On the exposed length it is likely that the screw is not providing progressive extraction so, at least in part, will be dragging the quartz from under a static bed. It is also not clear what the radial clearance has the screw and it probable does not have increasing tip clearance as it rotates, so will also probably have excessive tip wear. At least the bulk material is almost certain to be free flowing, so the best likely solution is to radically reduce the feeder outlet overpressures by fitting hopper inserts. The value of a specialist supplier should not be underestimated for such modifications. ■

Originally Posted by udithausk

Hi

Recently I visited the quatz silica processing plant. after grindng quatz , it will store silo , problem is silo unloading screw feeder.

feeder length is 1.4 M X diameter around 150 mm , product size is less than 4 mm . Specific gravity is 2.6 , they need control feeding rate acuratley , range 6~15 kg.

problem is screw is mage of S.S , wear and tear is very high ? that space is limited , there for very diificult to fixed vibratory conveyor or chute

can any body give me good solution ?

regards

Uditha

Dear uditha,

Does these screw feeders have been made Wear-resistant treatment? we made many feeder for silica by SS+WC.

It works well.so more informations,pls contact hanruipuzer@hanrui.cn lewis liu ■

Further to my comments on screw wear, addressing flight tip wear requires different techniques to dealing with flight face wear. Apart from any corrosion effects, wear on the surface of the screw flight is dependent on contact pressure and slip velocity that can be reduced by design, and resisted by harder constructional materials and patterns of hard weld deposit. High rates of high wear is usually due to the formation of a compacted boundary layer of product between the flight tip and the casing or the trapping of hard granules fin this clearance. The former can be mitigated by hard metal flights, hard weld deposit and flight tip construction. Trapping is subject to the probability similar to structural arching in flow channels and relieved by screw and casing construction. Both means of tip wear can benefit from use of a flexible casing. These methods generally demand non-standard manufacture that cost more than off-the-shelf items but pay off by increased reliability and extended service times. ■

Originally Posted by udithausk

Hi

Recently I visited the quatz silica processing plant. after grindng quatz , it will store silo , problem is silo unloading screw feeder.

feeder length is 1.4 M X diameter around 150 mm , product size is less than 4 mm . Specific gravity is 2.6 , they need control feeding rate acuratley , range 6~15 kg.

problem is screw is mage of S.S , wear and tear is very high ? that space is limited , there for very diificult to fixed vibratory conveyor or chute

can any body give me good solution ?

regards

Uditha

Originally Posted by Roland Heilmann

Dear Mr. Uditha,

there is different S. S. materials, also there's alternative steel materials like e. g. Hardox. What do other screw suppliers offer for option, considering the exact specificalities of the product?

Space limitation: Nevertheless some space as per a screw size could be available --> If size of screw would be increased, the relative utilization would drop which should also improve matters.

Regards

R.

Originally Posted by Lyn Bates

On the exposed length it is likely that the screw is not providing progressive extraction so, at least in part, will be dragging the quartz from under a static bed. It is also not clear what the radial clearance has the screw and it probable does not have increasing tip clearance as it rotates, so will also probably have excessive tip wear. At least the bulk material is almost certain to be free flowing, so the best likely solution is to radically reduce the feeder outlet overpressures by fitting hopper inserts. The value of a specialist supplier should not be underestimated for such modifications.

Originally Posted by Lyn Bates

Further to my comments on screw wear, addressing flight tip wear requires different techniques to dealing with flight face wear. Apart from any corrosion effects, wear on the surface of the screw flight is dependent on contact pressure and slip velocity that can be reduced by design, and resisted by harder constructional materials and patterns of hard weld deposit. High rates of high wear is usually due to the formation of a compacted boundary layer of product between the flight tip and the casing or the trapping of hard granules fin this clearance. The former can be mitigated by hard metal flights, hard weld deposit and flight tip construction. Trapping is subject to the probability similar to structural arching in flow channels and relieved by screw and casing construction. Both means of tip wear can benefit from use of a flexible casing. These methods generally demand non-standard manufacture that cost more than off-the-shelf items but pay off by increased reliability and extended service times.

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Both Lyn's and Roland's advice to you is spot on. Follow it completely to solve the issue. Your client has a wear problems with a

mineral that causes high wear and health issues with fine dust causing the lung/Pulmonary Disease "Silicosis"

The same wear issues you have occur with undercutter's used in underground mining to carry away the fine "bug dust" from the slot cut in the floor, side or roof of the tunnel entry to relieve the blast forces created by the explosive used to break the ore being mined for later removal and processing.

The client has to remember that auger tubes and augers are "wear parts" and there is no magic bullet that will solve this for you. ■