Rotary Dryer Research Articles

Analisis Proses Dewatering Konsentrat Mineral pada PT. Freeport Indonesia

A concentrate treatment process is needed to improve the quality of the concentrate. Processing of copper minerals by drying concentrate or dewatering. The slurry concentrate dewatering process is intended to inhibit the rate of damage to the concentrate, and it is easy to distribute the concentrate through shipping. PT. Freeport Indonesia has 2 types of machines for the dewatering slurry process, Rotary Dryer and VPA (Vertical Pressure Airblow). The dryer dries the slurry by evaporating the water in the slurry through a combustion process with temperatures reaching 1500o F. While the VPA machine only uses membrane compression and compressed air to dry the concentrate. A comparison of the power requirements needed to dry the slurry on the two machines is done to determine the effectiveness and energy needs of the input. The results obtained in this study that dryer requires an average power of 84.31 kW to dry every 1-ton slurry, and VPA machines only use power with an average of 0.0078 kW in every 1-ton slurry

Application of The Rotary Dryer Machine in The Semi Modern Herbal Herbs Business Group in Nguter District, Sukoharjo Regency

The purpose of this community service program is to apply the rotary dryer unit to the production of herbal herbs that do not require solar heat. Target on the management aspect, partners are able to manage business with standard business management. Partners have an entrepreneurial spirit and have a strong spirit. Activities are carried out with coordination and discussion with partners. A meeting to determine the capacity of the rotary dryer unit and the needs of electrical energy and heat sources. Whereas for the herbal medicine business entrepreneur group, coordination was carried out to determine the material and motivation management training to foster an entrepreneurial spirit. The rotary dryer unit consists of two main parts, namely: air heater and rotary dryer cylinder. Air heater is made from a range of 3/4 inch diameter mild steel pipes, while the shell wall is made of mild steel plates with 1.2 mm thickness. For air plants centrifugal blowers are used with a 2 inch pipe diameter. A heat source is used by a single burner with LPG fuel. The rotary dryer cylinder, is a concentric tube, from a perforated stainless steel plate used as a place for dried simplicia. While the outer tube is made of mild steel plates. The tube is rotated using a 200 Watt one pasha electric motor. Improved business management with standard management to improve marketing efficiency and development.

A machine learning approach in drying of microalga Chlorella minutissima in a single rotary drum dryer for biodiesel production

Drying of Chlorella minutissima slurry was carried out in a single rotary drum dryer at varied drum surface temperature and rotational speed to achieve higher lipid yield for biodiesel conversion. Residual moisture content and lipid yield of the corresponding drum speed and drum surface temperature were mapped. Application of the machine learning tool classified the range of residual moisture content to be <10% (wet biomass) for high lipid recovery with an accuracy of 97%. Based on the drying time, lipid recovery, and energy consumption, drying at 80°C drum surface temperature with 0.3 rpm resulted ˃90% lipid recovery as compared to the bone-dried biomass. The energy consumption of 7.328 kWh for 1 kg of dried biomass was recorded with profound reduction in drying time as compared to oven and tray drying of algal slurry. The fatty acid methyl ester profile of C. minutissima biodiesel constituted higher proportion of saturated fatty acids followed by monounsaturated fatty acid and polyunsaturated fatty acids. Various fuel characteristics, namely, viscosity, density, free glycerin, triglycerides, diglycerides, monoglycerides, copper strip corrosion, flash point, cetane index, iodine value, calorific value, acid value, saponification value, phosphorous, sulfur, water, and ash contents were analyzed, and showed values within the specified limits of national and international biodiesel standards. Thus, considering the drying time, energy consumption, and lipid recovery with suitable fuel properties, the drum dryer could be recommended for drying the microalgal slurry for large-scale operation.

Particle Engineering of Chitosan and Kaolin Composite as a Novel Tablet Excipient by Nanoparticles Formation and Co-Processing.

Chitosan is not a common excipient for direct compression due to poor flowability and inadequate compressibility. Co-processing of chitosan and kaolin is a challenging method to overcome the limitations of the individual excipients. The purpose of the present study was to develop co-processed chitosan–kaolin by the spray drying technique (rotary atomizer spray dryer) and to characterize the excipient properties. The formation of chitosan nanoparticles was the major factor for desirable tablet hardness. The ratio of chitosan/tripolyphosphate of 10:1 and 20:1 had a significant effect on hardness. The successful development of co-processed chitosan–kaolin as a novel tablet excipient was obtained from a feed formulation composed of chitosan and kaolin at a ratio of 55:45 and the optimum chitosan/tripolyphosphate ratio of 20:1. Co-processing altered the physical properties of co-processed chitosan–kaolin in such a way that it enhanced the flowability and tableting performance compared to the physical mixture.

Toasted yerba mate: Impact of drying methods on bioactive compounds, antioxidant capacity, and mate tea consumer acceptance

This work investigates the consumer's acceptance of hot and iced mate tea, bioactive compounds content and antioxidant capacity of toasted yerba mate leaves dried from various processes, aiming at presenting drying alternatives to the traditional, and mostly used, methods. Therefore, five drying methods were tested, traditional rotary dryer, conveyor dryer and three alternatives including microwave oven, over dryer at 40, 60, 80℃ and freeze-drying, which was followed by toasting. Overall, the microwave oven and freeze dryer were highly efficient and can be considered as drying alternatives with high values of total phenolic compounds (78.72 mg GAE g−1), antioxidant capacity by DPPH/ABTS (376.6 TEAC µmol g−1/1062.04 TEAC µmol g−1), caffeine (13.25 mg g−1) and caffeoylquinic acids (69 mg g−1). Using a reworked python script, the preference map of teas dried in microwave oven and freeze-drying resulted in similar sensory acceptance for hot tea, produced using traditional drying methods, with a slight decrease for the iced tea. Novelty impact statement The tea industry can adopt microwave and freeze drying as alternative methods for drying mate leaves, this is followed by toast in order to obtain the commercial tea. These methodologies present smaller equipment sizes and removes the dangerous traditional process known as “zapeco”. The microwave and freeze drying have a small decrease in sensory acceptance compared to traditional methods used in agri-food industry but with high content of total phenolic compounds, caffeoylquinic acids and high antioxidant activities; also, in the case of microwaves, this method has the advantage of reducing the drying time.

Analysis of the Sand Drying Process in the Biomass-Energized Rotary Drying Machine

Hebel brick (also known as a lightweight brick) is a product of modern building materials because it has a lighter weight but it is stronger than cement bricks and red bricks. Hebel bricks can withstand pressures of more than 4 MPa and are suitable as building wall materials, and speed up construction, and save on cement material costs. One of the most important materials is silica sand in the manufacture of Hebel bricks. The silica sand used in the manufacture of Hebel bricks must have a moisture content of 10 % to 15 %. The purpose of this study is to provide a solution in the form of a drying technique design using a rotational speed control method and a machine that uses biomass-based energy sources. This rotary drying machine is designed to be able to dry wet silica sand into silica sand with water content according to standards. The development of this drying machine begins with making an initial design and parameter analysis. Then proceed to the design, manufacture, and performance testing. The calculation results show that the wet base moisture content has decreased from 33.17 % to 16.58 %, the dry base moisture content decreased from 49.63 % to 19.88 % and drying efficiency also decreased from 63.11 % to 17.11 %. Hence it can be seen that the percentage of wet base moisture content reduced by 50 %, the percentage of dry base moisture content reduced by 59.94 %, and the percentage of drying efficiency reduced by 72.9 %.

Designing and manufacturing a solar rotary dryer for drying beef and studying its quality and storage characteristics

An indirect rotary solar dryer for drying beef has been manufactured and designed in the food engineering workshop at the College of Agriculture, Basrah University. The dryer contains a solar collector with a length of 1.70 m, depth of 0.25 m, and width of 0.30 m, a chimney and tubular met at mesh. Also, the solar collector includes a drying tube that has a capacity of 5 kg and is made of galvanized iron. Throughout the study period, there was a significant increase in the solar radiation energy (p &lt; 0.05) with daylight hours passed till 12:00 PM. In addition, the maximum level of solar energy has been 810.55 W/m2, which is after that reduced to 680.10 W/m2 at 4:00 PM. In the rotary solar dryer, the drying efficiency was 65.91 % at 60 oC and decreased with the increase in drying temperature. In the drying tube, the average temperature reached 80 oC at 1:00 PM, while the air temperature was 43 oC. Unsalted and salted beef were dried with the use of a different period of storage (0, 14, 28, 42, 56, and 70) days and various (60, 70, and 80 °C) to study their qualitative properties. The result indicated that there is a decrease in moisture content with the increase in drying time. Furthermore, the chemical composition related to dried unsalted and salted beef indicated that there is a decrease in moisture percentage. At the same time, there is an increased ash percentage, fat and protein after the process of drying. There is an increase in the moisture percentage throughout the periods of storage different from other percentages of the chemical composition, which have been reduced with the increase in the storage periods. It was shown via the results that there was a decrease in the re-hydration with increasing the drying temperature values for unsalted and salted dried beef. Results have reported that there has been a decrease in microbial content regarding dried unsalted and salted beef. Also, it was shown by the results that the model of Artificial Neural Networks (ANNs) showed good results of predicted content of the moisture.

Intelligent Control in the Application of a Rotary Dryer for Reduction in the Over-Drying of Cut Tobacco

The drying process is fundamental for cut tobacco processing. However, there are some problems related to the drying process such as overheating, or inconsistent control of moisture content. This paper shows how an intelligent controller is designed for an industrial rotary drying system. This controller is applied to a tobacco production unit to reduce overdried cut tobacco and improve the overall unit performance. The proposed control system aims to keep the content of moisture at the dryer outlet as close as possible to the optimal value and improve the homogeneity of the product without any operator intervention. The study shows that, if a reduction of humidity in the cut tobacco drying process is achieved using AI, the quality of the final product improves. In particular, if compared to regulatory control, the proposed method constantly monitors and adjusts the moisture content level in order to reduce the amount of overdried product. The findings of this paper indicate that the suggested process can save at least 222.2 kg of cut tobacco for each batch in the first stage of the drying process.

Embodiment design of Moringa Oleifera rotary dryer using VDI 2221 method

In order to find the solution to the current problems of drying process of Moringa Oleifera in East Nusa Tenggara (NTT)-Indonesia such as requiring a large enough space and power, expensive, non-ergonomic and need to turn the leaves over at least once manually using hand during the drying process that can contaminate the process, a new suitable drying method is necessary. Therefore, embodiment design of drying method using VDI 2221 method was studied. The results indicated that a new suitable drying method of moringa oliefera using VDI 2221 method can be made by successfully designing and manufacturing a rotary dryer based on the selection of the best concept from a variety of existing design concepts. In summary from the perspective of engineering design, after testing, the rotary dryer was suitable and can be used to solve current problems of drying process of Moringa Oleifera in East Nusa Tenggara-Indonesia.

EFFORTS TO IMPROVE SALTED FISH QUALITY USING ROTARY DRYING SYSTEM TECHNOLOGY IN GAMPONG KUALA LEUGE, PEUREULAK ACEH TIMUR

Gampong Kuala Leuge, Peureulak District is one of the National Priority Rural Areas (KPPN) which has been designated as a Capture and Cultivation Minapolitan area by the Ministry of Marine Affairs and Fisheries because most of its people are fishermen. The conditions faced by the community regarding climate and weather, when the weather is hot, it is very easy to dry the fish, while in the rainy season generally, the salted fish will decrease. Thus, household scale competition also faces increasing competition in the digital age because people still use traditional tools and are very dependent on the climate. Therefore, in an effort to balance the competition it is necessary to increase the quality, productivity, and efficiency of the business by taking into account the aspects of food safety through the activities of the Village Development and Empowerment Holistic Program by creating a Rotary Drying System technology as a substitute for stocking to ensure the quality of fish and avoid contamination of microorganisms. From the problems obtained in the form of the dependence of the drying process on weather conditions so that salted fish products are not optimal, conventional marketing techniques have changed to modern ones by providing online shops, and financial management that has not been recorded properly has changed using digital transaction software.&#x0D;

A study on a novel system for soybean seeds drying: Performance and seed quality

The proper choice of the dryer configuration for seeds drying is essential to preserve their quality during this process. Drying of soybean seeds was studied in this work using a non-conventional configuration of rotary dryer, named as roto-aerated dryer. The effects of temperature and velocity of the drying air on drying performance and on the capacity of germination and physical integrity of soybean seeds have been quantified. The results shown that this novel rotary dryer can be successfully used for seeds drying. The average residence time (between 22.2 and 24.9 min) was very short compared to other drying systems used for seeds. Conditions with appropriate drying performance and high quality of seeds have been identified.

Multi-objective optimization of a steady-state rotary dryer

The multi-objective optimization of a direct current rotary dryer that operates with pozzolan in a Paraguayan company is detailed in this article. Three objective functions in steady state are minimized using a NSGA-II algorithm, these are: (1) moisture at the exit of the rotary dryer, (2) heat released to the environment through the dryer and (3) operating costs of the production process in the Paraguayan company. Furthermore, the optimum operating conditions of the drying process are obtained and compared with the real process. Experimental results prove the ability of the proposed algorithm to decrease the moisture content of pozzolana by 28%, the heat released to the environment by 38 % and the operating costs by 52%.

A computational approach to determine the residence time distribution of biomass particles in rotary drum dryers

Wood pellet manufacturing involves drying of wet biomass from 50% m.c. down to 5%–7% m.c. Rotary drum dryers are the most common dryers in pellet industry. Mis-prediction of biomass residence time leads to fires and low-quality products due to over drying or under drying. The current study uses a CFD and DEM modeling approach to determine the residence time of particles with properties similar to biomass feedstock in a rotating drum. The developed model uses a Lagrangian approach to track the 3D particle trajectory from drum inlet to the outlet. The novelty of the current model is that it includes the contribution of biomass interactions with drum wall and internal baffles, which is mostly missing in the published models. Particles with an increasing mass and aspect ratio stayed longer in the dryer than particles with an aspect ratio closer to unity.

Improving the efficiency of a steam power plant cycle by integrating a rotary indirect dryer

This article deals with the integration of a rotary indirect dryer, heated by low pressure extraction steam, into the Rankine cycle. The article evaluates the power generation efficiency of a steam power plant, with an integrated indirect dryer, which combusts waste biomass with a high moisture content and is further compared to the same plant without the dryer. The benefits of the dryer’s integration are analysed in respect to various moisture contents of biomass before and after the drying. The evaluation of the power generation efficiency is based on parameters evaluated from experiments carried out on the steam-heated rotary indirect dryer, such as specific energy consumption and evaporation capacity. The dryer’s integration improves the efficiency of the cycle in comparison to a cycle without a dryer, where moist biomass is directly combusted. This improvement increases along with the difference between the moisture content before and after the drying. For the reference state, a fuel with a moisture content of 50% was dried to 20% and the efficiency rised by 4.38 %. When the fuel with a moisture content of 60% is dried to 10 %, the power generation efficiency increases by a further 10.1 %. However, the required dryer surface for drying the fuel with a moisture content of 60% to 10% is 1.9 times greater as compared to the reference state. The results of the work can be used both for the prediction of the power generation efficiency in a power plant with this type of dryer based on the moisture content in the fuel and the biomass indirect dryer design.

Development and validation of a heated drying air diffusion system to optimize rotary dryers and final coffee quality

The final quality of pre-processed coffees is influenced by the applied drying technology. Thus, the aim of the study was to develop and validate a heated air flow diffusion system to optimize and reduce the drying time of rotary dryers and improve the final quality of coffee. Computational fluid dynamics was used for the simulation of the air fluid dynamics in the combustion chamber of the heat generator. It was observed that the energy losses in the upper and lower walls of the heat generator chamber were higher with an increase in the convective heat transfer coefficient. It was found that the rate of fluid flow presented a fully developed profile, in which the higher speed value was found in the central region of the outlet. The reduction in moisture content during coffee drying was directly proportional to the increase in temperature. The Midilli model shows the best fit to describe the drying curves of the coffee. The effective diffusion coefficient increases with increasing temperature of the drying air. It was observed that the adjustments of the fluid dynamics in the burning of gas and the adaptation of the diffuser system significantly influenced the drying time and final quality of naturally processed and pulped coffees. In conclusion, the adapted technological set, a rotary dryer with gas heating and diffusion of heated air, had a high performance in the final quality of the coffee, and for this reason it is recommended to producers and the industry.

Sawdust drying process in a large-scale pellets facility: An energy and exergy analysis

Abstract Biomass is an important renewable resource that can be directly used as a raw material in energy converting processes, in wood-based industries, or it can be transformed into other types of biofuels. Its thermochemical properties, such as moisture content and chemical composition, directly influence the lower heating value and, consequently, systems' efficiency. To overcome these problems, drying processes are being optimized. This study aims to perform an energy and exergy analysis of a facility's sawdust drying process performance with an installed capacity to produce 1.8 tons per hour of high-quality pellets over two different seasons of the year. In this regard, energy and exergy analyses were carried out for the nominal operating conditions, and temperature measurements of the flue gases flow rate and moisture content were considered. Sawdust samples were collected before the drying process to determine the moisture content, corresponding to 53.49% and 50.23% for the winter and summer seasons, respectively. The analysis was conducted considering that the drying process should guarantee a reduction of the sawdust moisture content to a value of 10%, so the pellets produced at the facility could be certified following EN14961:2010 European certification standard. Consequently, energy and exergy efficiency values of the rotary dryer were found to be 1.5% and 2.2% higher in the summer season since the woodchips and sawdust moisture content are lower on that season and, therefore, less heat is necessary to dry the sawdust to 10% of moisture content. These results demonstrated that wood chips with higher moisture content require more effective fuel mass flow rates to the system to guarantee constant production. The ambient temperature does not seem to affect the efficiency of the dryer significantly. As a recommendation, using the waste enthalpy of flue gases for biomass pre-heating purposes is proposed.

The effect of drying temperature on cup quality of coffee subjected to mechanical drying

The objective of the work was to study the effect of drying temperature on cup quality of the robusta coffee subjected to mechanical drying in comparison with conventional sun drying. The robusta coffee processed by wet (parchment coffee) and dry (cherry coffee) methods were subjected to drying at different temperature regimes (40 oC, 50 oC and 60 oC) in a rotary mechanical dryer. The results of the study indicated that as the drying temperature increased, the time of drying reduced. Sun drying of parchment coffee took 48 hours (approximately seven days) to attain the desired moisture content of 11-12 per cent, while mechanical drying reduced the drying time to 16 to 24 hours. Similarly, cherry coffee subjected to sun drying took 88 hours (approximately 15 days), while mechanical drying reduced the drying time to 32 to 48 hours. The cup quality rating of coffee dried by different drying methods revealed that sun-dried robusta parchment coffee scored the highest cup rating. As the drying temperature increased, the cup quality ratings decreased. A similar cup quality rating was also observed with cherry coffee. These results indicate a considerable reduction of drying time when coffee beans are dried in a mechanical dryer. However, there is a need to regulate the drying temperature, which otherwise would negatively impact the quality of coffee. The drying temperature should not exceed 40oC for preserving the innate quality of robusta coffee because the high drying rates provoked by high temperatures can cause damage to the coffee quality due to the damage caused to the cell membranes. Overall, mechanical drying is more advantageous to sun drying in-terms of drying hours (indirectly reduces dependency on manpower) and preservation of innate quality of the coffee.

A Novel Rotary Dryer Filled with Alumina Ceramic Beads for the Treatment of Industrial Wastewaters: Numerical Simulation and Experimental Study

In this study, a new type of rotary dryer filled with inert alumina ceramic bead (ACB) fillers was introduced to treat the industrial wastewater, e.g., the high-salt wastewater and landfill leachate. Numerical simulations based on the Discrete Element Method (DEM) on the motion trajectory of ACB fillers in the rotary dryer were conducted, and the parameters of flight structure, rotational speed, and filling degree on the dynamic behavior of ACB fillers were optimized. Under various rotational speeds and filling degrees, the experimental results fit the numerical-simulated results very well. The optimized flight configuration was the straight flights with a length of 65 mm, and the optimized rotational speed and filling degree were 35 rpm and 15%, respectively. Under the optimized condition, both the response variables, the mass of particles in the airborne phase (MAP) and the percentage of occupied area in the airborne region (OAR), have the optimal values, in which the dryer will have a better drying performance. Besides, the lower-right area of the drum is empty which is convenient for the installation of the inlet pipe. The drying experiments of industrial wastewaters were also studied using this ACB filled rotary drum dryer under the optimized conditions. Under the optimal operational conditions, the evaporation capacities of the high-salt wastewater and landfill leachate could reach as high as 49.7 kg/h and 90 kg/h, respectively. This study highlights the integration of evaporation and drying processes of this novel ACB filled rotary dryer and provides an efficient and zero-liquid-emission strategy for the thermal treatment of industrial wastewater.

Modeling and cost analysis of drying of citrus residues as biomass in rotary dryer for bioenergy

The valorization of residues in any industrial processing activities aims at the reuse, recycling or composting of solid wastes, in such a way as to generate useful products or sources of energy. Citrus residues have been recognized as a promising biomass for renewable energy and liquid fuels. Drying is an interesting alternative to add value to solid waste, as long as it is economically viable, and one of the most important operations for efficient performance of the energy conversion technologies. In this work, a dynamic model of drying citrus residues in a rotating drum was developed and verified experimentally. From overall heat and mass balances, a series of perfectly stirred tanks was added together for each solid recycle and residence time in order to fully describe citrus solid wastes drying in the semi-industrial rotary drum. Process cost analysis was also performed to assess the most suitable drying level to balance process costs with the biomass quality in terms of the moisture content. Results showed that the model performed reasonably well so that simulation and measurements were in good agreement to be part of process optimization strategies.

Investigation of rotary dryer performance fueled with wood pellets for biomass processing

The drying process is necessary to reduce the biomass moisture content before it is processed into ready-to-burn fuel. Rotary dryer is one of the tools used for drying biomass, as it can produce a uniform moisture content, high power, and simple to use and maintain. This research aims to investigate the performance of a rotary dryer for drying biomass from tree felling waste. The dryer consists of a hopper, drum dryer chamber with flight, product discharge unit, heat exchanger, pellets burner, axial blower, and drum drive motor which is equipped with an electric variable speed. The variation of experimental is mass flow rate of material with drum rotating speed of 1, 1.25, 1.5 RPM, drying air flow rate of 0.6, 1 and 1.3 m3/s and fuel consumption rate of 48 and 123 g/min. The performance evaluation showed that this dryer is capable to drying chopped tree felling waste at the decreasing moisture content rate of 0.5-2.0 %/min. The system efficiency of the dryer was found to be 8.91-26.84% depending on the drum rotary speed, drying air flow rate, and drying temperature.