A better route for primary breakage can be gained with much more efficiency per ton by using a belt feeder breaker rather than a jaw crusher for primary breakage.

Thre are several hundred of the belt feeders working in surface and underground mines.

WR Stamler has the largest presence in the belt feeder breaker marketplace.

They will accept and break nickel ores and they are used in both surface and underground operations and have been in use for fifty plus years.

If you do a search on feeder breakers you will gain wealth of information about them and how well they work; they take a beating and come back for more and work tirelessly around the world around the clock in underground mines. That is where WR Stamler developed the first feeder breaker after he built and marketed the first underground railcar mover used in a coal mine as well.

The belt feeder breaker typically has one or more breaker rolls that break the shot ore to size by repeated impact of the replaceable teeth on the ore as it is drawn toward the breaker assembly and continues to do so until it is broken until it passes under the bottom of the breaker roll.

Many coal mines also use a belt feeder breaker to reduce the coal size further after it is broken at the mine face by a continous miner to improve production and reduce ore size.

The breaker assembly is powered by an electric motor through a gearbox reduction unit. The breaker assembly is also obtains additional breaking energy for rotation and breaking force via a heavy flywheel attached between the reduction gearbox and the breaker roll assembly. The flywheel is mounted with a ringfedder locking ring to hold it in place on the shaft.

Desired ore size is easily adjustable by unbolting the breaker assembly along the vertical rows of mounting holes holding it in place and raising or lowering the breaker roll to the desired height and reinstalling the mounting bolts at the desired throat ore size.

The flight chain is driven by another reduction gearbox and chain drive to move the ore towards the breaker assembly.

Both chain drives are adjustable for wear with a sliding table configuration which holds the elelctric motor and gear box mounted as one on the table using adjustment bolts to move the table for tensioning of the roller chain.

The voltage used to power the units is typically 480 volts and the electric motors vary in size and voltage depending on ore the broken and whether the units are driven by hydraulics as is done in some gassy mine environments.

There are four main brands on the market today; WR Stamler,

"Long Airdox Roscoe", Mclanahan and flSmidth.

There is much information available about these machines on the internet and from suppliers of the machines as well.

The belt feeders themselves have a very long working service life as they are very well built and have very few wear parts to go bad.

lzaharis

Disclaimer: I do not represent WR Stamler, Long Airdox or Mclanahan or FLSmidth. ■

Sizers perspective::

From when I worked for MMD (transmin) in the late 80's; Alan Potts's original design had toothed discs slid onto a splined shaft and the shaft came out quite reasonably. Sizers were very good with coal and limestone in the early days and seem to have progressed into harder feed quite well.If you are thinking of a sizer which will handle the same lumps as a jaw crusher then the throughput might be considerably higher than the single jaw crusher. MMD make some mighty machines. Specifically to

1. What life are we talking about? Throughput dependent.

2. Cutters can be hardfaced easily, if the shafts need attention then you have specified the wrong machine.

3. See 2 in part. More teeth means bigger rolls, for a given lump size, so they are roughly dependent on throughput factored by hardness.

4. What rolls?

5. Ask Richard Barber at MMD, Somercoates, for the truth. He's been there since 1987 and done the lot.

6. Maintenance facilities are a matter of personal conscience. If you put in proper monorails and slinging points on the chutework then any bit of kit is as good as the next.

Whatever you do get your information from the horse's mouth. Alan Potts designed a sizer for glass recycling that could strip glass off wire reinforced sheets and not tangle the wire round the teeth. It impressed me! ■

Dear Mr.Izaharis & Mr.Louispanjang,

I thank you very much for the explanations and time you have provided in answering this querry.

I suggest if you can attach the cross section drawing of the crushers, it may be more helpful in understanding the crusher for young engineers.

Hope you may agree. ■

I agree completely with you Mr. SGanesh and as soon as possible I will attach files for same as soon as possible as my computer is very outdated etc. As it will be easier for me to do it that way for everyone. ■

More material for sizers:

This is one example of a sizer breaker etc. it has twin breaker rolls to size and break the incoming ore.

It is the first picture/file I have ever uploaded on the site and I am glad it worked.

Attachments

mountaineer_sizer (JPG)

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A picture of a current low seam model of a WR Stamler belt feeder breaker used in coal mining.

The breaker has an integral track drive unit for propulsion.

The breaker assembly is powered with an electric motor or hydraulic motor powered reduction gear box and assisted by a flywheel weight for increased momentum for breaking ores and has multiple shear pin protection at the breakers chain driven sprocket-unseen in the picture.

The flight chain which carries the unbroken and broken ore is powered by an electric or hydraulic powered reduction gear box with multiple shear pin protection at the head shaft end of the flight conveyor chain.

The tail shaft of the typical belt feeder has one floating bearing housing and one fixed bearing as does the head shaft assembly.

The tail flap assembly which contains the tail shaft flap and bearings allows the flight chain to ride clearly around and over the bed of the belt feeder to allow dust and fines to clear the machine.

The flight chain is tensioned using two grease cylinders for initial tensioning and shims to hold it in place after the grease cyliders have been allowed to release pressure after an adjustment or repair.

The flight chain is held in place by twin shoes under the breaker roll assembly on both sides of the chute throat allowing the flight chain to follow the contour of the outby chute.

Depending on the design size/model breaker it can be loaded on one two or three sides of the machine for breaking and sizing.

The frame size 33 units I worked on were capable of breaking up to 900 tons per hour with the full open throat setting for the breaker roll at maximum height.

The design of the machines allow for easy positioning at a tail pulley right angle or at the end of the tail pulley allowing linear dumping on a conveyor belt.

Gary-If I missed anything I apologise-its been awhile.

leonz

Attachments

stamler_ugfb (GIF)

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The mobile unit: It doesn't look balanced over the tracks. None of these machines, from wherever, were balanced and they used to get stranded on brows in the heading floor or if a dint sprung up in the path. But they were still a lot better than what was done before! ■

Greetings and salutations Mr. Panjang,

The WR Stamler, Long Airdox and Mclanahan Belt feeders all have their major weight in the rear of the unit over the tracks along the incline of the flight conveyor cosisting of the gearboxes/sprockets/ roller chains for flight chain drive on the left side and the breaker roll and chain drive on the right side facing you.

We always ended towing them with the scoops any long distance too.

The WR Stamler units also have a pair of hoisting cylinders to raise the hopper/dump bed up and away from the tramming frame for movement as well which is normally included in the track drive packages.

I know you would not think it but these units are well balanced when they are assembled/specified for track drive as the dumping bed has a lot of weight in hardened structural steel.

They also balance very well even when a full size hopper is incorporated in the design.

Of course there is always hell to pay with a mud floor or a squeasing seam and brittle rock floor/shale/sandstone especially when you have a bad undercutter operator who just does not care, thats the nice thing about a drum miner or a road header the floors are always flat as a pancake no matter what.

I certainly di miss the Dosco TB 600 after it left us-it made such beautiful floors.

Of course dealing witrh operators who did not understand or care how a lock valve kept a tilt cylinder from sinking on an undercutter

to keep the floors flat and level.......................................

lzaharis

lzaharis@lightlink.com ■