Urea Feeder
This is the type of application where the details of the existing arrangement and the full requirements of the client should be examined in order to consider the best option. There is no doubt that a screw could undertake this task and various techniques are available to minimise particle attrition, but there is no substitute for an informed review by a specialist.
I would be pleased to look at this application and put forward my findings on receipt of arrangement drawings of the equipment with indication of the optimum objectives.
Please send to lyn@ajax.co.uk ■
Urea Screw Feeder / Conveyor
The main challenge is the length. With urea you really do not want hanger bearings in the flow of product, because of the corrosive material.
A one-piece 12 m long screw is not self supporting with outboard bearings. You need to consider 2 or more sections.
Therefore I recommend to use a screw feeder, followed by a screw conveyor. If you can live with a transfer point, then make the screw feeder no more than 6 m long and the screw conveyor 7 m or more to overlap at feeder discharge and conveyor inlet.
Another system often used is a continuous screw feeder, changing into larger diameter screw conveyor, using hanger bearings in the conveyor section. By using a larger diameter the loading in the second section, can be lower than 40% and not in full contact with the bearings.
My recommendation is a 600 mm diameter feeder and a 800 mm diameter or larger conveyor.
The other challenge is the feeder inlet. If the bin outlet is a long slot, the screw under the opening should be variable pitch or vary in diameter to produce better mass flow from the bin.
We can design and supplyif we have enough information.
Bill Potma
Industrial Equipment Manufacturing Ltd.
Delt, BC Canada ■
Re: Screw Conveyor For Urea Application
Hello Barry,
We are specialised in the design and manufacture of custom made
screw conveyor systems for difficult applications.
I absolutely agree with the comments made earlier by Lyn Bates.
If you provide us with some more detailed information to look at,
we will prepare a quote for you.
In the meantime I invite you to visit our website.
Regards,
Werner
JACMOR ENGINEERING
www.jacmor.com.au ■
Re: Screw Conveyor For Urea Application
Dear Gentlemen,
Thank you for the feedback. I shall be going to site tomorrow to have a discussion with the engineers to finalize the capacity, geometries and to take some photographs of the site. Will keep you posted. Appreciate the help.
Barry ■
Re: Screw Conveyor For Urea Application
Dear Gentlemen,
Wish to apologize for coming back late on the matter. After a lengthy discussion with the client, it was decided, in view of the conveying length, that they would be installing a belt conveyor instead. I have already begun to prepare the preliminary designs and would like to thank all who have contributed to this thread.
Best regards.
Barry ■
Screw Conveyor for Urea Application
Dear Gentlemen,
I have a client who needs to modify his truck loading system for pelletized urea (2 - 8mm size) to improve traffic flow. The existing equipment is a troughed belt (100 tph) and discharge pipe/swing nozzle arrangement. The belt is fed from an intermediate overhead storage bin of 50 mt capacity. As he needs to redirect the material flow, create more headroom and remove/reposition some of the vertical supports, he is considering moving to a screw conveyor system.
The proposed conveyor would be a fully enclosed horizontal unit mounted to the existing storage bin just after the knife gate. At the other end the material will discharge into a loading hopper with a bifurbicated arrangement to allow simultaneous twin loading. Ideally, he would like to maintain a feed rate of 100 tph with a conveying distance of about 12m.
Since the conveyor will be flood-fed, the client is concerned about compaction/lumping and crushing which will impact the contractual size distribution. Also since the distance is over 12m, can intermediate bearings be used to reduce the shaft size?
Will appreciate any comments and suggestions.
Best regards.
Barry ■