Plate material for chute design is determined by the degree of abrasion resistance that you need based on the product you are conveying . For example we use CHT 100 for most of our chutework in our rock salt environment when we run 6" minus material and then we use 304 stainless steel in rock salt 1/2" minus applications after product has gone through the mill.

As far as belting consideration. Steel cord is noramally used for high tension applications when minimal stretch is required. Fabric belt is much cheaper and should be used when stretch is not a concern.

Gary ■

Dear Mr. Mahmud,

There are two types of belts from carcass point of view. One is the textile fabric belt and the other is steel cord belt.

Designer opts for textile fabric belts for routine application, which are generally economical. The designer would opt for steel cord belt when textile fabric belt is unable to meet the tension rating or take-up becomes unmanageable when conveyor is very long. This is general statement. There are overlapping range of textile fabric belts and steel cord belts. It is difficult to describe in this forum the choice of fabric type among the overlapping range. Refer appropriate literature on the subject. The choice of belt requires good understanding of behaviour of both types of belts for varied situations and expectations.

Regarding chute and liner thickness, it will depend on chute layout, lump mass, lump fall height and abrasiveness of the material. In case it happens to be the feed chute below a large hopper, then forces are to be accounted accordingly. The required chute thickness cannot be mentioned blindly without knowing your application. However, you can have some indication from following values:

- St37 (MS) 6 mm plate for grains or granular material and chute cross section of small size.

- St37 (MS) 8 mm plate for average material bulk density up to 1000 kg/m3 and lump size up to 250 mm.

- St37 (MS) 10 mm plate for average material bulk density up to 1500 kg/m3 and lump size up to 300 mm.

The above values are without wear allowance.

The main plate thickness will increase depending upon the lump size. You have to take the support of your structural designer to know the stress and deformation, when main plate is subjected to force and impact force.

Regarding thickness for hardox liner, you have to get recommended thickness from manufacture of hardox who will have test and field data for their product. The liner is to be also checked for mechanical strength and wear life.

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.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

Dear Mr Mahmud

we normally use 8 mm Ms plate chute mother plate thicken 6 mm is used for grains or very low capacity conveyors.

Liner is very tricky issue

We use polymer / stainless steel 304 liner/ Low nagneese wear resistance plates/Cast manganese steel liner etc basd on application. Care is to be taken that in case of matalic liner its size should not be very big . Some times liner stuck between chute and belt and damages the belt

Regarding belting steel chord belt is generally used for High tension application . it is wrong impression that steel chord belts are expensive. In fact we found they are Cheaper than fabric belts in certain tension ranges.

A R SINGH ■