【作者】 赵伟；

【导师】 曹志清；

【作者基本信息】 北京化工大学 ， 机械设计及理论， 2008， 硕士

【摘要】 食品挤压技术是二十一世纪食品工业的发展方向之一。食用米粉在我国的发展历史源远流长,大米是我国的主要粮食作物之一,作为以大米为主要原料生产的米粉已经成为我国民众的热衷食品。尤其近年来,随着经济的发展、社会的进步、文化的交流,米粉正在冲出国门、走向海外。同时,我国米粉加工业技术也有了长足的进步,米粉品种、生产工艺不断创新;生产设备不断完善,市场规模日趋扩大。但目前的生产技术仍没有达到现代化生产的水平。本文在分析了传统米粉加工工艺特点的基础上,提出了新的适应于节能减排降耗的米粉加工方法,并设计改进了现有的生产设备。在大量米粉挤出实验的基础上,分析了加工工艺和挤出机结构对米粉品质的影响,并进一步改进了加工工艺,改进单螺杆挤出机的结构。本论文对影响米粉品质的一些因素如大米原料的品质(包括大米中直链淀粉的含量和大米的储藏期)、含水量、温度、螺杆转速等进行了综合考虑,对影响米粉的柔韧性、断条率、产量等因素进行了探讨,并进行了实验验证。本实验机台接口统一,便于更换不同部件和组合部件的安装顺序,以测试不同部件和不同部件排序对米粉品质挤出的影响。通过实验我们得知本实验采用新工艺并用所设计的单螺杆挤出机,可实现对大米的挤压加工,并且通过调整部件及其安装顺序,得出机械结构对米粉品质有很大影响,磨盘、屏障型螺杆、多孔盘以及挤出口模的改进对于米粉质量的提高起到了很大的促进作用,特别是多孔盘的改进对提高挤出机排气能力做出了很大的贡献。加工工艺对米粉品质也有很大影响,通过大米原料品种改为直链淀粉含量较高的大米,提高含水量防止了米粉的回生;排气可改善产品品质;随着螺杆转速的增加,挤出产量显著增加,但当转速提高到一定程度后,由于加料口设计的问题,产量的增加缓慢。而且转速越高时,物料加料难度增大。更多还原

【Abstract】 Extrusion cooking will become one of the directions of the food industry in 21st century. Rice noodle that comes of China is the most popular rice product in many countries of Asia, which is also the rice food with high rice consume. In recent years, with the development of the economy and society, the rice noodles are introduced into international market. The rice noodle processing technology as so as the rice noodles kinds and the processing technique have gained great development in our country these years. In addition, the processing equipments are getting more and more perfect and the sale markets are extending fast. But up to now, the technology keeps at the low level of modern industry.Based on the point of the traditional rice noodle processing technique that is analyzed in this paper, we advanced a new way of rice noodle processing technique and designed machine for producing. The new way of rice noodle processing technique is good at saving energy and reducing wastes. Based on many experiments we had done, we had done a lot of things to improve on the quality of rice noodles. In this paper, a new processing technique is brought forward and it is evaluated through experiments with the new single screw extruder. Otherwise, the influences of the processing technique and the extruder structure on the rice noodles qualities are analyzed in order to improve the processing technique and the extruder structure. Some important factors that affecting the quality of the rice noodles such as the containing amylase, the containing water, rotational speed of screw have been considered. The factors that affecting the pliability, breakage and viscosity of the rice noodles have been studied through some experiments. At the same time, some important conclusions are obtained.The joints of the single screw extruder are in the same size. So we can change parts and order of parts of the single screw extruder. The extruder can exhaust and get some different kinds of screw-segment. Some conclusions are obtained from various experiments. Firstly, the new technique is feasible and the rice can be processed with the new single screw extruder. Secondly, the structure of the extruder has a great influence on the rice noodles qualities, especially the disc, the barrier screw, many holes configuration and the model. Thirdly, we can avoid the aging of the rice noodle through increasing the containing water, but the high containing water will lead to reduce the yield. Fourthly, venting the gas can improve the quality of the rice noodles. In addition, the output will increase along with the enhancement of the screw speed. Furthermore, the high screw speed will lead to the difficulty of feeding the material. And the feeding part has to be improved on. And then the feeding progress will be reformed.更多还原