You've forgeotten to ask for detail drawings and a bill of material. ■

Originally Posted by mohandes

all of these questions are very normal in this site.

Ain't that the truth

Everybody wants something for nothing ..... ■

Mohandes,

Yes, we have made this site free of charge for all people all around the world, i.e. we present a platform for an exchange of information.

But you are asking for answers which usually are given by consultants, and these make a living from presenting solutions.

You can contact equipment manufacturers who may be interested in selling an inclined belt feeder, or any feeder, but you cannot expect to receive answers from consultants who depend on selling their know-how. Everything has its price.

You are trying to make money for your company, and so are they.

Perhaps you may find an operator somewhere, who may have had the same problem, and perhaps he tells you about his experience, but then, can you trust his experience?

Reinhard Wohlbier ■

Dear Shri Mohandes,

In general, inclination is not good for belt feeder because there is a less grip between material and belt as compared to the apron feeder. Also, if you intend to give expanding type of skirt board, then you will have difficulty with the inclination.

Whether to have expanding type of skirt board or not, depends upon the length of feed-zone, which is not mentioned by you.

Regards,

Ishwar G Mulani.

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

Author of Book : Belt Feeder Design and Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India.

Tel.: 0091 (0)20 25871916

Email: parimul@pn2.vsnl.net.in ■

Do not incline a belt feeder. The granular flow is inhibited due to the inclination angle. Look at a 2-D image. The back end has a larger area presented to the flow field, while the front end (discharge gate) is more restricted relative to the back (tail station). This will stall the tail zone mass flow causing additional wear on the belt and will stagnate the tail zone material reclaim. This is aggravated by the inclination angle and material grip action as noted on a prior thread.

Additionally, such belt feeders will normally have other restrictions beyond the discharge gate. Such feeders are often placed in tunnels where they suffer from convergence with the tunnel roof, making maintenance repairs more difficult and limiting the placement and size of the discharge head chute.

If the feeder is declined, then all noted above features have the opposite effect. ■

Originally Posted by mohandes

why I should not ask about belt feeder?

You can ask whatever questions you like, but it is up to the contributors to this site whether they give you an answer or not. The choice of giving an answer is theirs. ■

Inclined belt feeder/belt conveyors are sued eg FEL reclaim hoppers to belt conveyor or truck dump hopper with need to reduce depth and transfers...but what I have seen is low rate 200tph max

I would not consider this for 1000tph

You need to do material flow testing > to get the minimum recc. hopper opening sizes - for cone or slot hopper discharge...do not want arching etc.

Belt size will come from there...typ. 0.5m/sec maximum

Flat belt or picking belt type configuration

Given high rate, belt will be wide...so transfer to a conventional belt conveyor (narrower).

The hopper/belt feeder interface has to be designed well to make it work.

You mention funnell flow...well this is not for belt feeders!

Thanks ■

The lump size dictates the inimum width of outlet and minimum clearance hight at exit to avoid mechanical arching and wedging in non-mass Flow conditions. A publication fro Ajax equipment Ltd gives guidence on this feature as is information about hopper interface profiles for progressive extraction, but this is not a normal feeder translation operation . Optimisation of the belt interface is concerned with minimising contact pressure on the belt and extraction shear so the best approach would seem to be constructing a 'wear box chute' that allows the belt to carry away the repose flow from a non-slip transition surface. The transfer capacity of the inclined conveyor will then be self-regulating and exposed to neglible wear. This is an interesting design project. ■

The lump size dictates the minimum width of outlet and minimum clearance height at exit to avoid mechanical arching and wedging in non-mass Flow conditions. A publication fro Ajax equipment Ltd gives guidence on this feature as is information about hopper interface profiles for progressive extraction, but this is not a normal feeder translation operation . Optimisation of the belt interface is concerned with minimising contact pressure on the belt and extraction shear so the best approach would seem to be constructing a 'wear box chute' that allows the belt to carry away the repose flow from a non-slip transition surface. The transfer capacity of the inclined conveyor will then be self-regulating and exposed to neglible wear. This is an interesting design project. ■

Dear Shri Mohandes,

I would like to add some more information in respect of my earlier reply, for clarity.

One does come across incline belt feeder up to certain inclination depending upon material. Such installations are for limited size truck unloading transitional hopper and often for less mtph. In such cases, feed zone length needs to be small, say close to skirt board width. It would not be possible to give expanding type of skirt board in context of long feed zone, for inclined belt feeder. The issue has relevance to the qualitative performance. One can give inclined belt feeder in non-suitable situation, wherein it will appear to be working but it is having abnormally high rubbing of material with the belt, quicker wear of belt etc. It will also depend upon abrasiveness, lumpiness of material, whether installation for round the clock operation or for intermittent operation, etc. while opting for certain inclination.

In a simple statement, one should try to remain away from giving higher inclination unless he is well versed with the belt feeder and is in a position to predict the correct solution by taking in to account applicable influences.

Regards,

Ishwar G Mulani.

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

Author of Book : Belt Feeder Design and Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India.

Tel.: 0091 (0)20 25871916

Email: parimul@pn2.vsnl.net.in ■

12 degrees is not excessively steep for a belt conveyor handling a granular material. The abrasive nature of the material requires that both the bin and the belt are protected against high contact pressures and relative slip. The feed hopper therefore requires a funnel flow construction, which is quite practical provided that flow is reliable and adequate. Structural arching must be avoided by ensuring the cross section of flow is larger than a potential blockage. A key feature of the transfer to the belt would be to transform from a conventional cone or pyramid shape to a parallel sided chute inclined only slightly more than the angle of wall friction leading to a side outlet, the terminal repose condition of the material resting on the belt, which is wide enough to accept the transverse repose when extracted. Under these circumstances the belt acts as a moving valve plate taking away the iron ore without impact, sliding or pressure, other than self weight. Perhaps not a conventional soution, but it seems to offer sound scope for an effective feeder. No charge for the idea. ■

Dear Lyn,

I agree with your understanding as this applies to belt conveyor transfer chutes and granular dynamics. I disagree with this notion regarding belt feeder granular dynamics.

Typical belt feeders have substantial head pressure and have a much higher granular shear force interaction with particle-to-particle, particles-to-wall, and particles-to belt than a typical chute and skirt transfer regime. Thus, feeders are far more sensitive to these interactions and their consequences.

The basic issue is the convergence of the granular stream, when the belt feeder is positively sloped at a angle that constricts the flow stream as it approaches the exit shear gate.

We can demonstrate this dynamic granular action using DEM. The issue is not that it cannot be done, but, this slope can vastly accelerate belt wear and increase feeder power, depending on the severity of the slope.

A 12 degree positive slope on a belt feeder would be very severe. ■

Hi Nordell,

I believe that we are talking at cross purposes as my suggestion in not for a conventional form of belt feeder that interfaces directly with the belt, which would involve considerable stresses and belt wear. The proposal is to exploit the discharge from an inclined chute as a live flow stream with a horizontal, unconfined flow component in line with the belt motion. The lack of confinement is the key to eliminating both active and passive pressure on the belt and the repose flow velocity should virtually eliminate product acceleration, accoding to the belt size and speed.

regards,

lyn ■

Dear Lyn,

A further note on your comments. There are apron feeders that reclaim on a positive slope of up to 22 degrees. They are sometimes refered to a "glory hole" reclaimers.

The truck dumps the load into a pit which directs the flow onto the apron feeder. The feeder is buried below the heap. A natural repose angle is formed as the feeder moves up the incline with the product. Side walls are integral with the design. They work on a different principle. The head pressure diminishes with the incline as does the side pressure.

The granular flow dynamics are only restricted by particle interactions with a free unconfined top surface. Based on the feeder angle and material angle of repose the reclaim crossection produces a self regulated feeder head height.

These feeders are often used to regulate flow to gyrator and jaw crushers. ■

I agree with cross purposes. My second comment was answered by your second comment, just a short pause in responses.

Keep up the good work. ■

I have not seen the "Glory Hole" type feeder in a belt configuration, only with apron feeder pans due to high potential wear and grab (shear) action between pan and product. ■