dearman,
My understanding of mixing turnover time would be the time it takes the agitator to pump the equivalent of one vessel volume, i.e. turnover the vessel contents.
I have seen the data used as a relative guide to mixing intensity, usually as the number of turnovers per unit of time.
To...
rolands1,
You could install a false floor in the tank that slopes towards the drain nozzle. It should'nt affect your mixing dramatically, although you would need to monitor the new tank geometry for wear.
If your looking into air agitation, bear in mind that you will need to keep the slurry...
chemeng1357
The basic relationship between Power (P), speed (N), diameter (D) and fluid density ([ρ])is:
P [∝] N^3.D^5.[ρ]
Specific calculations need input from the suppliers with regards to the performance of the particular impeller type selected.
Regards,
NB
What your after is an isotherm. If it is a solvent extraction application for metals you will have one isotherm for extraction and one isotherm for stripping. The isotherm is a plot of metal concentration in the aqueous phase vs metal concentration in the organic.
The results are obviously...
drFCraft
You are on the right track.
There are a couple of material parameters, defined through standard tests of the ore, that will give you a basic guide.
For crushing, the Unconfined Compressive Strength (UCS) provides a guide. Units are MPa.
For ball milling you need the Bond Ball Mill...
Outokumpu of Finland developed an on-line XRD for use in analysis of nickel sulphide slurries in a flotation circuit.
I am not sure if it is part of the Courier analyser range. Contact them about options.
One issue you may have is that all the minerals of interest contain lighter elements...
The August 2006 edition of the IChemE Loss Prevention Bulletin has a good article describing three pigging incidents and the corrective actions to prevent recurrence.
www.icheme.org/lpb
Cheers,
NB
Ringo,
Interesting mix of elements.
I suggest you contact an engineering company about doing a scoping level study on process options. There are a few in Perth with relevant expertise.
One of the fundamental questions in selecting a suitable process is about the mineralogy of the deposit...
Ussuri,
The books, Why Buildings Stand Up and Why Buildings Fall Down by Mario Salvadori provide some insight into the historical approach to structural design, including a discussion on the Bent Pyramid at Dahshur mentioned by Ashereng.
Cheers
NB
Mark,
I have been involved in a few studies looking at a very similar application.
When you introduce the requirement to hydroclean scale you can forget about rubber or vinyl ester coatings. It is very difficult to avoid damage from the high pressure jet.
The options are; ceramic tile/brick...
A quick search of the IChemE Loss Prevention Bulletin turned up a number of articles about bund failure, including Buncefield.
http://www.icheme.org/shop/mainframeset.asp?/../shop/../lpb/textframe.asp
NB
Aside from the chemical compatability issues you have highlighted, there are significant differences in the SG of the two liquids, which needs to be assessed against the structural design basis of the tank.
NB
Could the 5 or 6 bar pressure observed be the discharge static head on the pump, which dissipates as the fluid drains back through the pump (presuming it is a centrifugal) via the small leakage through the check valve?
NB
Suggest you might get a better response by re-posting on the Measurement and Control Instrumentation Forum.
For mine, it looks like you should have a combination of feed forward control,based on analysis of component B fed into the reactor and the existing feed back arrangement.
Cheers,
Nigel
I have had a similar experience trying to pump a sulfur slurry into an autoclave using piston diaphragm pumps. The main problem area was the ball type check valves, which were bound up by solids settling out.
In the end we changed pump types to a helical rotor type with a variable speed drive...
I have recently selected, but not yet installed, the Komax Scepter for direct steam injection into an agitated slurry tank.
One thing to bear in mind is that the sparger has a diffuser head on the end, which is larger than the pipe size and hence your nozzle arrangement needs to accomodate...
Not sure of your specific duty, but I have used a device called the hydromixer from JS Melbourne Controls that does a good job of wetting difficult solids, in this case it was fine magnesia powder.
Try this address for more information.
www.ferret.com.au/articles/97/0c016f97.asp
Cheers,
NB
Guidoo raised a good point about nuisance alarms.
The issue of "alarm flooding" is topical, particular it being recognised as a contributing factor in accidents, where the control room operator is either de-sensitised to alarms or overwhelmed during a process upset.
In assessing the...
