intermediary arrangement allows the heater to function effectively for air heating without the harmful side effect of water vaporization into the washing chamber
4Volume of moving object
If the V-shaped flow tube length is reduced to miniaturize the dishwasher, then device size is reduced, but the heater size decreases and drying performance deteriorates
Solution Approach 1:
The patent transitions from a two-dimensional planar duct layout to a three-dimensional integrated duct structure. The condensing duct and return duct are arranged vertically and spatially within the integrated structure, allowing the ducts to be compact in horizontal footprint while maintaining sufficient length for effective condensing and heating. This dimensional change enables miniaturization of the dishwasher while preserving the functional performance of the drying system
5Reliability
If the V-shaped flow tube is used to prevent water contact with the motor, then fan reliability is improved, but the motor is still vulnerable to water vaporization from the heater
Solution Approach 1:
The motor is extracted from the water-prone environment by positioning it within the integrated duct structure, away from both liquid water and the heating zone. The motor is located in the return air stream path where it is protected from water contact and from exposure to heater-generated moisture vapor. This extraction provides dual protection: preventing liquid water ingress and eliminating exposure to harmful vaporization effects
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
The design improves drying efficiency, prevents water backflow, reduces bacterial and mold proliferation, and enhances durability by ensuring effective air circulation and heat transfer within a compact structure, maintaining high performance at a lower cost.
Implementation Method 1
a condensing duct configured to remove moisture from the air stream
Implementation Method 2
a heater configured to heat the air stream
Implementation Method 3
a fan configured to move the air stream through the drying system
Data Source
AI summary
A dishwasher includes a tub, a door, and a drying device configured to supply air to a washing space in the tub. The drying device includes a drying duct that is disposed outside the tub and includes a condensing duct and a return duct, a fan configured to cause a flow of air in the drying duct, and a heater configured to heat the air in the drying duct. The condensing duct includes a first condensing duct connected to an inlet port configured to receive moist air from the washing space, and a second condensing duct disposed vertically below a bottom portion of the tub and connected to the first condensing duct. The return duct includes a return upstream end connected to the second condensing duct and a return downstream end connected to an outlet port configured to supply air to the tub.