Fuel Flow Meter

[ndavid79]

If I still have a bag for my old food pump, I'll see how fast it can flow while maintaining drops, by this weekend.

The air (or a purge gas) in the top half is a critical part of the system... As the pump draws the level of the fluid in the lower half down, the air pressure inside reduces, inducing another drip to replenish.

[dubbleUJay]

If I still have a bag for my old food pump, I'll see how fast it can flow while maintaining drops, by this weekend.

The air (or a purge gas) in the top half is a critical part of the system... As the pump draws the level of the fluid in the lower half down, the air pressure inside reduces, inducing another drip to replenish.

OK Dave, if I may ask, what is a food pump
It probably has another name over here, but I cannot place it!

[ndavid79]

I have whats called a g-tube style feeding tube, for my primary nutrition (due to my Duchenne MD, I can't swallow enough to maintain weight).. The food pump I'm referring to pumps formula from a refillable bag, and through the g-tube at a user set rate, much like an IV pump.
Kangaroo Feeding Pumps, the 2100 looks my old one (recently got switched to a different style pump).
The Kangaroo pump uses a drip meter to watch its own flow rate & detect a plugged line or closed valve.

[dubbleUJay]

I had no idea it was a medical device David, thanks for that info. I actually was under the impression that its something used in the kitchen!!!
I just hope we wont infringe on any copyright stuff if we make one to feed "food" to out engines though.

[mobile_bob]

how do you figure a changfa uses a lot more fuel than a lister/oid?

my bet is a 12hp changfa 195 will compete very favorably with a 12hp lister/oid at full load particularly
and maybe across the load spectrum as well,

curious how you arrived at that conclusion

bob g

[dubbleUJay]

how do you figure a changfa uses a lot more fuel than a lister/oid?

my bet is a 12hp changfa 195 will compete very favorably with a 12hp lister/oid at full load particularly
and maybe across the load spectrum as well,

curious how you arrived at that conclusion

bob g

Hi Bob, I've got a feelin' your smileys are turned off ??
I just about bit my tong off when I stuck it in my cheek while writing that "comment" ;-) Sorry!

[mobile_bob]

GOTCHA!!!!




bob g

[Cornelius]

Now, i have no idea if this one would work, but i do see the possibilities.... (See pictures...)
Inside, there's a rotor with 6 blades, which spins very fast when blowing very lightly into it. I've never really testet it, but i think it is a part of some soda/beer dispenser system...

It needs some power (4,5v-24v) input, and there's some magnets on the rotor, which i guess gives pulses when it rotates...

Edit:
I found what looks like the specs for the one i have; it's for beverages only, and have a min. flow of 0,22 liter/min, but they do have similar flow meters for oils etc with min. 0,06 liter/min.: http://www.digmesa.com/digmesa/upload/pdf/FF/934-2540_GB.pdf

[Cornelius]

There's jewelled bearings, and they're easy to disassemble for easy cleaning (just twist apart), so i think they're rather tough...

Yes, 3,6 litres/hour would probably be in the upper range for several of our engines, but with two of these; one on the input side, and one on the return, the flow would be much more than that, and the difference would be fuel consumption...

[dubbleUJay]

Guys, so far it seems that even a commercial unit are hard to come by if available!
ndavid79's idea with an IV drip meter seems "practical" in theory.

Something that might be considered, also indirectly from one of the links David provided on another thread:
http://www.edcheung.com/automa/rain.htm

A DIY electronic rain meter, obviously not to that scale and probably inside the Drip Meter to auto-regulate the flow.

Would that be to complicated to manufacture with regularly available "stuff"?
This should give an accurate output over a short time, depending on the size of the 2x "containers" to fill
Almost like Bob's weighing idea.

dubbleUJay
PS-OK shoot the idea down! 

[dubbleUJay]

Jens, I though this idea might "tickle your fancy"

I was thinking though of incorporating the tipping buckets INSIDE a drip tube (sort of a "vacuum" as in an real IV, "vacuum" is not the right word, probably a set volume of air) so that the drip-rate would work automatically as David explained before and using it directly inline with one's current fuel supply.
This will stop us having to worry about start/stop of the drops as the fuel demand changes.

I just don't know if it will work on a bigger scale and if it can be done easily.

The electronics involved would be simplistic, just a switch/mag/IR-gap or such to count the tipping of the buckets and multiply that with the volume per bucket. (I presume the electronics should be on the outside "looking" through the glass or whatever)
Obviously the smaller the buckets, the better.

I've got to think some more!  Maybe it cannot be done easily and a cutoff like you said would do the trick!

dubbleUJay
PS- If all goes well, the guys from East will  steal" this idea and we can buy it over the counter next month!

[dubbleUJay]

OK guys, while you's in the US were sleeping, I did a test 2day. (I'm about 8h's ahead here in ZA!)
Here's a short description of an "alpha" drip-counter I made this morning:
(Picture at the bottom, bit out of focus, sorry)
I took a piece of 20mm ID PVC pipe and worked out that I need a piece 63mm in length to get a volume of approximately 20cm3 in the whole tube (1ml = 1cm3)
Then I cut it in half at an angle of about 33.3deg and glued the 2 pieces back to back onto a thin flat piece of plastic.
The plastic piece in the middle of the 2 angled pipes extrude at the bottom of the whole "thingy"
I started to cut it shorter in stages to find a medium where it will tilt when full. Not sientific, but it sticks out about 1/3 of the OD of the pipe.

This is how it operates:(Its my 1st vid on uTube, so please excuse the quality!)
http://www.youtube.com/watch?v=-QzedNZP1_k
It difficult to see, but I accelerated the water to a stream (not dripping) to illustrate the action faster.
I've made a mistake with my calculations somewhere I think as it only takes 5ml to tilt it to one side, but then it also does not fill up completely before it toggles.
Now I need to put this at the top inside a sealed container with inlet/outlet top/bottom and hope it does not flood the whole container past the counter

dubbleUJay

[quinnf]

Ndavid79 has a good idear.  My mom-in-law is on a feeding tube.  And wife is a nurse, and brings old IV solution sets home to hydrate her 20 year old cat with failing kidneys.  So I'm familiar with the setup.

It seems you could use an IV drip chamber http://www.stockphotospot.com/iv-infusion-drip-chamber-stock-photo-a24812.jpg and place an IR LED on one side, and a detector on the other side (cheap at Radio Shack), and use the output to trigger a transistor to pass a pulse of 12V to trigger a $7 electronic counter https://www.surpluscenter.com/item.asp?UID=2009112012282149&item=21-1498&catname= ? 

Then you could calibrate by counting the number of drops required to total whatever unit of measure you are comfortable with (mL, ozs.?) and convert drops to volume or weight of fuel.  Drop size for diesel will depend on temperature and surface tension of the particular fuel you're using.  Then count number of drops per unit time and calculate the flow rate.

Place the IV drip chamber between the tank and fuel filter and (I think) the air contained within the chamber should dampen out the pulses caused by the injection pump. 

Quinn

[BruceM]

I like NDavid's idea and I agree with Quinn, the drip measurement is going to be much more accurate than tilt buckets, and if you can't get the flow rate, just add a second unit.  

I played with an IR LED and phototransistor around a dripper many years ago. It does work with water and I don't think fuel would make a difference.

[dubbleUJay]

One thing that I am concerned about .... let's say you require 10 ml to tip the bucket. You have 9.5 ml in the bucket and an additional drop comes in giving you 10.5 ml and the bucket tips. You would register only 10 ml.
Jens

Jens, one will have to let the thing run over a longer time period and then divide the volume of fuel versus the amount of tilts to get an average. Each DIY "tilter" is different, because its so difficult to get both sides exactly the same and also the center of gravity.
That said, one should be able to get a very accurate average, I would thing to a resolution of 5ml per tilt.

Anyway, my experiment might be retired to my weather station in the future, (I was looking for something with a finer resolution as we dont get to much rain here) if David's drip meter can supply 20ml of fuel per minute without turning into a "stream" of fluid.
That will save a lot of hassles. (He mentioned he will try and have a look at it this weekend, I just hope it does work.)

David, if you do see this post before you try it, do you perhaps have some vegetable oil you can try in it once it does work with something thin like water? That should be the 2 extremes that we might use. Even if it does not work with your tube, I'm sure we can make something that will, its just nice to have some type of dimensions to start off with

dubbleUJay