Simulation Analysis And Design Application On Feeding System Of Slight Positive Pressure Pneumatic Conveying

Husked rice processing by rice huller could produce many byproducts, of which mainly is rice hull—about 22% the weight of all the rice grains[1,2].The annual production of unhusked rice in China is about 200 billion tons and rice hull shares more than 40 billion tons of it. This results in the piling of rice hull in rice industry,causing not only great waste of energy and economic loss but also environment pollution. However, the advancement of society, development of technology and increasingly abundant empirical experiences lead to a more specific social division of labor and a more competitive market, which forces many enterprises starting paying attention to the use and value of rice hull.As a result, recent years witness the rising researches by scholars in home and abroad on the usage of rice hull such as compressed rice hull as new energy and fuel, rice hull ash to produce water glass, cracked rice hull to make disposable dinnerware, makeup, fodder, and most of all rice hull as the accessories of Daqu and vinegar. However, its great bulk and small density increase the cost of storage and transport, slowering the development of rice hull for a long time.Traditional methods of rice hull transport including gravity, mechinery and energy cannot satisfy the need for massive piling rice hull. When rice hull is transported by mechines, problems such as bulky size, noisy sound and maintenance of the equipments as well as dropping out, spewing out ash and polluting environment in the process of transportation. And transporting by energy is inefficient and at the same time consuming.This research is based on the program of rice hull storage and transporting Phrase III in Hengshui Laobaigan Liquor Co.Ltd. According to the real situation and characteristics of this company, this program acquires three independent systems: unloading and transporting to silos, exporting to temporary storage, exporting to steamer.This paper tries to design a positive pressure feeding system for energy transporting of rice hull through theoretically calculating and analyzing the micro positive pressure which transports rice hull into the storage. The purposes are to solve the common problem of difficult feeding and to increase the material consistence in positive feeding pressure transporting system. The following aspects are specificly examined:1. Design the sample data of energy pressure transporting system through theoretical calculation and provide foundation for further accelerator design.2. Design geometric model of the accelerator and physical modeling.3. Proceed simulation analysis of the velocity fields, amount of materials and pressure scattering of the inner accelerator by numerical simulation analysis softwares. Compare different models and find the most suitable feeding system for rice hull transporting.According to the results of numerical simulation analysis of different models and theoretical calculation, this research supports the feasibility of simulation analysis and finds the most suitable accelerator for positive pressure transporting system is that with a 20 mm of oblate rim.