Material Handling Solution Solicited

perhaps a screw conveyor and a waste gate of sorts, or can the tank be flushed and a vacuum be applied?

Sounds very similar to removing silage from a silo. It uses a screw conveyor of sorts with tangs on the flights. The tangs fluff it up and screw conveyor moves it to center of silo and feeds blower to remove it. The time to remove it would vary on application. How do you empty it now?

Are you able to modify the tank?

Has the tank got a flat bottom?

There are multiple manufacturers of industrial vacuuming systems. The one I am familiar with and recommend is Hi-Vac in Marietta, Ohio.

Website http://www.hi-vac.com/

Regards, Delmar Schmidt
Melfi Technologies Houston
www.melfitechnologies.com

If possible, you might consider fitting the bottom of the tank with a "false bottom", incorporating a fluidizing section. When a sufficient flow of whichever gas is easiest and cheapest to use for your requirements, (probably compressed air), the husk will become fluidized (suspended in the gas stream) and can be easily removed by a hose or pipe (similar to vacuuming, except that it will output into ambient pressure provided the only tank outlet at that time is the aforementioned hose or pipe. The pressure in the tank would be minimal: on the order of one or two atmospheres and typically less.

Since the tank is so large in diameter, a means would have to be included to move the husk residue to the fluidizing/pickup area. This might be accomplished by the "false bottom" sloping towards that area (with the addition of mechanical vibration if required to move the husk down the slope) or alternately the inclusion of a mechanical stirrer. Fluidization is commonly used for the transport of dry material.

Alternately, if the moisture content is too high or the husk residue is not amenable to fluidization, mechanically stirring with the addition of a liquid to create a slurry which can then be pumped out is another potentially viable approach.

Lastly, there are devices that perform one of the above approches in a localized fashion by combining a liquid or gas injector with a suction head, similar in principle to a common carpet cleaner. This would then be moved around the bottom of the tank as necessary to remove the husk, with the advantage that no (or minimal) modications to the tank would be required.

I hope some of these ideas may be of some help.

All the solutions from the replies would work.

I think you better understand the nature of what you are moving. I think you understand half of it when you said they are not free flowing. This tells me you know a little about bulk material handling. The other half is even more fun. Husks can also be very abrasive. I have seen some husks eat right through a pnuematic conveying pipe (especial at the bends). The tips of the husks can be as hard as ceramic.

Now you know so it might be safe to assume that vacuum transfer systems would work, but there might be a replacement issue with piping and if you go cheap and use some cheap flexilble hose than keep some of that extra crap on hand. I am pretty sure after a few days you are going to need it.

Fluidizing might work pretty good. But one thing to think about is the open area between the husks. If they husk allow air to pass through them with out any resistance then they won't be fluidized to much to move them.

About your tank. You also said the tank was 12 meters in diameter. If you have a flat bottom, you might have some problems completely emptying the tank, because anything might not flow to well along a flat surface (that physics stuff and angle of repose). You might need some type of mechanical pusher or wiper that could move the product to the discharge point or just get a tank with conical hopper.

This is the heart of your problem. I don't think it was designed to be used in the manner that you wnat to use it. This would be a strong indicator that you have never worked in this application before (anybody who knows bulk handling would never do this and they would never let themselves get into this type of problem) or you don't have a lot of money (ebay seemed like a good idea at the time). If your supervisor said this is all you have to work with, I think your company must suck to work for.

If you have just scrolled through only the first paragrah hoping to just get the names of some foriegn companies so you can look at their website and steal their ideas by copying them or didn't read it, your are stupid. If you have read everything up to this point, you are not stupid. I don't care either way. I would like to hear anyones comments about my posting.

If you are on a budget and you have four hours to unload the tank, why don't you use a shovel (for some people this might be considered skilled labor, I used to work for them) and hire some general laborers to do it.

If these are problems that you are facing because some dick-head supervisor isn't giving you the right equipment for the job, I would like to help point you is some directions of companies that work with bulk transfer systems.

If you happen to be the dickhead, you are on your own.

I liked your response. I was talking to an engineer working for a company in China about a new product line. I asked him who designed their product lines. He said, "We are engineers. We find, we like we copy".

Hello,

Try using screw conveyor at the bottom of the collection chamber. The ash would be removed easily with ease. The negative side is - silica in the ash would erode the conveyor soon - so use Stainless steel conveyor.

Best wishes

Raymond.ranck - raymond.ranck@gmail.com