Rotary Dryer Research Articles

Enhancing prior-knowledge-based control with deep attention neural network for outlet moisture content of cut-tobacco

Monitoring and controlling the drying process is crucial, particularly for rotary dryers, to ensure optimal quality and efficiency. However, due to the process’s nonlinear behavior, delays, and input disturbances, achieving this can be quite challenging. Previous research has not adequately explored online forecasting for rotary dryer control in real production settings. To bridge this gap, our study focuses on tobacco drying in an actual plant and presents a novel online prediction model for moisture content. We conducted comparative experiments to validate the model’s practical application in production settings and demonstrate its effectiveness in enhancing drying control. Our approach, called MCTFormer, has proven to be scalable to high-dimensional problems. The results of our study indicate a 45% improvement in product quality through accurate prediction of outlet moisture content, better control over moisture levels, and reduced energy consumption.

Control-oriented modeling of direct-heat co-current rotary dryers for energy demand flexibility

The contribution presents a new control-oriented model for direct-heat co-current rotary dryers with a focus on demand-side flexibility considering the variation of material throughput and heat source. The dryer model is based on partial differential-algebraic equations covering time- and location-dependent gas and particle velocities taking phase interactions into account. In addition, a steady-state model of a heat supply unit covering electricity-based and chemical heat sources is presented. The model is qualitatively compared with measured data and models from literature showing good overall agreement. Furthermore, simulations of the flexibility mechanisms are performed and their effect on temperature and humidity profiles as well as input and output streams of the dryer are analyzed. On this basis, requirements to process control are discussed. The simulations show that the variation of the throughput is associated with significant changes to the gas input stream, while only small changes are observed for the variation of the energy carrier.

Mathematical modelling of pumpkin seed drying in a rotary thermosyphon dryer

ABSTRACT Pumpkin seeds swagger a wealthy vitamin and mineral composition. They contain vitamins (A, B, C, K, D, E), minerals (calcium, selenium, zinc, magnesium, copper, potassium, press, manganese and phosphorus), a few amino acids such as glutamic, linolenic and arginine, and greasy plant acids. The Peclet number includes the peripheral rotation speed of the RTS condenser tube. In our case, the Peclet number reflects how the heat transfer to the grain layer due to convection, when the RTS capacitor rotates, relates to the heat transfer due to the thermal conductivity of the grain layer. Thus, in the first drying period, the determining factors for mass transfer will be the conditions at the phase boundary – the mode of air movement outside the grain, the area of the grain, the surface temperature of the RTS condenser. In total, pumpkin seeds contain 12 essential and eight nonessential amino acids.

Deep learning based self-adaptive modeling of multimode continuous manufacturing processes and its application to rotary drying process

Deep learning based self-adaptive modeling of multimode continuous manufacturing processes and its application to rotary drying process

Banana Plant Waste Rotary Dryer Design and Simulation Using 3D Computer Aided Design

This research determines the optimal rotary dryer design for banana waste drying with Biot number. When banana waste is adequately dried, it can be repurposed into valuable resources. Based on the proposed banana plant waste rotary dryer, drying efficiency is significantly improved compared to conventional dryers as attributed to design calculations and simulation. Here, the design process involves the three-dimensional (3D) computer-aided design of individual parts, subassemblies, and main assembly, accompanied by detailed illustration drawings, and optimization of rotary dryer flight design. Biot number is crucial in the design calculations of the diameter and length of the dryer. The Design of Experiments (DoE) and computational fluid dynamics simulations are also used. Proper drying, facilitated by the proposed rotary dryer, enables efficient repurposing of banana waste into animal feed, biofuel, bioplastics, and other nanotechnology applications, contributing to sustainable waste management practices and a promising solution to environmental challenges.

Estimating the Lifetime of Rotary Dryer Flights Based on Experimental Data

The studies carried out address an important problem for the concrete and asphalt industry, referring to the wear phenomena that affect the elements (flights) of rotary dryers used to dry mineral aggregates. In this article, the authors propose a lifetime estimation method for rotary dryer flights. In order to benefit from greater credibility, the proposed method was applied based on the experimental results obtained, by the authors, in the laboratory, on a stand that reproduces a portion of the real equipment. Starting from these results, the authors identified the mathematical functions used to model the failure rates (wear) of the flights by referring to characteristic quantities for wear evaluation: mass loss of material; reduction in the thickness of the part; surface affected by wear. The experimental data—the input data for the proposed algorithm—correspond to six steels used in industrial applications. The wear phenomenon was modeled considering both the situation of uniform wear and the situation of differentiated wear on the flight surface. Therefore, the steel type with the highest service life values could be identified, namely, steel grades E and G. The method proposed in this paper can be extended to any category of material or part provided that the failure rate function is identified beforehand, possibly based on a laboratory experiment.

Sago Starch Modification by Combination of Lactic Acid Hydrolysis and Oxidation of Hydrogen Peroxide Under Ultraviolet Rotary Dryer Irradiation

Sago Starch Modification by Combination of Lactic Acid Hydrolysis and Oxidation of Hydrogen Peroxide Under Ultraviolet Rotary Dryer Irradiation

An innovative dryer for Arabica coffee (Coffea arabica L.) drying: Investigating heat and mass transfer

In the pursuit of advancing post-processing techniques for Arabica coffee, our research introduces a rotary dryer, known as a roto-aerated dryer, marking its first application in coffee drying and surpassing conventional methods. This study delves into the evaluation of heat and mass transfer dynamics between coffee and drying air within the innovative dryer. Characterization of raw materials precedes a series of drying experiments under varied conditions, forming the basis for a mathematical two-phase model elucidating the underlying dynamics of the drying process. Noteworthy is the significantly reduced material residence time (14.60–27.47 min) compared to conventional dryers. Drying rates (0.09–0.24 g water/100 g solid/min) surpass those achieved by other methods. Simulated results from the numerical solution of the two-phase model closely align with experiments (average error of 2.39% for moisture content and 0.89% for temperature). The effective preservation of material quality, particularly acidity, underscores the valuable insights offered for optimizing drying processes, holding substantial potential for advancing the specialty coffee industry.

Increasing of the unit capacity of MF process at Miike Smelter

MF (Mitsui Furnace) is a half shaft blast furnace developed by Mitsui Miike Smelter in the 1960’s to treat vertical retort residue. Currently MF mainly treats various secondary wastes (EAF dust, Secondary Fly Ash, etc.) and recovers zinc and lead as crude zinc oxide, copper and silver as matte, meanwhile other elements such as FeO, CaO, SiO2, Al2O3 are concentrated in slag.There are two steps in the MF process. The first step is pretreatment. In this process, various waste materials are blended in a certain proportion with reductant and dried adding binder in a rotary dryer, then grinded in a rod mill. The grinded materials are made into an oval briquette by briquetting machine. The second step is treatment process. The briquettes fed into the MF are smelted and reduced by blowing air through the tuyeres. By enriching the tuyere air with oxygen generated by the VSA (Vacuum Swing Adsorption) oxygen generator in 2005 and 2012, we have improved the throughput of wastes.By the improvement of oxygen enrichment in the MF, the unit capacity increased significantly. However shortage of the drying capacity in the pretreatment process became a problem. To ensure sufficient drying capacity, we installed one more rotary drier in series in 2016. Additionally in 2018, we installed a granulator after the rod mill to improve the bulk density in briquette. As a result of these efforts, the treatment amount in the whole MF process has increased.The MF can treat various kinds of materials containing various non-ferrous metal-valuables. Through these process improvements, we promote the treatment of wastes containing heavy metals and contributes significantly to the recycling of metal resources.

Discrete Element Method-Based Hybrid Compartment Model of a Rotary Dryer for Fertilizer Production

Discrete Element Method-Based Hybrid Compartment Model of a Rotary Dryer for Fertilizer Production

Analisis Perbandingan Kinerja Alat Pengering Rumah Kaca Tipe Rotari Sistem Tertutup Dengan Sistem Semi Tertutup Terintegrasi Dengan Tungku Biomasa Menggunakan Penukar Kalor Dua Tingkat Untuk Mengeringkan Ikan Nila

The aim of this research is to compare the performance of an open system rotary type greenhouse effect dryer (APERK-TR-STP) system 1 with a closed system (APERK-TR-SST) system 2 for drying tilapia fish. In the APERK-TR- system, 1 fish is dried from an initial weight of 90.56 kg (initial water content 69.08% wet basis (bb) to a final weight of 30.33 kg (final moisture content 20% bw) at an average temperature 56.38 oC with a mass air flow rate of 0.459 kg/s takes 12 hours. Meanwhile in the APERK-TR-SST system 2 tilapia fish are dried from an initial weight of 91.49 kg (initial water content 69.40% bw) up to final weight of 19.27 kg (final moisture content 20% bw) at an average temperature of 53.98 oC with an air mass flow rate of 0.459 kg/s required 12 hours

DESIGN OF RICE HUSK ROTARY DRYER USING WASTE HEAT ELECTROSTATIC PRECIPITATOR OF THE CEMENT INDUSTRY

ESP or electrostatic precipitator is a device used to capture particulate matter, such as dust, in exhaust gases using electrostatic principles. In the cement industry, ESP is commonly placed after the clinker cooler to clean the exhaust air from the cooling process, ensuring it is free from clinker dust. The clinker cooler is a device that cools down the clinker using air, reducing its temperature from an initial temperature of around 1450°C to approximately 100°C - 120°C. The exhaust air from the clinker cooler is then passed through the ESP at temperatures ranging from around 237°C to 311°C. Based on the temperature data, the exhaust air from the ESP has the potential for heat reuse for other processes, including as a heat source for drying rice husk, which is a common alternative fuel used in the cement industry and typically has a moisture content of around 25%-37%. The results of this design indicate that the exhaust heat from the ESP, with an input temperature of 275°C, is capable of drying rice straw pellets from a moisture content of 25% to 14.73% using a designed rotary dryer with a capacity of 21.6 t/h, a length of 41.58 m, and a diameter of 2.92 m. It is constructed using ASTM 283 C material with a thickness of 8.76 mm and is insulated with a 15.6 mm thick layer of aluminum foil.

The optimization of paddy drying in the rotary dryer: energy efficiency and product quality aspects analysis

Currently, paddy drying has been widely developed and applied. This research goal was to find the optimal condition of paddy dried in a rotary dryer. The process was conducted at various paddy capacities (10–40 kg) and temperatures (40–60°C). For main indicators, the drying time, physical quality of the product and energy efficiency were evaluated. In doing so, the optimization process with the response surface method (RSM) was conducted. Results showed that under higher temperatures, the moisture level in the paddy reduced quickly, resulting in a shorter drying time and higher efficiency. However, faster moisture reduction can break the texture of paddy, which increases the percentage of broken rice. Meanwhile, with the increasing paddy capacity, heat transfer becomes more effective, as seen in the increase in energy efficiency. Nevertheless, the excessive capacity requires a longer drying time. After optimizing by response surface method (RSM), the most favorable condition can be reached at paddy capacity of 45.8 kg with drying temperature of 56.4°C. For this condition, energy efficiency achieved 15.6% with percentage of broken rice 8.18%.

Performance evaluation of a rotary dryer for onion bulb drying

Drying is conducive in extending the storage life of fresh harvested onion. Currently, direct sun drying is not suitable in terms of fluctuating weather conditions. Rotary dryer assisted by combustion heating is a viable option to speed up onion drying process. In this case, 10 kg of fresh onion was placed in a rotary dryer operating for 2 hrs at 40°C and 14.6 m/s of air velocity. Moisture content was observed at every 30 mins and drying rate was predicted using several mathematical models. The drying temperatures were 50, 60, 70°C and the drying procedures were repeated. Results showed that the rotary dryer method can improve drying performance compared to the chamber and tray dryer methods and the drying rate of onion bulb drying can be well represented by the Page’s model with R 2 value near to 1, and the lowest average chi-square (X2 ) of 0.00027.

Effect of single step oxidation-esterification process on the physicochemical properties of modified cassava starch

The oxidation and esterification are examples of starch modification processes which is often carried out. The conventional combination of the oxidation-esterification process has many defects due to its wasting of time, energy-consuming and quality-damping. This research focuses on combining chemical modification processes to produce modified cassava starch by developing a single-step process of oxidation-esterification and a drying process using a rotary UV dryer. The oxidized-esterified cassava starch is characterized by Fourier-transformed insfrared (FTIR) spectroscopy, X-ray diffraction, scanning electron microscope (SEM) and physicochemical properties. The results revealed that the oxidizedesterified cassava starch (COAEC 14) meets the SNI requirements for several parameters such as water content of 13.10±0.141%, ash content of 0.0042±0.0002%, and crude fiber content of 0.6677±0.0424%. In addition, the single-step oxidation-esterification process also improved the quality of swelling power and starch amylose content. Meanwhile, in SEM analysis, the single-step oxidation-esterification process did not change the surface morphology but changed the crystal system and size of starch using XRD analysis.

Experimental Investigations on Wear Phenomena Specific to Rotary Dryer Flights (Blades)

The experimental research was carried out to study the tribological behaviour of materials used in the manufacture of rotary dryer blades (based on abrasive/abrasive-erosive wear analysis of the blades) using the Baroid tester. The test program included 2 series of tests consisting of subjecting the specimens to a wear process, generated by friction between their test surface and a rotating granite roller. Each set of tests was by specific parameters characterized: test medium, rotational speed of the granite roller, pressing force of the roller on the specimen surface, test time, number of test cycles. The test results highlight the erosion phenomenon (abrasive erosion) responsible for the damage of the rotary dryer blades and the conditions of accentuation of specific wear phenomena.

Preservation of fruits through drying—A comprehensive review of experiments and modeling approaches

AbstractA significant part of the world's population still has problems in accessing food. The growing world population will exacerbate this issue in the future. Innovative studies conducted in this field play a crucial role in addressing the issue of drying and storage of foods. Atmospheric drying methods, such as rotary, tunnel, conveyor, cabinet, tower, and kiln dryers, offer advantages in relation to high production capacities, cost‐effective initial setup, and economical operating conditions. However, concurrently, the weaknesses of these methods arise from factors such as drying duration, uneven moisture content, and space requirements. The solar dryer method is especially effective in dehydrating agricultural products, offering an energy‐saving advantage compared to other methods. However, it is important to note that this approach, which involves exposing crops to direct sunlight, comes with several drawbacks affecting both food quality and health. In cases where the quality of highly valued foodstuffs is crucial, subatmospheric drying methods like vacuum, freeze, and microwave freeze are typically preferred. However, the primary drawback of this approach lies in its high operating costs, particularly in terms of energy consumption. Artificial neural networks (ANNs) can be used for predictive modeling, helping to forecast drying behavior and optimize process parameters in food drying applications especially nonlinear connections among variables. ANNs are adept at managing nonlinearities, offering a more precise depiction of the intricate interactions within food drying systems. This review examines articles from the last 5 years in the literature, synthesizing research conducted in food drying. The findings indicate a predominant interest among researchers in methodologies with lower environmental impact, prompting increased attention to studies addressing this aspect. There is a notable emphasis on the frequent exploration of energy‐efficient systems. The ongoing research focuses on the development of methods utilizing ultrasonic, infrared radiation, and electrohydrodynamic techniques to achieve more effective, shorter‐duration, energy‐efficient drying processes with enhanced control over the final product.

Energy and carbon dioxide emission analysis of a batch-mode paddy drying process in a rotary dryer

Energy and carbon dioxide emission analysis of a batch-mode paddy drying process in a rotary dryer

Implementasi Sistem Monitoring Alat Pengering Biji Kopi Berbasis IoT (Internet of Things)

Indonesia holds the third position in global coffee bean supply, with a 3.3% increase in demand in 2021 according to ICO data. In line with ICO Resolution 407, coffee bean quality must be high, indicated by a 12.5% moisture content through drying processes. Mechanical drying is faster than traditional methods, thus becoming the focus of this research. This study implements an IoT-based monitoring system for coffee bean drying equipment. The aim is to create and implement a monitoring system for temperature (0°C - 70°C) and electrical energy consumption (kWh) in coffee bean drying, displayed on the ThingSpeak dashboard. Test results show that the temperature monitoring system using DHT22 sensors at the inlet and outlet of the rotary dryer tube has an average error of 2.1%. The energy monitoring system using PZEM-004T has a 0% energy measurement error. These results indicate a reliable monitoring system that enables remote monitoring via the internet. Furthermore, the study tests manual (on/off) and fuzzy logic control methods to achieve 12% moisture content in coffee beans. The fuzzy logic control method demonstrates better temperature stability and 11.2% cost savings in operational expenses. This research benefits coffee farmers by facilitating efficient monitoring of the bean drying process, and recommends the use of the fuzzy logic control method for stable temperature and lower operational costs.

Physicochemical and Sensory Properties of Arabica Coffee Beans of Arara cv. Dried Using Different Methods.

The coffee fruit is preferably harvested at the cherry stage, with high moisture and metabolic activity, and must then undergo a drying process for better preservation of the bean and its sensory attributes. In this context, this study aimed to characterize the final quality of the Arara cultivar Arabica coffee processed using the wet method and subjected to six drying methods: three conducted at the agro-industrial establishment (fixed-bed dryer, rotary drum dryer, and combined drying) and three laboratory-scale methods (convective oven, cast-tape drying, and suspended terrace). Drying was carried out to reduce the coffee's moisture content from an initial value of 46.2% on a wet basis (w.b.) to a final average value of 11.35% (w.b.). The fruits of in natura demucilaged coffee and the processed dry coffee beans were characterized for moisture, ash content, nitrogen compounds, lipids, total titratable acidity, organic acids, sugars, and the instrumental color of the beans. The sensory profile of the Arabica coffee was evaluated by five coffee specialists using the methodology proposed by the Specialty Coffee Association (SCA), and all the coffees were classified as a specialty.