Re: Slurry Pump Suction Liner Wear

"Gregg" <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>...
> - The 20" inch diameter didn't register the first time I read it. - is this
> possibly for a mining or dredging application? - just curious
> It sound like you have a good idea as to what may be happening - I was
> fortunate enough to never have had to deal with  2" rocks in a slurry.
> It sounds like a tough problem to cure inexpensively.
> For high wear applications I've seen some chrome coatings used quite
> successfully in pipes with abrasive slurries and to coat the interior liner
> of horizontal bead mills.  Chrome coatings can be expense if you can't find
> a low cost specialty coater and when the chrome wears through - the rest of
> the unit soon follows.
> I vaguely remember talk of using cryogenic steel for some high wear
> applications (the cost was not bad and the wear resistance was excellent)
> I'll try to contact some old co-workers to see if they have any info that
> could help
> 
> Good luck,
> Gregg
> 
> "dkichton" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]
> > "Gregg" <[EMAIL PROTECTED]> wrote in message
>  news:<[EMAIL PROTECTED]>...
> > > Sounds odd - but a good opportunity to play detective..
> > > Are you at the same fluid flow with the larger diameter discharge pipe?
> > > What kind of pump are you using - (I'm assuming a diaphragm pump)
> > > What is the solids loading?
> > > What is the wear pattern?
> > > If the fluid velocity decreased you could get partial settling in the
>  pipe.
> > > The increased solids at the bottom of the pipe may not be enough to
>  cause
> > > clogging, but it might increase the solids enough so slurry becomes
>  dilatant
> > > during part of the pumping cycle - increases wear.
> > > If you increased the fluid flow with the larger diameter outlet, the
>  slurry
> > > may be experiencing shear rates in the dlatant regime during the pump
>  cycle
> > > with out any settling.
> > > Or - depending on your answer to the initial 4 questions - none of the
> > > above.
> > >
> > > Good Luck
> > > Gregg
> > > "dkichton" <[EMAIL PROTECTED]> wrote in message
> > > news:[EMAIL PROTECTED]
> > > > Anyone experience excessive erosion wear (pumping a heavy sand slurry)
> > > > on slurry pump suction liners.  We had been testing a urethane product
> > > > with great success, then changed the discharge piping from 20" to 24"
> > > > diameter and reduced our suction liner wear from 52 weeks to 4 weeks.
> > > > Process conditions have not varied that much.  Any comments would be
> > > > appreciated.  Pumping a slurry density of 1.4 gms/ml, 16000 usgpm,
> > > > discharge pressure of 300 psig.
> >
> >
> > Flowrate is the same -hasn't changed, but velocity in discharge piping
> > dropped off dramatically (22 to 13 ft/sec).  We are using a GIW TBC46
> > slurry pump.  This train of 5 pumps tends to get more 2" rocks than
> > the other 4 trains due to feed distribution issues.  The density tends
> > to be somewhat lower on this train for this reason as well - 35 to 40%
> > solids loading.  We too are thinking we are experiencing settling of
> > the larger rocks which tends to cause a build up of backpressure on
> > the pumps - sort of like plug flow.
> >
> > Not sure what we can do about this, aside from going back to the 20"
> > diameter pipe (approximately 100 ft).  We went to the larger diameter
> > to reduce the wear that we have been seeing on the pipes.
> >
> > Some thoughts were to try a white iron suction liner to minimize the
> > gouging wear that we are seeing on the urethane liners.  Another
> > option would be to install a short reduced section of pipe ( say 10
> > feet) of 20" to allow free flow.  Not sure what other options we could
> > try?

Yes, we have been using a chrome carbide overlay in all of our high
abrasive slurry applications.  Have even tried tunsten overlay at the
flanges where wear is more prominent if pipes are not lined up
properly.  We are also experimenting with some urethane lined pipe.  I
would be interested in hearing more about the cryogenic pipe.