First,

what is the size and shape of your bin?

is the wear from the stored material sliding on the cone wall?

is the wear from the feed material impacting the wall on filling?

The more information you give, the more helpful will be the answers you receive. ■

you can find some way as following:

1.use the hard facing plate for hopper (We supply the hard facing plate which made in china. Cr7C3 plate mark:UP welding, The life is 14.8 times cabon steel

2.liner plate for hopper use hard facing plate

3.using densit as liner

4.using ceramic liner

5.using basalt liner

6.casing in cement

7.pile up as step chute ■

as attachment

Attachments

bin (JPG)

■

Dear Mahmud:

It is customary for silos to be lined with stainless steel plates.

Stainless steel works fine but on key wear areas, you have to replace it for better wear liners.

I used to service a buffer silo of similar dimensions but our key wear area was the central splitter that diverged the flow to 2 different feeders.

When it comes to doing repairs in silos, you just want to avoid them as much as possible due to the excessive strain on maintenance personnel and the safety risks involved (working in heights, confined spaces, repair material access inside the silo, etc.).

We could provide custom made liners made of ceramic cubes embedded in rubber which would significantly reduce maintenance on your silo.

For more information on detailed applications of our liners in silos feel free to contact me.

Regards, ■

The hopper is shown with a slot outlet, so is not a cone but either a chisel shape or square to round shape, with an effective Vee form in the centre of the outlet region. The respective wall angles on the sides and ends of the hopper section are 63 and 67 degrees, which are not usually steep enough for mass flow in a cone, but likely to generate wall slip on a vee shape hopper, i.e. near the final outlet. Presumably the discharge is controlled by an apron feeder for the size, length and abrasive nature of the product, but it is not clear whether the extraction mobilises flow over the total opening. The wear pattern will probably indicate the relative flow rate along the outlet, so will offer a guide as the to wall area most at risk. Various steps and rib protrusions are sketched on the diagram, so these would normally be expected to inhibit slip on the local walls. It is therefore somewhat surprising to see arrows indicating 'wearing surfaces' pointing to where some of these ribs are indicated.

At the design stage one would measure the wall friction value on a contact surface as the material of wall construction to establish the wall slope that would give mass flow and then determine the critical arch and potential rathole size to make a decision whether the opening to be provided is adequate to give reliable flow without wall slip. The outlet slot length is less than three times the width so the critical arch dimension would have to be less than about 750 mm and critical rathole size less than 2.235 mm for a non-mass flow construction to reliably discharge and self-clear. There is obviously no flow problem with the present arrangement and the 'steps' shown in the walls must restrain local slip, so the hopper is not total mass flow, therefore a long-term residence period of the contents is not an issue. The only reason for selecting 'mass flow', or more appropriately an 'expanded flow' for of hopper construction, would be because the outlet size or rathole potential of a non mass flow constructions were greater than the outlet size available.

The best way to avoid wall wear is to avoid wall slip. Securing the critical arching span and critical rathole diameter will indicate how far above the outlet flow inhibiting ribs may be fitted to leave a totally reliable effective orifice. If, as is likely, this is near or less than the final opening size, upstands can be fitted sticking out from the wall close to the outlet to inhibit wall slip. Should the drained angle of repose be unacceptably steep, this is one of those rare occasions that I would suggest an air cannon be used, fitted just above the flow restraint, to collapse the repose surface when the central core of product is nearly empty. If the flow retraints are reasonably near the outlet, wall pressures, and wear, in the outlet region will be greatly reduced. Otherwise, glass tiles offer good abrasion resistance properties for the small distance between the flow restraints and the final outlet. ■

Do not get too technical

We have

45deg wall angles - with Bissalloy 400 (Hardox 400).

Suggest cone shape and then have a secondary bolted lower section with your transitions to the slot outlet....this will wear faster and can be replaced. Use same materials - Bissalloy 400 and just go thicker!!

Works for years and years!!! Am assuming that you will not empty the bin out all the time ie min/max levels!!

Cheers

James ■

As an employee in one of the big three, i second the above statement..

With the exeption that i would use Hardox 500 over 400.. in any case, no one in their right mind would use above 45° cone/hopper angle, and i much doubt if you will find any lasting sollution i you maintain the design from the sketch.

R ■