Prominent Gamma/L 0232 Flow Rate Test

  • IH Fanboy and I have a project : I have ordered a used Prominent Gamma/L 0232 and will test the flow rate.


    Edit: I'm fronting the purchase (large credit line, low cash flow) IH Fanboy is covering my costs/losses ... at the end of the project I'll probably re-sell it on eBay.


    Smith Sez 32l/hr (misreading MINIMUM and MAXIMUM)

    RossiSez(tm) 75l/hr.

    Edit: Spec sez ... (complicated graphs for backpressure etc etc ...) I sez : F* the specs -- I'm an experimentalist first.

    Pump says ...


    Stay tuned.

  • Phase 1 :


    Set to maximum flow rate : maximum stroke, maximum stroke count.

    Will just pump from a bucket and time the outflow into a highly-callibrated receptacle, like a quart jar or something.
    Start with output tube level with the pump. Increase 10cm up to about 2m

  • This IS the microcontroller model. Won't be using the data ports, just the manual settings.

    I initially considered buying the manual model ... same pump ($50+) OR the similar Gamma/4 OR a different flow-rate/pressure version for $60.

    But with IHFB's support I've gone high class.

  • Yes I kinda agree with this. But I would also see if anything other made claims people are interested in that can be tested. I would like to nail this down a bit before more replicators spend more time and address all the complaints at once. Just my 2cts.

  • Phase 2 : I'll adjust the flow rate to match Penon's report.


    Phase 3 : I'll run the project at (est) $20/month at that setting to see what the variation is. This is to disprove Jed's claim that the constant flow-meter reading can't be true.

    This needs a bit more equipment/instrumentation ... probably just a tipping-bucket rain gauge, a camera stream and a bit'o'software.

  • I can't see this pump doing more than 45 L/h going flat out 0.2 bar, water practically falling through it.


    From the remarks of Rossi in his comments the pressure was .1 Bar.

    Given .1 bar my guess is about 55 L/h.

    However Rossi stated that there was an additional effect of the re-circulation pump


    So if somebody is going to test the Prominent, then don't forget to also add a re-circulation pump, otherwise the test will not be an equivalent one.

  • Nice idea.


    I haven't looked at pumps since college, but some thoughts for what they're worth...


    This is a solenoid pump, they are designed for reproducible flow rates over large pressure ranges. I think Rossi is purposely making a big deal of the pressure dependence knowing full well it is mostly relevant for centrifugal pumps. The pump manual shows a capacity correction factor of 1.1 for 0.5 bar relative to 1 bar, with a very slow increase with reducing pressure. It is highly unlikely that it will increase above 1.2 for pressures of 0.1 or 0.2 bar (I haven't looked at the test system but these pressures seem quite low for any system involving work or losses) leading to an optimistic capacity of 43.2 l/h at max stroke and rate. Connecting other pumps etc shouldn't make a difference here, the flow is driven by a moving diaphragm in a fixed size container with inflow and outflow stopper valves, this is very different to a centrifugal pump. There is no chance in hell of reaching 75 l/h without using trickery to exceed the max stroke rate, as the container surrounding the diaphragm would need to be nearly twice the volume that it currently is for this to happen.


    Regarding the 'minimum' capacity, this is more word-play. Minimum here is the manufacturer saying that they guarantee the capacity won't be below this for water at a certain temp etc. They show an expected range of -5 to+10%, so again being generous that is 1.15*43.2 = 50 l/h absolute tops. I think it is pretty fair to replace 'minimum capacity' with 'expected capacity' here.


    Also I hope the poor pump didn't get too hot with all the excess heat, since its max operating internal and external temps are only about 50 degrees.

  • Thinking aloud here.


    Being in the US I'll work partly in US Gallons. (Numbers are examples ... Ill put them all in a spreadsheet later).


    Initially a 2-tank setup. Maybe about 10 gallons each.

    The maximum expected flow rate is 75l/hr (RossiSez). Let's say 60l/hr, or 1 l/minute

    A liter is 0.26 gallons ... say 0.25 .. so 4 liters to a gallon, 40 liters to a tank.


    Callibration: fill the output tank to about 1/4 and make a mark. Carefully measure 20 liters (5 gals) and make a

    mark every 5 liters : the last mark will be when the tank is 3/4 full.


    Measurement:


    1. set the pump stroke and pulse count (LOOP)

    2. set the outlet height (LOOP)

    3. empty the output tank.

    4. start the pump

    5. based on its reported flow rate (or a spot check into a small container) select the high-mark for timing

    6. when the water crosses the low-mark, start timing (taking into account parallax, meniscus etc etc)

    7. when the water crosses the high-mark, stop timing.

    8. stop the pump

    9. calculate the flow rate

    10. repeat from LOOP 2 and LOOP 1 as desired.


    For a flow of 60l/hr the timed section of 20l will take about 20 minutes.

    At 30l/hr the timed section of 10l will also take about 20 minutes.


    Mark-crossing timing: I'll probably take a video and single-step the frames to the crossing point.

    Timing accuracy will thus be about 1/30 second. Mark accuracy : a couple of mm

    Volume accuracy ... depends on the cross section of the tank * mark accuracy

    I'm guessing at about 1% liters/hour accuracy.
    This will also leave me free (if I have no assistant) to read the liter-counter on the pump.


    I'll try and find a fairly tall output tank.

  • Just to collect the source of the "0.2 bar" number for future reference, it was mentioned in a question of Mats Lewan that he put to Rossi. (Presumably the number came from Rossi at some point earlier in the interview.)

    Eric,


    You are right on the interview with Mats Lewan where indeed .2 Bar is stated

    However that contradicts his published notes about the Smith report in which he states that the average water column height was 1 meter, (or .1 Bar)

  • LDM, I'm not trying to assert that it was 0.2 bar. I just wanted to have the data point on hand for easy reference, and also so that it could be considered as one of the parameter values being tested.


    I personally would not even want to attempt to sort out what the true pressure was on the basis of statements and evidence available to us.

  • Regarding the 'minimum' capacity, this is more word-play. Minimum here is the manufacturer saying that they guarantee the capacity won't be below this for water at a certain temp etc. They show an expected range of -5 to+10%, so again being generous that is 1.15*43.2 = 50 l/h absolute tops. I think it is pretty fair to replace 'minimum capacity' with 'expected capacity' here.


    Good comment. But I would like to point out that Smith clearly went with "Maximum" of 32 l/h in his "expert" report. And Rossi has called him on it.