In this study,a low-capacity single-screw cooking extruder for the manufacture of expanded snacks was designed based on theoretical models and guided operating data and practices of existing cooking extruders.Construc...In this study,a low-capacity single-screw cooking extruder for the manufacture of expanded snacks was designed based on theoretical models and guided operating data and practices of existing cooking extruders.Construction was carried out using locally available engineering materials in modest machine shops satisfying sanitary design criteria and tested using blends of cassava and defatted soybean flour.The extruder developed has throughput,screw speed,barrel diameter,length-to-diameter ratio and power requirement of 13.0 kg/h,200 rpm,40 mm,12 and 1.908 kW,respectively.The cost of the extruder developed was estimated N650,000 in 2016.Extrudates had expansion ratio and trypsin inhibitor reduction which ranged from 1.82 to 2.98 and 61.07%to 87.93%,respectively,across all treatments.This study demonstrates that a low-capacity and affordable experimental single-screw extruder can be designed and built domestically which can be scaled-up for pilot and industrial applications for the production of expanded snacks.展开更多
The use of single and twin-screw extruders for solid-phase reactions is a promising method to intensify a process in a more sustainable manner.In this manuscript,we report a detailed analysis of the residence time dis...The use of single and twin-screw extruders for solid-phase reactions is a promising method to intensify a process in a more sustainable manner.In this manuscript,we report a detailed analysis of the residence time distribution(RTD)in vertical single-screw reactors.The results will help in the selection of the right screw design that would help achieve the desired residence time,which is necessary for a reaction to happen.Experiments were conducted in three vertical screw reactors(having fixed shaft diameter)with varying dimensions using granular free-flowing powders of sodium chloride and silica with a mean particle size of∼25μm.RTD behavior was modeled using the radial particle velocities in the screw reactor's centrifugal field.Further,a method is proposed for estimating the axial dispersion coefficient of dry powders in such sheared flows using true and bulk densities of the powder and the screw shear rate.This dispersion coefficient is used in the axially dispersed plug flow model to describe the RTD behavior of screw reactors with acceptable accuracy.The theoretically predicted and experimentally obtained dispersion coefficients are found to be similar thereby confirming the suitability of the model.展开更多
文摘In this study,a low-capacity single-screw cooking extruder for the manufacture of expanded snacks was designed based on theoretical models and guided operating data and practices of existing cooking extruders.Construction was carried out using locally available engineering materials in modest machine shops satisfying sanitary design criteria and tested using blends of cassava and defatted soybean flour.The extruder developed has throughput,screw speed,barrel diameter,length-to-diameter ratio and power requirement of 13.0 kg/h,200 rpm,40 mm,12 and 1.908 kW,respectively.The cost of the extruder developed was estimated N650,000 in 2016.Extrudates had expansion ratio and trypsin inhibitor reduction which ranged from 1.82 to 2.98 and 61.07%to 87.93%,respectively,across all treatments.This study demonstrates that a low-capacity and affordable experimental single-screw extruder can be designed and built domestically which can be scaled-up for pilot and industrial applications for the production of expanded snacks.
基金funding from CSIR(MLP100926)and SERB(DST,Govt.of India)(CRG//2023/001897-G)for this work.
文摘The use of single and twin-screw extruders for solid-phase reactions is a promising method to intensify a process in a more sustainable manner.In this manuscript,we report a detailed analysis of the residence time distribution(RTD)in vertical single-screw reactors.The results will help in the selection of the right screw design that would help achieve the desired residence time,which is necessary for a reaction to happen.Experiments were conducted in three vertical screw reactors(having fixed shaft diameter)with varying dimensions using granular free-flowing powders of sodium chloride and silica with a mean particle size of∼25μm.RTD behavior was modeled using the radial particle velocities in the screw reactor's centrifugal field.Further,a method is proposed for estimating the axial dispersion coefficient of dry powders in such sheared flows using true and bulk densities of the powder and the screw shear rate.This dispersion coefficient is used in the axially dispersed plug flow model to describe the RTD behavior of screw reactors with acceptable accuracy.The theoretically predicted and experimentally obtained dispersion coefficients are found to be similar thereby confirming the suitability of the model.
