DOI: https://doi.org/10.32515/2414-3820.2021.51.203-210
System of Automatic Control for Solid/liquid Ratio in Mills with Circulating Load
About the Authors
Vasily Kondratets, Professor, Doctor in Technics (Doctor of Technics Sciences), Central Ukrainian National Technical University, Kropyvnytskyi, Ukraine, ORCID ID: 0000-0002-1411-168Х
Oleksandr Serbul, Associate Professor, PhD in Technics (Candidate of Technics Sciences), Central Ukrainian National Technical University, Kropyvnytskyi, Ukraine, e-mail: serbulan@ukr.net, ORCID ID: 0000-0003-1836-5529
Oleksandr Didyk, Associate Professor, PhD in Technics (Candidate of Technics Sciences), Central Ukrainian National Technical University, Kropyvnytskyi, Ukraine, ORCID ID: 0000-0003-1454-0828
Anatolii Matsui, Associate Professor, PhD in Technics (Candidate of Technics Sciences), Central Ukrainian National Technical University, Kropyvnytskyi, Ukraine, ORCID ID: 0000-0001-5544-0175
Abstract
The operation of a ball mill operating in a closed loop with a spiral classifier depends on the vacuum of the pulp in it, which is characterized by a solid / liquid ratio. Supply to the entrance of the ball mill at the same time ore and sand classifier, as well as changes in the circulating load in a wide range greatly complicate the definition of this technological parameter. This situation has led to the fact that the solid / liquid ratio in mills operating in such conditions can not be automatically adjusted, in turn, the deviation of the pulp vacuum from the required value leads to significant losses.
The study of the ball mill as a controlled object on the pulp vacuum channel made it possible to describe it using the mathematical expression given in the article. The solution of this expression makes it possible to characterize the change in the mass of the material in the mill over time, provided that a stepwise action is introduced at the entrance - the volume flow of water or ore. A constant value of the mass of material in the mill will clearly characterize the corresponding solid/liquid ratio. It has been found that it is important to study the filtering capabilities of the control object, as control actions on water and disturbing actions on ore can significantly change the vacuum of the pulp in some areas of the mill. The filtering capabilities of the mill can be investigated by its amplitude frequency characteristics, which showed that at low circular frequencies the amplitude frequency characteristics depend on the mode of operation of the mill - the magnitude of the circulating load and the cost of the source ore. Using computer technology, spatial diagrams of the relative oscillations of the mass of material in the mill from the amplitude and frequency of influences at its entrance through the ore and water.
In the course of theoretical research it was determined that the only approach to ensure the required accuracy of determining the solid / liquid ratio in these conditions is to filter the signals before applying to the input of the identification unit of the ratio. Thus, the system of automatic control of the solid/liquid ratio at the entrance to the mill is implemented on microprocessor means. Its operation on the laboratory test bench made on the microcontroller showed high accuracy of stabilization of technological parameter, reliability in various conditions of change of characteristics of input signals.
Keywords
measurement of the solid/liquid ratio, optimization of the choice of measuring instruments
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References
1. Goncharov, Ju.G., Davidkovich, A.S., Gejzenblazen, B.E. & Gulenko, G.V. (1968). Avtomaticheskij kontrol' i regulirovanie tehnologicheskih processov na zhelezorudnyh obogatitel'nyh fabrikah [Automatic control and regulation of technological processes at iron ore processing plants]. Moskow: Nedra [in Russian].
2. Author's certificate. 388790 USSR, MPK V03V 11/00. Ustrojstvo dlja avtomaticheskogo kontrolja zagruzki i stabilizacii razzhizhenija pul'py v mel'nice [The device for automatic control of loading and stabilization of pulp liquefaction in the mill]. No. 1420849/29-33; stated. March 30, 1970; has been published July 5, 1973, Bul. No. 29. [in Russian].
3. Pat. 62627, Ukraine, MPK G05D7/01, V03V11/00. Sposib avtomatychnoi stabilizatsii vytrat ridyny [The method of automatic stabilization of fluid flow]. No. 2003043482; stated. April 17, 2003; has been published July 15, 2005, Bul. No. 7. [in Ukrainian].
4. Pat. 74393, Ukraine, MPK G05D9/02, G05D7/01. Prystrij avtomatychnoi stabilizatsii vytrat ridyny [The device for automatic stabilization of fluid flow]. No. 2003043879; stated. April 25, 2003; has been published December 15, 2005, Bul. No. 12. [in Ukrainian].
5. Pat. 59644, Ukraine, MPK V03V11/00, V02S25/00. Sposib avtomatychnoi stabilizatsii rozridzhennia pul'py v mlynakh z tsyrkuliuiuchym navantazhenniam [Method of automatic stabilization of pulp rarefaction in mills with circulating load]. No. 2002118758; stated. November 5, 2002; has been published April 15, 2005, Bul. No. 4. [in Ukrainian].
Citations
- Гончаров Ю.Г., Давидкович А.С., Гейзенблазен Б.Е., Гуленко Г.В. Автоматический контроль и регулирование технологических процессов на железорудных обогатительных фабриках. М.: Недра, 1968. 227 с.
- Авторское свидетельство СССР № 388790, кл. В 03 В 11/00. Устройство для автоматического контроля загрузки и стабилизации разжижения пульпы в мельнице /Дегтярёв Ф.Н., Мерзляков А.А., Кондратец В.А., Новохатько В.И., Кучма Н.И., Гуленко Т.И. - № 1420849/29-33; заяв. 30.03.1970; опубл. 5.07.1973, Бюл. № 29.
- Патент України № 62627, G 05 D 7/01, В 03 В 11/00. Спосіб автоматичної стабілізації витрат рідини /Кондратець В.О., Сербул О.М. - № 2003043482; заяв. 17.04.2003; опубл. 15.07.2005, Бюл. № 7.
- Патент України № 74393, G 05 D 9/02, G 05 D 7/01. Пристрій автоматичної стабілізації витрат рідини /Кондратець В.О., Сербул О.М. - № 2003043879; заяв. 25.04.2003; опубл. 15.12.2005, Бюл. № 12.
- Патент України № 59644, В 03 В 11/00, В 02 С 25/00. Спосіб автоматичної стабілізації розрідження пульпи в млинах з циркулюючим навантаженням /Кондратець В.О., Сербул О.М. - № 2002118758; заяв. 5.11.2002; опубл. 15.04.2005, Бюл. № 4.
Copyright (c) 2021 Vasily Kondratets, Oleksandr Serbul, Oleksandr Didyk, Anatolii Matsui
System of Automatic Control for Solid/liquid Ratio in Mills with Circulating Load
About the Authors
Vasily Kondratets, Professor, Doctor in Technics (Doctor of Technics Sciences), Central Ukrainian National Technical University, Kropyvnytskyi, Ukraine, ORCID ID: 0000-0002-1411-168Х
Oleksandr Serbul, Associate Professor, PhD in Technics (Candidate of Technics Sciences), Central Ukrainian National Technical University, Kropyvnytskyi, Ukraine, e-mail: serbulan@ukr.net, ORCID ID: 0000-0003-1836-5529
Oleksandr Didyk, Associate Professor, PhD in Technics (Candidate of Technics Sciences), Central Ukrainian National Technical University, Kropyvnytskyi, Ukraine, ORCID ID: 0000-0003-1454-0828
Anatolii Matsui, Associate Professor, PhD in Technics (Candidate of Technics Sciences), Central Ukrainian National Technical University, Kropyvnytskyi, Ukraine, ORCID ID: 0000-0001-5544-0175
Abstract
The operation of a ball mill operating in a closed loop with a spiral classifier depends on the vacuum of the pulp in it, which is characterized by a solid / liquid ratio. Supply to the entrance of the ball mill at the same time ore and sand classifier, as well as changes in the circulating load in a wide range greatly complicate the definition of this technological parameter. This situation has led to the fact that the solid / liquid ratio in mills operating in such conditions can not be automatically adjusted, in turn, the deviation of the pulp vacuum from the required value leads to significant losses. The study of the ball mill as a controlled object on the pulp vacuum channel made it possible to describe it using the mathematical expression given in the article. The solution of this expression makes it possible to characterize the change in the mass of the material in the mill over time, provided that a stepwise action is introduced at the entrance - the volume flow of water or ore. A constant value of the mass of material in the mill will clearly characterize the corresponding solid/liquid ratio. It has been found that it is important to study the filtering capabilities of the control object, as control actions on water and disturbing actions on ore can significantly change the vacuum of the pulp in some areas of the mill. The filtering capabilities of the mill can be investigated by its amplitude frequency characteristics, which showed that at low circular frequencies the amplitude frequency characteristics depend on the mode of operation of the mill - the magnitude of the circulating load and the cost of the source ore. Using computer technology, spatial diagrams of the relative oscillations of the mass of material in the mill from the amplitude and frequency of influences at its entrance through the ore and water. In the course of theoretical research it was determined that the only approach to ensure the required accuracy of determining the solid / liquid ratio in these conditions is to filter the signals before applying to the input of the identification unit of the ratio. Thus, the system of automatic control of the solid/liquid ratio at the entrance to the mill is implemented on microprocessor means. Its operation on the laboratory test bench made on the microcontroller showed high accuracy of stabilization of technological parameter, reliability in various conditions of change of characteristics of input signals.Keywords
Full Text:
PDFReferences
1. Goncharov, Ju.G., Davidkovich, A.S., Gejzenblazen, B.E. & Gulenko, G.V. (1968). Avtomaticheskij kontrol' i regulirovanie tehnologicheskih processov na zhelezorudnyh obogatitel'nyh fabrikah [Automatic control and regulation of technological processes at iron ore processing plants]. Moskow: Nedra [in Russian].
2. Author's certificate. 388790 USSR, MPK V03V 11/00. Ustrojstvo dlja avtomaticheskogo kontrolja zagruzki i stabilizacii razzhizhenija pul'py v mel'nice [The device for automatic control of loading and stabilization of pulp liquefaction in the mill]. No. 1420849/29-33; stated. March 30, 1970; has been published July 5, 1973, Bul. No. 29. [in Russian].
3. Pat. 62627, Ukraine, MPK G05D7/01, V03V11/00. Sposib avtomatychnoi stabilizatsii vytrat ridyny [The method of automatic stabilization of fluid flow]. No. 2003043482; stated. April 17, 2003; has been published July 15, 2005, Bul. No. 7. [in Ukrainian].
4. Pat. 74393, Ukraine, MPK G05D9/02, G05D7/01. Prystrij avtomatychnoi stabilizatsii vytrat ridyny [The device for automatic stabilization of fluid flow]. No. 2003043879; stated. April 25, 2003; has been published December 15, 2005, Bul. No. 12. [in Ukrainian].
5. Pat. 59644, Ukraine, MPK V03V11/00, V02S25/00. Sposib avtomatychnoi stabilizatsii rozridzhennia pul'py v mlynakh z tsyrkuliuiuchym navantazhenniam [Method of automatic stabilization of pulp rarefaction in mills with circulating load]. No. 2002118758; stated. November 5, 2002; has been published April 15, 2005, Bul. No. 4. [in Ukrainian].
Citations
- Гончаров Ю.Г., Давидкович А.С., Гейзенблазен Б.Е., Гуленко Г.В. Автоматический контроль и регулирование технологических процессов на железорудных обогатительных фабриках. М.: Недра, 1968. 227 с.
- Авторское свидетельство СССР № 388790, кл. В 03 В 11/00. Устройство для автоматического контроля загрузки и стабилизации разжижения пульпы в мельнице /Дегтярёв Ф.Н., Мерзляков А.А., Кондратец В.А., Новохатько В.И., Кучма Н.И., Гуленко Т.И. - № 1420849/29-33; заяв. 30.03.1970; опубл. 5.07.1973, Бюл. № 29.
- Патент України № 62627, G 05 D 7/01, В 03 В 11/00. Спосіб автоматичної стабілізації витрат рідини /Кондратець В.О., Сербул О.М. - № 2003043482; заяв. 17.04.2003; опубл. 15.07.2005, Бюл. № 7.
- Патент України № 74393, G 05 D 9/02, G 05 D 7/01. Пристрій автоматичної стабілізації витрат рідини /Кондратець В.О., Сербул О.М. - № 2003043879; заяв. 25.04.2003; опубл. 15.12.2005, Бюл. № 12.
- Патент України № 59644, В 03 В 11/00, В 02 С 25/00. Спосіб автоматичної стабілізації розрідження пульпи в млинах з циркулюючим навантаженням /Кондратець В.О., Сербул О.М. - № 2002118758; заяв. 5.11.2002; опубл. 15.04.2005, Бюл. № 4.