4 replies to this topic

Hi all.
I have to dose 30% Ca(OH)2 slurry into a process stream for pH control at a very low rate (1.2 lpm - 2.4 lpm). I want to circulate a large flow (maybe 70lpm through a 1" line = 6.3 fps / 1.9 m/s) from the storage tank up to the dosage point and return to the tank and then take off a small 3/8" line through a peristaltic dosing pump to control the lime addition rate according to the pH probe readings. My question is: Can I use a centrifugal pump for the feed loop pump or must I use a positive displacement pump (eg hose pump) due to the abrasion of the solids and high viscosity? Would 316SS be fine for the pump internals?

Does anyone have a reasonable way to estimate the viscosity of a 30% Ca(OH)2 slurry?? The best I can find is that it could be in a range of 45-700cP.

All advice would be appreciated.
Trevor in Ottawa, Canada.

[breizh]

Hi all.
I have to dose 30% Ca(OH)2 slurry into a process stream for pH control at a very low rate (1.2 lpm - 2.4 lpm). I want to circulate a large flow (maybe 70lpm through a 1" line = 6.3 fps / 1.9 m/s) from the storage tank up to the dosage point and return to the tank and then take off a small 3/8" line through a peristaltic dosing pump to control the lime addition rate according to the pH probe readings. My question is: Can I use a centrifugal pump for the feed loop pump or must I use a positive displacement pump (eg hose pump) due to the abrasion of the solids and high viscosity? Would 316SS be fine for the pump internals?

Does anyone have a reasonable way to estimate the viscosity of a 30% Ca(OH)2 slurry?? The best I can find is that it could be in a range of 45-700cP.

All advice would be appreciated.
Trevor in Ottawa, Canada.

Hi Trevor ,
Yes you can use a centrifugal pump , body cast cast iron , gland packing , water flush . operating condition was 280 g/l Cao , 95 C 98C
Breizh

Hi Breizh
Thanks for the reply.
Best regards
Trevor

[Qalander (Chem)]

Hi Breizh
Thanks for the reply.
Best regards
Trevor

Hi Trevor,

Although its usual,but do not forget to have appropriate type strainer used at suction.

As for lime slurry one has to be cautions I believe.

Good Luck

[fallah]

An important point regarding slurry containing Ca(OH)2 is considering flushing line connected to pump suction line.