The liquid feed nozzle assemblies for a circulating fluid bed reactor comprise (i) a throttle body premixer to combine liquid feed with atomization steam upstream of a nozzle body to form a liquid feed/steam mixture comprising liquid feed droplets; (ii) a conduit connected to the venturi premixer and to a discharge nozzle body to convey a flow of the liquid/steam mixture created by the premixer to the nozzle body; (iii) a discharge nozzle connected to the flow conduit to shear the liquid feed/steam mixture to create liquid feed droplets of reduced size and (iv) a disperser at the outlet of the discharge nozzle to provide a spray jet of liquid feed having an increased surface area relative to a cylindrical jet. The nozzle assembles are particularly useful in fluid coking units using heavy oil feeds such a tar sands bitumen.