| A series products of Pseudo-boehmite has been widely used in the fields of chemistry industry, chemistry fertilizer and petrochemicals etc. Pseudo-boehmite and the products are substances with many pores. It likes a griddle of molecule and can be used as segregator, purificant and desiccant. It also has the characteristic of adsorption and can be used as catalyzer or the carrier of catalyzer. Desiccation is the last technics of producing Pseudo-boehmite. Proper design and parameter matching may directly affect the quality and throughput of the products. So it is important to study the drying system of Pseudo-boehmite for improving the quality and throughput of the products and reducing the costs.This paper studies the third drying machine of Chemistry Alumina Co. of China Aluminum Industry Shandong filiale. By theoretic research and trial testing, build the mathematic model of the aggrandizement boil drying system of Pseudo-boehmite and optimize it. Put forward a feasibility project which can reduce the costs and increase the throughput for 50% each. This paper focuses on the following aspects concretely.1. It studies the developing of all kinds of drying technic, especially the gas flow drying system. Pyrogenation medium contacts the solid granule directly and the solid granule suspends in the liquid. Thus the interface is great. This intensifies the transmission process of heat and matter. The efficiency is high, the desiccation time is short and the disposal quantity is great. The structure is simple and compact. The volume is small, but the throughput is great. The operation is easy and it is convenient for auto control. Analyse and compare the characteristic of all kinds drying equipment of gas flow, application area and peculiarity. Explain the application of gas flow drying in producing Pseudo-boehmite.2. It analyses the heat balance mechanism of aggrandizement drying process and study the relationship between the surface area of substances and the efficiency of drying. Analyse the character of the material in, the temperature of the hot wind and the quantity of the hot wind etc. Study the relation of the balance of the material during the drying process. Based on the four hypothesizes, build the process mathematic model of aggrandizement boil drying system of Pseudo-boehmite. They are the differential equations of material temperature, hot wind temperature, granule velocity, hot wind humid content and material containing water rate.3. It designs the locale test project. Accord to the testing data, do the orthogonal tests. Study the effects of the main parameters to the guideline. Any more, analyse the matching relations between the main parameters. In order to reduce the cost of energy and improve the produce efficiency, research the better combination of the parameters. Use the main working parameters gettingin the locale test: hot wind quantity, gas flow temperature, granule velocity, material initial containing water rate and air humidity etc. as the boundary condition of simulation tests to distinguish the unknown parameters in the mathematic model. Use the testing data as the check standard to validate the mathematic model and the results of the simulation tests and receive the model which can accord with the practical process.4. Apply the mathematic model, design the target function of the work expense and the assistant target function of the final humidity quantity, caudal temperature and material disposal quantity. Simulation analysis of the effects of the operation parameters to the optimization results, can clear the direct of the optimization design. According to the basic simulation process, can change the initial parameter and do many simulation experiment to make clear the effect of all factors to the experiment results. Then find the best design and operation parameters. Use the orthogonal tests method to do the simulation tests. Through several orthogonal tests, gradually approach the best design and operation parameter and get the best matching of the existing condition... |
