Dear vishy,

For selecting a paricular type of silo the following factors are to be also taken in to conideration.

1.location of the silo.

2.capacity of the silo.bearing capacity of the soil.

3.availability of the raw material at that place.

4.whether this will be a permanent facility or temporary.

5.generally it is not advisable to go for steel silo for more then 2000 t capacity.

Extraction of fly ash from all type of silo can be designed suitably.

Generally in India methods for storage of fly ash has been very crude due to its availability of free of cost from power stations,but you must know its values—

1.it is being mixed with clincker between @30--40%but in hawai people have increased its % of mixing with clincker between 80-90%.

2.being used in making bricks.

3.you can also make grits/(similar to crushed stone used in making roads and in cement concrete) if you will mix the same with gypsum.the strength of this grits is more then granite.

4.you can earn foreign exchange by selling this @ 90-100 US $ per tones.if you are planning to go for export then please also go for seperation unit to get the proper size of fly ash.

5.if your plant /facility is near to port then you can earn handsome money.

We can provide you the following services—

1.to design the system from boiler out lets or from ash ponds to conveying it to storage silos.

2.packing in to bags/bulk bags/bulk tankers for export or loading systems in to barge.

3.to find out client to buy the same.

4.to find out venders for the same.

5.to provide you the total cost tof the project.

Regards, ANIL SETH

http://www.indiamart.com/libran-engineering ■

Dear Vishy,

You had two questions - fly ash

Question one - Are there any thumb-rules for choosing between steel or concrete silo? Like above a certain volumetric capacity/diameter/height etc.?

There will be those that argue this point as technology improves, designs also improve and therefore it improves preformance. However, if you have reason to be worried about it than it probably means that you should go concrete.

Question two - Is aeration normally provided for conical bottom silos also? Yes, for fly ash it is standard procedure to aerate in silos.

The link below is a resume card of just a few of the Fly Ash Storage facilities we have built at Dome Technology. http://www.dometech.com/assets/collages/flyash.pdf

You can also go to http://www.dometech.com/media/media.html and see other types of domes that we have built for other products like cement, gypsum, grain, etc.

The versatility of Dome Storage is demonstrated in the different shapes of the dome and the different reclaim methods that can be used to meet your bulk storage requirements. Whether it is a tall Dome-Silo, a Low Profile flat storage Dome, a hemisphere shaped Dome, or any shape in between, Dome Technology can adapt the structure to fit your needs. Concrete domes are very flexible in both the filling and the reclaim of the stored material. Because of the Domes inherent strength, it can support an in loading conveyor system on top of it. Without internal supports this allows the material to fill the dome through one or more openings in the top of the Dome. The material is then reclaimed using Mechanical Screws, Fluidized Floor, Gravity Reclaim or a Front End Loader.

Dome Technology also has an innovative system to build the tunnels used in the reclaiming or bulk materials handling process allowing the tunnel to be built safely in a rapid and economical manner.

Please visit us at http://www.dometech.com for more info on Dome Technology and the solutions we can provide. ■

There are no specific guidelines for selecting steel or concrete. Let economics make the decision. Both are good for the application. Steel will be cheaper in smaller sizes - concrete potentially cheaper (but not necessarily) in larger sizes. We will be happy to quote (without obligation) pre-engineered steel storage tanks (hopper or flat bottom) for your review.

You may contact me at trenich@tanks.com.

Websites for basic information are www.tanks.com and www.columbiantectank.com.

I hope to hear from you.

Tom Renich ■