Research On Grey Model Of Chip Qualified Rate And Cutting Force Of Typical Biomaterials

The biomass resources such as bush, branch and straw are the main materials processed compact fuels at present, and their chip sizes directly affect the bio-fuel's quality. Therefore, the step of chipping and pulverizing for raw materials is the most essential working procedure in the pretreatment of solidification.Main contents and conclusions are as follows by a vast amount of theoretical analyses and experimental researches:1. According to the chip requirement of briquette on normal temperature, which different from papermaking and wood-based panel industries, taking characteristics of biomaterials such as bush, branch and straw in consideration, and on the basic of chipping and pulverizing equipments' structures current used in domestic, a biomass chipper-pulverizer is designed and manufactured to prepare and study chip granularity below 10mm. And experiments are carried on to further consummate its performance.2. Experimental study for chip granularity is conducting through changing raw material moisture content, cutting rotated speed and cutting gap. Also variance analysis and grey correlative analysis are done with these data. The variance analysis results indicate that, influence on moisture content to chip qualified rate of the four biomaterials in experiment is highly remarkable. Cutting rotated speed certainly influences the chip qualified rate of arundo donax L., but highly to the other three materials. Cutting gap affects highly remarkable on chip qualified rate of arundo donax L., while remarkably on that of robinia pseudoacacia and poplar branch, and it is less relative to chip qualified rate of caragana korshinskii kom. The results of grey correlative analysis show that cutting rotated speed is the most contributing factor to chip qualified rate of robinia pseudoacacia, caragana korshinskii kom and branch of poplar, while water content affects chip qualified rate of arundo donax L. highest because of different physical performance and other conditions of the four materials when test.3. Grey model, called GM (1, 1), is established between cutting rotated speed and wood chip qualified rate. And the criterion of posterior-variance-test is used to test precision of the model. The examination result is the appraisal of this forecast is good. With the grey model of the four materials in test, predict of chip qualified rate when cutting rotated speed reaches 1595r/min can be examined, and the maximal error is 4.74%. The model and the conclusion may analyze the tendency of chip qualified rate at different cutting rotated speed, and also can predict the development of chip quality in the near period. It is helpful to the production quality in actual.4. Main cutting force of the typical biomaterials is tested. A cutting force data acquisition systemis built with data collection card and LabView software. The system will record the cutting force value when test. With these data, variety of cutting force can be studied. This research will be the basis to select and verify the power of self-made biomaterial chipper-pulverizer, and be the reference to design and manufacture biomaterials' harvester.5. Reasonable operational parameter for the chipper-pulverizer is proposed by the result of weighted average method, which takes improvement of chip quality as the goal and consider the production efficiency, power consumption, cutting force and noise for the four typical biomaterials. It lays the foundation to large-scale chip preparation for biomass briquette at normal temperature. The proposed parameter is: 1mm cutting gap and 1276 r/min cutting rotated speed is selected for robinia pseudoacacia, 1mm cutting gap and 957 r/min cutting rotated speed is selected for arundo donac L. but moisture content is less than 28%, 3mm cutting gap, 319 r/min cutting rotated speed and moisture content less than 15% is selected for branch of poplar and chip qualified rate can reach 81.73%. It is difficult to cut off because the bark content of caragana korshinskii kom achieves 26.7%. So in this experimental scope, in order to obtain higher than 80% chip qualified rate, the parameter of the chipper-pulverizer is below 26% moisture content, 1mm cutting gap and 1595 r/min cutting rotated speed.This research will be helpful to large-scale development and comprehensive utilization of biomass materials, especially to the smaller diameter biomaterial below 20mm, and speed up the step of bio-fuel industry, also lay down theoretical foundation for technology parameter optimization of the new type biomass chipper-pulverizer.