Red mud is a kind of industrial waste residue produced in the process of alumina production,which has strong suspension and is difficult to precipitate and filter.This study compared the effects of 4 kinds of filter a...Red mud is a kind of industrial waste residue produced in the process of alumina production,which has strong suspension and is difficult to precipitate and filter.This study compared the effects of 4 kinds of filter aids,including CaCl2,polymerized ferrous sulfate(PFS),steel slag(SS),and Portland cement(PC),on the filtration rate,filter cake moisture content,and Na2O content of red mud slurry.At a dosage of 10 g·L^(-1),the filtration effects were in the following order:PFS>CaCl_(2)>SS>PC.Under the combination of 5 g·L^(-1) SS and 5 g·L^(-1) PC,the better filtration effect was achieved with a filtration time of 205.17 s,which was reduced by 58.52%compared to the original red mud.The combined use of SS and PC exhibits better advantages in terms of cost and filtration effect.This study provides a data foundation for the rapid filtration of red mud slurry.The use of SS and PC as filter aids for red mud holds broad application pro-spects.展开更多
In this paper, a study to enhance the filtration for solid/liquid materials difficult to be filtered, such as highly viscous, highly compactible or gel like materials, is presented. Filter aids diatomaceous earth and ...In this paper, a study to enhance the filtration for solid/liquid materials difficult to be filtered, such as highly viscous, highly compactible or gel like materials, is presented. Filter aids diatomaceous earth and wood pulp cellulose are used to enhance the filtration by improving filter cake structure and properties in the filtration of a biological health product and a highly viscous chemical fiber polymer melt product. The property of solid/liquidsystems, filtration at different flow rates, specitic cake resistance, cake wetness, filtration rate, filtrate turbidity for filter aid selection and evaluation, and operation optimization are investigated. The results are successfully applied to industrial process, .and can be used as a reference for similar filtration applications.展开更多
The dewatering of fine, flotation cleaned coals from Huaibei and Xuzhou (bituminous) and Yongcheng (anthracite) were studied. The supernatant and filter cake were examined to determine the rate and extent of flocculat...The dewatering of fine, flotation cleaned coals from Huaibei and Xuzhou (bituminous) and Yongcheng (anthracite) were studied. The supernatant and filter cake were examined to determine the rate and extent of flocculation and dewatering. A starch-based filter aid was used to increase flocculation and dewatering rates. The filtration constant, K, and compression index, s, of the Yongcheng slurry were measured under various conditions. A designed experiment was performed to determine optimum conditions for dewatering. The results showed that the filter aid enhanced flocculation and coagulation of the fine cleaned coal slurry, enhanced the structure of the filter cake and promoted dewatering of the cake. Moisture content in the cake was reduced to 17% after vacuum filtration.展开更多
Pressure filtration and filter aids should be adopted in filtration of high-viscosity molten chemical fiber containing foreign materials and gel particles. Theoretical analysis and argumentations on manners of assiste...Pressure filtration and filter aids should be adopted in filtration of high-viscosity molten chemical fiber containing foreign materials and gel particles. Theoretical analysis and argumentations on manners of assisted filtration and specific requirements of filter aids are performed. Measurement and comparison on properties of several filter aids are also carried out, conclusions and suggestions are put forward.展开更多
Wax obtained from the pyrolysis of polyethylene waste can contain inorganic contaminants and must be purified before application.We evaluated different filter aids(perlite,sand,and rice husk ash)for the filtration of ...Wax obtained from the pyrolysis of polyethylene waste can contain inorganic contaminants and must be purified before application.We evaluated different filter aids(perlite,sand,and rice husk ash)for the filtration of a crude wax and a pyrolysis wax through a filter medium that was coated with nylon 6 nanofibers to improve filtration efficiency.We first examined the performance of the filter aids in improving crude wax filtration,with the filtration time,temperature,and pressure held constant at 1 h,170℃,and 2.5 bar,respectively.Oily wax was then produced by pyrolysis of high-density polyethylene(HDPE)waste in the temperature range 425-475℃.The best filter aid was perlite,which had a filtrate production rate of 5.47×10^(-5)m^(3)/h.The highest oily wax yield(87.8%)was achieved at a pyrolysis temperature of 425℃.The assembly comprising the filter medium coated with nylon 6 nanofibers plus perlite as a filter aid was most suitable for removing impurities from the oily wax generated by the HDPE pyrolysis as it achieved a purification efficiency of 99.9%.展开更多
Gravity-aided inertial navigation is a hot issue in the applications of underwater autonomous vehicle(UAV). Since the matching process is conducted with a gravity anomaly database tabulated in the form of a digital mo...Gravity-aided inertial navigation is a hot issue in the applications of underwater autonomous vehicle(UAV). Since the matching process is conducted with a gravity anomaly database tabulated in the form of a digital model and the resolution is 2’ × 2’,a filter model based on vehicle position is derived and the particularity of inertial navigation system(INS) output is employed to estimate a parameter in the system model. Meanwhile, the matching algorithm based on point mass filter(PMF) is applied and several optimal selection strategies are discussed. It is obtained that the point mass filter algorithm based on the deterministic resampling method has better practicability. The reliability and the accuracy of the algorithm are verified via simulation tests.展开更多
In this paper, the variational method combined with Green's function is used to analyze the characteristics of suspended, stripline. The result is in good agreement with references. The design of mm-wave end-coupl...In this paper, the variational method combined with Green's function is used to analyze the characteristics of suspended, stripline. The result is in good agreement with references. The design of mm-wave end-coupled bandpass filter with suspended substrate is discussed. The computer programs for design of suspended stripline and bandpass filter are established.展开更多
According to the filtration mechanism and filtration formula, it is considered that the surface area, bulk density and grain size distri- bution of filter-aid are the main factors affecting the filtration rate. On the...According to the filtration mechanism and filtration formula, it is considered that the surface area, bulk density and grain size distri- bution of filter-aid are the main factors affecting the filtration rate. On the basis of analysing phy- sical and chemical properties of diatomite and per- lite, the scientific bases for preparation of filter aid are discussed. It is possible that the complex filter aid, which is made up of low grade diatomite and perlite, is favourable to build-up a fine 'steely-bridged structure' for the filter cake, and its filtration performance of beer could be improved as good as that of commercial filter-aid made from high grade diatomite. The above points have been demonstrated by the results of laboratorial and industrial experiments of beer filtration.展开更多
In this paper, the marginal Rao-Blackwellized particle filter （MRBPF）, which fuses the Rao-Blackwellized particle filter （RBPF） algorithm and the marginal particle filter （MPF） algorithm, is presented. The state...In this paper, the marginal Rao-Blackwellized particle filter （MRBPF）, which fuses the Rao-Blackwellized particle filter （RBPF） algorithm and the marginal particle filter （MPF） algorithm, is presented. The state space is divided into linear and non-linear parts, which can be estimated separately by the MPF and the optional Kalman filter. Through simulation in the terrain aided navigation （TAN） domain, it is demonstrated that, compared with the RBPF, the root mean square errors （RMSE） and the error variance of the nonlinear state estimations by the proposed MRBPF are respectively reduced by 29% and 96%, while the unique particle count is increased by 80%. It is also found that the MRBPF has better convergence properties, and analysis has shown that the existing RBPF is nothing more than a special case of the MRBPF.展开更多
This paper considers the problem of the HIV/AIDS Infection Process filtering characterized by three compounds, namely, the number of healthy T-cells, the number of infected T-cells and free virus particles. Only the f...This paper considers the problem of the HIV/AIDS Infection Process filtering characterized by three compounds, namely, the number of healthy T-cells, the number of infected T-cells and free virus particles. Only the first and third of them can be measurable during the medical treatment process. Moreover, the exact parameter values are admitted to be also unknown. So, here we deal with an uncertain dynamic model that excludes the application of classical filtering theory and requires the application of robust filters successfully working in the absence of a complete mathematical model of the considered process. The problem is to estimate the number of infected T-cells based on the available information. Here we admit the presence of stochastic “white noise” in current observations. To do that we apply the Luenberger-like filter (software sensor) with a matrix gain, which should be adjusted at the beginning of the process in such a way that the filtering error would be as less as possible using the Attractive Ellipsoid Method (AEM). It is shown that the corresponding trajectories of the filtering error converge to an ellipsoidal set of a prespecified form in mean-square sense. To generate the experimental data sequences in the test-simulation example, we have used the well-known simplified HIV/ AIDS model. The obtained results confirm the effectiveness of the suggested approach.展开更多
除了降低用户的听觉效果和佩戴舒适度外,数字助听器中的回声也很容易形成啸叫,从而导致系统的不稳定。为了保持自适应算法的收敛速度与稳态误差之间的平衡,研究了助听器中的回声消除模型和自适应回声消除算法,并提出了一种改进的归一化...除了降低用户的听觉效果和佩戴舒适度外,数字助听器中的回声也很容易形成啸叫,从而导致系统的不稳定。为了保持自适应算法的收敛速度与稳态误差之间的平衡,研究了助听器中的回声消除模型和自适应回声消除算法,并提出了一种改进的归一化最小均方(normalized least mean square,NLMS)算法。该方法引入误差信号自动调整步长因子,以加快滤波器收敛和降低稳态误差。仿真结果表明,改进算法在回声消除方面表现出更好的性能。通过比较算法的均方误差(mean square error,MSE)曲线,改进算法具有更好的收敛速度和稳态误差,平均均方误差比NLMS算法低4.01 dB。改进后的NLMS算法性能良好,耗时相对较短,易于实现。展开更多
基金supported by the Science and Technology Innovation Program of Hunan Province,China(No.2023RC3053)the National Key Research and Development Program of China(No.2023YFC3904201)the National Natural Science Foundation of China(No.52004343).
文摘Red mud is a kind of industrial waste residue produced in the process of alumina production,which has strong suspension and is difficult to precipitate and filter.This study compared the effects of 4 kinds of filter aids,including CaCl2,polymerized ferrous sulfate(PFS),steel slag(SS),and Portland cement(PC),on the filtration rate,filter cake moisture content,and Na2O content of red mud slurry.At a dosage of 10 g·L^(-1),the filtration effects were in the following order:PFS>CaCl_(2)>SS>PC.Under the combination of 5 g·L^(-1) SS and 5 g·L^(-1) PC,the better filtration effect was achieved with a filtration time of 205.17 s,which was reduced by 58.52%compared to the original red mud.The combined use of SS and PC exhibits better advantages in terms of cost and filtration effect.This study provides a data foundation for the rapid filtration of red mud slurry.The use of SS and PC as filter aids for red mud holds broad application pro-spects.
文摘In this paper, a study to enhance the filtration for solid/liquid materials difficult to be filtered, such as highly viscous, highly compactible or gel like materials, is presented. Filter aids diatomaceous earth and wood pulp cellulose are used to enhance the filtration by improving filter cake structure and properties in the filtration of a biological health product and a highly viscous chemical fiber polymer melt product. The property of solid/liquidsystems, filtration at different flow rates, specitic cake resistance, cake wetness, filtration rate, filtrate turbidity for filter aid selection and evaluation, and operation optimization are investigated. The results are successfully applied to industrial process, .and can be used as a reference for similar filtration applications.
基金the financial support for this work provided by the Doctoral Fund of Ministry of Education of China (No.200802900503) the Science and Technology Foundation of China University of Mining & Technology (No.2008A027)
文摘The dewatering of fine, flotation cleaned coals from Huaibei and Xuzhou (bituminous) and Yongcheng (anthracite) were studied. The supernatant and filter cake were examined to determine the rate and extent of flocculation and dewatering. A starch-based filter aid was used to increase flocculation and dewatering rates. The filtration constant, K, and compression index, s, of the Yongcheng slurry were measured under various conditions. A designed experiment was performed to determine optimum conditions for dewatering. The results showed that the filter aid enhanced flocculation and coagulation of the fine cleaned coal slurry, enhanced the structure of the filter cake and promoted dewatering of the cake. Moisture content in the cake was reduced to 17% after vacuum filtration.
文摘Pressure filtration and filter aids should be adopted in filtration of high-viscosity molten chemical fiber containing foreign materials and gel particles. Theoretical analysis and argumentations on manners of assisted filtration and specific requirements of filter aids are performed. Measurement and comparison on properties of several filter aids are also carried out, conclusions and suggestions are put forward.
基金The authors are grateful for the financial support provided by CAPES(Brazilian Agency for Improvement of Graduate Personnel),CNPq(National Council of Scientific and Technological Develop-ment),FAPERGS(Foundation for Research Support of the State of Rio Grande do Sul),and SDECT(Department of Economic Develop-ment,Science and Technology of the State of Rio Grande do Sul).
文摘Wax obtained from the pyrolysis of polyethylene waste can contain inorganic contaminants and must be purified before application.We evaluated different filter aids(perlite,sand,and rice husk ash)for the filtration of a crude wax and a pyrolysis wax through a filter medium that was coated with nylon 6 nanofibers to improve filtration efficiency.We first examined the performance of the filter aids in improving crude wax filtration,with the filtration time,temperature,and pressure held constant at 1 h,170℃,and 2.5 bar,respectively.Oily wax was then produced by pyrolysis of high-density polyethylene(HDPE)waste in the temperature range 425-475℃.The best filter aid was perlite,which had a filtrate production rate of 5.47×10^(-5)m^(3)/h.The highest oily wax yield(87.8%)was achieved at a pyrolysis temperature of 425℃.The assembly comprising the filter medium coated with nylon 6 nanofibers plus perlite as a filter aid was most suitable for removing impurities from the oily wax generated by the HDPE pyrolysis as it achieved a purification efficiency of 99.9%.
基金supported by the National Natural Science Foundation of China(61673060)the National Key R&D Plan(2016YFB0501700)
文摘Gravity-aided inertial navigation is a hot issue in the applications of underwater autonomous vehicle(UAV). Since the matching process is conducted with a gravity anomaly database tabulated in the form of a digital model and the resolution is 2’ × 2’,a filter model based on vehicle position is derived and the particularity of inertial navigation system(INS) output is employed to estimate a parameter in the system model. Meanwhile, the matching algorithm based on point mass filter(PMF) is applied and several optimal selection strategies are discussed. It is obtained that the point mass filter algorithm based on the deterministic resampling method has better practicability. The reliability and the accuracy of the algorithm are verified via simulation tests.
文摘In this paper, the variational method combined with Green's function is used to analyze the characteristics of suspended, stripline. The result is in good agreement with references. The design of mm-wave end-coupled bandpass filter with suspended substrate is discussed. The computer programs for design of suspended stripline and bandpass filter are established.
文摘According to the filtration mechanism and filtration formula, it is considered that the surface area, bulk density and grain size distri- bution of filter-aid are the main factors affecting the filtration rate. On the basis of analysing phy- sical and chemical properties of diatomite and per- lite, the scientific bases for preparation of filter aid are discussed. It is possible that the complex filter aid, which is made up of low grade diatomite and perlite, is favourable to build-up a fine 'steely-bridged structure' for the filter cake, and its filtration performance of beer could be improved as good as that of commercial filter-aid made from high grade diatomite. The above points have been demonstrated by the results of laboratorial and industrial experiments of beer filtration.
基金National Natural Science Foundation of China （60572023）
文摘In this paper, the marginal Rao-Blackwellized particle filter （MRBPF）, which fuses the Rao-Blackwellized particle filter （RBPF） algorithm and the marginal particle filter （MPF） algorithm, is presented. The state space is divided into linear and non-linear parts, which can be estimated separately by the MPF and the optional Kalman filter. Through simulation in the terrain aided navigation （TAN） domain, it is demonstrated that, compared with the RBPF, the root mean square errors （RMSE） and the error variance of the nonlinear state estimations by the proposed MRBPF are respectively reduced by 29% and 96%, while the unique particle count is increased by 80%. It is also found that the MRBPF has better convergence properties, and analysis has shown that the existing RBPF is nothing more than a special case of the MRBPF.
文摘This paper considers the problem of the HIV/AIDS Infection Process filtering characterized by three compounds, namely, the number of healthy T-cells, the number of infected T-cells and free virus particles. Only the first and third of them can be measurable during the medical treatment process. Moreover, the exact parameter values are admitted to be also unknown. So, here we deal with an uncertain dynamic model that excludes the application of classical filtering theory and requires the application of robust filters successfully working in the absence of a complete mathematical model of the considered process. The problem is to estimate the number of infected T-cells based on the available information. Here we admit the presence of stochastic “white noise” in current observations. To do that we apply the Luenberger-like filter (software sensor) with a matrix gain, which should be adjusted at the beginning of the process in such a way that the filtering error would be as less as possible using the Attractive Ellipsoid Method (AEM). It is shown that the corresponding trajectories of the filtering error converge to an ellipsoidal set of a prespecified form in mean-square sense. To generate the experimental data sequences in the test-simulation example, we have used the well-known simplified HIV/ AIDS model. The obtained results confirm the effectiveness of the suggested approach.
文摘除了降低用户的听觉效果和佩戴舒适度外,数字助听器中的回声也很容易形成啸叫,从而导致系统的不稳定。为了保持自适应算法的收敛速度与稳态误差之间的平衡,研究了助听器中的回声消除模型和自适应回声消除算法,并提出了一种改进的归一化最小均方(normalized least mean square,NLMS)算法。该方法引入误差信号自动调整步长因子,以加快滤波器收敛和降低稳态误差。仿真结果表明,改进算法在回声消除方面表现出更好的性能。通过比较算法的均方误差(mean square error,MSE)曲线,改进算法具有更好的收敛速度和稳态误差,平均均方误差比NLMS算法低4.01 dB。改进后的NLMS算法性能良好,耗时相对较短,易于实现。
