Re: Loading Problem
Dear Mr. Waloni,
The material discharge height of 5m can be handled if you adopt the correct chute design and construction. In your case, the chute should contain stone boxes (shelves) at certain interval so that no material falls directly on to the belt, and material velocity at chute exit is within permissible limit, for loading on belt without damage.
You have not mentioned the size of rock, which is important to give proper suggestion. I presume it would not be of very unusual size. Mostly, you may be referring to sand mixed with gravel.
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 ■
Your Loading Problem
Greetings,
Your problem sounds like your drop is vertical at the transfer
point, I would try increasing the angle of the drop chute to the
tail pulley up to twenty or thirty degrees below horizontal to
allow for the material to fall at or near the bottom of the new
chute and then it will fall the rest of the way by its self. this will
stop the wear problem on the belt itself and you can always add
ar- Attack ressistant plate steel later to seal holes or adjust for
wear without shutting down the plant for long periods. ■
Re: Loading Problem
Need more information to make a reasonable, accurate, and informative opinion.
CDI has designed and buit a number of chute systems that handle such composite material streams with large drop distances. There are a number of geometric features, flow rheologies that need to be understood, to optimize the geometry and minimize liner wear.
UHMW will not always solve the problem. I can give photos of material sticky and building on a vertical wall.
I am willing to give more advise. You need to contact me so that I do not unduly spend time shot-gunning your needs.
See our website for an introduction on our methods.
www.conveyor-dynamics.com
Lawrence Nordell
Conveyor Dynamics, Inc.
ph USA 360-671-2200
fx 360-671-8450
email: nordell@conveyor-dynamics.com ■
Loading Problem
Gentlemen
Dear mr Mark Hupertz.
Please send me a drawing of the loading chute in DWG., then I will show you how to make the neccesary modifications. It is relative simple, to do. It will solve your impact problem and increase your capacity of the system. ■
Re: Loading Problem
Mark,
If you cannot reduce the velocity of the falling rocks you will have to provide a superior system to reduce the impact forces. Probably the best way of absorbing the energy from these rocks is to have a belt support system that can move downwards, under impact, thereby providing a longer deceleration distance. With the impact idlers you describe, the total movement will be relatively short and hence the high forces that are destroying the idlers. With some energy absorbing impact systems that can move downwards problems can be experienced at the skirt line with material getting trapped under the skirts when the belt moves under impact. This problem can be solved by supporting the edges of the belt along the skirt line by using a thick bar of UHMW Polyethelene on each side of the conveyor. These edge slide bars are mounted on a fixed structure. With this system only the centre 2/3rds of the belt will be moving up and down on the suspension system. I have had quite good success with this type of belt support system on a conveyor handling primary crushed iron ore with lumps up to 600 mm long falling 3m. The suspension system was based on heavy duty industrial rubber mounts, the idler rollers were 200 mm diameter incorporating 50 mm thick rubber discs and spherical roller bearings, the belt was 36mm thick. Belt life on this installation was increased at least 3 fold compared to the old system that used rubber impact slide beds.
Hope this is of some assistance.
Regards,
David Beckley,
Conveyor Design Consultants of WA
Perth, Western Australia. ■
Impact Detection
We have very good experience with a simple rigid steelplate under the loading point and no rollers, HMPE bars or what so ever.
Our installations have conveyed undefined heavy waste. Even a diesel engine had passes it without any problem.
Make the steelplate 20 mm thick, support it and there you go. Th efriction is less than you might think it will be. Put some greasing talc powder on the steelplate before starting it up.
Jur Lommerts
Jansen & Heuning Bulk Handling Systems
www.jh.nl ■
Re: Loading Problem
Hi Mark Hupertz,
As indicated by Lawrence Nordell, additional information is needed.
However, certain options are immediate possibilities (I'm surprised that the grissly did not aleviate the problem - unless it caused a jam).
1) Redesign the chute to eliminate a straight drop.
2) Install a feed conveyor with a sacrificial belt (straight warp belt will provide improved impact resistance).
3) Redesign the conveyor impact load zone, in conjunction with chute changes.
Regards, ■
Loading Problem
Hi
We are trying to solve a problem for a customer on a coal plant in South Africa who is busy backfilling a section and with top layer (sand, stones etc).
Where the material is loaded onto the conveyor it falls through a basic chute and onto the belt with little to no deflection.
The material can fall from a height of up to 5m vetically onto the belt below.
This is fine if its just sand but when a rock comes down you can imagine the damage to both belt and impact idlers.
They have at present a 35 deg 3 roll system garland type rollers in plain steel as the impact side with rubber cushions on the ends to give some form of spring action.. However these rollers have a 60 dia shaft and a 150 dia roll with a 16mm wall thickness.
The conveyor transports 3000 tons per hour on a 1350mm wide belt running at 4.5m/s
We have suggested that they use a UHMWPE lining on the chute as this will eliminate the build up of material but how can one decrease the impact. They have tried Grizzley bars, but no joy.
The conveyor is at approx 25-30 deg incline.
Any comments welcome.
Thanks
Mark Hupertz
Waloni Industrial cc
www.waloni.com
mark@waloni.com ■