Integrated Dishwasher Pump Heating Layout to Reduce Calcification
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Solution Overview
Problem
Existing pumps used in household appliances like dishwashers and washing machines face issues with calcification due to uneven heating, leading to local overheating and reduced efficiency, as current heating elements do not effectively manage heat distribution across the pump chamber wall.
Innovation Solution
The pump design incorporates sheet heating elements with decreasing output in the axial direction from the impeller to the outlet, ensuring greater heating power where water is colder and reducing the risk of calcification by minimizing overheating, with a configuration of multiple heating elements arranged to provide a continuous but decreasing heat distribution along the pump chamber wall.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If heating elements are applied uniformly across the pump chamber wall, then the pump chamber can be heated, but local overheating occurs leading to calcification on the pump chamber wall
Solution Approach 1:
The heating elements are designed with varying output along the axial direction of the pump chamber. The heating output is highest near the water inlet where water is coldest and decreases toward the outlet where water becomes warmer. This non-uniform heating distribution prevents local overheating and subsequent calcification on the pump chamber wall while ensuring adequate heating where needed most.
2Productivity
If heating elements provide high heating power, then heat transfer to pumped liquid is efficient, but local overheating increases precipitation of lime and calcification
Solution Approach 1:
The heating elements undergo parameter changes in their output characteristics along the axial direction. The heating power is progressively reduced from the inlet region toward the outlet region, creating a gradient that matches the temperature profile of the water flow. This ensures high heating efficiency in colder regions while preventing overheating and lime precipitation in warmer regions near the outlet.
3Use of energy by moving object
If heating elements are positioned to maximize heat coupling into water, then heating efficiency improves, but overheating of water increases calcification risk
Solution Approach 1:
The heating elements are positioned and configured to provide localized heating zones with varying intensities. Maximum heat coupling is achieved near the water inlet where the greatest temperature differential exists, while heating intensity is reduced toward the outlet. This local optimization of heat transfer efficiency prevents water overheating and subsequent calcification on the heating elements themselves.
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 design effectively reduces calcification and maintains efficient heat transfer, enhancing the pump's performance and longevity by ensuring a consistent and controlled heating pattern across the pump chamber.
Implementation Method 1
heating elements (26) are provided on the pump chamber wall (16)
Implementation Method 2
heat coupling into the pumped liquid
Data Source
Figure 1
Figure 2~4
Figure 5~7
AI summary
A pump for a dishwasher is designed as an impeller pump with a central water inlet onto a rotating impeller in order to displace the water out of the impeller into a pump chamber in a radial direction, said pump chamber annularly surrounding the impeller and having a heated pump chamber wall on the outer face of the pump chamber. The pump has an outlet in the end region of the pump chamber at an axial distance from the impeller. Heating elements are arranged on the pump chamber wall, said heating elements having an output which decreases with respect to the output per unit area in the axial direction of the pump towards the outlet. Thus, an energy input can be varied dependent on a turbulent or laminar flow in the pump chamber and thereby adapted.