화학공학소재연구정보센터
Journal of Food Engineering, Vol.50, No.1, 19-24, 2001
Flow modeling of continuous Indian unleavened flat bread (chapatis) former
A mathematical model was developed to predict the flow rate and torque requirements in continuous Indian unleavened flat bread (chapatis) forming system, based on mechanical extrusion. Variables included were screw speed, length to die width, and product moisture. Flow rate and torque were effected by product moisture and die width. For a constant pressure drop, flow rate increased as die width and product moisture increased. The flow rate and torque equations used for modeling were: Q = G(1)NF(dt)(1-delta /H) + G(2)F(pt)/mu (P-1-P-2)/L(1+f) and tau = G(3)N(G(4)mu + G(5)mu (delta)) + G(6)(P-2 - P-1), respectively where Q is the volumetric flow rate, tau the torque input, N the screw speed, F-dt the total drag flow, F-pt the total pressure flow, delta the flight clearance, H the channel depth, mu viscosity of dough in the channel, mu (delta) viscosity in the flight clearance, P-1 dough pressure at input end, P-2 dough pressure at output end, L the length of extrusion section under study in axial direction, f correction for pressure flow and G(1)-G(6) are the constants.