Studies On Extrusion Processing Technique For Blood Meals

Extrusion can improve the quality of blood meals, increase blood meals protein digestibility percentage, simplify the technology of production, protect environment, etc. The influence regularity of extrusion machining parameters on the quality of blood meals is the basement of which the technology of extrusion can use in processing in blood meals. Up to now, the main shortcoming of extrusion is low level automation control and sole specification of extruder, etc. The object of the paper was extrusion of blood meals, and improved the die of extruder, studied into the influence regularity of extrusion machining parameters on expanding blood meals protein digestibility percentage, the productivity of extruder and the pressure between die and anti-rod in processing, to find the optimum combination of extrusion machining parameters.1. The experiment designed and machined five extruder's screw of different pitch to explore influence that bring on the quelities of blooding meals and system parameter in changing screw parameter on blooding meals.2.The research preliminarily summarized the influence regularity of the extrusion parameters( moisture content, screw speed, screw pitch, and die diameter) on the quality— digestibility of expanding blood meal and the pressure between die and anti-rod by single factor experimentation. The regularity of the digestibility of expanding blood meals by single factor experimentation showed: Water content 21%, screw speed 240r/min, screw pitch 34mm and die diameter 14mm could get the highest blood meals protein digestibility percentage, and the machine worked stably.3. From the analysis by comparing every extruder machining parameter on the blood meals protein digestibility percentage and pressure between die and anti-rod the research also found the pressure between die and anti-rod had a strong impact on expanding blood meals protein digestibility percentage by single factor experimentation ;When the pressure between die and anti-rod is in 2. 2-2. 4MPa, expanding blood meals protein digestibility percentage is good;The extruder don't run stably and expanding blood meals protein digestibility percentage is not good when the pressure between die and anti-rod is too great or small.4. Based on single factor experimentation, the research studied the influence regularity of digestibility of expanding blood meals, the productivity of extruder and the pressure between die and anti-rod by the method of quadratic orthogonal rotation combination design test of four factors and five levels, which established the mathematics model between each evaluation index sign and extrusion cooking factors.5.The research evaluated the optimum solution of multi-targets nonlinear programming...