Congratulations for your new developed return belt cleaner (V Scraper). Word plough is frequently used for V-Scraper / straight-scraper for discharge of material from carrying run, and hence I understand it is return belt cleaner.

May I know how much gap is kept between blade edge and belt surface. This may be somewhere like 0.75 mm or so. This clearance will have relation to tolerance in belt thickness for its unevenness in surface.

Is your development specifically in response to extreme abrasive nature of material?

You may clean escape of fine dust by blowing air. I hope this suggestion may be of use to you.

Regards,

Ishwar G Mulani

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

Emaiil : parimul@pn2.vsnl.net.in ■

Oakpoint

How do you keep rocks larger, but close to the gap size, from becomming trapped between blade and belt; thereby damaging the belt?

We recommend using a scraper in conjunction with a downward semi twist of the belt edges using reverse V-return rolls. Gravity assists the scraper/plough in deflecting rocks. The angled rake of the scraper blade minimizes the potential for rock entrapment. The scrapers are located before the inverted V-return rolls.

Lawrence Nordell

Conveyor Dynamics, Inc.

website: www.conveyor-dynamics.com

email: nordell@conveyor-dynamics.com ■

Oakpoint:

You mentioned that the sole job of a plow is to prevent large debris from entering between the belt and pulley. I agree that this is an important duty of the plow, but I also suggest that the plow should be used to prevent fines (wet or dry) from entering between the pulley and belt. Fines can create two problems -- that of uneven build-up on the pulley, which creates a belt training problem; and that of gradual build-up and hardening which acts the same as a large stone between the pulley and belt, which can do damage to the belt carcass.

This problem exists with materials such as gypsum, cement, salt, fertilizer, and others. I've also seen problems of this nature with belts carrying limestone. ■

On the Zambian Copperbelt there is/was an inclined conveyor feeding ore into the Converter Hall. Spillage at the feed point was severe enough to develop piles against the gantry sidewalls. These piles were up to the handrail height. Fresh spillage would cataract down these piles at a fair speed and bounce over the plough into the tail pulley nip. Lump size was about 250mm.

Regardless of what material is selected for the plough blades; what clearance is maintained or what other criterion is considered there is no point in operational staff blaming the conventional equipment if it is correctly specified and maintained.

Ploughs can work at least as well as head end cleaners if they are correctly installed and adjusted along with the rest of the gear.

I could not take any photographs of the situation because it was illegal to do so in Zambia in 1988. But they would have been worth a second glance! ■