Transition device for textured protein foodstuff
A device for transferring molten proteinaceous extrudate material from the exit of an extrusion cooker barrel to a cooling die whilst promoting or maintaining laminar flow of said molten extrudate.
1. A device for transferring molten proteinaceous extrudate material from an exit of an extrusion cooker barrel to a single-channel cooling die whilst maintaining laminar flow of said molten extrudate; wherein said device includes:
a transfer channel, through which extrudate flows immediately upon exiting the extrusion cooker barrel;
wherein said transfer channel incorporates a transition zone, immediately adjacent the exit of the extrusion cooker barrel, that has an internal profile that transitions from a shape matching an extrusion cooker barrel exit profile, said shape having a wider horizontal dimension than a corresponding vertical dimension, to a circular profile of diameter ‘d’, and a laminar flow development zone that has said circular profile;
wherein said laminar flow development zone has a minimum length (L e ) equal to 0.06×d×Re, where d=transfer channel diameter and Re=a Reynolds number associated with the flow of said molten extrudate molten extrudate in said laminar flow development zone; and wherein
a internal profile of said laminar flow development zone incorporates a laminar flow transition zone wherein the horizontal dimension of the internal profile transitions to a smaller diameter and then diverges to the circular profile of diameter ‘d’.
2. The device of claim 1 , further comprising a transformation zone wherein the transfer channel has an internal profile that transitions from the circular profile of the laminar flow development zone to a profile that matches an internal profile of said cooling die.