scholarly journals Application of the ARMA Model to Describe and Forecast the Flotation Feed Solids Flow Rate

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8587
Author(s):  
Jarosław Joostberens ◽  
Aurelia Rybak ◽  
Joachim Pielot ◽  
Artur Dylong

The flow rate of solids is subject to random disturbances of the changing feed and can significantly affect the quantitative and qualitative parameters of the coal flotation products. This quantity can be described as a stochastic process. The paper presents the results of the solids flow rate model for coal flotation identification calculations, treated as a disturbance to the process. This is an innovative approach to modelling those quantitative parameters of the flotation feed that are measurably available and whose random changes have a significant impact on the enhancement process under industrial conditions. These include the volumetric flow rate of the feed and, in particular, concentration of solids in the feed. Therefore, it is suggested that random changes of these two parameters of the feed should be mapped using a model of one quantity—the flow rate of solids. This solution is advantageous because this quantity, as a quantitative parameter of the feed, has a significant impact on the course of the coal flotation process. The model is necessary in the process of designing an automatic control system through simulation tests. It allows us to generate a data string simulating random changes to this quantitative parameter of the feed. On this basis, in the simulation model, the correct functioning of the automatic control system is tested, the task of which is to compensate the influence of this disturbance. To determine the empirical model of the feed solids flow rate, measurement data obtained during the registration of the solids concentration and volumetric flow rate of the feed were used in four consecutive periods of operation of an industrial facility of one of the Polish coal processing plants. The time courses of the solids flow rate in the feed were described by ARMA (autoregressive–moving-average model) means, and the two-stage least squares method was used to estimate the model parameters. The results of the identification and verification of the designated model showed the correctness of adopting the third-order ARMA model, with parameters a1 = −1.0682, a2 = −0.2931, a3 = 0.3807, c1 = −0.1588, c2 = −0.2301, c3 = 0.1037, and variance σ2ε = 0.0891, white noise sequence εt, determined on the basis of a series of residuals described by the fifth-order model. It has been shown that the identified model of the flow rate of solids of the feed to flotation as disturbances can be used to develop a predictive model that allows forecasting the modelled quantity with a prediction horizon equal to the sampling period. One-step forecasting based on the determined predictor equation was found to give results consistent with the recorded values of the solid part flow rate of the feed and the extreme values of the prediction error are within the range from −1.08 to 2.90 kg/s.

2012 ◽  
Vol 524-527 ◽  
pp. 2092-2096
Author(s):  
Xiang Hu ◽  
Li Xie ◽  
Bo Chen ◽  
Ho Jae Shim ◽  
Qi Zhou

In this paper, in order to ensure stable and efficient operation of a pilot-scale modified A2/O (anoxic/anaerobic/aerobic/pre-anoxic) -MBR plant, the automatic control system based on PLC is designed and introduced from the views of system configuration and unit control methods. The master computer undertakes the monitoring and managing task by Siemens WINCC 7.0 configuring software, while the slave computer implements the function of data collection and automatic control based on Siemens S7-300 PLC. Intelligent PID algorithm is utilized to precisely control the influent flow rate, recycled flow rate and DO concentration in aerobic tank in this system. The commissioning and operation practice has proved that the PLC-based automatic control system greatly improved the degree of automation and achieved high nutrient removal efficiency in this plant.


Author(s):  
M.N. Fel’ker ◽  
◽  
K.D. Bakhtereva ◽  

The article discusses the creation of an algorithm and the synthesis of a two-loop automatic control system for level and density, instead of the current single-loop one. Aim. Density stabilization and stabilization of the flotation machine power supply by creating a two-circuit automatic level and density control system in order to improve the quality of the final product. Materials and methods. Since there is no net lag in the system, the controller is tuned using the parametric optimization method, namely: according to the criteria of modular (MO) or symmetric optimum (CO). The MO/CO criterion is also used to adjust the contour. All automatic control systems are obtained in the MATLAB Simulink software package. Control quality is measured by metrics such as transient time, overshoot, and system error. The first two indicators show the dynamics of the process, and the last indicator shows the accuracy of the system. Conclusion. The finished two-loop automatic control system, developed in the software package MATLAB Simulink, according to the analysis of the obtained process parameters, provides stabilization of the density and level in the agitation tank for flotation.


2003 ◽  
Vol 3 ◽  
pp. 297-307
Author(s):  
V.V. Denisov

An approach to the study of the stability of non-linear multiply connected systems of automatic control by means of a fast Fourier transform and the resonance phenomenon is considered.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1257
Author(s):  
Alexey Dorokhov ◽  
Alexander Aksenov ◽  
Alexey Sibirev ◽  
Nikolay Sazonov ◽  
Maxim Mosyakov ◽  
...  

The roller and sieve machines most commonly used in Russia for the post-harvest processing of root and tuber crops and onions have a number of disadvantages, the main one being a decrease in the quality of sorting due to the contamination of working bodies, which increases the quantity of losses during sorting and storage. To obtain high-quality competitive production, it is necessary to combine a number of technological operations during the sorting process, such as dividing the material into classes and fractions by quality and size, as well as identifying and removing damaged products. In order to improve the quality of sorting of root tubers and onions by size, it is necessary to ensure the development of an automatic control system for operating and technological parameters, the use of which will eliminate manual sorting on bulkhead tables in post-harvest processing. To fulfill these conditions, the developed automatic control system must have the ability to identify the material on the sorting surface, taking into account external damage and ensuring the automatic removal of impurities. In this study, the highest sorting accuracy of tubers (of more than 91%) was achieved with a forward speed of 1.2 m/s for the conveyor of the sorting table, with damage to 2.2% of the tubers, which meets the agrotechnical requirements for post-harvest processing. This feature distinguishes the developed device from similar ones.


2021 ◽  
Vol 1864 (1) ◽  
pp. 012039
Author(s):  
B. G. Ilyasov ◽  
G.A. Saitova ◽  
A.V. Elizarova

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