Fuel Dispensing Nozzle Check Valve Residual Fuel
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Solution Overview
Problem
Existing fuel dispensing nozzles retain residual liquid in the spout and vacuum orifice after dispensing is stopped, leading to environmental issues due to volatile organic compounds and hazardous air pollutants, as well as inefficient designs that require complex valves and result in dripping.
Innovation Solution
A liquid-dispensing apparatus with a spout featuring a main channel, a vacuum channel with a fluid-sensitive valve and a check-valve at the venturi, which prevents backflow and residual fuel from entering the vacuum channel, ensuring dry shutoff and minimizing post-dispense fuel retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If existing fuel dispensing nozzle designs are used, then the nozzle can dispense fuel, but residual fuel remains in the spout and vacuum orifice after dispensing is stopped, causing environmental issues
Solution Approach 1:
The patent extracts the harmful residual fuel from the vacuum channel by introducing a check valve that prevents fuel from entering the vacuum channel in the first place. This separates the fuel flow path from the vacuum channel, eliminating the source of residual fuel retention while maintaining the auto-shutoff function.
Solution Approach 2:
The check valve acts as an intermediary element between the venturi and the vacuum channel. It allows the vacuum channel to function for auto-shutoff while blocking the path that would otherwise lead to residual fuel accumulation, thus mediating between the need for fuel dispensing and the need to prevent residual fuel.
2Object-affected harmful factors
If complex valves are added to prevent residual fuel, then residual fuel retention is reduced, but the device complexity increases
Solution Approach 1:
The check valve is a passive component that automatically prevents backflow of fuel into the vacuum channel without requiring external control or complex mechanisms. It serves itself by utilizing the pressure differential to block fuel flow, eliminating the need for additional complex active valves while still preventing dripping.
3Ease of operation
If the vacuum channel is used for auto-shutoff, then dispensing control is achieved, but residual fuel enters the vacuum channel and causes delayed drips
Solution Approach 1:
The patent segments the flow path by introducing a check valve that divides the system into two separate zones: the fuel dispensing path and the vacuum channel. This segmentation allows the vacuum channel to perform its auto-shutoff function while preventing fuel from contaminating it, thus eliminating delayed drips without compromising auto-shutoff operation.
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 reduces residual fuel retention and dripping, enhancing environmental safety by ensuring that fuel nozzles can dispense liquids without leaving behind volatile organic compounds and hazardous air pollutants, and simplifies the design by eliminating the need for complex valves.
Implementation Method 1
at least one check-valve associated with the at least one venturi, wherein the check-valve prevents the backflow of liquid and air through the venturi
Implementation Method 2
a vacuum channel operatively associated with the dispensing apparatus, said vacuum channel having an open end in proximity with the discharge end of the spout and connecting to, and providing a source of intended fluid (e.g., vapor) to, at least one venturi located in proximity to the inlet end of the spout
Data Source
AI summary
Disclosed is a method and apparatus for the dispensing of liquids (e.g., fuel) where the apparatus and method include an improved nozzle that reduces residual liquid retained in the nozzle when dispensing is stopped.