I'm currently working on a fuel pump project that includes an overflow line. I'm seeking advice on the best method to detect if petrol is overflowing onto the floor. Would you recommend an IR sensor, a radiowave motion sensor, an ultrasonic sensor, or something else?
The fuel will be flowing from the overflow output vertically to the ground, with a fuild thickness of 3-4mm, from a height of 20-30cm. I want to detect that motion to stop the pump.
Any guidance on this project would be greatly appreciated.
Since your tank MUST also have an air vent, I would investigate a differential air pressure sensor. When the gasoline fills the overflow line, the air pressure will be less than the tank air vent.
Please note that the overflow act as an air vent as well, the fuel pump is external to fill up a gas powered rc airplane, only motion type sensor can be used. I tried the SR04 ultrasonic sensor, but the flow if two thin to be detected properly.
That's the whole point of this automation, filling the rc aircraft can take several minutes, so the fuel pump would detect the overflow to stop. Do you think that infrared would be more suitable than ultrasonic sensor?
Suppose that next to the fuel pipe into the tank there's a sucction pipe, succing air until the fuel level gets close to the stop. When fuel enter this tine tube a pressure can be detected. It ough to besimilar to the commersial pumps on the gas stations.
Needs a sucction pump, but no spilling....
The overflow is also the air vent, we can't use pressure sensor, as it would need to stay on the aircraft. The fuel pump is an external device that only connect the filling/emptying tube.
I appreciate your input.
Our main objective is detecting the movement of the fuel dripping from the overflow. It's crucial to note that we cannot employ the following methods for this specific scenario:
Measuring pressure
Monitoring the level of fuel inside the airplane
Tracking the quantity of fuel pumped in
Instead, our focus should be on detecting the fuel dripping from the overflow.
I'm not sure what other ambient noise in the ultrasonic region may be present to interfere but there are industrial drip detection systems that use ultrasound. You could use the receiver module from your SR04 to make a detector.
I meditated on this thread while eating lunch and realized the OP wants to detect a "drip" from the overflow while pumping in a flow of fuel. The overflow rate will = the incoming fuel flow, not a "drip"!
A catch-pan under the vent with a float sensor would be my choice. Another option is a quick-connect on the vent to direct the overflow to a container. Sense when the container starts filling up with fuel.
If your fuel contains ethanol you should be able to sense conductivity. Likely on the floor (or hopefully some container). Or it might work if you push two electrodes into opposite sides of your overflow tube.
The sound that the air bubble created when the fluid hits the liquid in the overflow container is a very distinctive sound. If a microphone is placed in contact with the vessel you should be able to produce a pulse that can be sensed by a microcontroller.
I'd be inclined to lose as little fuel as possible. I guess that's your aim too. I'd have the overflow run down into a vented bottle that's sitting on a sensitive pressure sensor. Find an acceptable range of weight differential that show fuel flow and now just a bit of wind shaking the bottle. Then you can do multiple fillups and when the weight hits a 2nd tolerance level, you'll know that it's full and you can then recover the overflowed fuel.
Just to save anyone the trouble, I did experiment with this in the past, specifically with "Nitro" fuel for RC aircraft (60% methanol, 30% nitromethane, 10% castor-oil / other lubricant).
It would work fine, at first, but the electrodes very quickly become coated with an insulating sludge. My uneducated guess was the lubricant fraction was the issue.
Maybe a square or circle of some stiff - fuel resistant - material with a piezo disc mounted on the underside. Fluid hits disc piezo vibrates and sends pulse to controller. Controller shuts off fuel flow.