Dishwasher Pump Venting Mode to Prevent Fluid Recirculation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In water-conducting household appliances like dishwashers, a proportion of rinsing fluid is recirculated back into the sump via the ventilation opening, impairing the delivery rate of the discharge pump during operation.
Innovation Solution
Implementing a venting operating mode where the pump impeller performs intermittent rotational movements to displace gas bubbles into the fluid pump inlet, eliminating the need for a conventional ventilation opening and enhancing the pump's delivery rate by preventing fluid re-entry into the sump.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a ventilation opening is provided in the pump chamber to allow gas to escape after pump shutdown, then the pump impeller can be submerged further into residual fluid for low-noise operation, but rinsing fluid that has already been filtered is passed back into the sump, impairing the delivery rate
Solution Approach 1:
The pump is operated in a venting operating mode before normal operation to actively remove gas bubbles from the pump chamber. This preliminary action ensures that when normal operation begins, the pump chamber is free of gas bubbles that would otherwise cause fluid recirculation through ventilation openings, thereby preventing filtered rinsing fluid from re-entering the sump and maintaining high delivery rate while enabling low-noise operation
2Reliability
If a conventional ventilation opening is used to vent gas from the pump chamber, then gas can escape after pump shutdown, but this creates a pathway for filtered rinsing fluid to re-enter the sump
Solution Approach 1:
The invention eliminates the ventilation opening from the pump chamber design. Instead of providing a permanent opening that allows fluid recirculation, the system extracts the gas venting function and implements it temporarily through a control device that operates the pump in a venting mode before normal operation, removing gas bubbles without creating a pathway for filtered fluid to re-enter the sump
Solution Approach 2:
The pump chamber vents itself through the pump's own operation. By running the pump at high rotational speed in venting operating mode, the pump impeller actively pumps gas bubbles out through the pump inlet, using the pump's own pumping action to clear the chamber without requiring a separate ventilation pathway that could allow fluid recirculation
3Productivity
If the pump operates continuously in normal mode, then maximum delivery rate is achieved, but gas bubbles remain in the pump chamber causing fluid recirculation
Solution Approach 1:
The pump operation is divided into periodic phases: a venting operating mode phase followed by a normal operation phase. During the venting phase, the pump runs at high rotational speed to remove gas bubbles. This periodic alternation ensures that gas is removed before normal delivery-critical operation begins, maintaining both high delivery rate and effective gas removal without compromising either function
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 improves the pump's delivery rate by effectively removing residual gas bubbles, allowing for faster and quieter operation with minimal energy consumption and reduced time required for the venting process.
Implementation Method 1
during the venting operating mode the gas bubble is at least partially displaced by the annular flow in the pump, which is produced by the pump
Implementation Method 2
a discharge pump which is connected to a sump on the suction side. A pump chamber, in which a pump impeller runs
Data Source
AI summary
A water-conducting household device, particularly a dishwasher, includes a pump having at least one normal operating mode in which fluid is pumped in a pumping direction, and a venting operating mode which can be carried out before the normal operating mode. The venting operating mode is provided to allow venting of the pump by pumping a gas bubble in opposition to the pumping direction during the normal operating mode at least partially out of a pump chamber of the pump to a fluid pump inlet of the pump.