Research On Low Temperature Screw Press Equipment Of Tigernut(Cyperus Esculentus L.) And Pressure Distribution Of Squeezing Chamber

Tigernut is rich in high-quality oil,and it has the characteristics of high starch and high sugar content.At present,there is no experience of its screw pressing.Therefore,it is necessary to develop a new screw press structure for its low-temperature press.As an emerging oil crop,its optimal pressing pressure distribution remains to be explored.In this paper,the structural parameters of the pressing components are optimized for low-temperature pressing of tigemut,and low oil residue pressing at 65? is realized.At the same time,the real-time collection of the pressure in the squeezing chamber during the squeezing process of tigernut is alized.This article mainly carried out the following aspects of research:1.Based on the 40 kg/h oil press,this paper designed five sets of press spirals,cooling parts,feeding parts to make it suitable for the low-temperature press test of tigernut,Use SolidWorks to build a three-dimensional model,and complete the assembly of each component and virtual prototype.2.In this paper,a hydraulic oil press is used to perform the pressing test and the pressure-strain curve is obtained during the pressing process.Depending on this curve,the pressure boundary conditions of each spiral in the screw press are predicted.Using ANSYS software to analyze the pressure distribution of the fluid in the squeezing chamber the pressure cloud map of the spiral surface and the radial cross section is obtained,which provides the basis for the pressure range and distribution characteristics of the sensor selection and installation.3.In this paper,resistance strain gauges and melt pressure sensors are selected to collect the pressure in the squeezing chamber.The resistance strain gauge is calibrated using a material testing machine to obtain the pressure-current relationship of the strain gauge.Connect the sensor and get through the test:the highest pressure per minute measured by the resistance strain gauge and the melt pressure sensor at the same position is the same,which proves that the strain gauge sensor is accurately calibrated and can be used for real-time pressure collection in the squeezing chamber.4.This article complete the manufacture of the prototype and optimizes the structural parameters through orthogonal experiments.The results show that the primary and secondary factors that affect the squeezing effect are the total theoretical compression ratio of the screw,the squeezing gap between the bars,and the cake gap.The optimal structural parameters of tigernut oil squeezing at low temperature are:the theoretical total compression ratio is 10,the squeezing gap between the bars is 1.2 mm,1.0 mm,0.8 mm,0.8 mm,0.6 mm,and the cake gap is 1.5 mm.Under this condition,the residual oil rate of the pressed cake is 5.1%,and the impurity rate of the oil sample is 7.11%.The pressure sensors were utilized to collect the pressure in the squeezing chamber during the squeezing process of the optimal structure parameters of tigernut.The maximum pressure in the squeezing chamber measured to be 40 MPa,and the pressure distribution in the squeezing chamber that was most suitable for the low-temperature pressing of tigernut was obtained.