Not sure I follow your post. Help us help you by giving more detail.

- Will it be a vertical drop to the conveyor below?

- Is the 33M the distance from the top of the head pulley on conveyor above to the conveyor below?

- You want to size the chute for 2500 TPH?

- A drawing or sketch is worth a thousand words.

You are asking for free consultancy services. You will get general answers but unlikely you will get an answer of any great value especially with the limited information. ■

As gary has said we need more information, help us to help us help you!

You have not mentioned Bindicators/mercury tilt switches either. ■

Originally Posted by KARTHIK.T

Dear Sir,

One of our project my belt conveyor discharge height is 33m. It has to flow to ground conveyor from there. The lump size of coal will be about 250mm and 50 mm.

So normal chute of MS of 10mm will with stand. Capacity of conveying rated will be 2000 T/h and 1000T/h. Design shall be 2500 T/h and 1250 T/h

Please suggest the suitable chute size and any where such fall height is feasible.

Originally Posted by Gary Blenkhorn

Not sure I follow your post. Help us help you by giving more detail.

- Will it be a vertical drop to the conveyor below?

- Is the 33M the distance from the top of the head pulley on conveyor above to the conveyor below?

- You want to size the chute for 2500 TPH?

- A drawing or sketch is worth a thousand words.

You are asking for free consultancy services. You will get general answers but unlikely you will get an answer of any great value especially with the limited information.

Originally Posted by KARTHIK.T

Thank you for you suggetions.

Here with I attached the drg for your review. Here my discharge conveyor is about 34.0 m and further feeding conveyor is at ground.

I can design my further feeding conveyor at 5.0m to reduce the structrual cost planning at ground portal.

Whether chute design is possible for such a high fall.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

About your design its a very large muddy cricket pitch unfortunately

as it has several very large bottle necks that will cause problems.

The idea is to always make it as simple as possible.

IN my opinion:

Your very large feeder belt should be feeding a very large bin/silo that holds one hours

product volume with mercury tilt switches to prevent overflow and belt jam ups.

The bin will feed the takeaway conveyor(s)using twin opposing apron feeders to permit

the flow to always be moving and prevent hang ups of material.

The bin silo with the opposing apron feeders also eliminates the closed chutes, flop gates

and any possible use of vibrators to permit the material to flow.

You want an active flow of material rather than passive using both gravity and mechanical force.

Even the smallest apron feeder will permit you to do this quickly and easily.

I am not trying to muddy your football pitch, I only want you to suceed as I have been through

living with other peoples mistakes that have caused loss of life dealing with clearing bins and silo's. ■

Your layout will create a HUGE impact on the "kicker" section of the chute where it feeds on to the bottom conveyor. With the velocity that will be generated, preventing spillage over the edges of the receiving conveyor will be extremely difficult to contain and the impact on the belting of the receiving conveyor will also be huge causing high wear to the belting.

I would recommend designing in at least 3 preferably 4 rock boxes on the way down with the final rock box being right at the conveyor on the ground. This will create a cascading effect on the fall of material and eliminate the high impact on the chute bottom and the belt below. The rock boxes if designed properly can prevent wear of the chute. I would highly recommend designing the chute with wear plate like AR400 hard plate. MS (I am assuming that is mild steel - but may be different in your country) would not last very long.

The appears to be ample room to angle the chute as well and create a ribbed chute to slow down the fall of material to the conveyor below.

I would be interested in seeing the profile at 90 degrees to your current view. There may be an opportunity to angle the chute also in that direction some but no way to tell from the drawing provided.

My company offers custom transfer chute design services and DEM bulk flow analysis should you be interested. ■

It appears there are flap gates around the 7m level. This reinforces Gary's suggestion for a side elevation.

Who is saying you will get much +249.9mm after such a drop. Even without a side elevation it is quite clear that this proposed plant is seriously unreal. You should examine the upstream issues before pursuing this adventure. ■

Originally Posted by KARTHIK.T

Dear Sir,

One of our project my belt conveyor discharge height is 33m. It has to flow to ground conveyor from there. The lump size of coal will be about 250mm and 50 mm.

So normal chute of MS of 10mm will with stand. Capacity of conveying rated will be 2000 T/h and 1000T/h. Design shall be 2500 T/h and 1250 T/h

Please suggest the suitable chute size and any where such fall height is feasible.

Originally Posted by Gary Blenkhorn

Not sure I follow your post. Help us help you by giving more detail.

- Will it be a vertical drop to the conveyor below?

- Is the 33M the distance from the top of the head pulley on conveyor above to the conveyor below?

- You want to size the chute for 2500 TPH?

- A drawing or sketch is worth a thousand words.

You are asking for free consultancy services. You will get general answers but unlikely you will get an answer of any great value especially with the limited information.

Originally Posted by lzaharis

As gary has said we need more information, help us to help us help you!

You have not mentioned Bindicators/mercury tilt switches either.

Originally Posted by KARTHIK.T

Thank you for you suggetions.

Here with I attached the drg for your review. Here my discharge conveyor is about 34.0 m and further feeding conveyor is at ground.

I can design my further feeding conveyor at 5.0m to reduce the structrual cost planning at ground portal.

Whether chute design is possible for such a high fall.

Originally Posted by lzaharis

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

About your design its a very large muddy cricket pitch unfortunately

as it has several very large bottle necks that will cause problems.

The idea is to always make it as simple as possible.

IN my opinion:

Your very large feeder belt should be feeding a very large bin/silo that holds one hours

product volume with mercury tilt switches to prevent overflow and belt jam ups.

The bin will feed the takeaway conveyor(s)using twin opposing apron feeders to permit

the flow to always be moving and prevent hang ups of material.

The bin silo with the opposing apron feeders also eliminates the closed chutes, flop gates

and any possible use of vibrators to permit the material to flow.

You want an active flow of material rather than passive using both gravity and mechanical force.

Even the smallest apron feeder will permit you to do this quickly and easily.

I am not trying to muddy your football pitch, I only want you to suceed as I have been through

living with other peoples mistakes that have caused loss of life dealing with clearing bins and silo's.

Originally Posted by Gary Blenkhorn

Your layout will create a HUGE impact on the "kicker" section of the chute where it feeds on to the bottom conveyor. With the velocity that will be generated, preventing spillage over the edges of the receiving conveyor will be extremely difficult to contain and the impact on the belting of the receiving conveyor will also be huge causing high wear to the belting.

I would recommend designing in at least 3 preferably 4 rock boxes on the way down with the final rock box being right at the conveyor on the ground. This will create a cascading effect on the fall of material and eliminate the high impact on the chute bottom and the belt below. The rock boxes if designed properly can prevent wear of the chute. I would highly recommend designing the chute with wear plate like AR400 hard plate. MS (I am assuming that is mild steel - but may be different in your country) would not last very long.

The appears to be ample room to angle the chute as well and create a ribbed chute to slow down the fall of material to the conveyor below.

I would be interested in seeing the profile at 90 degrees to your current view. There may be an opportunity to angle the chute also in that direction some but no way to tell from the drawing provided.

My company offers custom transfer chute design services and DEM bulk flow analysis should you be interested.

Originally Posted by johngateley

It appears there are flap gates around the 7m level. This reinforces Gary's suggestion for a side elevation.

Who is saying you will get much +249.9mm after such a drop. Even without a side elevation it is quite clear that this proposed plant is seriously unreal. You should examine the upstream issues before pursuing this adventure.

Originally Posted by KARTHIK.T

Dear Sir,

Thank you very much for your information.

However I have attached the other side view also for your review.

Is it required to provide any hopper kind of arrangment.

=====================================================================================

Greetings,

The short answer for this is yes, as gravity, vertical drop, and a hopper will be your friend.

Please understand we only wish to help you.

NOW;

The issues are again the following

1. the vertical drop.

2. the flap gates.

3. the vertical drop

4. the three transfer points

5. the chutes.

6. the vertical drop

7. the vertical drop.

8. the vertical drop.

9. the narrow drawdown width.

A hopper or pair of roofed and covered hoppers permit the end user a buffer period between the time of discharge

and the point in time when the material is drawn down by the belt conveyor.

Let me give you an example which was relevant in my case for 22 years.

We had a 450 ton per hour belt that fed a 75 ton bin that fed an apron feeder that fed a

two screen Tyler Screen which then fed a series of 30 mesh screeners to remove

fines and the oversize was conveyed to a surge pile on the upper mine level.

YOU have to remember that every time that belt stops the material that falls off

the upper belt is going to land on those impact idlers or impact beds with a THUD

and pack there!!!!

This is only UNLESS the belt timers for the lower belts run for a much longer period to take the material away-

BUT in a high humididity environment that will be problematic if the ores are wet anyway.

ANY wet ore will continue to complicate things on a continuos basis.

Any dust that builds up on the elbows will also create a choke point that will impede flow

especially in a high humidity environment.

If the bin or bins is equiped with apron feeders the material will always be drawn down

propely as long as the width of the exit point is as wide as the apron feeders bed. ■

Originally Posted by Gary Blenkhorn

Your layout will create a HUGE impact on the "kicker" section of the chute where it feeds on to the bottom conveyor. With the velocity that will be generated, preventing spillage over the edges of the receiving conveyor will be extremely difficult to contain and the impact on the belting of the receiving conveyor will also be huge causing high wear to the belting.

I would recommend designing in at least 3 preferably 4 rock boxes on the way down with the final rock box being right at the conveyor on the ground. This will create a cascading effect on the fall of material and eliminate the high impact on the chute bottom and the belt below. The rock boxes if designed properly can prevent wear of the chute. I would highly recommend designing the chute with wear plate like AR400 hard plate. MS (I am assuming that is mild steel - but may be different in your country) would not last very long.

The appears to be ample room to angle the chute as well and create a ribbed chute to slow down the fall of material to the conveyor below.

I would be interested in seeing the profile at 90 degrees to your current view. There may be an opportunity to angle the chute also in that direction some but no way to tell from the drawing provided.

My company offers custom transfer chute design services and DEM bulk flow analysis should you be interested.

Sires

This type of diverter works for coal?

Would not it be better to have two valves on off? One on each line?

Paulo ■

Hi Paulo,

This type of diverter works for coal? Not if its wet: which of course it will be; coming out of a stockpile on its way to the boiler bunkers.

Would not it be better to have two valves on off? One on each line? The single flap diverter or sometimes a trouser leg is always used. The lines must be cleared before, or while, any switch is made. Hung up wet material can dry out and then the 'valve' won't open, or, if it does open downstream then the collapsing material will smash the impact idlers to hell and gone. Diverters are the bulk handling engineers forte. To lay out a plant you have to decide where to split the material flows. After that cometh the unblocked chute and the conveyors can arrive any time later. But first of all you have to know where and how you are going to split off. Those split points determine the heights of the incoming discharge. I've seen transfer towers where this French oil and gas contractor specified a building 10m high overall, within which he expected to accomplish a 3-way split with very wet petcoke. It took a change of sub-contractor before the clown agreed to a reasonable 18.4m betwixt inbye and lowest level outbye. Those people put the fun back into bulk handling. ■

A lot of these ideas look very good. Is your coal always delivered dry? At St-Constant Quebec we designed for dry delivery of coal in all of our transfer points on the way to a ball mill. The port of Montreal moved the material storage ourdoors and when it rained and snowed the coal that was delivered looked more like a slop than coal. Changes in chute work going from square to round created hang-ups and blockage. We ended up with a lot of rework especially around the square airlocks located prior the mill and also had to hang rubber in the conveyor head to prevent build-up from happening there.

Good luck with your design

Liam ■

Looking at all these replies I suggest you read the paper we presented (Technical Paper section of the Forum) as here we had a drop height of 17 metres with iron ore at the flow rate was 20,000 tph. Operating now for 8 months, no maintenance, no dust, no spillage, receiving belt looks like it could last for a very long time. So conceptually drop height is not an issue as far as transfer design is concerned although such a tall transfer is not what you would normally recommend. Putting in a bin or similar just moves the maintenance burden from the transfer to the bin. How do you design a low maintenance viable transfer, if it is free flowing ore I suggest you get a copy of our book that is advertised on the Forum banners, if the material is at cohesive or adhesive in nature, can still be done but this is the subject of our patent and the paper above.

Cheers

Colin Benjamin

Gulf Conveyor Systems Pty Ltd

www.conveyorsystemstechnology.com ■

Hello T Karthik,

Your requirement is to bring down the material at reasonable speed from 33 m high discharge, by using chute. For this, the traditional method is to use ladder chute i.e. vertically spaced overlapping shelves within chute, where material drops from one shelf to next till it reaches bottom. The ‘reasonable’ speed that can be achieved by chute of such a height will not be stable (accurate) enough to suit feeding on outgoing belt conveyor, although it could be ok for stockpiling or feeding into hopper etc.

1) The resulting outlet speed is by loss of kinetic energy at each shelf which could vary due to characteristic variation of material (hardness, size, moisture content, etc. within the usual range of material), so instantaneous material flow volume as well as velocity would not be suitable for belt conveyor.

2) Also, using shelf (stone box) for coal would be hazardous, because it is said that it increases the chances of spontaneous fire (Indian power station do not use stone box arrangement for coal).

3) Review the system layout avoiding such transfer of material.

4) In case the other readers have suitable suggestion, you can think about it.

Ishwar G. Mulani

Author of Book : Engineering Science And Application Design For Belt Conveyors (new print November, 2012)

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: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■

What prevents you from lifting the tail pulley to reduce fall distance and to gain power back from ore running on decline? ■