Dear Shri P J Talreja,

Regarding screw feeder, its selection is not governed by capacity and material characteristics only. The screw feeder type and overall arrangement also depends upon feed length (hopper outlet length) and screw feeder length (i.e. feeder length beyond outlet opening). If the hopper outlet length is large, then whether you need material draw-out uniformly along outlet length, or whether non-uniform draw-out is acceptable.

In case the feed zone is long, one can opt for short pitch screw. For average feed length, one can use regular pitch.

The screw feeder / conveyor speed is used as per past experience, traditional practice, material characteristic, etc. Excessive speed will result into faster wear, undue churning, etc. Lesser speed will result into more price.

Refer screw feeder / conveyor manufacturers for specific data, because recommendation depends on overall arrangement of hopper and screw feeder.

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 ■

I would endorse Mr Mulani's comments about the need to seek specialised advice when dealing with bulk materials that may be awkward. Pulverised coal is prone to 'flush' so the feed hopper desigs, feeder interface and screw construction are inter-related to determine how the equipment will perform. Account must be taken of the method of loading and the storage capacity and whether there is any pressure differential or temerature considerations at the discharge.

The sizing of the screw is dead easy, the important parts are the design of the extraction section from the hopper and the discharge configuration into the kiln. I hesitate to encourage inexperienced selection in such an instance, but my book, 'Guide to the Design, Selection and Application of Screw Feeders' gives some pointers to these various aspects. ■

Dear Mr. Mulani

We are designing one screw conveyor of 1000 mm dia for conveying sugar crystals. the hanger bearing diameter selected is 175mm, centre pipe is 356OD and thickness is 16mm. the capacity of the screw conveyor is 80 tph. bulk density of sugar is 950 kg / cum.

I request you to help me in designing the arrangement of hanger bearing with bracket. You can suggest me how I can connect the hanger bearing between the two pipe segments.

thank you

V.Manoj kumar

Originally Posted by I G Mulani

Dear Shri P J Talreja,

Regarding screw feeder, its selection is not governed by capacity and material characteristics only. The screw feeder type and overall arrangement also depends upon feed length (hopper outlet length) and screw feeder length (i.e. feeder length beyond outlet opening). If the hopper outlet length is large, then whether you need material draw-out uniformly along outlet length, or whether non-uniform draw-out is acceptable.

In case the feed zone is long, one can opt for short pitch screw. For average feed length, one can use regular pitch.

The screw feeder / conveyor speed is used as per past experience, traditional practice, material characteristic, etc. Excessive speed will result into faster wear, undue churning, etc. Lesser speed will result into more price.

Refer screw feeder / conveyor manufacturers for specific data, because recommendation depends on overall arrangement of hopper and screw feeder.

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

■

I'm sure Mr. Mulani will be only too pleased to quote you his consultancy rates. ■