Dear crisapacastillo,

Rotary lock capacity =

Pocket volume * number of pockets * rpm * 60 * bulk density * volumetric efficiency

The volumetric efficiency depends on product flow properties, pressure difference, pocket venting and decreases with increasing rpm.

success

Teus ■

Crisapacastillo,

Be careful not to over-fill the pockets when deciding an increase in capacity. It is a good idea to allow for no more than 80% full.

Also, ask the manufacturer for the recommended maximum speed.

Michael Reid. ■

Is it possible to “control” the volumetric efficiency, rather than live with the resulting volumetric efficiency after having chosen a rpm?

Zero speed results in 100% filling and capacity zero

Infinite speed results in 0% filling and capacity zero

Between zero and infinite, there is a rpm with maximum capacity, not necessarily with a volumetric efficiency of 80%

Or do I overlook something?

BR

Teus ■

Maximum capacity of a rotary valve is imited by its speed. If the speed is too high, rotary valve capacity will reduce because its pockets will not empty out completely.

For your application you should find out the present rotary valve speed. For the new rate of 21600 kgs/hr from 18000 kgs/hr you need to increase the speed by about 20%. This increase should not be a problem unless the present speed is already at the maximum.

For your case, test data shows that the maximum speed should be 25 to 30 rpm. Therefore if your present speed is less than 20 rpm, increasing it by 20% will give you the desired capacity.

Amrit Agarwal

Consulting Engineer

Pneumatic Conveying Consulting

Email: polypcc@aol.com

Ph and Fax: 304 346 5125 ■