Consider a shuttle conveyor. ■

debashisde:

Although I agree that a shuttle conveyor would be an acceptable answer to your problem, you state that you do not have sufficient headroom for a transfer mechanism.

Possibilities include:

1) Using a shuttle conveyor that has a very shallow feed chute from the feed conveyor, or no chute at all. The shuttle must run faster than the feed belt.

2) Turn your feed conveyor into a combination feed/shuttle conveyor. This will require an automatic horizontal or vertical belt storage (take-up) arrangement at some point where there is space.

3) Use plows at the unload stations with a retractable belt straightening mechanism to remove the belt trough for unloading purposes. (This is possible but is both messy and unecessarily complex.)

4) Use a retractable belt tipper mechanism at the first three discharge points. I've seen this used in Saudi Arabia for iron ore - it is messy and hard on the belt.

5) Use an enclosed belt system, such as the Enerka one, which can be opened for discharge purposes and closed for general conveyance. This is a clean approach and has been used for similar purposes.

These are possibilities that come immediately to mind and doubtless there are many other possibilities.

Good luck with your research. ■

debashisde:

It may be possible, but I have very limited experience with pneumatic systems. I suggest that you e-mail Dr. David Mills, who moderates the Pneumatic Conveyer forum. He is an expert in those systems.

You can e-mail him by clicking on his name that is located on the Pneumatic Conveyor row and Moderator column; and then clicking on the e-mail link once his profile block appears.

Alternatively, you may want to start a thread in the pneumatic conveyor forum. If you do, include the details that you put in with your last input. With this low tonnage, I would have focused on the Becker-Enerka or Sicon Roulund systems over shuttles or other open belt options.

Regards, ■

The plow arrangement you desribe is quite often done in the foundry industry for multiple discharge points. Some suggestions should you decide to go this route:

1. A full support bed should be placed under each plow to allow as much material to be scraped from the belt with plow as possible. Our Guard-A-Seal (CR) support beds work great for this.

2. A means to accept the small amount of material that will not be removed by the plow should be placed at the end of the belt.

3. Additional horsepower may be required due to the plows and support beds.

4. The belt can be flat, but containment skirtboards with dust seal should be placed along the discharge area. ■

Dear Shri debashishde,

You may use the plough if you wish, however, you have to keep the belt speed very low. Multi-point discharge ploughs are often used for foundry sand discharge. You have to also accept the wear of belt and plough.

In the event if the conveyor and system is to operate round the clock, then shuttle conveyor or tripper is used. The plough can give satisfactory result when system is to operate continuously and if the material is relatively less abrasive. Generally, such arrangement is not preferred in heavy class application such as power station etc.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

Gentlemen

Dear mr debashisde

10 years ago I made a project with plough scrapers to discharge coal to 12 siloes in a large power plant.

The belt width was 1200 mm and the capacity was 1000 t/hour.

coal - 100 mm. In full load period it was conveying 12-13000 tonnes pr 24 hours.

The belt was flattened by a sliding plate under the belt, lifted by a hydraulic system. Ths plough vas altso hydraulic lifted but was pressed against the belt by its own weight.

The plough consists of 3 scraper systems.

1. -A pre scraper, taking the main amount of material and not toughting the belt.

2. - A main scraper profile in PE running against the belt, removing the rest material.

3. - A final scraper in PUR cleaning the belt for fines.

The belt was cleaned 99 % only dust was remained.

The wear of the belt was not more than a knife scaper would do at the drive drum, and the power consumption was messured to app 1,5 kw pro plough ( under estimation)

The wery interesting thing about this plough system was that it saved time compared to the shuttle belt, used before this installation.

They had to stop the conveying during the moving of the shuttle belt,between the siloes.

Now they could shift between the siloes with full belt capacity,and so keep a higher conveying rate pro hour. ■

Dear Debashisde, Erik and Associates,

I know this sounds like me too. I am just confirming what Erik is saying.

In 1977, I designed and installed a petroleum coke V-plow that cut 400t/h x -150 mm lump off the conveyor. Like Erik, the belt was elevated by a flat platen to allow the plow to bifricate the load into chutes on either side of the belt. The conveyor was running at about 2 m/s and was about 1067mm wide by my memory.

A stainless steel V plow (45 degree angles) first stage blade was used. The V-plow was raked into the flow stream about 45 degrees similar to a train's cow catcher. The plow had a self-relieving center to edge at about 6 degree bias. The first blade removed all material above the 40x80 mm gap.

A vertical, polyethylene vee was used for the second blade. It was placed about 250 mm behind the primary blade and had a 50 degree vee angle to the belt. Enough space has to be allowed between blades to transport the remaining material passing below the first blade's gap, factoring for belt speed.

The third blade was made of a series of blades to remove spittle and dust by sucessive discharge and displacement. The blades overlaped and were individually articulated. They were vertical to the belt.

For what its worth.

Lawrence Nordell

www.conveyor-dynamics.com ■

Dear debasishde,

Retractable plow scrappers are qute common and looks like the ideal solution against the constraints you have referred.Please take care that your belt speed should be quite low-say, 1M/sec-and,provide a conservative top cover thickness.

Regards,

diptasmallick ■

dear friend.

we used scrappers in sponge iron in the pt krakatoasteel plant in indonesia as a temporary measure for storage reoxidation fire fighting.

It worked well , some material though bypasses the plough and remains in the belt. being the particles pellets this is hard to avoid as the particle rolls in contact with the belt linning the scraopper.

Just consider a final position wher you can dump the material remaining on the belt.

otherwise you will do ok.

marco ■

dear Friend

This is a simple enough application, try it yourself.

if you use singlke blade plough you will excert a lateral force in your belt, but that can be tolerable.

If you ise a v sape plough . you need a larger discharge hopper.

I have installed both types, with and without secondary blades.

If your material is large and can wedge below the scrapper, consider spring loadig it to reduce damage to your conveyor.

Use a dumb bin at the head pulley to pick up the leftovers.

If there a possibility of metal pieces to be carried over with your feed . Consider a magnetic pickup.

Do not be afraid , try it yourself , observe and modify as needed.

Do not iuse pistons in your first try use an articulated lever.

If you do not have access to the field test.

Then buy it from an external supplier. The poassibilities of being right in the first try if you haven¨t done it before are not good.

Rgards

marco ■

We have designed a unit that is suitable for your application and can be PLC controled. The bed will lift from being a trough and flatten to a flat deck. In this movement the blade is lowered automaticly. When lowered the blade is also raised allowing the product to pass. You may contact us for further details. ■