In order to better understand and motivate students to the needs of dynamic modeling and multivariable (MVSISO) design consideration, the case-study of a twinscrew food extruder provides a real-life example with all the requisite components necessary for unit operations management. The study provides a two-input, two-output system able to be simulated via Simulink model that requires knowledge ...

Flow of a polymer in an intermeshing co-rotating twin-screw extruder is simulated. Effect of elongational viscosity on the flow is analyzed using independent powerlaw models for the shear and elongational viscosities. Axial component of the velocity is found to be maximum in the intermeshing region of the extruder. Axial component of velocity, which determines the throughput of the extruder, de...

Autonomic control of food extruders has attracted considerable in recent years. With limited understanding of the complex physio-chemical interactions during the food extrusion process, designing a control system for food extruder is not easy. The common approach is to determine the operating conditions and then to maintain these values as closely as possible using various control loops, if not...

In this paper, a new polymer processing machine--centrifugal extruder is introduced. The pressure and temperature distribution of centrifugal extruder have been studied by theoretical analysis, which is based on mathematics and experiments. The results show that the pressure and temperature Distribution can provide the processing of solid-plug conveying sufficiently and stably, which can prove ...

Accepted: 12/10/2014 Abstract Extrusion is a thermodynamic process which combines several unit operations including mixing, cooking, kneading, shearing, shaping and forming. The principles of operation are similar in all types: raw materials are fed into the extruder barrel and the screw(s) then convey the food along it. Further down the barrel, smaller flights restrict the volume and increase ...

Feed ingredients and complete feeds are exposed to varying degrees of heating during manufacturing and processing. Heat treatment of soybeans is necessary to de-nature endogenous trypsin inhibitors and maximize nutritional value, but overheating can damage protein and reduce nutritional value. This study was conducted to determine the effects of extrusion cooking, the primary method of aquafeed...

A mathematical model was developed to simulate fluid flow, heat transfer, and melting kinetics of starch in a co-rotating intermeshing twin-screw extruder (TSE). The partial differential equations governing the transport phenomena of the biomaterial in the extruder were solved by a finite element scheme. For validating the model, the predicted product pressure, bulk temperature at the entrance ...

In this paper, a delay-compensated bang-bang control design methodology for the control of the nozzle output flow rate of screw extruder-based three-dimensional printing processes is developed. A geometrical decomposition of the screw extruder in a partially and a fully filled regions allows to describe the material convection in the extruder chamber by a one-dimensional hyperbolic partial diff...