High Pressure Fuel Nozzle Vacuum Shut-Off
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Solution Overview
Problem
Conventional fluid dispensing nozzles malfunction at high pressures (above 50 p.s.i.) due to premature shut-off or failure to shut-off fluid flow, caused by inadvertent disablement of the venturi vacuum in the spout adaptor region, leading to fluid backup and improper shut-off mechanisms.
Innovation Solution
The novel high pressure spout assembly incorporates a center axial bore and back-pressure tube in the spout adapter, which limits excess fluid interference with the venturi, ensuring proper vacuum creation and diaphragm activation for accurate shut-off, even at elevated pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional nozzles are used with traditional spout assemblies, then the nozzle operates correctly at low and moderate pressures (below 50 p.s.i.), but the venturi vacuum is inadvertently disabled at high pressures (above 50 p.s.i.), causing premature shut-off or failure to shut-off
Solution Approach 1:
The spout adapter is segmented into multiple functional regions: a first region with radial bores for venturi vacuum generation, a second region with axial bores for fluid passage, and a third region with a center axial bore for vacuum communication. This segmentation isolates the venturi mechanism from high-pressure fluid backup while maintaining vacuum generation capability, allowing reliable operation across both low and high pressure ranges
Solution Approach 2:
The center axial bore acts as an intermediary pathway that communicates the venturi vacuum generated in the first region directly to the diaphragm assembly in the third region. This intermediary channel ensures that the vacuum signal reaches the shut-off mechanism even when the second region is subjected to high pressure fluid flow, preventing premature or failed shut-off
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 solution effectively prevents fluid backup and ensures reliable shut-off at high pressures, maintaining efficient fluid dispensing without premature activation, enhancing nozzle performance across a range of pressure conditions.
Implementation Method 1
The venturi vacuum created in the spout adaptor communicates with the diaphragm to control the operation of the diaphragm. That is, when the vacuum created by the venturi reaches a predetermined strength, the diaphragm will trigger and shut off the flow of fluid through the nozzle.
Implementation Method 2
when the vacuum created by the venturi reaches a predetermined strength, the diaphragm will trigger and shut off the flow of fluid through the nozzle
Data Source
AI summary
An automatic shut-off fluid nozzle having a primary fluid path, a vacuum-actuated fluid shut-off assembly in the fluid path, said shut-off shutting off flow through the fluid path when the pressure chamber is subjected to a predetermined vacuum. The nozzle having a venturi port in said fluid path and connected to a vacuum channel, and a vacuum vent extending away from the vacuum channel, said vacuum vent communicating with a low vacuum environment. The nozzle further having a segregated fluid channel in the primary fluid path, the venturi port communicating with said segregated fluid channel, such that the flow of fluid past the venturi port creates a venturi vacuum in the vacuum channel. The vacuum exhausts the vacuum through the vent port when the vent port is in an open condition, and creates a vacuum in the vacuum-actuated fluid shut-off assembly when said vent port is in a closed condition.