Providing a higher skirt clearance or a higher weir
Decreasing the number of rows of caps through which the liquid flows or by decreasing the velocity of liquid flow past the caps or by reducing the distance along the tray through which the liquid must
Using split flow, radial flow or cascade flow for column diameter large than 4 ft
Tendency towards stable operation is increased by increasing the skirt clearance of the caps, lowering the rate of liquid flow per unit plate width or increasing the spacing between the caps
The dimensionless ratio of liquid gradient to pressure drop head caused by the bubble cap assembly should be less than 0.4
None of these
The pressure drop due to the caps & slots and the static submergence should be as high as practicable for reasonable operation