Advanced Materials Research Vols. 550-553

Abstract: A new method of detecting the content of ultra-low sulphur in stainless steel with ultra-high strength is founded in the article by using of infrared carbon-sulphur detector. The tests are choice experiments controlled by relevant factors such as combustion conditions and blank test. And the result of the detection is accurate and practical.

Abstract: Combustion curves of lignite samples from China in four different particle sizes and Oxygen-enriched condition were analyzed using non-isothermal thermogravimetric method. The lignite samples separated into -150+100 μm, -100+75 μm, -75+50 μm, and -50μm sizes. Combustion profiles shift to lower temperature zone as particle size decrease. Combustion profiles have little difference when the particle size below 100 μm in oxygen atmosphere; Oxygen-enriched combustion experiment were carried out in O₂/N₂ mixture atmospheres with the volume fraction of oxygen was 21%, 30%, 40%, 50%, 60% and 70%, respectively. As oxygen concentration increase profiles shift to lower temperature zone. and gets the proper range of oxygen concentration is about 50%.

Abstract: Through the laboratory experiment, the foaming properties of six kinds of foaming agent was evaluated comprehensively. Through the primary selection, foaming agent concentration selection and salt tolerance evaluation, HY-2 foaming agent was selected in follow-up experiments. The Liquid viscosity effect for foaming performance showed that there exists an optimal value of the liquid viscosity, corresponding to the concentration of foam stabilizing agent should not be less than 700mg/l. The impact of temperature on the performance of foaming agent was mainly on the foam stability, the higher the temperature, the stability of the bubble the worse. Due to the presence of crude oil, foaming volume and stability of the foam appeared a downward trend, the character of which is very advantageous to adjust fluidity difference between the layers of high permeable formation and low permeable formation.

Abstract: Based on the issue of enhancing oil recovery of heavy oil reservoir after steam injection, this paper studied the development characteristics of hot water flooding in different rhythm (positive rhythm, anti-rhythm, complex rhythm) reservoir after steam drive by means of physical simulation. The research shows that the positive rhythm reservoir has a large swept volume with steam flooding under the influence of steam overlay and steam channeling. Anti-rhythm reservoir has a large swept volume with hot water flooding, because hot water firstly flows along the high permeability region in upper part of the reservoir, in the process of displacement, hot water migrates to the bottom of reservoir successively for its higher density.

Abstract: The single model of oil shale development, which is, burning in boiler for power generation and distillation for shale oil, may cause enormous waste of oil-gas resources and semi-coke. For energy conservation and efficiency improvement, it is necessary to realize the comprehensive utilization of oil shale. The development of experimental system is foundation of further studying. In the paper, an experimental system for comprehensive utilization of oil shale is designed and realized. These includes: spouted bed combustor and shale ash collection system, oil shale retort with solid heat carrier and shale oil recovery system. With the system, the realistic simulation under different condition such as different kinds of oil shale, operation condition can be studied. This work lays an experimental foundation for the further study of comprehensive utilization of oil shale.

Abstract: The spontaneous combustion in coal mine goaf badly influences the underground safe work and regular production, which has become one of the major disasters that get much attention and need to be controlled. This paper analyzes the causes of spontaneous combustion and the relationship between the significant gas and temperature, the degree of spontaneous combustion, and coal category to monitor the composition and concentration of the significant gas of the spontaneous combustion in coal mine goaf and graphically visualize the change trend in a certain period. At the same time, when the composition and concentration of the significant gas approach the spontaneous combustion point, the system can make a sound-light alarm. The system not only provides robust technical support for the prediction of the spontaneous combustion in goaf, but also gives some reference for the prevention of underground spontaneous combustion in coal industry.

Abstract: An attempt has been made to study the pretreatment of sulfidic refractory gold ore with pyrolusite. The influences of various parameters were studied to optimize the conditions. The optimum leaching conditions were pyrolusite/gold ore mass ratio of 3.0, H₂SO₄ concentration of 3.0 M, temperature of 100°C, particle size of 45μm, stirring speed of 200 rpm. After the pretreatment, gold and silver were exposed, these made the extraction of the precious metal in the gold ore much easier.

Abstract: A calandria liquid distributor device was designed for horizontal falling film evaporation. The guide plate was introduced in this, which is easy to manufacture and can effectively reduce splash phenomenon. This paper studies the liquid distribution from the relation between distributive unwell-distributed coefficient and liquid flux of distributor tube and distributor hole. The result showed that the distributive unwell-distributed coefficient of in liquid distributor was decreased along with accretion of liquid flux, as apposed to homogeneous perforated. The unwell-distributed hole coefficient of distributor tube No.0 was increased along with accretion of flux, as apposed to distributor tube No.1 and distributor tube No.2.

Abstract: The hydrodynamics in a high and narrow turbulent fluidized bed of FCC particles is investigated by using computational fluid dynamics (CFD) method. The axial bed density, particle volume fraction and particle velocity in the fluidized bed are predicted and compared with the experiments. The results indicate that there exist two different coexisting regions in the bed: a bottom dense and an upper dilute region. As increasing superficial gas velocity, bed density decreases in the dense phase whilst increases in the dilute phase. In this high and narrow turbulent fluidized bed, however, the bed density decreases sharply even in the dense phase because of the wall restriction. The hydrodynamics resembles slug flow at the initial fluidization stage; as a steady fluidization is achieved, the fluidized bed produces larger bubbles than the conventional one.

Abstract: In this work, a Neural network based predictive controller is analyzed to a non linear continuous stirred tank reactor (CSTR) carrying out series and parallel reactions: A→B→C and 2A→D. In the first step, the neural network model of continuous stirred tank reactor is obtained by Levenburg- Marquard training. The data for the training the network is generated using state space model of continuous stirred tank reactor. The neural network model of continuous stirred tank reactor is used in model predictive controller design. The performance of present neural network based model predictive controller (NNMPC) is evaluated through simulations for servo & regulatory problems of CSTR. The performance of neural network based predictive controller is found to be superior than conventional PI controller for setpoint tracking problems.