The Experimental Research On Separating Cover-Pith-Leave Of Corn Straw

In recent years, more attention was attracted by the comprehensive utilization of corn straw. On the basis of summarizing the comprehensive utilization's meaning and status of corn straw, and the domestic and foreign research status of mechanical separation technology for cover, pith and leaf of corn straw, one of the key technologies in comprehensive utilization of corn straw——mechanical separation technology for cover, pith and leaf of corn straw was experimented in the paper.The main technics of cover, pith and leaf of corn straw separation processing: remove leaves——cut stem——strip pith. By analyzing the key processing technics, the three test stands for separating cover-pith-leaf of corn straw were designed and experimented in this paper. On the basis of preliminary experiments, the combination experiments of structure parameters and motion parameters for the key mechanisms were made by using quadratic orthogonal rotating combination test method. The relation curves and regression equations between evaluation indexes and corresponding factors were obtained by using the Design-Expert software. The optimization parameters for structure and motion were obtained by farther optimization, and the verification experiments were made. The paper supplied reference for designing separating cover-pith of corn straw machine. The concrete content was as follows:1. In the separation experiment of stem and leaf, de-leafing ratio and damage ratio were applied as evaluation indexes, and rotation speed of de-leafing roller (650 ~ 1050 r/min), clearance value of adjacent teeth-plate (35 ~ 45 mm) and moisture content in stem and leaf(15 ~ 65%) were applied as the main influence factors. The experimental method of the three-factor and five-level quadratics rotary orthogonal combination design was adopted. The experimental datas were processed by Design-Expert software and frequency analysis method. By experiments, the suitable parameters in structure and motion were obtained: rotation speed of de-leafing roller 760 ~ 980 r/min, teeth-plate clearance 39 ~ 40 mm and moisture content in stem and leaf 65%. When rotation speed was fixed in 851 r/min, clearance was fixed in 39 mm, moisture content is fixed at 65%, by verification test, obtained de-leafing ratio and damage ratio closed to the theoretical value.2. In the cutting stem experiment, cutting performance was applied as evaluation index, and rotation speed of riving knife roller(700 ~ 1100 r/min) and grooves width (10 ~ 50 mm) were applied as main influence factors. The experimental method of the two-factor and five-level quadratics rotary orthogonal combination design was adopted. The experimental datas were processed by Design-Expert software and frequency analysis method. By experiments, to get the best cutting performance, rotation speed of riving knife was 961 ~ 1031 r/min, grooves width was 19 ~ 28 mm.3. In the separation experiment of cover and pith, stripping ratio and damage ratio were applied as evaluation indexes, and rotation speed of stripping-pith roller (1200 ~ 2000 r/min), clearance between cutting blade and bottom plate (1 ~ 5 mm), cutting blades (1 ~ 5 pieces), moisture content in corn straw (15 ~ 75%)were applied as the main influence factors. The experimental method of the forth-factor and five-level quadratics rotary orthogonal combination design was adopted.The experimental datas were processed by Design-Expert software and frequency analysis method. By experiments, the suitable parameters in structure and motion were obtained: rotation speed of stripping-pith roller 1275 ~ 1700 r/min, clearance between cutting blade and bottom plate 2.2 ~ 2.6 mm, cutting blades 5 pieces and moisture content in straw 60%. When rotation speed was fixed in 1495 r/min, clearance was fixed in 2.3 mm, cutting blades was fixed in 5 pieces and moisture content is fixed at 60%, by verification test, obtained stripping ratio and damage ratio closed to the theoretical value.