Pressure drop for Slurries

[chogben]

Greetings,

I'm interested in some feedback on methods people have used to determine friction loss in slurry piping.

The applications have ore from -28 mm to +1.5 mm with a specific gravity of 2.5 and a dense medium for separation with a d50 of approximately 30 microns and a specific gravity of 7.

There are some people in the office that prefer the Hazen-Williams equation and those like myself that were trained with the D'Arcy equation.

What are the experiences of the forum?

Regards,

Chris

 

[bulkhandling]

The above posted at wrong location.

 

[Artisi]

bulkhandling,

I general I agree with your latest comments as it's always hard to be specific or to generalise when it comes to "solids" handling duties.
In some cases pumps with rubber casing liners and hard irom impellers are needed and in others, the reverse - pump selection usually comes from site or previous experience. One other important factor in R/L pumps is the peripheral speed of the impeller - the maximum is about 9m/sec - above this you have no alternative other than to use metal impellers.

It is now quiet a few years since I was invloved in this area but at that time, rubber-lined pumps were being introduced into grinding mill discharge with apparent success, these were being called "extra thick" rubber-lined pumps, ie, casing liners of 50mm or so and very thick rubber impellers. Warman, Sala and Allis Chalmers- Canada were supplying this equipment.

For interest, one application I have come across which proved to be very arduous is in the waste-paper industry, this is the first pump in a waste paper plant which handles the repulped waste straight from the pimary pulper - this can contain anything from paper staples, broken bottles, beer cans (empty I hope), house bricks and ever pieces of broken machinery - a typical selection here would have to be a hard-metal pump for obvious reasons.

Naresuan University
Phitsanulok
Thailand