scholarly journals Modelling and CFD Simulation of Temperature and Airflow Distribution Inside a Forced Convection Mixed-Mode Solar Grain Dryer with a Preheater

2021 ◽  
Vol 10 (4) ◽  
pp. 33-40
Author(s):  
Johannes P. Angula ◽  
Freddie Inambao
Keyword(s):  
Forced Convection ◽  
Solar Collector ◽  
Mixed Mode ◽  
Cfd Simulation ◽  
Mass Transfer Process ◽  
Maximum Temperature ◽  
Drying Process ◽  
Airflow Distribution ◽  
Average Maximum ◽  
Drying Chamber

In this study, a 3D Computational Fluid Dynamics (CFD) model was developed to simulate the drying process of maize ears/cobs in a mixed-mode solar grain dryer. The dryer system is aimed to operate under forced convection and is integrated with a preheater to heat air prior to entering the solar collector. The 3D model was developed with great accuracy using SolidWorks software and the CFD simulation was carried out using ANSYS Fluent software. The study was aimed at analyzing and predicting temperature and airflow distribution in the mixed-mode solar dryer system. The CFD simulation was conducted at different airflow velocities varying from 0.5 m/s to 2 m/s for different temperature values of the preheater. Results from the simulation of the solar collector were satisfactory, indicating a minimum and maximum temperature of 59.7 ℃ and 70.5 ℃ at minimum and maximum drying conditions, respectively. The variation of temperature inside the drying chamber was predicted with an average maximum of 64.1 ℃ at the inlets. Results of airflow distribution in the solar collector and drying chamber indicated high turbulence and flow recirculation. This is a desirable flow combination that promotes good moisture evaporation from the maize ears during the drying process. This study proves that the use of computer software can allow one to clearly gain an understanding of the development, heat and mass transfer process, and performance of dryers used in the food drying industry. This approach can promote improvements in existing drying processes and increase food productivity.

The CFD Simulation of Tray Dryer Design for Kenaf Core Drying

2013 ◽  
Vol 393 ◽  
pp. 717-722 ◽  
Author(s):  
Suhaimi Misha ◽  
Sohif Mat ◽  
Mohd Hafidz Ruslan ◽  
Kamaruzzaman Sopian ◽  
Elias Salleh
Keyword(s):  
Cfd Simulation ◽  
Successful Operation ◽  
Drying Time ◽  
Good Design ◽  
Kenaf Core ◽  
Hot Air ◽  
Air Stream ◽  
Airflow Distribution ◽  
Drying Chamber ◽  
Different Levels

Tray dryer is the most extensively use for kenaf core drying because of its simple and economic design. The product is spread out on trays at an acceptable thickness so that the product can be dried uniformly. Most tray dryers use hot air stream where water is vaporized from the product and removed by air stream. In a tray dryer, more products can be loaded as the trays are arranged at different levels. The drawback of this dryer is non-uniformity in the desired moisture content of end product. The key to the successful operation of the tray dryer is uniform airflow distribution over the trays. Therefore, the good design of the drying chamber configuration in a tray dryer is necessary to obtain optimum performance. This research is to design the uniform airflow distribution throughout the drying chamber using CFD simulation for kenaf core drying. Several configurations of drying chamber and trays position was designed and simulated to determine the tray dryer which can produce better airflow distribution. It was found that the design B gives a more uniform airflow distribution compared to others design. The good design of kenaf core dryer should be able to produce uniform drying at high drying capacity and shorter drying time.

scholarly journals Drying of cherry tree chips in the experimental biomass dryer with solar collector

2012 ◽  
Vol 58 (No. 1) ◽  
pp. 16-23 ◽  
Author(s):  
T. Ivanova ◽  
B. Havrland ◽  
P. Hutla ◽  
A. Muntean
Keyword(s):  
Solar Collector ◽  
Biomass Conversion ◽  
Monitoring And Evaluation ◽  
Drying Process ◽  
Cherry Tree ◽  
Drying Time ◽  
Solid Biofuels ◽  
Relative Air Humidity ◽  
Drying Chamber

Drying significantly influences the process of a biomass conversion into the renewable energy source as well as quality of solid biofuels (briquettes, pellets). The research is focused on monitoring and evaluation of the drying process in the case of cherry tree chips drying in experimental biomass dryer with solar collector. The dryer has been conceived as a result of the project which was realized at the State Agrarian University of Moldova. Technological and construction specifics of the biomass dryer are described in the paper. The moisture content of the cherry tree chips was observed in dependence of the drying time and at different locations of the drying chamber. The drying process in the biomass layer was found as non-uniform. Further parameters such as relative air humidity and the air temperature were measured and analysed, as well. It was concluded that the experimental biomass dryer with solar collector can work well in the conditions of the Central Moldova during the sunny period of the year.

Prediction of Water Vapor Concentration of Moist Air inside Batch Solar Dryers

2018 ◽  
Vol 69 (8) ◽  
pp. 2035-2039
Author(s):  
Adrian Gabriel Ghiaus ◽  
Yannis Caouris ◽  
Viorel Fatu
Keyword(s):  
Solar Collector ◽  
Operation Time ◽  
Vapor Concentration ◽  
Temperature Profiles ◽  
Drying Process ◽  
Moist Air ◽  
Moisture Concentration ◽  
Transfer Processes ◽  
Operation Parameters ◽  
Drying Chamber

Design optimization and evaluation of existing solar dryers can be done through numerical simulation of the complex and coupled transfer processes taking place inside drying units. Analysis of moisture concentration and relative humidity evolution of the drying air along with pressure, velocity and temperature profiles was done both inside the solar collector and drying chamber. Prediction of operation parameters for different design configurations allowed the identification of unwanted recirculation regions, saturation moist air zones and optimum operation time for an efficient drying process.

scholarly journals Working Productivity Analysis on the Process of Drying Fish Using Solar Dryers

2021 ◽  
Vol 12 (1) ◽  
pp. 70-73
Author(s):  
I Gede Santosa ◽  
◽  
I Gede Bawa Susana ◽  
Keyword(s):  
Solar Collector ◽  
Heat Exposure ◽  
Sun Exposure ◽  
Weather Conditions ◽  
The Other ◽  
Productivity Analysis ◽  
Drying Process ◽  
Worker Productivity ◽  
Continuous Heat ◽  
Drying Chamber

The process of drying fish using solar energy is strongly influenced by weather conditions. Sunlight is needed by household scale workers because it is cheap. On the other hand, sun drying creates additional workload for workers. Workers are exposed to hot sun during drying. Continuous heat exposure results in an increased work pulse. This affects the level of worker productivity. To anticipate this, a solar dryer is used by utilizing a solar collector as an absorber of sunlight and a drying chamber for the drying process of fish. The use of solar dryers has been shown to increase drying temperatures and reduce workers' sun exposure. This decreases the workload of workers, so that it has an impact on increasing productivity. Worker productivity increased by 133.94%.

scholarly journals Implementation of an automated dryer with solar collector

2022 ◽  
Vol 2163 (1) ◽  
pp. 012002
Author(s):  
F J Regino-Ubarnes ◽  
H Y Jaramillo ◽  
F E Moreno-Garcia
Keyword(s):  
Solar Collector ◽  
Research Work ◽  
Physical And Mechanical Properties ◽  
Drying Process ◽  
Brick Kilns ◽  
Strength Tests ◽  
Drying System ◽  
The Difference ◽  
Percentage Of Water Absorption ◽  
Drying Chamber

Abstract This research work consists of the development of an automated sustainable drying system using forced and preheated air to reduce the production time of handmade bricks, so a dryer witha solar collector wasimplemented to take advantage of the energy from solar radiation. A virtualinstrument was developed, which allows to visualize the variables of temperature and humidityinside the drying chamber, additionally a temperature control was implemented, this control allows the system to maintain a constant temperature during the drying process. Samples were taken from the production of the brick kiln “El Tejar” and dried by this device, thenthe drying times and their physical and mechanical properties were compared, finding that the bricks dried with the proposed prototype retained these properties. As for the compressive strength tests for samples of both processes was around 30.6 Kgf/cm2 and 31.2 Kgf/cm2, the deflection resistance was around 1.2 Kgf/cm2 and 1.3 Kgf/cm2, the initial absorption rate was around 0.3 g/cm2/min and 0.4 g/cm2/min, and finally the percentage of water absorption for both processes were around 12.9% and 13.1%. The difference lies in the drying times, since drying in the artisanal brick kilns takes about 15 daysin the proposed dryer takes 9 days, resulting in a decrease of 40% in this process.

scholarly journals Design and Analysis of a Novel Drying Chamber in Indirect Forced Convection Solar Drying

2020 ◽  
Vol 9 (9s) ◽  
pp. 11-16
Keyword(s):  
Energy Efficiency ◽  
Forced Convection ◽  
Solar Collector ◽  
Ambient Air ◽  
Drying Rate ◽  
Solar Drying ◽  
Drying Time ◽  
Hot Air ◽  
Drying Chamber ◽  
Effective Distribution

Long drying time and less control on drying parameters in natural convection drying give way to forced convection indirect solar drying. In forced convection drying, an external blower supplies ambient air into the solar collector. The incoming air gets heated inside the collector and this air then flows into the drying chamber where the product to be dried is kept. The hot air absorbs the moisture from the raw crops and exits through the chimney. Along with the temperature and humidity of incoming air, its distribution inside the drying chamber is also important in the process of drying. The drying rate and quality can be improved if these parameters are under control in forced convection solar drying. In this paper, design and analysis of a novel drying chamber are presented to improve the performance and energy efficiency of solar drying with effective distribution of air inside the chamber. The variation of velocity with respect to different positions inside the drying chamber is also studied numerically.

scholarly journals Performance Assessment of Banana Drying using a Forced Convection Solar dryer

2020 ◽  
Vol 9 (9s) ◽  
pp. 1-6
Keyword(s):  
Forced Convection ◽  
Raw Material ◽  
Solar Drying ◽  
Drying Process ◽  
Sun Drying ◽  
Musa Paradisiaca ◽  
Different Types ◽  
Drying System ◽  
Drying Rates ◽  
Drying Chamber

Among all the noteworthy preservation techniques for food items, drying is considered to be one of the most consequential one. Different types of drying systems exist bottomed on the manner in which air flow takes place in the drying chamber and method of utilising incident solar radiation for drying. An indirect forced convection solar drying system with a dryer of varying cross section was considered in the present work. Banana (Musa Paradisiaca) was the raw material to be dried. Performance of the system at discharges of 0.03 and 0.02 kg/s, respectively for the specified mass of product was obtained and compared with open sun drying in the range of 66.3% - 9.9% of wet basis moisture content. Drying process in chamber drying was completed four and two hours earlier than open sun drying at discharges of 0.03 kg/s and 0.02 kg/s, respectively. Cumulative and tray wise instantaneous drying rates were found and obtained maximum drying rates of 75 g/h and 15 g/h, respectively. Trend of moisture ratio against time was obtained by polynomial fitting which has satisfactory agreement with available mathematical model.

Influencia de las condiciones de secado solar en la coloración de plantas medicinales

2019 ◽  
pp. 28-34
Author(s):  
Margarita Castillo-Téllez ◽  
Beatriz Castillo-Téllez ◽  
Juan Carlos Ovando-Sierra ◽  
Luz María Hernández-Cruz
Keyword(s):  
Medicinal Plants ◽  
Forced Convection ◽  
Rural Areas ◽  
Color Change ◽  
Drying Process ◽  
Scientific Medicine ◽  
Drying Time ◽  
Bacterial Proliferation ◽  
Wide Range ◽  
Very High

For millennia, humans have used hundreds of medicinal plants to treat diseases. Currently, many species with important characteristics are known to alleviate a wide range of health problems, mainly in rural areas, where the use of these resources is very high, even replacing scientific medicine almost completely. This paper presents the dehydration of medicinal plants that are grown in the State of Campeche through direct and indirect solar technologies in order to evaluate the influence of air flow and temperature on the color of the final product through the L* a* scale. b*, analyzing the activity of water and humidity during the drying process. The experimental results showed that the direct solar dryer with forced convection presents a little significant color change in a drying time of 400 min on average, guaranteeing the null bacterial proliferation and reaching a final humidity between 9 % and 11 %.

scholarly journals The Effect of the Thermal Mass of the Building Envelope on Summer Overheating of Dwellings in a Temperate Climate

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4117
Author(s):  
Tadeusz Kuczyński ◽  
Anna Staszczuk ◽  
Piotr Ziembicki ◽  
Anna Paluszak
Keyword(s):  
Building Materials ◽  
Heat Waves ◽  
Residential Buildings ◽  
Building Envelope ◽  
Temperate Climate ◽  
Maximum Temperature ◽  
Thermal Mass ◽  
Occupant Behavior ◽  
Average Maximum ◽  
Night Ventilation

The main objective of this paper is to demonstrate the effectiveness of increasing the thermal capacity of a residential building by using traditional building materials to reduce the risk of its excessive overheating during intense heat waves in a temperate climate. An additional objective is to show that the use of this single passive measure significantly reduces the risk of overheating in daytime rooms, but also, though to a much lesser extent, in bedrooms. Increasing the thermal mass of the room from light to a medium heavy reduced the average maximum daily temperature by 2.2K during the first heat wave and by 2.6K during the other two heat waves. The use of very heavy construction further reduced the average maximum temperature for the heat waves analyzed by 1.4K, 1.2K and 1.7K, respectively, giving a total possible reduction in maximum daily temperatures in the range of 3.6 °C, 3.8 °C and 4.3 °C. A discussion of the influence of occupant behavior on the use of night ventilation and external blinds was carried out, finding a significant effect on the effectiveness of the use of both methods. The results of the study suggest that in temperate European countries, preserving residential construction methods with heavy envelopes and partitions could significantly reduce the risk of overheating in residential buildings over the next few decades, without the need for night ventilation or external blinds, whose effectiveness is highly dependent on individual occupant behavior.

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