Developing Pump Performance Curves

[Discreet544]

Hi Folks;

I am developing a series of pump performance curves for pulp slurries. I am running a closed-loop Lab-Scale pipeline facility. My question is about measuring head vs. flow rate at constant RPMs. I did it for pure water by continuously feeding the system with water, and gradually opening the discharge valve of the loop, while the RPM was kept constant, to record data for various flow rates. However, I can not do it for slurry, as I can't discharge it.

I see people have done it in papers, but I do not know how. I would really appreciate if you could help me. So here I rewrite the question:

On a closed-loop pipeline, how can I gradually increase/decrease the flow rate, while keeping the pump RPM constant ?

Thanks;

 

[BigInch]

Seems like you already did this.

"I did it for pure water by continuously feeding the system with water, and gradually opening the discharge valve of the loop, while the RPM was kept constant,"

Do you want to change something about that?

You normally would't do this with a slurry. No need to, as head should be approximately the same for any fluid, after compensating for viscosities.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[Artisi]

Pulp slurries -- are you refering to paper pulp??

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[Discreet544]

Hi;

My mistake ! After analyzing the results, I found even it did not work for pure water. So, forgetting about the slurry, here is the basic question: What is the standard procedure to develop a pump performance curve ? I looked for in several pump handbooks, while I couldn't find anything. The problem is still changing the flow rate, without changing the RPM. I tried gradually opening discharge valve, but it increased the rate instead, which makes sense! What if I wanna keep the RPM constant, and change the velocity from 3.5 m/s to 5 m/s ?

Thanks;

 

[TD2K]

I'm not following you. What velocity are you referring to? The water velocity? Aren't you doing that as you open your discharge valve?

Pump performance curves are usually flow versus head, is that what you are trying to create?

 

[Discreet544]

Yes TD2K ! I am trying to develop Head vs. Flow Rate !

 

[TD2K]

If you want to make a flow versus head curve, measure the differential pressure created by the pump, convert that to head and with the flow, there's one point on your curve. Repeat as needed.

Am I missing something here?

 

[BigInch]

Want more velocity? Use a smaller discharge pipe nozzle.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek