Abstract: Disclosed herein is a heat exchange apparatus. The apparatus comprises one or more double walled conduit, each having an outer conduit and an inner conduit located coaxially inside the outer conduit. The conduits define a first fluid passageway for cold water at a first temperature. A drain defines a second fluid passageway for grey water at a second temperature and is located in the drain and downstream of the grey water flowing therethrough. The grey water when flowing in the second fluid passageway effects heat transfer to the cold water flowing in the first fluid passageway across the inner and outer conduits.

Abstract: A rotary coke drum un-heading valve adapted for engagement to an extremity of a coke drum having an orifice therein. The rotary coke drum un-heading valve includes a valve body, having a passage which extends therethrough along a mass flow axis and at least two valve seats that circumscribe the passage. The passage is aligned for mass flow communication with the orifice. A rotatable flow obstructing member defines a bore therein and is rotatable within the valve body between an open position, wherein the bore is in communication with the passage permitting mass flow through the un-heading valve, and a closed position, wherein mass flow through the un-heading valve is prevented by the flow obstructing member. In one embodiment, the flow obstructing member is a gate pivotable in a plane perpendicular to the mass flow axis by a valve stem rotatable about its central axis which intersects the plane.