11 replies to this topic

[vis1979]

i have to design a rotary drum vacuum filter as given me an assignment. Anybody can help me regarding this topic? This is for the filtration of magnesium hydroxide slurry coming from thickener/clarifier. please suggest any book or link providing the formula for the design.

[ankur2061]

vis1979,

Some guidelines are available in Chapter 7, Vol. 2, Coulson & Richardson's Chemical Engineering.

Regards,
Ankur

[vis1979]

thanking you for your reply and help.

[breizh]

Vis1979,

Consider this resource :

http://www.filtratio.../filtration.htm

Perry's chemical handbook should support your query as well.

Note : I've added a link to support your studies , you can find at the bottom of the document a flowsheet to give you the full picture of the process:
http://www.premierpe...om/process.html


Hope this helps
Breizh

Edited by breizh, 27 October 2012 - 10:41 PM.

[kkala]

Thanks, breizh, for the interesting process description of (caustic or deadburned) magnesia from limestone and sea water.
Information on filtration can be seen in any relevant book, e.g. "Unit Operations in Chemical Engineering" (McGrawHill, 1993) by McCabe, Smith, Harriot; Chapter "Mechanical Separations", paras on Filtration, Cake Filters, Principles of Cake Filtration (excluding centrifugal filtration). An example of rotary drum filter for CaCO3 is included. Specific cake residence is theoretically dependent on particle size and porosity, yet in practice other factors also intervene (slurry does not contain only rigid particles, but also agglomerates affecting resistance to flow); see above, especially "compressible or incompressible filter cakes" at the end of Principles of Cake Filtration. I have seen disk (not rotary) vacuum filters (separating gypsum from phosphoric acid) to produce mud instead of cake, for "the resistance is sensitive to the method used in preparing the slurry and to the age and temperature of the material".
So empirical equation for cake resistance had better be derived experimentally, as books indicate; if not included in the scope of student work, something has to be adopted through instructor's help; or apply ready specific data from practice, based on operation of an actual Mg(OH)2 drum filter. The latter (even in pilot plant) could be more useful, yet such data may be hard to find.
Some filter suppliers may be willing for help or supply brochures, e.g. http://www.ekcp.com/drum_filters.html, probably http://www.komline.com/docs/rotary_drum_vacuum_filter.html, etc.
The thread may be continuation of http://www.cheresources.com/invision/topic/16361-manufacturing-20-tonnesday-of-magnesium-hydroxide/#entry65749, but "assignment" is understood to mean work much longer than an exercise.
Note: http://www.cheresources.com/invision/topic/13939-filter-press-operation-concept can be of some usefulness (not specific on rotary drum filters).

Edited by kkala, 30 October 2012 - 03:45 PM.

[vis1979]

how can i design for the valve-head for the drum filter. how is the detailed design of valve head assembly for the rotary vacuum filter. pl. suggest any guideline

[kkala]

"Valve-head" is not clear (to me), can you explain and give a sketch? This would help someone able to give guidelines.

[vis1979]

Valve head for rotary drum filter is the main part of the rotary filter, from this filtrate and vacuum will go through the pipe. perhaps this all assembly will be the valve head. please give any hint about this topic. thanks.

[kkala]

So valve head includes internal suction pipes and central duct, as indicated in the picture of http://en.wikipedia....uum-drum_filter '> http://en.wikipedia....uum-drum_filter . I do not have experience on this (not resembling horizontal disk vacuum filters seen for phosphoric acid). A more knowledgeable member could probably help (giving the essentials for a student study). I assume you have to clarify what is filtered and give pulp data and capacity required.

[breizh]

http://www.flsmidth....DrumFilter.ashx

http://web.ist.utl.p...mFilter_Rev.pdf



Using Google , hope it helps you .

Breizh

Edited by breizh, 10 November 2012 - 02:35 AM.

[alhuthali]

really useful indeed

[kamiarae]

check

www.trace.ir

Edited by kamiarae, 04 June 2013 - 08:56 AM.