Fuel Flow Meter

[ndavid79]

Did some google research on IV drip chambers, check this out:
IV Administration Set 10 Drops/ml 72" Long
Not only dirt cheap, but at 10 drops/ml, thats 3.3 drops/sec at 20ml/mins. Looks doable.

Water & Veg oil, good idea, I'll see what we can do.

ETS: looks like they'll ship to practically any country.

[dubbleUJay]

Not only dirt cheap, but at 10 drops/ml, thats 3.3 drops/sec at 20ml/mins. Looks doable.

David, this IV seems to be 10drops = 1 milliliter (1cm3) of fluid, but I cannot see the flow-rate anywhere

How did the experiment go with the tube? I hope you didn't use your own one!

dubbleUJay

Post amended:
Now this looks very interesting for a standalone application!
http://www.freepatentsonline.com/4681569.pdf (291kb)
I don't know if they are available commercially though, does someone in the US knows?
With a bit of tinkering the idea will work for my PC application, I particularly like the way that it reads the drops!
Still, now to find an IV that will give the required flow-rate

[ndavid79]

David, this IV seems to be 10drops = 1 milliliter (1cm3) of fluid, but I cannot see the flow-rate anywhere

Ya, unfortunately I haven't found that spec anywhere, for any such device. But I think 3 drops a sec is doable

How did the experiment go with the tube? I hope you didn't use your own one!

Haven't gotten to do it yet, maybe tomorrow! No, it won't be connected to me, lol. 
I plan to use a plain bag, hook it up to a suction pump with a reservoir to simulate an engine's fuel pump, & adjust the bag's flow clamp to find where drips become a stream. Then adjust back to max drip rate and time a 100ml via tick marks on the bag (don't know the drops per ml on these).

[dubbleUJay]

David, this IV seems to be 10drops = 1 milliliter (1cm3) of fluid, but I cannot see the flow-rate anywhere

Ya, unfortunately I haven't found that spec anywhere, for any such device. But I think 3 drops a sec is doable

OK, I see what you meant, I thought you were under the impression that the 10drops/ml mean it will give a flow-rate of 3drops/sec

Obviously you were referring to what WE actually need.
I probably sometimes come across as a bit  , but English isn't my 1st language and I've got to read stuff a few times!

Did you look at the Pattern for a drop counter in this link?
http://www.freepatentsonline.com/4681569.pdf

I amended my post & I'm not sure you saw it.
Not exactly what we need, but a start. I haven't seen anything like it in ZA hospitals, maybe by you guys?

dubbleUJay

[Carlb]

if anyone has an old weather station with a rain gauge you could probably convert the inches of rain into gallons of fuel,  just an idea,  by the way I do have one around and I will give it a test when I get back from Vacation.

[dubbleUJay]

Hi Carlb, not to shoot you down, but we're trying to automate it as far as possible to either an digital meter or for that matter a data logger in the most affordable and simple way if possible.

Enjoy your vacation, some of us has to fiddle with µCogen stuff to relax!

dubbleUJay

[ndavid79]

1st test with water done!
At fastest drip rate (that was quite visible), it flowed 100ml in 3:30, which by my math is 28ml a min. Visible estimate of drip rate, ~4 a sec.

[Carlb]

Hi Carlb, not to shoot you down, but we're trying to automate it as far as possible to either an digital meter or for that matter a data logger in the most affordable and simple way if possible.

Enjoy your vacation, some of us has to fiddle with µCogen stuff to relax!

dubbleUJay

I had to take my vacation this week, I am starting my 11.2kw ground mount solar array install next week (that will give me a total of 22.2kw of solar panels on my property)when I get back from vacation.

this internal workings of the rain gauge i am talking about is exactly the same principle as what is being discussed here with the swinging see/saw microswitch, each time the water comes down the center of he rain gauge housing it flip flops the see/saw and trips the microswitch.  Just a thought

carl

carl

[dubbleUJay]

Hi Carl, I wish I had some more solar, only 2x 75w panels on this side and we have ample sunshine in South Africa, but as always (in my case anyway), $$$ talk!  

The idea for the "see/saw" came from a rain gauge, it will work I'm sure, but it seems that the general feeling in this thread is that it might not be very accurate, or as accurate as David's IV drip-meter.

David's idea seems to be the best one so far if it works IMHO anyway.
Lets see what he comes up with and take it from there, we might come back to the rain gauge, I don't know at this stage.

Good luck with the solar installation, please open a thread in this forum about your progress, I for one would be very interested and I'm sure a lot of other guys as well.

[dubbleUJay]

1st test with water done!
At fastest drip rate (that was quite visible), it flowed 100ml in 3:30, which by my math is 28ml a min. Visible estimate of drip rate, ~4 a sec.

Great David, now I suppose that the "proof is in the pudding" if it works with VO! 
Water: 100ml in 210sec= 0.476ml/sec and that's 28.57ml/min, you're quite correct!
I've got a feeling that the VO will be substantially less, but I'm sure if the orifice of the dripper is made bigger we can get an acceptable drip-rate for VO.
I wish I had the formula that the guys use to make these with, I presume it has to do with the surface tension of the fluid as well, but this will probably be a hit&miss thingy!

I'll wait till you come back with the VO test run and then I'll probably built one here, I've got some clear PVC piping with removable end-caps that might work, we'll see.

dubbleUJay

[cognos]

I'll be very curious to see if the low surface tension of any oil will allow much dripping to be measured. I think there will be a tendency to "stream" at anything but very small draw rates...

I wish you well...

In the trade, very low flows are measured by differential pressure across an appropriately sized orifice plate in the line. After calibration, these are extremely accurate... but pricey...

[dubbleUJay]

Cognos, I saw those somewhere and clicked away when I saw the costs! Also I don't think there was a way to make them DIY, but maybe I should look at it again if the drip-meter doesn't work, I forgot about those, thanx! 
I think it was when I was looking for an oil pressure/flow sensor for the low pressure from the ListerCS oil pump IIRC.

[BruceM]

Orifice sizing should handle the oil viscosity issue , I think.  You can buy an IV drip set at any drug store here in the US without a needle.

Viscosity of oil varies with temperature, so for good accuracy, you will have to calibrate with a measure at a range of temperatures, and add fuel temperature to your drip table lookup for calculations.  The fuel temp might be measured with an epoxy puttied LM34/35 right near the dripper (stuck in a cut off barb Tee).

The beauty of the IV dripper is the demand vacuum regulated flow rate, the gravity tilt doesn't get you that. 

[quinnf]

One thing to watch is the tubing length.  My idea was that you'd probably want to cut most of the tubing off the drip set, perhaps keep the flow shutoff/regulator, though.  If you know a nurse, you should be able to sweet talk a used IV administration set or two out of her/him.  It will contain a drip chamber and a flow regulator/shutoff.

You can adapt to the tubing with barbed fittings available for vacuum lines at the auto parts store.

Quinn

[dubbleUJay]

In the trade, very low flows are measured by differential pressure across an appropriately sized orifice plate in the line. After calibration, these are extremely accurate...

Cognos (or anyone else for that matter), I'm off topic now, but can fluid pressure be "amplified" by hydraulic action?
In other words, can I use a sort of master/slave setup on a low-pressure line to amplify the pressure proportionally and use a pressure gauge of higher calibration and work out the pressure from a pre-defined chart

dubbleUJay
PS-I'm still going to find a way to read my "low" oil pressure on my CS!