Let me preface my question by saying I am a recent chemical engineering graduate and apologize if my inexperience shows.

I have designed a batch process which results in a water slurry stream containing an insoluble precipitate (biurea) with impurities such as chloride, complex salts and DOC which leaves the reactor at high temperature.

I would like to separate the precipitate, remove impurities and produce a dry product (with no particular size distribution requirements).

To achieve this I plan to use a plate filter press to produce an output stream of about 50-70 wt% solids. Is this a good choice? it seems to have low capital and operating costs (higher labour intensity) than a centrifuge and more suited to a batch process compared to a belt filter press.

I am unsure how cleaning is typically implemented in an industrial process. I would like to wash the precipitate thoroughly to remove as much chloride, salt, DOC etc. impurities as possible.Is washing supposed to be performed INSIDE the plate filter press? or is the solids washed in a separate tank to be recycled to the filter press until the desired level of washing is achieved? Should I heat the washing liquid to improve solubility?

For drying I would like to use a simple tray vacuum dryer but read that this does not scale well - I need to produce about 600kg/day dry product.

Thank you and please let me know if I should clarify.

EDIT: stream leaving the reactor is at 120 degC before entering the filter press and contains 5-15 wt% solids of precipitate. I am designing that the stream leaving the filter via conveyor is about 50-70% solids

  • $\begingroup$ Define high temperature? 80 Deg C, 200 Deg C ? $\endgroup$ – Solar Mike Feb 28 '19 at 16:38
  • $\begingroup$ "To achieve this I plan to use a plate filter press to produce an output stream of about 50-70 wt% solids." You want the output stream of the filter unit to be 50% to 70% solids or is the stream you want to separate 50% to 70% solids? $\endgroup$ – J. Ari Mar 3 '19 at 3:12
  • $\begingroup$ @SolarMike High temperature being reflux approximately 120 degC $\endgroup$ – SimpleJack Mar 3 '19 at 16:03
  • $\begingroup$ @J.Ari the stream entering the filter press is about 5-15% solids and I would like the stream leaving the filter press (via conveyor) at 50-70 wt% before entering the drying operation $\endgroup$ – SimpleJack Mar 3 '19 at 16:04
  • $\begingroup$ You may be able to do the washing of the filter cakes inside the press, but the feasibility will be determined by pressure requirements. $\endgroup$ – J. Ari Mar 3 '19 at 16:35

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