Washing Machine Drain Duct Layout to Prevent Siphon Emptying
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing washing machine discharge systems are prone to the 'siphon effect' due to prolonged activation of the discharge pump, leading to unintended emptying of the liquid content from the tub, caused by sudden voltage changes or control electronics drifts.
Innovation Solution
Incorporating an auxiliary duct branching off from the lower transition region of the discharge duct, which allows pressurized air to be introduced and split the water flow, preventing the siphon effect by equalizing pressure and ensuring the buoyant open/close element occludes the upper valve seat.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the discharge pump is activated to raise liquid level in the discharge duct to prevent washing agent loss, then the washing agent retention in tub is improved, but the pump may remain active too long causing excessive liquid rise and triggering siphon effect
Solution Approach 1:
The patent introduces a buoyant open/close element as an intermediary device that automatically responds to liquid level changes in the discharge duct. This element mediates between the pump operation and the tub discharge opening, closing the opening when liquid level rises excessively and preventing siphon effect without requiring complex pump control mechanisms.
Solution Approach 2:
The buoyant open/close element operates autonomously based on liquid level conditions. When the liquid level in the discharge duct rises above a certain threshold, the buoyant element automatically rises and occludes the discharge opening, preventing further liquid loss without external intervention or complex control systems.
2Loss of substance
If the discharge pump activation time is extended to ensure proper liquid level, then the washing agent retention is improved, but the risk of triggering siphon effect increases
Solution Approach 1:
The patent applies preliminary anti-action by having the buoyant open/close element ready to close the discharge opening before excessive liquid rise can trigger siphon effect. The element proactively responds to rising liquid levels by occluding the opening, preventing the harmful siphon effect from occurring in the first place.
Solution Approach 2:
The buoyant open/close element provides automatic feedback control based on liquid level in the discharge duct. When liquid level rises and contacts the buoyant element, it triggers immediate closure of the discharge opening, creating a feedback mechanism that prevents both washing agent loss and siphon effect.
3Loss of substance
If the discharge pump is activated briefly to prevent washing agent loss, then washing agent retention is improved, but insufficient activation may not prevent liquid reflux
Solution Approach 1:
The buoyant open/close element acts as a mediator that provides dual protection: it prevents washing agent loss by closing the discharge opening when liquid level rises, and simultaneously prevents liquid reflux from drains by maintaining the closure during pump operation. This single intermediary device addresses both harmful effects.
Solution Approach 2:
The buoyant open/close element automatically adjusts its position based on liquid level, providing self-service protection against both washing agent loss and liquid reflux without requiring complex control logic or multiple active components.
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 solution effectively prevents the siphon effect by ensuring the buoyant open/close element occludes the upper valve seat, preventing further liquid exit during agitation, thus maintaining the washing agent and water within the tub during the washing cycle.
Implementation Method 1
the buoyant open/close element is in any case maintained by hydrostatic thrust at the lower valve seat
Implementation Method 2
activate briefly the discharge pump, for example for a couple of seconds, to cause part of the liquid to rise further in the discharge pipe
Implementation Method 3
triggering of the so-called 'siphon effect': in practice, after the water has exceeded the uppermost point of the duct, it starts to flow out along the descending stretch of the duct itself
Data Source
AI summary
A washing machine has a control system, a treatment tub (3) with a discharge opening (12), a washing-agent dispenser device, an arrangement for loading liquid into the tub (3), a discharge duct (14) having an inlet connected to the discharge opening (12) of the tub (3),and a pump (16) along the discharge duct (14). The discharge duct (14) has a substantially S-shaped development, with a lower transition region (14a) and an upper transition region (14b), the transition regions (14a, 14b) being in an intermediate position with respect to the inlet and to an outlet of the discharge duct (14). One of the discharge duct (14) and the tub (3) has a valve arrangement (17) that includes a buoyant body (17a) and that is operative substantially at the discharge outlet (12) of the tub (3). The control system (6) is pre-arranged for controlling activation of the pump (17) in the course of a process of loading of liquid (W) into the tub (3), and the valve arrangement (17) is pre-arranged for preventing outflow of liquid from the discharge opening (12) of the tub (3) when the level of the liquid (W) in the discharge duct (14) is at a height that is greater than the level of the liquid (W) in the tub (3) and that is comprised between the lower transition region (14a) and the upper transition region (14b). In the lower transition region (14a), branching off upwards from the discharge duct (14) is an auxiliary duct (20) that is closed at its upper end (20a).