7 replies to this topic

[ChE student17]

Good day,

For our plant design requirement, we are employing a decanter centrifuge for our process. The stream at inlet of the decanter only has around 1-2 wt% of solid. Is there a way to know how much of the liquid would adhere to the solid? Or is there any general heuristics on the value of the adhered solution? I've been searching so much about this but I just can't find any information on it.

For reference, the liquid is glycerol-methanol-water (with little separate oleic acid phase) mixture and the solid is monopotassium phosphate.

Thanks for taking the time to read my inquiry. Any help is greatly appreciated.d 

[ChE student17]

Additionally, i need to separate all of the solids present. In that case, it's not possible to separate it without any liquid adhering to it. That's why i need to know how much of the liquid will go with the solids. Thank you!

[breizh]

Hi,

To me only pilot test with product will give you the answer . It will depend on the shape of the solid, the temperature, the viscosity , the rotation speed,etc .

 

You may contact companies like Andritz, Robatel ,....

 

http://www.ohiowea.org/docs/Smith.pdf

 

good luck

Breizh

Edited by breizh, 25 May 2019 - 01:42 AM.

[ChE student17]

Hi,

To me only pilot test with product will give you the answer . It will depend on the shape of the solid, the temperature, the viscosity , the rotation speed,etc .

 

You may contact companies like Andritz, Robatel ,....

 

http://www.ohiowea.org/docs/Smith.pdf

 

good luck

Breizh

 

Thanks for the reply. It's true that only a pilot test can really determine the true amount. I just hoped to find any general information on the amount of adhered solution to the solids, whatever the system is. (Although I know it really varies from case to case)

[thorium90]

If the objective is the solids and you need them dry, then you can consider a press. Specifically, dewatering presses. Centrifuge is for when the target is the liquid. Presses are for when the target is the solids. Although, generally both separate liquid from the solid, the objective would change the preferred equipment type. Although a centrifuge can still be used if there are other consideration factors such as flow rate and hydrophilicity etc...

If you need them even drier, then you need a second drying step. First step should take you about 20 to 30% dryness. Second step would take you to much higher such as 95%. Bone dry will need a third step although this is only needed if >>99% is required.

Edited by thorium90, 25 May 2019 - 02:42 AM.

[ChE student17]

If the objective is the solids and you need them dry, then you can consider a press. Specifically, dewatering presses. Centrifuge is for when the target is the liquid. Presses are for when the target is the solids. Although, generally both separate liquid from the solid, the objective would change the preferred equipment type. Although a centrifuge can still be used if there are other consideration factors such as flow rate and hydrophilicity etc...

If you need them even drier, then you need a second drying step. First step should take you about 20 to 30% dryness. Second step would take you to much higher such as 95%. Bone dry will need a third step although this is only needed if >>99% is required.

Thanks for the response

I actually need the liquid phase to not have any solid present anymore. The dryness of the solid doesn't matter in our case. Is this possible to achieve (considering that the feed only have low solid content which is about 1-2 wt%)? and how much of the liquid will go with the solid (even just a rough estimate of it)? Thanks again.

Edited by ChE student17, 25 May 2019 - 05:42 AM.

[thorium90]

If the objective is for getting a liquid without any solids, then you can try filtration. Membrane filtration is a common method. Ceramic membrane ultrafiltration is a possible option.

[breizh]

hi ,

 For you and others

 * a lot of technical information about filtration in the link attached :

     http://bhs-filtratio...cal-articles/#1

 

  ** a general comment about  decantor centrifuge , you need to add flocculant , is this compatible with your process ?

      With solid concentration so low  you need a tickner prior to centrifugation or hydrocyclone .

 

good luck

Breizh 

Edited by breizh, 26 May 2019 - 05:21 AM.