Design and experiment of biomass briquetting machine with vertical double circular mould

Abstract: China is a large agricultural country with rich straw resources. According to the nationwide crop straw survey, although the annual amount of straw resources which can be collected is 687 million ton, the utilization rate can only reach 69%. Therefore, such situation leads to the resources waste, and irrational treatment can caused serious environmental pollution. Biomass briquetting fuels, which have the characteristics of excellent combustion performance and high production rate, can be suppressed by special equipment to block with a certain density. Therefore it can be one of the effective methods of the straw utilization. At present, the briquetting device applies the circular mould structure, and has the problems like low productivity and high energy consumption. Based on the vertical circular mould and double circular mould structures, this article designed new type of double mould and the corresponding pressure roller, had the work principle and main structures research, determined the main parameters of this kind of structure. The angle of the moulds was 8°, the die hole eccentric angle was 4.3°, dual bore centerline angle was 10°, and angles between two pressure rollers was 170°. The production test, applying this kind of equipment, whose material was furfural residue (moisture content and particle length were 26.2% and 6-0.15 mm, respectively) had been finished. The test results included becoming normal particles ratio of lower and upper mould, productivity, density, durability and energy consumption and so on. Test results indicated: The production rate of the briquetting machine was 2.39t/h, energy consumption per ton was 55.86kW·h/t, the ratio of becoming normal particles was more than 96%, and the particle density was more than 1.1 g/cm3. The indicators reached the requirements. Compared with production parameters of single circular mould briquette machine, this innovative device had better performance. Compared with the upper ring mould, the lower ring mould was better in the aspects of productivity and normal particles ratio, density and mechanical durability had the same level. This kind of double circular mould machine promoted the Chinese biomass solid fuel industrial development.