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Radiotracer Residence Time Distribution (RTD ) method was used to investigate the process of clinker grinding in Ghana Cement Plant (GHACEM) at Tema with the objective of determining hold-up and grinding efficiencies of two ball mills operating in close circuit regime. The experiment was conducted using 40Ci Au-198 radiotracer in liquid state and h...
Contexts in source publication
Context 1
... clinker is usually grounded using a ball mill. This is essentially a large rotating drum (Fig. 2), containing grinding media; normally steel balls (Fig. 3). As the drum rotates, the motion of the balls crushes the clinker. The drum which is divided into two chambers with different sizes of grinding balls rotates at a speed of approximately 16 rpm. As the clinker particles are crushed, smaller balls are used for more effective reduction of particle size. In cement and other mineral ...
Context 2
... fine cement product (powder of fine grains 0-13 :m) and rejects (coarse grains more than 13 :m) that are returned to the mill. The drum of each mill is made of two chambers. The first chamber, which is equipped with a coarse grinding media, is separated from the second chamber (has a fine grinding media) by an intermediate diaphragm as shown in Fig. ...
Citations
... This implies that the mill should behave as a plug flow reactor. Residence time distribution (RTD), a characteristics parameter of continuous flow reactors, provides the desired information i.e. mean residence time and axial dispersion that can help to characterize solid flow in a ball mill and optimize its performance (Mumuni et al., 2011). ...
... Secondly, the online monitoring and availability in wide range of compatible radiotracer makes them most suitable for tracing process materials in industrial plants. RTD measurement is one of the most frequently carried out applications of radiotracers in industrial process material including milling equipment (Plasari et al., 1999;Mumuni et al., 2011;Makokha et al., 2014;Adzaklo et al., 2016;Ahmad, 2018). The measured RTD is used for troubleshooting, process optimization and flow characterization in industrial systems as well as evaluation of design of pilot and laboratory-scale systems at design stage itself. ...
A radiotracer investigation was carried out in a ball mill of a cement plant in Kenya. Residence time distribution (RTD) of raw feed to the mill was measured using Technetium-99m adsorbed on the clinkers as a radiotracer. From the measured RTDs, solid holdup and mean residence times (MRTs) in the ball mill and associated separator were determined. The measured RTDs were modelled using axial dispersion model (ADM) and tank-in-series model both connected with a plug flow component in series. The results of the modelling indicated significant degree of backmixing within the ball mill and no axial mixing in the separator.
... In, addition, quantitative knowledge of the above-mentioned flow parameters is also required for the control and optimum operation of the reactors. The radiotracer technique is the most suitable approach for the online measurement of RTD in chemical reactors in chemical, petroleum, petro-chemical, and mineral processing industries (Charlton, 1986;IAEA, 1990IAEA, , 2004Thyn et al., 2000;Pant et al., 2001Pant et al., , 2009Pant et al., , 2012Pant et al., , 2017Sharma, 2015, 2016;Stegowski and Furman, 2004;Dagadu et al., 2012;Diaz et al., 2013;Mumuni et al., 2011;Zaharan et al., 2009;Datta et al., 2017;Kumar et al., 2017;Sheoran et al., 2018). The present paper describes the measurement and analysis of the RTD of phosphate pulp by the radiotracer technique in three different reactors, which operate in three different plants in Tunisia. ...
Radiotracer investigations were carried out in two identical phosphoric acid production reactors and a triple super phosphate (TSP) production reactor in three different plants in Tunisia. The main objective of the study was to investigate and compare their flow behavior and identify flow abnormalities, if any. Residence time distribution (RTD) of the process material (ore pulp) was measured in the three reactors using Iodine-131. The measured RTDs were treated and analyzed to obtain flow parameters such as the mean residence time (MRT), dead volume, and extent of bypassing. The treated RTD curves were modeled using a suitable mathematical model, and the values of the parameters were obtained. The results of the investigations were used to evaluate and compare the flow performance of the reactors, quantify the degree of mixing, and visualize the prevailing flow patterns. The results of the investigations are expected to be used to make necessary modifications to enhance the efficiency and optimize the performance of the reactors or the production process.
... Many radioisotopes such as americium-241, bromine-82, caesium-137, chromium-51, gold-198, hydrogen-3, iodine-131, krypton-85, krypton-79, lanthanum-140, mercury-197, mercury- 203, molybdenum-99, silver-110m, strontium-90, technetium-99m and xenon-133, can be used in industrial applications, especially in chemical and petrochemical industries. (Broadhead, and Heady, 1962; Lane, Nuckolls & Railey, 1963; Brownell, Farvar, Gyorey & York, 1965; Pilgrim, 1978; Campbell, Mirza, Thomson & Webb, 1984; Collins and Archundia, 1984; Iller, Przybytniak & St. Golembiowski, 1984; Larry, 1984; Burgio, Capannesi, Ciavola & Sedda, 1995; Torres, Olivares, De La Rosa & Lima, 1999; Kenneth, Janick, & Mark, 2006; Suga, 2002; Varga, Szalóki, Gáncs & Marczona, 2002; Adam and Laplace, 2003; Bondareva et al., 2005; Ding, Lin, Logan, Benveniste & Carter, 2005; Catán et al., 2007; Guevara, Repin, Catán, Jaćimović & Horvat, 2007; Pramanik, Bhattacharyya & Chattopadhyay, 2007; Yelgaonkar, Jayakumar, Singh & Sharma, 2007; Abu– Khadra, Abdel–Sabour, Abdel-Fattah & Eissa, 2008; Al-Dahhan, 2008; Shehee, Martin & Nash, 2009; Sukhoruchkin and Soroko, 2009; Pant et al., 2009; Jung et al., 2010; Kasban et al., 2010; Stęgowski et al., 2010; Guo et al., 2011; Mumuni et al., 2011; Pant et al., 2011; Kumar, Pant, Sharma, Mohan & Mahajani, 2012; Koron, Bratkič, Guevara, Vahčič, Horvat, 2012; Rhodes, 2012; Singare, 2012; Ugur and Sahan,. 2012; Affum, Adu, Dagadu, Coleman & Addo, 2013; Sugiharto et al. 2013b; Assadnassab, 2014; Belov, Kulkarni, Sohn & Murch, 2014; Othman et al., 2014; Takata, Tagami, Aono & Uchida, 2014; Vieira, Eduardo, Brandão & Braz; Zych et al., 2014; Dwivedi, Pathak, Kumar, Tripathib & Bajaja, 2015). ...
... These techniques are divided into three categories namely RTD measurement, sealed source for gamma-ray and x-ray transmission measurements, and radioactive and positron emission particle tracking. Al-Dahhan, 2008; Jung et al., 2010; Stęgowski et al., 2010; Vieira et al., 2014; Mumuni et al., 2011 Hydrogen Yelgaonkar et al., 2007 Lanthanum-140 139 La (n,γ) 140 La Gamma: 1.16(95%) 0.92(10%) 0.82(27%) 40 h Lanthanum Chloride solids (absorbed) Lane et al., 1963; Pant et al., 2009; Affum et al., 2013 Mercury-197 196 Four catalytic beds and three internal intermediate heat exchangers with total height of the reactor is 13.0 m. ...
Radioisotope techniques are constantly and extensively used all over the world as a method to identify process systems malfunctions in various industries without requiring the shut down of the processing plant thus leading to high economical benefits to the plant owner. Different aspects of industrial radiotracer technology for troubleshooting, process control and optimization are evaluated through an exhaustive literature survey. The review covers the advantages of radiotracers, most commonly used radiotracers in industry for specific studies, applications of radiotracer techniques in various chemical industries, the design of radiotracer technology experiments, radiation detection and data acquisition in radiotracer technology as well as radiological safety aspects. Two industrial radiotracer techniques of residence time distribution (RTD) measurements and radioactive particle tracking (RPT) are discussed. The design of radiotracer technology experiments are also divided into two categories - radioactive particle tracking applications and residence time distribution applications.
... This technique was employed to ascertain the extent and cause of abnormal behavior ( slight stripping problems) around the bottom stripping section of a pressure column in a petroleum refinery. Any success in this direction will definitely assist in improving process equipment design and/or choosing optimal operating and environmental conditions that could possibly lead to the development of new approach toward energy saving during production in process industries [3]. ...
Keywords Abstract Gamma scanning sealed source scan profile shutdown Gamma scanning radioisotope technique was employed to understand the severerity of stripping problem experienced on a bottom section of an atmospheric column of a petroleum refining industry. It is an online technique that can effectively investigate the hydraulic performance of an operating column without shutdown. The technique is Cost effective, and Efficient, and when applied periodically, can extend column run times. The scan was carried out on bottom two single-pass trays across the live area of the column using a 20 mCi (740 MBq) cobalt sixty (60 Co) radioactive sealed source. The scan profile obtained indicated a regular attenuation " peaks " at the tray positions, which confirmed that both bottom trays are in their designed position and carries a significant amount of liquid on them. It was also found that there is a good liquid/vapor disengagement in the vapor space between the two trays and that the lower tray carries slightly more liquid than the tray above it (not indication of abnormally). A base level at 2.5m was also detected on the scanned section of the column.
In this work the relation between the change in mill output and cement fineness caused in the ball mill grinding process of composite cement with respect to different operating input parameters like litre weight of clinker in grams/litre clinker feed rate in tonnes per hour, fly ash feed rate in tonnes per hour have been investigated. Response surface methodology (RSM) technique has been used to plan the experiments and class F type fly ash selected as additive. A historical data design with 27 experimental runs was selected for modeling and analyzing the relationship between the input factors and the responses. Analysis of variance (ANOVA) technique was used for calculation of regression coefficients and for checking the significance of the models developed. This work aims to consider a predictive system for the operational input parameters that will reduce the related unpredicted responses. Some data were used to validate the model and the proposed models were used to develop the best operational input parameters.
