Process of pasta products forming in matrix wells with pre-compaction, plasticization and heating of dough

Abstract

The existing designs of domestic and foreign matrices lack pre-compaction, plasticization and heating of dough, which leads to significant hydraulic resistance in the area where dough flow enters the forming holes of the dies and increases energy consumption, while in typical matrices the cross section of deep and empty wells is much larger than the total area of forming holes. The dough flow almost becomes uncontrollable, and this leads to water hammer effect and destruction of dies. This problem can be solved by installing special inserts in in the matrix wells (depth of wells is 50-120 mm). The paper shows a new direction in design of matrices for production of pasta, in particular, it is proposed to install spiral inserts in the wells of matrix, manufactured in the form of Venturi tubes. Rheological basis of dough flow in the cylindrical channels of the insert are considered, mathematical models for determination of the dough volume flow rate and dough flow rate are constructed. It is theoretically established that the volume flow rate of the dough Q0 and its flow rate depend on the length of the cylindrical channel and the viscosity of dough. The results of experimental researches are presented. It is empirically established that the inserts located in the wells of the matrix pre-compact dough, plasticize and heat it, the productivity of the press machine MIT-2 due to increasing the speed of extrusion is increased averagely by 25-26 % with significant improvement in quality of the formed semi-finished products and reduction of energy consumption.