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PUMPING: GIW asks – do you know what Murphian particles are?



Wilson’s deposition velocity nomogram.

GEORGIA – There is a tiny particle that can cause big problems for any slurry pumping operation. GIW Industries shares how to adjust transport velocity to avoid the issue.

The answer to avoiding the issue comes from Reab Berry, former head of global mining training and development for GIW.

“There’s a particle size that’s well known in the slurry transport industry as the Murphian particle size,” Berry says. “In the world of slurry pumping, it is – without a doubt – a very difficult particle to pump.”

What makes this 500-micron particle such a challenge for slurry pumping experts around the globe?

As Berry explains, the Murphian particle is the perfect size to get stuck in the boundary layer that exists inside all slurry pipelines.

“There’s a boundary layer around the inside of pipe that happens to be about 500 microns thick, and the Murphian particle gets trapped in that layer,” he says. “It’s too small to stick up out of the boundary layer and get pushed along by brute force, and it’s too large to get kicked up out of the boundary layer into turbulent suspension like particles smaller than 500 microns, so it just gets trapped.”

Clearly, Murphian particles can present significant problems in pipelines. Luckily, you can adjust the transport velocity to avoid these issues.

So, how do you know what velocity to use if you pump significant amounts of this 500-micron material?

That’s where Wilson’s deposition velocity nomogram (above) comes in handy.

“This chart is a standard for slurry transport,” Berry says. “It’s very simple: You can determine the transport velocity for different particle sizes in any size pipeline using this nomographic chart.”

While this chart is remarkably helpful for slurry professionals struggling with the Murphian particle, many are interested in learning more about this difficult – and sometimes counterintuitive – pumping concept. If you’d like more information, operators are encouraged to take part in GIW’s annual five-day Slurry Transport Course. There is a wealth of other knowledge to be gained from this hands-on slurry transport course.

Berry says, “We’ve been doing it for 40-plus years, and you can learn everything about slurry transport you’ve ever wanted to know – and maybe more!”

To better understand how Murphian particles can cause difficulty in slurry transport pipelines take a look at the video on that topic at www.GIWminerals.com by clicking on the Blog link.