Curing Screw Feeder Problems, A Case Study

AJAX Equipment

Milton Works, Mule Street, Bolton, UK, BL2 2AR
Tel: (0)1204 386723      Fax: (0)1204 363706

Case Study - Screw Feeder Problems.

A specialised herbicide manufacture was experiencing perennial feed and operational problems with an inclined agitated screw feeder which required virtual constant operator attention to prevent arching.

The unit had been manufactured by a local fabricator who had based the design upon a common form of feeder layout incorporating twin agitators above the screw to counter arching. Whilst the standard of engineering and construction were adequate, the performance as a feeder was abysmal, a classic example of the crucial importance of apparent minor differences of design and the need for specialised attention when dealing with poor flow materials.

Steps which had been taken by the customer to overcome some problems had, in turn, introduced others and had damaged some parts of the equipment.

Ajax Equipment was asked to provide a consultancy service and identified 13 detailed design features which were adverse to good performance and led to poor feed accuracy and consistency, unreliable flow, excess residue left in the hopper at the end of the run and erratic overloading of the drive unit. Apart from some actual damage, the working stresses gave concern for future durability of the equipment.

In addition to setting out an economical program for rectification directed to prevent these problems as well as securing unattended reliability well within the design capacity of the equipment, Ajax also advised on good practice for operational matters and the fundamentals to hopper design including features of different options relating to inclined feeders fed from inclined hoppers. They also demonstrated, by means of in-house wall friction tests, the methods and results for determining necessary wall inclinations for mass flow and self clearing duties.

Whilst the modified equipment is capable of meeting the duty, it is compromised by its original form and consideration is in hand for a replacement offering additional benefits such as extra holding capacity and greater flexibility of use.

Ajax Equipment provide a powder testing service as a part of their wider consultancy services for evaluating new appliances and 'trouble shooting' problem areas.

facebook   youtube

Click Here to receive electronic copies of our Newsletters, Publications and Papers