Abstract:Abstract-This paper deals with physical modelling and control of dynamic foaming in the LD-converter process. An experimental setup consisting of a water model, DSP and P C hardware is built up and showed to be useful for studying dynamic foaming. Furthermore, a foam height estimation algorithm is presented and validated through experiments. Finally, sound signals from the LD-converter and water model are compared and similarities between them are found.
“…Recently, for example, Buydens et al [10] published results from a technique including sound as well as vibration measurements for optimization and control of slag foaming in the EAF. In addition to the plant studies, several investigations on foaming behavior were carried out using physical modeling, as exemplified by the works of Komarov et al [11] and Birk et al [12].…”
This study focused on slag‐foaming phenomena, the main emphasis being on slags used in the electric arc furnace (EAF) practice in the manufacture of stainless steel. Plant trials were carried out at Sandvik Steel for slags of high and low chromium content. The viscosity of the slags was predicted using a mathematical model for multi‐component slags developed at KTH, Stockholm. Next, the foaming characteristics were predicted using different relationships suggested in the literature. The predicted foaming behavior was then compared to estimations of foaming determined visually and acoustically by operators. Sound measurements were also carried out during the trials. In comparing foaming characteristics determined from sound measurements with the operator estimations, a relationship was found to exist between the two.
“…Recently, for example, Buydens et al [10] published results from a technique including sound as well as vibration measurements for optimization and control of slag foaming in the EAF. In addition to the plant studies, several investigations on foaming behavior were carried out using physical modeling, as exemplified by the works of Komarov et al [11] and Birk et al [12].…”
This study focused on slag‐foaming phenomena, the main emphasis being on slags used in the electric arc furnace (EAF) practice in the manufacture of stainless steel. Plant trials were carried out at Sandvik Steel for slags of high and low chromium content. The viscosity of the slags was predicted using a mathematical model for multi‐component slags developed at KTH, Stockholm. Next, the foaming characteristics were predicted using different relationships suggested in the literature. The predicted foaming behavior was then compared to estimations of foaming determined visually and acoustically by operators. Sound measurements were also carried out during the trials. In comparing foaming characteristics determined from sound measurements with the operator estimations, a relationship was found to exist between the two.
“…Various methods for detecting slopping during blowing have been reported, including detection by a surveillance camera at the furnace mouth, [57][58][59] measuring furnace vibration with an accelerometer 60) and detection by acoustic signals. 61) M. Shakirov et al 62) reported the classification of slopping. Cicutti et al 63,64) conducted detailed research by an acoustic analysis during blowing.…”
Section: Sensing Techniques For Convertermentioning
The development of refining techniques in the steelmaking process over the last 60 years and the prospects for the future were reviewed. In Japan, hot metal pretreatment started in the 1960s with the aim of reducing refining costs and improving quality, and its purposes have now transitioned to meeting new requirements for reduced treatment time, reuse of steelmaking slag and use of diverse iron sources. In converter refining, in addition to high speed decarburization, visualization of phenomena and sensing modeling techniques are becoming more important for combined use with data science techniques. In ladle metallurgy (secondary refining), techniques to realize high speed treatment and heating of the molten steel are key issues. The necessity of process revolution to contribute to a sustainable social environment is also discussed briefly.
“…Physical modeling of foaming is an arduous process as it requires estimation of foam height, which is dynamic in nature and differs for different bioprocesses . Machine learning based modeling helps mitigate the necessity for foam height estimation, and it can be generalized for any process, as it uses the available operational data for prediction.…”
Section: Introductionmentioning
confidence: 99%
“…Physical modeling of foaming is an arduous process as it requires estimation of foam height, which is dynamic in nature and differs for different bioprocesses. 9 Machine learning based modeling helps mitigate the necessity for foam height estimation, and it can be generalized for any process, as it uses the available operational data for prediction. Recently, machine learning based methods have found several applications in sectors where mechanistic modeling is precluded by the inability to develop a model or generalize it for a process.…”
In the industrial sector, foaming remains an inevitable side effect of mixing, shearing, powder incorporation, and the metabolic activities of microorganisms in a bioprocess. Excessive foaming can interfere with the mixing of reactants and lead to problems such as decreased effective reactor volume, microbial contamination, product loss, and increased reaction time. Physical modeling of foaming is an arduous process as it requires estimation of foam height, which is dynamic in nature and varies for different processes. This work demonstrates a novel application of ensemblebased machine learning methods for prediction of different fermenter types in a fermentation process (to allow for successful data integration) and of the onset of foaming. Ensemble-based methods are robust nonlinear modeling techniques that aggregate a set of learners to obtain better predictive performance than a single learner. We apply two ensemble frameworks, extreme gradient boosting (XGBoost) and random forest (RF), to build classification and regression models. We use real plant data for 64 batches from four fermenters with different material, geometry, and equipment specifications. Our first task is to develop an ensemble-based fermenter classification model that uses well-known fermentation independent variables for each batch alone, without having to incorporate explicitly the design specifications. The resulting fermenter classification model is able to differentiate or classify the fermenter type with an accuracy of 99.49% for our integrated data sets of over 183 000 instances. This enables us to integrate multiple plant data sets from different fermenter specifications and develop a generalized foaming prediction model. Next, we build classification and regression models for foaming prediction. The resulting models are able to predict the foaming indicator (the exhaust differential pressure) to achieve an accuracy of 82.39% and an RMSE value of ±12 mbarg, which is well within the tolerance for foaming prediction in industrial practice. These results demonstrate the effectiveness of ensemble-based machine learning models for fermenter classification, data integration, and foaming prediction involving multiple fermenter design specifications. Using these tools, we can orchestrate the addition of chemical antifoam agents (AFA) or defoamers in an ad hoc manner to mitigate the adverse effects of excessive AFA addition. Our work differentiates itself from previous work in this area through the following contributions: (1) accurate ensemble-based classification modeling to differentiate fermenter types on the basis of known independent variables alone, without prior knowledge of fermenter design specifications, thus allowing for data integration of multiple plant data sets to build better prediction models; (2) accurate prediction of foaming based on exhaust differential pressure using both classification and regression models; and (3) usage of a large, industrial, multivariate fermenter data set.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.