Abstract: A trickle valve useful for removing solids from the bottom of a cyclone separator dipleg includes a valve seat and a reverse angle, integrally counter-weighted flapper plate pivotally mounted on the valve and closed against the valve seat which opens to release particulate solids built up in said dipleg before the solids build to a level greater than their angle of internal friction, thereby clogging the dipleg. The valve seat is at an angle of less than 90.degree. to the horizontal (i.e., 60.degree.) and the counterweight is flush mounted on the plate by welding as an integral part of the plate so that the plate can easily open to 90.degree.. This is useful with cyclones in catalytic crackers and particularly with secondary cyclones in which the fluidized solids loading is relatively light.

Abstract: Disclosed is a fluid catalytic cracking apparatus. The apparatus includes means for decreasing and increasing the slip velocity of a hydrocarbon reaction stream to further enhance catalytic cracking of the hydrocarbon within the reaction stream. The apparatus allows for control of residence time within both a riser and a collection and velocity reducing means to provide for more complete cracking of the hydrocarbon without leading to additional coking of the catalytic cracking catalyst.

Abstract: Disclosed is a system for fluid catalytic cracking. The system includes a method and means for decreasing and increasing the slip velocity of a hydrocarbon reaction stream to further enhance catalytic cracking of the hydrocarbon within the reaction stream. The system also allows for control of residence time within both a riser and a collection and velocity reducing means to provide for more complete cracking of the hydrocarbon without leading to additional coking of the catalytic cracking catalyst.