Performance of Desiccant Solar Crop Dryers in Makurdi, Nigeria

2019 ◽  
Vol 35 (2) ◽  
pp. 259-270 ◽  
Author(s):  
Isaac N Itodo ◽  
Joshua O Ijabo ◽  
Japheth A Charles ◽  
Nathaniel N Ezeanaka ◽  
Solomon O Akpa
Keyword(s):  
Relative Humidity ◽  
Moisture Absorption ◽  
Drying Rate ◽  
Sun Drying ◽  
Ambient Relative Humidity ◽  
Significant Difference ◽  
Drying Rates ◽  
Fan Speed ◽  
Further Development ◽  
Range Test

Abstract. Dryers in humid tropical locations like Makurdi, Nigeria (Lat. 7°7´N), have not performed significantly better than the open air sun drying of crops because of the high ambient relative humidity that is often not less than 70% all year round, hence the need to use desiccant augmented dryers. The performance of three types of non-regenerative desiccant solar crop dryers was undertaken to determine the best performing dryer configuration for further improvement and use in the location. The dryers developed were the indirect-active desiccant dryer (IADD), direct-active desiccant dryer (DADD), and the direct-passive desiccant dryer (DPDD). The dryers were designed, constructed, and their performance evaluated and compared to open air sun drying (OASD). The drying rate (kg/h) and Dryer Performance Coefficient (DPC) were used to evaluate the performance of the dryers. The active dryers were operated at a fan speed of 1.2 m/s. Moisture absorption rate and % moisture absorbed to its weight were used to evaluate the performance of the desiccant. The desiccant used was a composite of rice husk ash (RHA) and calcium chloride binded with cement in the ratio of 1:1:1 by weight. The analysis of variance (ANOVA) at p = 0.05 was used to determine if there was a significant difference in the measured parameters of the dryers. The Duncan’s New Multiple Range Test (DNMRT) at p = 0.05 was used to separate the means where there was a significant difference. The drying rates were 0.23, 0.19, 0.16, and 0.13 kg/h for the DADD, DPDD, IADD, and OASD, respectively. The drying rate of the OASD was not significantly different from that of the IADD. The DPC was 1.53, 1.40, and 1.15 for the DADD, DPDD, and IADD, respectively. The DPC of the dryers were significantly different. The direct active desiccant dryer had the highest temperature of 45°C, the lowest relative humidity of 50% at the drying unit and the highest rate of moisture absorbed by the desiccant of 0.24 kg/h. The non-regenerative RHA desiccant had maximum moisture absorption of 28% of its weight. The direct active desiccant dryer is recommended for further development for use in humid tropical locations. Keywords: Crop, Desiccant, Dryer, Humid tropic, Performance, Solar.

CATFISH DRYING (Clarias Batraclus) USING ‘TEKO BERSAYAP’ SOLAR DRYER

2012 ◽  
Vol 2 (1) ◽  
pp. 14-20
Author(s):  
Yuwana Yuwana
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Ambient Temperature ◽  
Drying Rate ◽  
Drying Process ◽  
Drying Time ◽  
Ambient Relative Humidity ◽  
Solar Dryer

Experiment on catfish drying employing ‘Teko Bersayap’ solar dryer was conducted. The result of the experiment indicated that the dryer was able to increase ambient temperature up to 44% and decrease ambient relative humidity up to 103%. Fish drying process followed equations : KAu = 74,94 e-0,03t for unsplitted fish and KAb = 79,25 e-0,09t for splitted fish, where KAu = moisture content of unsplitted fish (%), KAb = moisture content of splitted fish (%), t = drying time. Drying of unsplitted fish finished in 43.995 hours while drying of split fish completed in 15.29 hours. Splitting the fish increased 2,877 times drying rate.

scholarly journals “TEKO BERSAYAP” MODEL SOLAR DRYER FOR FISH DRYING

2016 ◽  
Vol 6 (2) ◽  
pp. 51-56 ◽  
Author(s):  
Yuwana Yuwana ◽  
Bosman Sidebang ◽  
Evanila Silvia
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Ambient Temperature ◽  
The Sun ◽  
Drying Process ◽  
Drying Time ◽  
Sun Drying ◽  
Ambient Relative Humidity ◽  
Chamber Temperature ◽  
Drying Chamber

This objective of this research was to design a dryer called “Teko Bersayap” model and then to test its performance in drying fish in order to solve problems arising from open air sun drying. The dryer consisted of drying chamber with trays inside, heat collectors equipped with air inlets at their lower ends, chimney with an exhaust fan inside and humid air outlet at its upper end, was constructed to dry fish, “Bleberan (Pepetak Leiognatus spp)” species. The results of the experiment indicated that the dryer produced the drying chamber temperature 8.83oC higher than the ambient temperature and the relative humidity 13.91% lower than the ambient relative humidity. The fish moisture content decreased exponentially with drying time and the dryer completed the fish drying process in 18.9 hours compared to 27.6 hours of drying time needed to complete the sun drying for the fish, suggesting that the dryer was ready for utilization

Moisture Uptake of Bisbenzocyclobutene (BCB) Films for Electronic Packaging Applications

1990 ◽  
Vol 203 ◽  
Author(s):  
Hartono Pranjoto ◽  
Denice D. Denton
Keyword(s):  
Relative Humidity ◽  
Integrated Circuit ◽  
Electronic Packaging ◽  
Moisture Absorption ◽  
Dielectric Material ◽  
Transient Behavior ◽  
Equilibration Time ◽  
Moisture Uptake ◽  
Ambient Relative Humidity ◽  
Conflicting Demands

ABSTRACTElectronic packaging has been changing.rapidly to meet the often conflicting demands of higher speed and lower cost. In the multichip module (MCM), an array of semiconductor chips is mounted on a substrate and interconnected via a network of multilevel metal lines with polymer layers used as a dielectric between orthogonal metal signal paths. A potential reliability problem that must be investigated is the absorption of moisture by the dielectric in the MCM package. Moisture absorption may lead to long term problems such as loss of adhesion, corrosion of the metal interconnect and increased insulator conductivity.Bisbenzocyclobutene (BCB) is an insulating polymer that is being used in the MCM package as a dielectric material. In this work, the moisture uptake in BCB is investigated gravimetrically using a Cahn-1000 microbalance with a resolution of I pgram. The BCB films are spincoated onto silicon substrates and cured yielding film thickness ranging from 7 to 20µm. The moisture uptake of the BCB film is monitored in situ and non destructively to reveal the performance of the film as used in an integrated circuit environment. The moisture uptake of the films was monitored at different ambient relative humidity (RIH) values between 20% and 80% at 23°C. The transient behavior of the moisture absorption in BCB films has been characterized. Moisture uptake in BCB films increases as the relative humidity is increased, and reaches a maximum of less than 0.2% by weight at 80% RH. By comparison, this moisture uptake is significantly lower than that of fully cured PMDA-ODA polyimide, which is about 2.5% by weight under similar conditions. The transient data show that the equilibration time for a 22.8 µ.m film is approximately 220 seconds, yielding a diffusion coefficient of about 4.5µm2/s.

Drying of Castor Bean Fruits (Ricinus communis L., "BRS Energia" Variety): An Experimental Investigation

2017 ◽  
Vol 371 ◽  
pp. 31-36
Author(s):  
E.M.A. Pereira ◽  
J.V. Silva ◽  
J.P.S. Santos ◽  
T.H.F. Andrade ◽  
A.G. Barbosa de Lima
Keyword(s):  
Experimental Investigation ◽  
Relative Humidity ◽  
Moisture Content ◽  
Castor Bean ◽  
Thermal Stresses ◽  
Ricinus Communis ◽  
Average Moisture Content ◽  
Drying Rate ◽  
Air Temperatures ◽  
Drying Rates

This work aims to realize an experimental investigation of the drying of castor bean fruits (Ricinus communis L., “BRS Energia” variety) in oven. Results of the average moisture content and surface temperature of the product as a function of time were analyzed for different drying air temperatures (40, 50, 60, 70, 80, 90 and 100°C). Results shows that increasing drying temperature and decreasing air relative humidity we have an increases in the drying rate and more quickly the castor fruits reaches both thermal and hygroscopic equilibrium. It was found that high drying rates generates hydric and thermal stresses inside the product, causing cracks and deformations in the castor bean fruits.

The Potential Migrated Mechanism of Water-Soluble Components in Pellets Prepared by Wet Extrusion/Spheronization: Effect of Drying Rate

2020 ◽  
Vol 17 ◽  
Author(s):  
Bingwei Wang ◽  
Jianping Liu ◽  
Zhenghua Li ◽  
Yulong Xia ◽  
Shuangshuang Zhang ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Water Soluble ◽  
In Vitro Dissolution ◽  
Drying Rate ◽  
Scanning Calorimetry ◽  
Drying Temperature ◽  
Wet Extrusion ◽  
Extrusion Spheronization ◽  
Soluble Components

Background: At present, there were numerous researches on the migration of components in tablets and granules, the investigation in the pharmaceutical literatrue concerning the effect of drying rate on the migration of water-soluble components of pellets was limited. Temperature and relative humidity (RH) were crucial parameters during the drying process which was an essential step in the preparation of pellets via wet extrusion/spheronization. To quantify these variables, the water loss percentage of pellets per minute was defined as drying rate. Objective: The study aimed to investigate the influence of drying rate on the migration of water-soluble components in wet pellets and the potential migrated mechanism. Methods: The pellets containing tartrazine as a water-soluble model drug and microcrystalline cellulose as a matrix former were prepared by extrusion/spheronization and dried at four different drying temperature and relative humidity. Afterward, the extent of migrated tartrazine was assessed regarding appearance, in-vitro dissolution test, Differential Scanning Calorimetry, X-Ray Powder Diffraction, Attenuated total reflectance Fourier transform infrared spectroscopy and Confocal Raman Mapping. Results: Results demonstrated that red spots of tartrazine appeared on the surface of pellets and more than 40% tartrazine were burst released within 5 minutes when pellets dried at 60℃/RH 10%. While pellets dried at 40℃/RH 80%, none of these aforementioned phenomena was observed. Conclusion: In conclusion, the faster drying rate was, the more tartrazine migrated to the exterior of pellets. Adjusting drying temperature and relative humidity appropriately could inhibit the migration of water-soluble components within wet extrusion/spheronization pellets.

scholarly journals Radial Water Barrier in Submarine Cables, Current Solutions and Innovative Development Directions

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2761
Author(s):  
Leszek Resner ◽  
Sandra Paszkiewicz
Keyword(s):  
Moisture Absorption ◽  
Wind Farms ◽  
High Moisture ◽  
Water Barrier ◽  
Operational Factors ◽  
New Challenges ◽  
Submarine Cables ◽  
Further Development ◽  
Lead Aluminium

With wind turbines increasing in size, installed at greater distances from the mainland, and greater depths, submarine cables are facing new challenges. Materials and technologies used so far for the production of submarine cables with lead, aluminium, or copper sheaths make them unsuitable or even obsolete for modern solutions such as floating wind farms. The article discusses types of submarine cables, their construction, working conditions, and operational factors, with emphasis placed on the role of the radial water barrier. The focus has been placed on dry and semi-dry designs. The article is also devoted to a discussion regarding directions of further development, possible materials, and constructions that may appear in the future. Current research and results regarding the use of multi-layer coatings with the use of thermoplastic block copolymers for the layer with high moisture absorption are also presented.

scholarly journals Effects of different drying rates on the physiological quality of Coffea canephora Pierre seeds

2005 ◽  
Vol 17 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Sttela Dellyzete Veiga Franco da Rosa ◽  
Delacyr da Silva Brandão Júnior ◽  
Édila Vilela de Resende Von Pinho ◽  
André Delly Veiga ◽  
Luiz Hildebrando de Castro e Silva
Keyword(s):  
Water Content ◽  
Storage Temperature ◽  
Removal Rate ◽  
Coffea Canephora ◽  
Development Stage ◽  
Seed Vigor ◽  
Drying Rate ◽  
Physiological Quality ◽  
Drying Rates

Desiccation tolerance in seeds depends on the species, development stage and drying conditions, especially the water removal rate. Coffea seeds are considered of intermediate performance, because they tolerate relative dehydration compared to orthodox seeds and are sensitive to low temperatures. The objective of this study was to verify the effect of different drying rates on the viability and storability of Coffea canephora seeds. A complete randomized experimental design was used, in a factorial 3 x 5 x 2 design, with three drying rates (fast, intermediate and slow), five final mean water contents after drying (51, 42, 33, 22 and 15 %) and two storage temperatures (10 and 20°C). The germination and seed vigor assessments, using radicle protrusion, cotyledon leaf opening, seedling emergence and emergence speed index, were performed shortly after drying and after two and four months storage. It was observed that with reduction in the water content there was reduction in the germination values and seed vigor, for all the drying rates. The greatest reductions in physiological quality occurred when the seeds were dried quickly and the best results were obtained at the intermediate drying rate. There was an effect of drying rate and storage temperature on the physiological quality of the seeds, and lower germination and vigor values were observed in seeds with lower water content stored at 20°C. C. canephora seeds were tolerant to desiccation down to 15 % water content and can be stored for four months at 10°C. A temperature of 20ºC can be used to store C. canephora seeds, as long as the water content is not reduced to values below 22 % water content.

Slow rehydration improves the recovery of dried bacterial populations

1992 ◽  
Vol 38 (6) ◽  
pp. 520-525 ◽  
Author(s):  
J. W. Kosanke ◽  
R. M. Osburn ◽  
G. I. Shuppe ◽  
R. S. Smith
Keyword(s):  
Relative Humidity ◽  
Rhizobium Leguminosarum ◽  
Moisture Absorption ◽  
Rhizobium Meliloti ◽  
Bacterial Populations ◽  
Bulk Powder ◽  
Alfalfa Seed ◽  
Powder Samples ◽  
Cellular Stresses ◽  
Rhizobium Leguminosarum Biovar Trifolii

Slow rehydration of bacteria from dried inoculant formulations provided higher viable counts than did rapid rehydration. Estimates were higher when clay and peat powder formulations of Rhizobium meliloti, Rhizobium leguminosarum biovar trifolii, and Pseudomonas putida, with water activities between 0.280 and 0.650, were slowly rehydrated to water activities of approximately 0.992 before continuing the dilution plating sequence. Rhizobium meliloti populations averaged 6.8 × 108 cfu/g and 1328 cfu/alfalfa seed greater when slowly rehydrated from bulk powder and preinoculated seeds, respectively. Bulk powder samples were slowly rehydrated to 0.992 water activity by the gradual addition of diluent, followed by a 10-min period for moisture equilibration. Preinoculated seed samples were placed in an environmental chamber at 24 °C with relative humidity greater than 80% for 1 h to allow moisture absorption. "Upshock," osmotic cellular stresses that occur during rehydration, was reduced when dried microbial formulations were slowly rehydrated and equilibrated before becoming fully hydrated in the dilution plating sequence. These procedures may also be applicable when estimating total viable bacterial populations from dried soil or other dry formulations. Key words: rehydration procedure, microbial rehydration, desiccation, Rhizobium, Pseudomonas.

Effect Of Moisture On The Physical Properties Of Polyimide Films

1991 ◽  
Vol 227 ◽  
Author(s):  
Rajeevi Subramanian ◽  
Michael T. Pottiger ◽  
Jacqueline H. Morris ◽  
Joseph P. Curilla
Keyword(s):  
Dielectric Constant ◽  
Steady State ◽  
Electrical Properties ◽  
Relative Humidity ◽  
Quartz Crystal ◽  
Moisture Absorption ◽  
Relative Dielectric Constant ◽  
Moisture Uptake ◽  
Polyimide Films ◽  
Effect Of Moisture

ABSTRACTMoisture absorption and its effect on electrical properties were measured for several polyimides. A Quartz Crystal Microbalance (QCM) was used to investigate the moisture absorption in BPDA/PPD, PMDA/ODA, and BTDA//ODA/MPD polyimides. The steady-state moisture uptake in polyimides as a function of relative humidity (RH) was determined by exposing film samples to successively higher RH values ranging from 10 to 85% at 25°C. The isothermal moisture absorption as a function of percent RH was found to be nearly linear for all of the polyimides studied. The effect of moisture on the electrical properties of a BPDA/PPD polyimide was also investigated. The relative dielectric constant at 25 °C was found to be a linear function of the moisture absorbed.

Experimental Study on Hygroscopicity of Rapeseed (Brassica Napus)

2012 ◽  
Vol 479-481 ◽  
pp. 2275-2278
Author(s):  
Ming Jin Yang ◽  
Wu Ming Xu ◽  
Tian Tang ◽  
Ling Yang ◽  
Feng Liu
Keyword(s):  
Experimental Study ◽  
Brassica Napus ◽  
Relative Humidity ◽  
Moisture Absorption ◽  
Early Period ◽  
Critical Relative Humidity ◽  
Temperature And Humidity ◽  
Higher Temperature

The hygroscopicity property of the rapeseed at different temperature and humidity was experimental studied in this paper. Tested results show that: the moisture absorption rates increase with the increase of relative humidity at the early period of absorption, and higher temperature leads to earlier reach of moisture equilibrium; the critical relative humidity(CRH) increases with the increase of temperature; the optional relative humidity for safety storage of rapeseed should be controlled less than 60%.

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