Prominent Gamma/L 0232 Flow Rate Test
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The curve is actually slightly nonlinear (concave up). You can see this if you use a ruler.
I tried to sample the data with an optical recognition software and extrapolating a 3rd degree polynomial fit to 0 bar:
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No it doesn't.IF you set the pump to its maximum operating parameters (180 strokes/min, 100% stroke length) and provide 2 Bars Back-pressure
THEN Prominent GUARANTEES that it will deliver AT LEAST (MINIMUM) 32 l/hr.IF you provide 1 bar Back-Pressure then Prominent GUARANTEES that it will deliver AT LEAST (MINIMUM) 36 l/hr. (36 from memory)
You may well limit yourself to using it within these guidelines.
You may well call this the "practical maximum"BUT I have shown that if you bend the rules you can get 35% more flow (measured for MY pump).
OK, we agree on what the pump specs mean. So if that isn't helpful to you, I'm confused as to why. But whatever.
Thanks for showing us how it performs when you 'bend the rules'.
Because if it's outside the spec, then empirical evidence is the most reliable way to characterize the pump's performance.
I really do appreciate your efforts.
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I tried to sample the data with an optical recognition software and extrapolating a 3rd degree polynomial fit to 0 bar:
Nice! If this reasonably estimates the correction factor (and it looks good but this is extrapolating so there is always that important caveat), this would yield 36 * 1.21 = 43.6 l/h at 0 bar.
Which would make my 42 l/h bet out of the money (depending on which back-pressure value that Rossi gave - .15 bar or 0 bar) and put me back to Quatloo beggar status.
But it would also be a flow rate that is not reconcilable with Penon's report, and it would be consistent with Smith's overall conclusions, even if he underestimated the maximum flow.
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This is why I bet Quatloos that Alan will measure less than 42 l/h. I've given some substantial error margin for measurement, to be safe.
Looks like you owe me those quatloos now as well (or more appropriately, you probably owe them to Alan F. for all of his efforts).
So we are now at > 42 l/h at effectively 0 bar back pressure. And just over 33 l/h at only ~0.15 bar back pressure, which indicates that this specific pump is likely under performing. With these latest tests, I agree with Alan F. that it is well worth continuing (as long as Alan F. is willing to continue contributing his time to the increase and betterment of our body of knowledge), preferably with Alan S.'s adjustable back pressure valve near the front of the queue. Then followed up with a simulated head pressure, possibly by raising the intake tank above the pump.
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Bruce__H, you may be right. But I think it is very important, conceptually, to distinguish between what might have been measured in Doral, and what was claimed to have been measured in Doral. (E.g., 0 bar pressure, 70C, etc.)
Hi Eric. The 0 bar pressure I am referring to is the water backpressure on the outlets of the Prominent pumps sitting beside the Big Frankies. You appear to be thinking of the "0 bar" that is often quoted as the steam pressure at the outlet of the entire ECat plant. That isn't what I was referring to though.
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What document is that from? (Fig 64).
I've done a bit of good-old-fashioned eyeballing :I just extended the scale left from 0.5 bar down to 0.0 bar.
(A) is the original curve(B) are my results (scaled to k = 1 at 1 bar or 36 l/hr) On the face of it, my pump is underperforming. Sloppy diaphragm?
But I don't give up easily :
(C) extrapolate their curve and then tack on mine at 0,15 bar.
(D) But there are indications (see above) that theirs is non-linear. (Just a wild guess which looks pretty) and then continue with my curve. I read that as about k = 1.5 or 54 l/hr when corrected.
This is getting pretty close to one of the RossiSeztm which is 60 l/hr ??
EDIT : I think I goofed on adding in my curves. I just added them to the end of the extrapolated Prominent curve "(A)".
I should SCALE the 0.15 bar value to match the curve and then SCALE the 0 bar point by the same amount.
Version 2 coming up soon.Edit 2 : I haven't replotted it, but my 0-bar point moves up to k = 1.55 -- giving 56 l/hr.
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This is getting pretty close to one of the RossiSeztm which is 60 l/hr ??
I think that Rossi does say 60 L/H somewhere. But in Mats Lewan's article he gives the figure of 72 L/H, and in his sworn deposition where he represented Leonardo corporation he thought the top pumping rate was 100 L/H
"These pumps have a capacity. Each of these pumps, we have calibrated them. I have calibrated them together with ‐‐ with Barry and with Fabiani when we started, just to be sure. They have a capacity, if I remember well, starts from zero to 100 liters per hour each. So basically we had a capacity of 600 liters per hour with all the six pumps in full ‐‐ in full power for each BF." (from doc 326 on the RvD docket)
So it is a bit of a moving target.
In terms of accounting for Penon's stated flow results of 36,000 L/day, what is needed is 62.5 L/H on days at Doral when all Big Frankies with their 24 pumps are working. But that number needs to go up to 83.3 L/H on days such as October 14, 2015 when Penon reported 36,000 L were pumped but when only 18 pumps were in action because one of the Biug Frankies had been shut down.
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NOTE: I'm treating the discharge height as back-pressure. Is that right?
Seems correct. I think however, that some people might add in any suction at the inlet. So, for instance, if you have a 1 m column of water at the discharge side and the pump is drawing up water from a reservoir 0.5 m below it, the entire backpressure could be calculated as equivalent to 1.5 metres of water. I get the impression that the Prominent literature does not do this but it is not clear.
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Seems correct. I think however, that some people might add in any suction at the inlet. So, for instance, if you have a 1 m column of water at the discharge side and the pump is drawing up water from a reservoir 0.5 m below it, the entire backpressure could be calculated as equivalent to 1.5 metres of water. I get the impression that the Prominent literature does not do this but it is not clear.
That is correct. The total lift height of the water column has to be paid for- no free rides.
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But one of the things that confuses me is the picture (2017 Catalog) of a suggested set-up, which is basically what I have:
Note "10 Manometer for precise adjustment of the back pressure valve".
That is measuring pressure on the discharge only. It has NO idea what's happening on the suction side.
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But one of the things that confuses me is the picture (2017 Catalog) of a suggested set-up, which is basically what I have
Alan,
Since you are the owner of a Prominent pump you should have the right to contact the technical support and discuss the "confusions" you have with them
Technical Support Tier 1
Please call 412-787-2484 or email [email protected] and you will be directed to the appropriate technical representative. -
Note "10 Manometer for precise adjustment of the back pressure valve".
That is measuring pressure on the discharge only. It has NO idea what's happening on the suction side.
I think you are right on the money here. Prominent does not seem to include inlet pressure in its definition of back pressure.
Good clarification!
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That is correct. The total lift height of the water column has to be paid for- no free rides.
Has to be paid for in electric energy to operate the pump.
However I disagree about adding the negative column seize at the inlet with the column height at the outlet (But correct me if I am wrong)
Why ? Because when the pump is pulling the water in, the outlet valve is closed and the water column at the inlet will not see the column height at the outlet.
And when pushing the water out of the pump, the inlet valve will be closed and the water column at the outlet will not see the column at the inlet.
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Please call 412-787-2484 or email [email protected] and you will be directed to the appropriate technical representative.
eMail sent.
Edit : we are not alone in our confusion. eg http://www.eng-tips.com/viewthread.cfm?qid=326076
This response is interesting :
QuoteDisplay Morebimr (Civil/Environmental)17 Jul 12 16:59A
pump can not develop pressure unless the piping system creates backpressure (ie: Static (vertical height), and /or friction loss). Therefore the performance of a pump can not be estimated without knowing full details of the system in which it will be operating.
Back pressure is not important to positive displacement pumps. Positive displacement pump provides an approximate constant flow at fixed speed, despite changes in the back pressure. Changing back pressure on a positive dieplacement pump results in a minimal flow change.
However, the flow of a centrifugal pump will change considerably with back pressure.
Back pressure is simply the resistance to fluid flow in a piping system. Back pressure is measured by obtaining the discharge head of the operating pump.
I agree with everything he says ... until his last sentence (my bold, not his) ... where he reverts to "head". They all discount the suction end, though.
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Question : Can you please clarify exactly what the manual means by "back pressure" ... is it JUST the pressure at the discharge end (eg a 5 foot head of water = 0.15 bar), or does it depend in some way on the pressure at the suction port?
Can you also ask them under which exact circumstances the pump can achieve several times the stated feed rate.
