scholarly journals Effects of Extrusion Conditions on Physical Properties of Sorghum Based Extruded Products

Author(s):  
Byreddy Naveena ◽  
Mohan Singh

Extrusion cooking is a high temperature short time multivariable unit operation. In this study, response surface methodology (RSM) was used to evaluate the effect of feed parameters i.e., feed moisture (8-16%), blend ratio of sorghum:barley:bengal gram, (70:15:15 to 50:35:15) and machine parameters of twin screw extruder i.e., barrel temperature (120-200oC) and screw speed (120-200 rpm) on physical properties of extrudates i.e., mass flow rate, bulk density and moisture content. The results showed that maximum mass flow rate (0.974 g/s) was observed with the blend ratio 60:25:15, having 8 percent moisture (w.b) extruded at 160oC barrel temperature and a screw speed of 160 rpm. The bulk density of extrudates was found minimum (0.08 g/cc) at 10% moisture content, 65:20:15 blend ratio, 180oC barrel temperature and 180 rpm screw speed and the moisture content of extrudates was found minimum (4.74%) at 10% moisture content, 55:30:15 blend ratio, 180oC barrel temperature and 140 rpm screw speed.

Author(s):  
Dan Huang ◽  
Wei Li ◽  
Wei Zhang ◽  
Guo-Qiang Xu ◽  
Zhi Tao

A research on the heat transfer performance of kerosene flowing in a vertical upward tube at supercritical pressure is presented. In the experiments, insights are offered on the effects of the factors such as mass flow rate, heat flux and pressure. It is found that increasing the mass flow rate could enhance the heat transfer performances, while increasing the working pressure will deteriorate the heat transfer. Besides, the effect of heat flux on heat transfer is complicated. Based on the analysis of experimental data, enhancement of heat transfer occurs when the inner wall temperature of tube is higher than pseudo-critical temperature while the bulk fluid temperature is lower than the pseudo-critical temperature. At the supercritical conditions, heat transfer is influenced by the significant changes in thermo-physical properties, thus accurate evaluations of the thermo-physical properties become the key for the supercritical heat transfer calculations. The extended corresponding-state principle could be used for evaluating the density and the transport properties of kerosene, including its viscosity and thermal conductivity, at different temperatures and pressures. In order to obtain the numerical values of the heat capacity, a Soave–Redlich–Kwong (SRK) equation of state is used. The correlation for predicting heat transfer in kerosene at supercritical pressure is established, the calculation results from this correlation are in good agreement with the experimental results.


2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Prashant Singh Chauhan ◽  
Anil Kumar ◽  
Chayut Nuntadusit ◽  
Shyam Sunder Mishra

A greenhouse dryer under forced convection mode is designed and fabricated with the integration of solar collector and variable speed exhaust fan. The developed system is used for bitter gourd flakes drying under three different air mass flow rates (0.0275, 0.0551, and 0826 kg/s). Moisture content of bitter gourd flakes was decreased effectively from 96.8% to 12.2% in 17 h with optimum air mass flow rate 0.0551 kg/s, whereas open sun drying has taken 26 h to reach 20.7% moisture content. The average greenhouse dryer efficiency was found to be 19.7% at 0.0551 kg/s air mass flow rate. Shrinkage (in terms of percentage) of dried bitter gourd flakes was found to be higher as 74% at 0.0275 kg/s air mass flow rate because of higher greenhouse room air temperature. Hardness of dried bitter gourd flakes was found to be highest as 365 g at 0.0275 kg/s air mass flow rate due to less air exchange rate and high inside room temperature. On the basis of statistical analysis, Prakash and Kumar model and Logarithmic model were selected as best drying models for greenhouse and open sun drying, respectively. The dehydration of higher moisture content crops inside developed greenhouse dryer was found to be more consistent. The designed greenhouse system is recommended for small farmers.


Author(s):  
S Venkata Sai Sudheer ◽  
K Kiran Kumar ◽  
Karthik Balasubramanian

This paper aims to present the steady-state behaviour of two-phase natural circulation loop at atmospheric and sub-atmospheric conditions. One-dimensional numerical approach is adopted to evaluate various system parameters, with special emphasis on spatial variation of thermo-physical properties and flashing. Homogeneous equilibrium model is applied for two-phase flows. An in-house code is developed in MATLAB to solve numerical model iteratively. It is observed that consideration of spatial variation of thermo-physical properties can precisely predict the loop behaviour. The evaluated results are validated with the open literature and reasonably good agreement is observed. The heater inlet temperature, inlet pressure and heat flux are found to have significant influence on spatial variation of pressure, temperature and enthalpy. As system pressure decreases from atmospheric to sub-atmospheric (1–0.8 atm), it is observed that the sub-atmospheric loop gives a higher mass flow rate compared to atmospheric loop at lower heat fluxes. However, as the heat flux increases in the sub-atmospheric loop, the mass flow rate is reduced due to increased drag force in the loop.


2019 ◽  
Vol 35 (5) ◽  
pp. 815-822
Author(s):  
Thomas R. Way ◽  
Haile Tewolde ◽  
Dexter B. Watts

Abstract. Broadcast application is the typical application method for poultry litter, which is a mixture of poultry manure and a bedding material. Applying poultry litter in subsurface bands reduces concentrations of nutrients from the litter in surface runoff water, reduce loss of ammonia to volatilization, and has been shown to increase cotton lint yield, relative to conventional broadcast application. An impeller blower was developed for conveying poultry litter a short distance horizontally and downward to the soil. When relatively dry pine shavings-based broiler litter with a moisture content of 27% w.b. was used, and the impeller speed was 930 r min-1 [14.9 m s-1 (48.9 ft s-1) circumferential speed], the blower performed well conveying litter at a rate of 1.2 kg s-1 (2.6 lb s-1) [0.88 kg dry matter s-1 (1.9 lb dry matter s-1)]. The blower performance was unsatisfactory, however, when relatively moist litter with a moisture content of 45% w.b. was used because the litter adhered to the interior of the blower outlet and clogged the outlet. The blower was mounted beneath a litter hopper, and safety of people in the vicinity of the blower is a concern if the litter contains rocks or other hard objects, and there is no shield to prevent these objects from being flung upward, out of the hopper, from the blower inlet. When the blower was run at 889 ± 14 r min-1 without any litter, so it was conveying only air, as the area of the circular blower inlet increased by a factor of 25 from 0.00051 to 0.0127 m2 (0.79 to 19.6 in.2), the mean outlet air velocity increased by a factor of 4.0 from 3.0 to 12.0 m s-1 (9.8 to 39.4 ft s-1). The blower conveyed dry litter successfully for a single-band implement [1.2 kg s-1 (2.6 lb s-1) mass flow rate at 930 r min-1 impeller speed], for subsurface band application of poultry litter. Mesh chain conveyors, however, perform better for litter moisture contents up to 40% w.b. The mass flow rate of litter, up to 40% w.b. moisture content, can be controlled quite well with mesh chain conveyors (litter mass flow rate coefficients of variation typically 5% or less), but is more difficult to control with this impeller blower. Keywords: Animal waste, Band application, Impeller blower, Manures, Manure application equipment, Pneumatic conveying, Poultry manure, Subsurface banding.


2014 ◽  
Vol 60 (No. 4) ◽  
pp. 148-154 ◽  
Author(s):  
O.B. Oduntan ◽  
O.A. Koya ◽  
M.O. Faborode

This paper reports on the design of fabrication and testing of a machine for cottage level production of pellets from cassava mash. The pelletizer consists of a barreled screw auger which compresses cassava mash against perforated end plate, through which the pellets are pelletized. The result derived from the calculated design parameters (shaft diameter, tensile stress, torque, screw length, volumetric capacity mass flow rate and power rating) were used for the fabrication. The testing of the pelletizer was determined in terms of throughput of the machine, against the moisture content of the mash (18, 20 and 22% w.b.), die size (4, 6 and 8 mm) and the auger speed (90, 100 and 120 rpm). Test results showed that the pellets with the best quality attributes were obtained from cassava mash at 18% moisture content (w.b.) through the 4 mm die at 90 rpm and a maximum throughput of 54 kg/h.


Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1628
Author(s):  
Soonmo Cho ◽  
Euntaek Lee ◽  
Seunggi Jo ◽  
Gyu Man Kim ◽  
Woojin Kim

As the market for minimally invasive surgery has grown, the demand for high-precision and high-performance catheters has increased. Catheters for the diagnosis and treatment of cardiovascular or cerebrovascular disease mainly use a braided wire tube with a polymer inner liner and outer jacket to improve the pushability and trackability. The outer jacket should have an accurate inner and outer diameter and while maintaining a wall thickness of 150 µm or less. In this study, we designed and manufactured a tip and die capable of extruding an outer jacket with a wall thickness of 150 µm or less using a medical thermoplastic elastomer for manufacturing 8Fr (2.64 mm diameter) thin-walled tubes. The ovality and inner/outer diameters of the tube were studied according to changes in the screw speed (mass flow rate), puller speed, air pressure applied to the lumen, and distance between the quench and head, which are the main variables of microextrusion processes. The screw speed (mass flow rate), puller speed, and air pressure affected the inner/outer diameter of the tube, with screw speed and puller speed having the largest influence on diameter. The air pressure and distance between quench and head had the greatest influence on ovality. The results show the effect of different processing parameters on the characteristics of the extruded tube, which will help to establish a stable extrusion process for the manufacture of outer jackets for braided catheter shafts.


Author(s):  
V.N. Petrov ◽  
◽  
V.F. Sopin ◽  
L.A. Akhmetzyanova ◽  
Ya.S. Petrova ◽  
...  

Author(s):  
Roberto Bruno Bossio ◽  
Vincenzo Naso ◽  
Marian Cichy ◽  
Boleslaw Pleszewski
Keyword(s):  

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