Tobacco Drying Research Articles

Influences of cold atmospheric plasma pretreatment on drying kinetics, structural, fractional and chemical characteristics of tobacco leaves

Cold atmospheric plasma (CAP) treatment is a promising technology for the processing of agricultural products. The effect of cold atmospheric plasma pretreatment on the drying rate and quality of tobacco leaves (Virginia 202) during natural drying were studied. Naturally dried tobacco leaves were analyzed for their microstructural changes, fractional composition, and chemical composition. It was observed that cold atmospheric plasma pretreatment reduces the duration of natural drying of tobacco leaves by 37.7% and 19.5% for a leaf vein and for entire lamina of a leaf respectively. Along with that, a positive effect on increase in fiber yield during fractional analysis was shown for CAP pretreated tobacco leaves. Chemical analysis determined that CAP pretreatment of tobacco leaf improved the carbohydrate:protein ratio, increased the Schmuck’s value from 0.8 to 1.3 when processing tobacco leaf veins, but reduced the Schmuck’s value to 0.3 when processing the entire lamina of tobacco leaf. It is shown that nicotine content of dried tobacco leaves can be decreased by CAP treatment and controlled by applying to whole leaf or leaf vein only. The obtained data show that technology of cold atmospheric plasma pretreatment, in particular, when processing the vein (midrib) of a tobacco leaf has a promising application in industry, as it can significantly reduce the drying time of the leaves and affect the qualitative composition of the final product obtained in result.

Structure Optimization of Outlet Uniformity for a Comas Tower Dryer

Tobacco drying is an important part in the whole process of cigarette production, and its quality is directly related to the quality of cigarettes. CTD (Comas Tower Dryer) is a new type of airflow dryer, which is widely used in the tobacco industry because of its high drying efficiency. In actual production, the uneven outlet of the tobacco cutter leads to a stacking phenomenon, which affects the subsequent process of production. In this paper, the distribution of the internal flow field of the drying tower was studied from the aspects of the overlap degree of the orifice plate and deformation of the top structure at the top of the drying tower to explore the way to optimize the inner flow field to lead to the uneven distribution of the outlet. The results show that the structure whose contact position between the wall and the outlet extending outward can improve the uniformity of the outlet, while the overlap degree of the orifice plate had no effect on the uniformity of the outlet.

Integration of Safety Aspects in Modeling of Superheated Steam Flash Drying of Tobacco

Knowledge of the drying properties of tobacco in high temperatures above 100 °C and its dust are crucial in the design of dryers, both in the optimization of the superheated-steam-drying process and in the correct selection of innovative explosion protection and mitigation systems. In this study, tobacco properties were determined and incorporated into the proposed model of an expanding superheated steam flash dryer. The results obtained from the proposed model were validated by using experimental data yielded during test runs of an industrial scale of a closed-loop expansion dryer on lamina cut tobacco. Moreover, the explosion and fire properties of tobacco dust before and after the superheated steam-drying process at 160, 170, 180, and 190 °C were experimentally investigated, using a 20 L spherical explosion chamber, a hot plate apparatus, a Hartmann tube apparatus, and a Godbert–Greenwald furnace apparatus. The results indicate that the higher the drying temperature, the more likely the ignition of the dust tobacco cloud, the faster the explosion flame propagation, and the greater the explosion severity. Tobacco dust is of weak explosion class. Dust obtained by drying with superheated steam at 190 °C is characterized by the highest value of explosion index amounting to 109 ± 14 m·bar·s−1, the highest explosion pressure rate (405 ± 32 bar/s), and the maximum explosion pressure (6.7 ± 0.3 bar). The prevention of tobacco-dust accumulation and its removal from the outer surfaces of machinery and equipment used in the superheated steam-drying process are highly desirable.

Relation between Energy Efficiency and GHG Emissions in Drying Units Using Forest Biomass

The impacts of climate change are inevitable and driven by increased levels of greenhouse gases (GHG) in the atmosphere, requiring mitigation and re-adaptation measures. In this context, this article critically analyzes the influence of drying technology type, forest biomass, and GHG emissions resulting from the energy required for drying agricultural crops, by presenting a case study of tobacco drying. In this study, the influence of increasing the technological level of drying unit (curing units CUs), using E. saligna and E. dunnii firewood and Pinus sp. pellets, was evaluated; considering consumption efficiency, energy efficiency, and concentration of gas emissions (CO, CO2, CXHY and NOX), as well as emission factors in tCO₂-eq. The results showed that when increasing the technological level of the CUs, there is a decrease in fuel consumption and emissions. The reduction can reach 60.28% for the amount of biomass consumed and 67.06% in emissions in tCO₂-eq; for the scenario of a production crop, using a CU with a continuous load (Chongololo) and firewood from E. dunnii. The use of pellets proved to be efficient, with the lowest consumption of biomass and emissions with more technological CUs.

Plate heat exchanger design for the utilisation of waste heat from exhaust gases of drying process

The vapour condensation is typical for processes of waste heat recovery from exhaust gases. It complicates the selection of condensers and requires reliable correlations for estimation of heat transfer coefficients and pressure drop in the unit. In the presented paper, a novel model was elaborated to be applied for commercially produced plate heat exchangers (PHEs) assembled from plates with different geometries of corrugations, which accounts the change of process parameters at the main corrugated field, in PHE collectors and channels distribution zones. The process of waste heat recovery from exhaust gases after tobacco drying is discussed in the case study. The pilot unit assembled with PHE of TS-6MFG type manufactured by Alfa Laval was installed at a tobacco factory. The examined condensing media was an incoming air-steam mixture with 10% of air content and temperature equal to 140 °C. The comparison of modelling results and data of industrial operation has shown good accuracy of prediction. It allowed recommending obtained correlations and developed mathematical model for the design of plate heat exchangers in applications with heat utilisation from exhaust gases after drying processes in the industry, with a considerable saving of heat energy. In the considered example, it is up to 640 kW or 2090 kJ/kg of exhaust gases.

Integration of low-grade heat from exhaust gases into energy system of the enterprise

The paper presents a Process Integration application for waste heat utilisation from exhaust gas streams with partial condensation. It is based on the hot composite curve construction representing the gaseous mixture cooling with accounting for the condensable vapour part's gas–liquid equilibrium. With cold composite curve for streams requiring heating, the Pinch Point is determined. On this basis, the heat exchanger network (HEN) structure for utilised heat integration into the factory's energy system is developed. It accounts for the possible splitting of two-phase flow on gas and liquid streams and plate heat exchanger (PHE) type selection for specific positions in HEN. The method is illustrated by a case study of heat utilisation from exhaust gases after superheated steam tobacco drying and flue gases from natural gas-fired boiler. Heat transfer areas of PHEs in HEN are optimised with the total annualised cost as an objective function. The received solution's payback period is less than four months, with a substantial saving of energy, up to 10.9 TJ/y. It also leads to the reduction of CO2 emissions up to 600 t/y. About 3830 t/y of steam is not discharged to the atmosphere and as the water returned to the production process. To manuscript “Integration of Low-Grade Heat from Exhaust Gases into Energy System of the Enterprise”

Deep multi-sequence multi-grained cascade forest for tobacco drying condition identification

The term, “drying condition” refers to the actual dehydration capacity of a rotary dryer in the tobacco drying process which is directly related to the drying effect. However, identifying different drying conditions relies heavily on the judgment of field engineers who have rich domain knowledge and practical experiences. In this study, we proposed an improved multi-sequence multi-grained cascade forest model, MSgcForest, to classify and identify different drying conditions. An improved multi-sequence multi-grained feature scanning mechanism is added to perform spacial and sequential feature extraction from raw production-related data, which transforms the input features into high-dimensional feature vectors and increases the discriminative power of the drying condition features. Comparison with existing models indicates that the proposed MSgcForest outperforms the other alternatives even for small-scale training data. In particular, this method successfully transforms the fuzzy artificial judgment of the drying condition into a data-driven identification with high precision, which provides a promising prospect for identifying working conditions in industrial processes.

Preventive Detection Method for Leakage of Sheet Tobacco Dryer

Content Sheet Tobacco Dryer is an important and key equipment in the tobacco making workshop of cigarette factory, its function is mainly to expand and dry cut tobacco, and the drying process is mainly carried out by the sheet heating plate in the drum through heat conduction, while the energy of the sheet heating plate mainly comes from the steam inside, and there is a risk of leakage through continuous operation of the sheet and its accessories, once leakage occurs, it will cause quality accidents of tobacco products, and leakage can be well prevented and eliminated through regular leakage detection.

Simulation of Heat and Mass Transfer of Cut Tobacco in a Batch Rotary Dryer by Multi-Objective Optimization

Summary To simulate the drying process of cut tobacco in a batch rotary dryer, six different models of equilibrium moisture content were selected to calculate the driving force of mass transfer, and a mathematical model of heat and mass transfer was numerically solved. The multi-objective nonlinear problem of heat and mass transfer coefficients was optimized by employing a weight factor. The simulation results showed that the weight factor r was an important parameter for fitting results of moisture content and temperature. The model evaluation indices almost reached their minimal values with r at 0.1. For all the six equilibrium/classic models the fit was better for moisture content than for temperature. One model (M-Hen/C) was superior to other equilibrium/classic models and the REA (reaction engineering approach) model. This study aims for an understanding of heat and mass transfer in the tobacco drying process, and provides a theoretical framework to support the prediction of temperature and moisture in various drying situations.

Human health risk and potential environmental damage of organic and conventional Nicotiana tobaccum production

Tobacco is the most widespread non-food crop in the world. In Brazil, tobacco cultivation is one of the main commodities of the southern region. However, its production is associated with environmental impacts and risks to human health, which have yet to be quantified. This paper uses midpoint and endpoint life cycle assessment (LCA) to analyze the potential environmental damage and human health risk associated with agricultural production of conventional Virginia (CV), organic Virginia (OV), and Burley (BU) tobacco varieties. Organic tobacco production substitutes synthetic fertilizers and pesticides with organic compounds in the cropping stage. The results show that for one ton of dried tobacco, BU, CV, and OV emit 1,610, 1,426, and 1,091 kg CO2 eq, respectively. For organic production, greater impacts are linked to the land use (LU) impact category. The endpoint results showed that OV production resulted in a higher potential for human and environmental damage than BU and CV. The drying of green OV and CV tobacco requires the burning of firewood, which emits high levels of particulate matter and is associated with human health (HH) damage. Overall, the HH damage category accounts for 68%, 82%, and 78% of the total score points associated with the production of BU, CV, and OV.

Optimization of tobacco drying process control based on reinforcement learning

Drying is an important procedure in tobacco production. The current PID based drying suffers from issues such as overheating or inconsistent control of the amount of moisture content. In order to boost quality assurance, reinforcement learning has been employed in this paper to facilitate dynamic configuration of dryer. A novel actor-critic based intelligent system is built on top of the current PID control. The new data-centric approach collects environment and machine states, incorporates historical production data and learns temperature adjustment strategies. Compared to automatic PID control and manual intervention, the introduced intelligence proves to be remarkably more effective to govern the drying and control the moisture content level with consistent performance. The proposed method provides new insights into precision achievement in industrial control process.

Two-Layered Model Predictive Control Strategy of the Cut Tobacco Drying Process

In this article, a two-layered model predictive control strategy is proposed for the nonsquare system of nonlinear cut tobacco drying process. The control objective is to optimize the drum dryer temperature, hot air temperature, and cut tobacco outlet temperature meet the process constraints while meeting the moisture content of cut tobacco. Firstly, the tobacco drying process system was introduced, and the nonsquare system model and performance index function were established. Then a nonlinear moving horizon estimator (NMHE) and real-time optimization (RTO) are designed. NMHE provides state and parameter estimation for the controller, and RTO provides an optimal operating setpoint for the controller. Subsequently, a two-layered model predictive control (SSTO-MPC) design integrated with a steady-state target optimization layer (SSTO) is proposed for the nonsquare system of nonlinear cut tobacco drying process. Extensive simulations under different scenarios illustrate the effectiveness of the proposed SSTO-MPC design compared with the conventional MPC.

RANCANG BANGUN DAN UJI KINERJA ALAT PENGERING TEMBAKAU MOLE TIPE EFEK RUMAH KACA (ERK) KONSTRUKSI BAMBU

ABSTRAK
 Tanaman tembakau merupakan salah satu komoditas unggulan perkebunan di Kabupaten Sumedang. Proses pengolahan tembakau yang berpengaruh pada mutu tembakau tersebut yaitu proses pengeringan dan pengembunan. Saat ini proses pengeringan tembakau mole yang dihasilkan di Kecamatan Sukasari masih menggunakan energi cahaya matahari yang sangat dipengaruhi oleh kondisi cuaca dan sangat rentan untuk terkontaminasi oleh material lain saat penjemuran. Proses pengeringan menggunakan energi cahaya matahari ini memerlukan waktu 14 - 20 hari tergantung cuaca. Untuk mempercepat proses pengeringan, perlu dilakukan rancang bangun alat pengering tembakau mole tipe ERK konstruksi bambu. Tujuan dari penelitian ini untuk merancang bangun dan uji kinerja alat pengering tembakau mole tipe ERK konstruksi bambu, sehingga dapat mempercepat proses pengeringan tembakau dalam jumlah besar. Metode penelitian menggunakan metode rekayasa dengan melalui beberapa tahap proses kegiatan yaitu: perancangan alat pengering tipe ERK, racangan fungsional, rancangan struktural, analisis teknik dan uji kinerja. Alat pengering tembakau mole tipe ERK konstruksi bambu yang telah dibuat memiliki panjang keseluruhan 5 m, lebar 3 m dan tinggi 2,5 m. Konstruksi alat pengering menggunakan bambu betung dan ikat, dinding sebagai pelapis alat pengering menggunakan plastik UV 6%. Berdasarkan analisis menggunakan software Ansys didapatkan tegangan pada rangka masih dibawah ambang batas yang disarankan yaitu sebesar 20,42 Pa, sedangkan ambang batas bambu petung yaitu sebesar 177 MPa. Pada pengujian tanpa beban menggunakan exaust fan, suhu yang diperoleh setelah pengambilan data selama 24 jam didalam alat pengering ERK yaitu sebesar 14ᵒC - 46ᵒC dan sedangkan suhu diluar alat pengering ERK sebesar 16,4 – 30,5ᵒC. Penurunan kadar air tembakau yang dihasilkan alat pengering ini sebesar 66% selama 5 hari, sedangkan diluar alat pengering sebesar 71% selama 14 hari. Efisiensi termal dan pengeringan alat pengering ini sebesar 55,79% dan 17,24%.
 
 Kata kunci: Rancang Bangun, Uji Kinerja, Alat Pengering ERK, Tembakau Mole, Bambu
 

Application of Heat Pump Energy-Saving Flue-Cured Tobacco Technology

In view of many problems caused by the traditional “coal + electricity” flue-cured tobacco method, such as the environmental pollution, the high cost, the unguaranteed quality, and the demanding reliability of power supply, the researcher put forward the heat pump energy-saving flue-cured tobacco technology based on the field investigation. The technology equipment, including heat pump, condensing and draining roasting room and self-control system, uses smokeless hot air as medium to realize the drying of tobacco leaves, which solves the quality problem of residual sulfur in products. Moreover, the energy saving effect is remarkable, nearly 70% of the heat in the process of dehumidification is recycled. At the same time, the baking performance is stable, and the various indexes can be effectively and accurately realized to ensure the quality of the tobacco leaves. It only consumes 2kW·h of electricity to dry 1kg of tobacco leaves. Compared with traditional method, it’s conducive to environmental protection.

SEGURANÇA E SAÚDE DO TRABALHO EM FUMICULTORES COM CERTIFICAÇÃO DO SISTEMA DE GESTÃO INTEGRADO

O Brasil é o segundo maior produtor de tabaco do mundo e o maior exportador do produto. No campo, há predomínio de produtores de agricultura familiar que produzem a matéria-prima, vendendo-a exclusivamente para a agroindústria do tabaco, sob Sistema de Integração de Produção. Nesse sistema, todos os trabalhadores envolvidos nos diferentes processos produtivos, inclusive fornecedores e subcontratados, devem seguir normas entre as quais as de Segurança e Saúde Ocupacional. O presente estudo objetivou verificar se a indústria fumageira com certificação do Sistema de Gestão Integrado está repassando as questões de Segurança e Saúde do Trabalho aos seus fornecedores de matéria-prima. O estudo foi conduzido em um município do Núcleo Regional de União da Vitória, PR. Para a coleta de dados foram realizadas entrevistas em 11 propriedades agrícolas, que comportam diretamente 29 trabalhadores rurais envolvidos na fumicultura. A metodologia utilizada foi de estudo de caso múltiplo, por meio de observação direta e entrevistas. As atividades realizadas nas propriedades pelos fumicultores na época de colheita e secagem do fumo caracterizaram-se pela carga horária média de trabalho de 11 horas. Observou-se falta de treinamento efetivo do modo de usar o Equipamento de Proteção Individual (EPI) e de procedimentos de sua manutenção. Os sintomas relacionados à Doença da Folha Verde do Tabaco (DFVT) ou intoxicações com agroquímicos informados pelos trabalhadores foram semelhantes nas diferentes propriedades. Os resultados obtidos demonstram a ausência de diferenciação no tema segurança e saúde do trabalho entre as indústrias com ou sem certificação do Sistema de Gestão Integrado na Região.

Implementasi Teknologi Fuzzy Logic Controller untuk Pengendalian Temperatur pada Proses Pengeringan Tembakau

Tobacco is one of the six most important commodities in Indonesia. This sector is the most strategic that can absorb millions of workers, ranging from tobacco farmers, laborers or workers to tobacco companies. One of the stages in tobacco processing is the drying process. Drying using sunlight is often distracted by erratic weather changes such as rain, this can cause the drying process to be slow and require very long drying time. Based on the above, a tobacco dryer was developed by implementing the fuzzy logic controller (FLC) method as the temperature controller and its moisture meter. This tool uses LM35DZ type temperature sensors and Soil Moisture YL-69 type moisture sensors. In addition, this artificial drying process also uses heating elements instead of heat from sunlight. Programming tool is made using Arduino uno microcontroller. When compared to conventional drying, the drying results using the tool will be superior in terms of time efficiency, human power and product quality.

Fast drying of cut tobacco in drop tube reactor and its effect on petroleum ether tobacco extracts

ABSTRACTEntrained flow drying is an important fast drying tool in tobacco industry. This study used a drop tube reactor (DTR) as an entrained flow dryer to investigate drying process of flue-cured cut tobacco. Lab-scale cold and hot DTRs were set up to obtain drying kinetics for three types of cut tobacco using different drying gases and temperatures. The effective diffusion coefficients of cut tobacco in DTRs were compared with those in a general cylinder dryer. Moreover, the effects of different drying gases and temperatures on petroleum ether extract content were investigated. The results showed that the effective diffusion coefficients of cut tobacco in the DTRs were between 2.296 × 10−8 and 8–6.244 × 10−8 m2/s, which are two orders of magnitude higher than those in the cylinder dryer. Compared to hot air as a drying medium, superheated steam improved the effective diffusion coefficient of cut tobacco. The petroleum ether tobacco extract had a higher retention ratio when the superheated steam was used in the DTRs. An increase in the drying temperature resulted in a lower retention of the petroleum ether tobacco extract.

Complementing firewood with alternative energy sources in Rio Pardo Watershed, Brazil

ABSTRACT: Wood is the primary energy source for grains and Tobacco drying in the Rio Pardo Watershed (RPW). The amount of firewood produced in the RPW is not enough to supply the demand. Recently, an automatized supply system was introduced in the region enabling the use of sawdust and pellets. In this context, this study aims to compare firewood, sawdust and pellets as energy sources for Tobacco curing in air-forced curing systems. Energetic density was used to estimate the biomass consumption in Tobacco curing. The consumption of biomass is lower for pellet, followed by firewood and sawdust. Pellets and sawdust could complement firewood in the region; however, research is necessary to ascertain the economic feasibility.

Improvement on Cleaning System of SIROX Tobacco Expander

Based on analyzing SIROX the tobacco expander of its pitfalls on cleaning system like poor drainage, valve leakage, cleaning time consuming, etc., this article proposes an improvement of its cleaning system as well as an optimization of its control mode. Furthermore, this article presents a new design of automatic drainage system of the cleaning pipe as well as a real- time monitoring system. This set of system not only addresses quality issues like the over temperature of cylinder wall of the tobacco dryer and the abnormal fluctuation of the tobacco moisture after dryer, but also visualizes the valve leakage thus helps to improve the prompt maintenance of these devices. Observing the two-year operation in HCF, this system proves a high application value.

Analysis on efficiency optimization of tobacco leaf flue-curing process

Tobacco leaf flue-curing process consumes large amounts of energy. Comparing to the traditional heating approach using coal, the heating source like heat pump would be more energy efficient and environmental friendly. Using heat pump for tobacco drying is proposed in this study. A 3D numerical model is established based on the theory of heat and mass transfer in porous medium. Field measurements were conducted in an actual curing barn in Chongqing. The effects of wall insulation performance and circulating air volume were obtained by comparative analyses of the key parameters. The feasibility and energy efficiency were proved by comparative analyses and experimental data. The result can help improve energy efficiency of relevant projects in agriculture baking.