new iwaki pump :D

[skycrane]

hey Maxxx,

talk about an extreme pump from iwaki :D



Part Number: WP-IKMDM-326

Description: Iwaki commercial pump with non-contact bearing system for run dry capability, 7.5 through 20 horsepower capacity, patented spline-pinned impeller design, carbon fiber reinforced, ceramic inner and outer thrust collars, 3 inch inlet and 2 inch outlet, maximum flow is 367 gpm, maximum head is 182 feet, 180 gpm at 49 feet of head, 3500 RPM. :eek:

http://www.customaquatic.com/customaquatic/brandcategory.asp?brandID=IK&catID=wp&offset=45

BTW, if ya have to ask the price.... you cant afford it :toast:

although im not sure even 20 monster cores with panflow's could cool your water :D

[nikhsub1]

BTW it is not new...

[One_Hertz]

6000 bucks.... and you'd need a bix3 just for the heat dump of that pump....

[MaxxxRacer]

BIX3 wouldnt even come close.. try several car radiators with blow fans.

20Hp is ALOT of heat..

And as nik pointed out this is not new.. They have had these style pumps for as long as I have been interested in Iwaki.. and most likely longer...

[cartmanea]

20 Hp is approximately 14.8 kW, but not all that goes to heat. Only the energy that isn't converted to kinetic energy in the water is turned into heat. Basically, the more restrictive your system is, the more heat dump your pump will produce.

[MaxxxRacer]

u serious... wow... i knew it was alot... but 14.8kW..... I take back the several car radiator... more like 10 or so.. lol.

[cartmanea]

edited previous post with an explanation :)

[Bloody_Sorcerer]

basically they require a dedicated AC unit.

[nikhsub1]

Basically, the more restrictive your system is, the more heat dump your pump will produce.
Actually this is quite wrong. The pump will produce the most heat at wide open unrestriced flow, and less heat as restriction goes up. Maxxx and Cathar have done the testing on this.

[cartmanea]

I'll have to think about this. I know pumps work less at zero flow, but at low flow when they are still moving liquid they should be working harder than at optimal flow.

[MaxxxRacer]

Indeed niksub1 is correct... the lower the flow, the less amperage is drawn, and less mechanical heat is created due to less friction from the bearings and whatnot...

I have seen upwards of a 25% decrease in amperage at very low flow/ dead head compared to unrestricted flow..



The pump is brushless.. as are any decent pump.. this means that the pump doesn't know or care how fast it is moving... Thus the pump has no ill effects when the flow is low. if you take apart an Iwaki you will quickly realize that the only thing controlling the pump is a small black box which gives out a particular pulse rate for the motor, and the motor will spin at that rpm no matter what. even if the pump is at dead head the armature will still spin (maybe a bit slower due to magnetic forces of the impeller being slow) at close to full speed and the impeller will be spinning, albeit at a reduced speed.

[cartmanea]

Ok wait, you say less friction in the bearings contributed to this. So were you reducing flow by lowering the electrical power driving the pump or by restricting flow? If you only restrict flow, the pump will run at nearly the same speed, so losses due to friction will be approximately the same.

[Bloody_Sorcerer]

he did it by increasing flow restriction IIRC

[MaxxxRacer]

lower flow through restriction...

yes the pump will be moving at nearly the same speed, but slightly slower.. BUT its moving slow enough to where the power consumption is decreased.. and that is a FACT. you can measure it in the heat dump and with the clampmeter.

[cartmanea]

Ok, and I know how permanent magnet motors work, I'm a graduate student in EE studying motors and power conversion :)

[cartmanea]

Ok, at zero restriction, heat dump is not as high as when the pump is working harder. Heat dump will increase with restriction to a point where the flow is so little that the pump actually receives less restriction by the water, at which point it no longer works hard and heat dump decreases.

[MaxxxRacer]

Thats not what the data says..

[cartmanea]

Ok, here it is, this should make us both happy :)

Electrical power used by a pump increases with restriction until zero flow is achieved. At this point, due to cavitation, etc, the pump receives less restriction by the water and so it is working easier. The increased electrical power, with less converted to kinetic energy in the water, produces more heat energy.

However, the majority of heat dump is not due to the heat produced by the pump, but rather in then energy of the moving liquid. Power gained by a fluid from a pump is given as P=mw; where P=power, m=mass flow rate, and w=specific work. Specific work increases with head, however mass flow rate decreases with the volume flow rate of the liquid. The decrease in flow rate creates a greater decrease in heat dump than the increase caused by head.

So, in regards to heat dump into the water, it decreases with flow rate. However, total energy converted to heat increases. This heat will mostly be confined to the motor and dissipated through the casing and not transferred to the liquid.

Sound good now?

[MaxxxRacer]

Electrical power used by a pump increases with restriction until zero flow is achieved. At this point, due to cavitation, etc, the pump receives less restriction by the water and so it is working easier. The increased electrical power, with less converted to kinetic energy in the water, produces more heat energy.


this is FALSE! Cathar and I can both attest to this...




However, the majority of heat dump is not due to the heat produced by the pump, but rather in then energy of the moving liquid.

Again this is TOTALY false.. before you get serious heat from the friction of water you would need thousands of GPM.. in the low gpm situations we run, the electrical component of the pump is causing the heat... that is a fact.. VERY testable.. ive done a number of tests with this to support my statements.

[cartmanea]

I'm going to have to test a pump myself before I'm satisfied....

Can you show me some scientific data supporting your theories, or is this just what you observed?

[nikhsub1]

cartmanea you are getting this all wrong... centrifigal pumps draw less power as restriction goes UP, this has already been proven, heat from water friction is not going to happen in the pumps we are currently using.

[MaxxxRacer]

I have my threads I created on my testing... I have a clampmeter sitting right next to me... I have REAL test data.. not just observations...

systemcoolings' Lee "robotech" tested the same thing with the 12VDC pumps.. its in one of his reviews wheren he notes the pumps wattage change as flow changes.. i think it was the mcp655..

[cartmanea]

Can you link me to those threads please?

[MaxxxRacer]

http://www.xtremesystems.org/forums/showthread.php?t=64157&highlight=2.9gpm

http://www.xtremesystems.org/forums/showthread.php?t=68760&highlight=brandon

read through those threads and you shall see the light!

[Cathar]

It's quite easy really. Power = torque x RPM.

The amount of power drawn is proportional to the RPM. In centrifugal pumps, as you increase the restriction they start to slow down - you can hear it. The magnetic force (the torque) being applied to the impeller doesn't change, and so power is directly proportional to the rpm. Slower rpm = less power.

There's your answer.

Don't mistake dead-heading a pump for a locked rotor condition of a fixed magnet motor. They are two TOTALLY different scenarios. In a dead-head pump, the motor is not locked, it's just spinning at its slowest because it's working against the highest amount of restriction and all that back pressure slows the rotor down.

[cartmanea]

Double check your sources Cathar...that is mechanical power, quite different from electrical power. The total amount of electrical power has to be equal to the sum of the mechanical power produced and any heat produced. Any electrical power not converted to mechanical power is lost in resistance, heat, etc.

[MaxxxRacer]

cart, he knows that... that is rather elementary..

[Cathar]

/me sighs heavily

If there's less mechanical energy being produced, then is there a corresponding need for as much electrical energy? Think about it. Please. No random theory, think about it.

If you still can't see it, then test it for yourself then mate. Quit flapping stubbornly in the wind.

Until then, I'll leave you with Page 4 of this PDF

http://www.laing.de/10Produkte/40Pumpen/20Gleichstrompumpen/Gleichstrompumpen_Laing_Ecocirc.pdf

Where even the pump manufacturer is showing that electrical power decreases with increased resistance.

[cartmanea]

It's quite easy really. Power = torque x RPM.

The amount of power drawn is proportional to the RPM. In centrifugal pumps, as you increase the restriction they start to slow down - you can hear it. The magnetic force (the torque) being applied to the impeller doesn't change, and so power is directly proportional to the rpm. Slower rpm = less power.
Sorry Cathar, this is the part I had a problem with. You are relating power drawn (electrical power) and saying it is proportional to rpm, this is simply not true. Electrical power is reduced because as the rotor slows down, the effective resistance in the stator is increased which limits the current.

[Cathar]

Additionally, for the Laing DDC

http://www.laing.de/10Produkte/40Pumpen/25GleichDDC/3.gif

[Cathar]

Sorry Cathar, this is the part I had a problem with. You are relating power drawn (electrical power) and saying it is proportional to rpm, this is simply not true. Electrical power is reduced because as the rotor slows down, the effective resistance in the stator is increased which limits the current.

If one observes these pumps in action, with an RPM sensor in place, there is no denying that there is a near direct proportional relationship between RPM and power drawn.

[MaxxxRacer]

The relationship may not be 1:1 but there is an equation for every pump (1 eq. per pump) to explain electrical draw vs. flowrate... and the equation IS directly related..

[shadowing]

At the same time, I seriously have got to wonder who in the world would pay even $6000 for it... :P

[cartmanea]

You guys are taking that info out of context. When they show flow vs. power like that, power is the variable. Just because flow varies with input power like that doesn't mean restricting flow will control input power the same in a proportional relationship.

[Cathar]

You guys are taking that info out of context. When they show flow vs. power like that, power is the variable. Just because flow varies with input power like that doesn't mean restricting flow will control input power the same in a proportional relationship.

FFS mate - what will it take to convince you? You're like a dog with a bone here and won't give it up. You're talking to people who have seen and measured this effect in action, have witnessed it take place, have witnessed that the pumps draw less power and dump less heat as the level of restriction is increased, yet for everything we throw out to you, you keep on stubbornly denying it.

I, for one, give up. If you don't want to believe it, then I suggest you try it with a decent multi-meter and any DC powered pump with a fixed voltage supply PSU, just like I and many others have done.

It boils down to this. Reality doesn't care how convinced you are that you are right and we're all wrong, the simple reality is that as the level of restriction is increased, the level of current draw (amperage, I) drops off. Now since voltage is held constant, and P=VI, you do the math.

We're not misinterpreting anything. You're just refusing to believe it. Would suggest that before continuing on this path that you first check with reality rather than continuing to spout what you believe.

[MaxxxRacer]

Quote of the day goes to Stew

"It boils down to this. Reality doesn't care how convinced you are that you are right and we're all wrong."

P=VI
P=torque * RPM

set p to an abitrary 24.. with the voltage being 12volts

24 = 12volts * 2 amps
24 = 1 torqe * 24RPM.

now lets put some restriction on it and slow down the pump... see what happens..

X<24
torqe = 0.5 (torque goes down as RPM goes down)
RPM = 15.0 we all know RPM goes down when the flowrate goes down

X = 12volts * Z amps
X = 0.5 * 15 RPM

now lets solve for X and Z...

X = 7.5 Power
Z = 0.625 Amps


viola... there you have it.. we gave it to you in plain english, now I give it to you in math.. If you dont believe now, I suggest you break out the multimeter and a pump and have at it...

[cartmanea]

I believe that the pump performs that way, but the data you were showing me was taken out of context, I just wanted to point that out.

[Cathar]

I believe that the pump performs that way, but the data you were showing me was taken out of context, I just wanted to point that out.

How so? It's a graph of the PQ (Pressure/Flow) curve and wattage consumed given a fixed 12v input. Pressure equates to restriction. It's graphing what the flow is against some level of restriction with a fixed 12v input.

How can it possibly be taken out of context?

To suggest otherwise would be to suggest that they're reducing the voltage since P=VI and you're arguing that P goes up with restriction, and so if P is going down then V must be going down too, and now THAT would be taking the meaning of that graph out of context.

[MaxxxRacer]

and cathar I though you said you were done :p:

[cartmanea]

Sorry, I don't speak German, or whatever that is, I didn't realize they were at a fixed 12v.

[Cathar]

and cathar I though you said you were done :p:

I was done trying to convince him. He brought up a different point. ;) :nono:

[MaxxxRacer]

loophole...cathar.... loophole... :lol:

[greenman100]

Don't mistake dead-heading a pump for a locked rotor condition of a fixed magnet motor. They are two TOTALLY different scenarios. In a dead-head pump, the motor is not locked, it's just spinning at its slowest because it's working against the highest amount of restriction and all that back pressure slows the rotor down.


An excellent point.

A DC fixed magnet motor produces max torque and max current draw at 0RPM.

An interesting concept, when applied to electric cars.

[greenman100]

You guys are taking that info out of context. When they show flow vs. power like that, power is the variable. Just because flow varies with input power like that doesn't mean restricting flow will control input power the same in a proportional relationship.
it is basic math that the independent variable goes on the bottom (flow) and the dependent goes on the side (power)


so, power depends on flow.

[MaxxxRacer]

greenman, I dont know if its the same for DC as AC, but the motor is using less amperage at lower RPM's in the Iwakis case.. Maybe there is some magic that it goes up at 0 RPM but i dont believe so.