Electric Dryer Research Articles

Portable Household Vegetable Dehydrator

Vegetable storage and preservation are issues in many nations, including India. Particularly, certain veggies are safe to consume and fresh during a particular season. Drying is one method of vegetable preservation that has been around for a while. However, sun drying veggies is not feasible due to small kitchens or houses. The goal of this initiative is to find a solution for households. The electric vegetable dryer can be used sparingly and takes up less room. It takes care of the problem of how to store green vegetables, which are best kept fresh and healthy in the winter and go bad even when kept in the refrigerator for three to four days. The project's goal is to enable people to keep veggies at home for their own personal consumption.

Effect of Drying Methods on the Moisture Content and Microbiological Properties of Three Varieties of Dried Onion Slices (Allium cepa)

Post-Harvest losses of onions occurring due to poor handlings and spoilage by microorganisms is worthy of concern. Value addition through drying during peak seasons can reduce losses remarkably. This study sought to evaluate the effects of different drying methods on the microbial load of dried onion slices. Three varieties of onion (red, white and cream) were purchased National Institute for Horticultural Research (NIHORT) Kano sub-station and processed into dried slices using three dryers namely; Solar Cabinet Dryer (SCD), Electric Powered Dryer (EPD) and Kerosene Powered Dryer (KPD) at three different temperatures (50, 60 and 70oC). The dried onion slices were then evaluated for their microbial load; Aerobic Plate Counts (APC), Coliform Counts (CC) and Fungal Counts (FC) using three different media and according to standard methods. The results revealed that MC of onions were reduced from 88.29% to as low as 5.19% during drying. The APC, CC and FC of red onion ranged from 3.67–5.39×102 cfu/g, 1.35–5.39×102 cfu/g and 3.44–4.83×102 cfu/g respectively. The load for white onion ranged from 3.11–5.19×102 cfu/g, 1.31–5.29×102 cfu/g and 3.43–4.53×102 cfu/g respectively while that of cream onion ranged from 3.30–5.33×102 cfu/g, 1.33–5.39×102 cfu/g and 3.42–4.57×102 cfu/g respectively. All the readings fell below the international recommended safe limit for food consumption. The EPD samples at 60oC and 70oC had the significant lowest (p≤0.05) fungal counts in all the onion varieties. Therefore, electric oven dryer at 70oC was the best drying methods and temperature for onion for long time storage.

Pharmaceutical Analysis and Evaluation of In-vitro Antibacterial Activity of Gomutra Ghana: A Concentrated and Solidified Form of Cow’s Urine

Introduction: Cow’s urine has been described as a highly effective animal-derived substance. Its therapeutic and pharmacological actions make it effective in the treatment of a variety of disorders. One of its notable properties is its antibacterial action, where the drug’s ability to target and inhibit the growth of bacteria. However, due to the pungent odour and taste of cow’s urine, it is difficult to consume in its natural form. Additionally, the collection of fresh cow’s urine can be challenging, especially in urban areas where access to cows may be limited. So, it is important to modify it into a dosage form, like Gomutra Ghana, which improves palatability and shelf life. Aim: To study the pharmaceutical development, quality control assessment, and in-vitro antibacterial activity evaluation of Gomutra Ghana. Materials and Methods: The pharmaceutical and analytical studies were carried out in Mahatma Gandhi Ayurved College Hospital and Research Centre and Dattatraya Ayurved Pharmacy, Salod (H), Wardha, Maharashtra, India. The in-vitro (antibacterial) study was carried out in JNMC, Sawangi (M), Wardha, Maharashtra, India, from April 2022 to August 2023. The in-vitro antibacterial study of cow’s urine and Gomutra Ghana was performed on five bacterial strains. Fresh cow’s urine was collected from a goshala (cowshed), and Gomutra Ghana was prepared in three batches by boiling the cow’s urine to a thicker consistency, then sun-drying it, followed by drying in an electric dryer. The final product was stored in a clean, sealed glass jars. Analytical parameters like pH, loss on drying at 105ºC, total ash, water-soluble ash, acid-insoluble ash, water-soluble extractives, alcohol-soluble extractives, and microbial contamination were studied. The in-vitro antibacterial activity was evaluated using the agar disc diffusion method at concentrations of 5 μL, 10 μL, and 15 μL, with results compared to those of a broad-spectrum and commonly used antibiotic, ciprofloxacin (5 μg). Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) version 27.0, employing Analysis of Variance (ANOVA) to compare three groups (Ciprofloxacin, cow’s urine, and Gomutra Ghana) at all three concentrations. A significance level was set with a p-value of <0.05 for the antibacterial study. Results: High-Performance Thin-Layer Chromatography (HPTLC) showed a peak from cow’s urine and Gomutra Ghana, with maximum heights of 500.1 and 450.4, which were nearly the same, so they may contain similar constituents. An extra peak was observed in Gomutra Ghana, suggesting the presence of additional compounds formed during its preparation. Gomutra Ghana extract showed the highest zone of inhibition against Escherichia coli. Conclusion: Gomutra Ghana showed antibacterial properties, which warrant further exploration in humans for safety and efficacy in humans.

Isotropic ΙoT-Based Magnetic Flux Density Meter Implementation for ELF Field Measurements

This article presents the basic principles for an Extremely Low Frequency (ELF) IoT-based isotropic meter implementation, which can measure magnetic flux density from 100 nT up to 10 μT. The identical sensor probes are used for isotropic field measurements in the X, Y, and Z planes. The prototype has a flat response across the frequency range from 40 Hz to 10 kHz, detecting and measuring several magnetic field sources. The proposed low-cost meter can measure fields from the power supply network and its harmonic frequencies in the operating frequency band. The proposed magnetic flux density meter circuit is simple to implement and the measured field can be displayed on any mobile device with Wi-Fi connectivity. An Arduino board with the embedded Wi-Fi Nina module is responsible for data transferring from the sensor to the cloud as a complete IoT solution, supported by the Blynk application via Android and iOS operating systems or web interface. In addition, an ELF energy harvesting (EH) circuit was also proposed in our study for the utilization of the alternating magnetic fields (50 Hz) derived from the operation of several consumer devices such as transformers, power supplies, hair dryers, etc. using low-consumption applications. Experimental measurements showed that the (DC) harvesting voltage can reach up to 4.2 volts from the magnetic field of 33 μΤ, caused by the operation of an electric hair dryer and can fully charge the 100 μF storage capacitor (Cs) of the proposed EH system in about 3 min.

Performance evaluation of solar tunnel dryer and electric tray dryer for drying date palm fruit (Pheonix dactylifera L.) in arid region of Rajasthan

Date palm (P. dactylifera, L.) is an important fruit of arid and semi-arid regions.In Western Rajasthan the dates are harvested in the month of July-August but preferred to eat during winter months, so it becomes necessary to dry and store the fruits at least for 4 to 6 months. The use of an appropriate temperature for drying of dates is quite crucial as a higher temperature may encourage case hardening, caramelization and a higher hygroscopicity; whereas a lower temperature would be insufficient to remove significant moisture leading to a clumpy powder. Farmers generally dry the dates in open sun. This traditional uncontrolled drying method is unhygienic and required more time, also weather dependent, so alternate economical methods are being tested in the region by the scientists and the farmers for drying of dates in the form of Pind. The paper deals with the performance of solar tunnel dryer and electric tray dryer installed at the farmer’s field in Bikaner district of Rajasthan. The results reveal the drying time of Medjool date palm fruits in solar tunnel dryer and electric tray dryer.

Evidence of a Homeowner-Renter Gap for Electric Appliances

This paper provides the first empirical analysis of the homeowner-renter gap for electric appliances. Using U.S. nationally representative data, the analysis shows that renters are significantly more likely than homeowners to have electric heat, electric hot water heating, an electric stove, and an electric dryer. The gap is highly statistically significant, prevalent across regions, and holds after controlling for the type, size, and age of the home, as well as for climate and household characteristics. The paper argues that this gap arises from the same split incentives that lead to the “landlord-tenant problem” and discusses the implications of the gap for an emerging set of policies aimed at reducing carbon dioxide emissions through building electrification.

Study on the Effect of Different Drying Methods on the Proximate, Nutritional and Mineral Composition of Clarias gariepinus (Catfish)

Aim: This study investigated the effect of modern drying methods on the proximate, nutritional, and mineral composition of Clarias gariepinus in Port Harcourt, Nigeria.
 Methods: Fresh C. gariepinus were purchased from Mile 3 Market in Port Harcourt, Rivers State. Samples were dissected using a sharp knife, intestinal components, and gills were removed and the edible portion was washed properly and rinsed with distilled water. Samples were treated in four groups: fresh, smoking using firewood, electric drying (200oC), and non-electric drying (200oC for 30 minutes) methods. Samples were blended using mortar and pestle into powder and kept in an air-tight container prior to analyses.
 Results: The proximate composition of C. gariepinus revealed that crude protein concentration was in the following proportions; electric drying method (52.16+0.01%), non-electric drying method (43.40+0.00%), smoking method (32.72+0.00%) and fresh (23.01+0.00%). The lipid content of smoked and electric-dried C. gariepinus was significantly (p<0.05) higher compared to the fresh sample. However, there was no significant difference between the lipid content of fresh C. gariepinus sample and non-electric dried sample. The carbohydrate content increased in the smoking and electric drying methods but decreased in the non-electric drying method. The ash content increased only in the smoking method but decreased in both the electric dryer and non-electric dryer methods. Fresh samples had the highest moisture content (74.03+0.00%) while the least was observed in the electric dried sample (38.84+0.00%). The percent anti-nutrient composition of C. gariepinus showed that smoked samples had the highest flavonoid concentration (3.252±0.00%) which was not significantly higher (p>0.05) than the flavonoid content of electric dried C. gariepinus (2.89±0.33). The levels of selected minerals showed varying concentrations of potassium, sodium and calcium for the various processing methods.
 Conclusion: Modern drying methods had a significant effect on the proximate component, flavonoids, and oxalate composition of C. gariepinus. Electric drying method showed to be a better method of drying Clarias gariepinus compared to other drying methods.

Drying of onion shreds in corrugated electric and solar-conduction dryers: Techno-economic evaluation and quality degradation kinetics

Drying of onion shreds in solar conductive dryer (SCD) and corrugated electrical solar conductive dryer (CESCD) are explored in this study. An attempt to improve the sample loading volume of SCD and CESCD is made using a fixed bed dryer (FBD) for initial drying. The techno-economic analysis is carried out for different pattern loading on SCD and CESCD. The techno-economic aspects analyzed include efficiency of dryer, payback period, life cycle savings, and internal rate of returns (IRR). Drying characteristics—drying rate, moisture ratio, and temperature profile of both dryers were compared. CESCD showed higher drying rate and IRR than SCD. Data fitted best in Page model. In terms of energy requirement, the overall drying efficiency of SCD was better than CESCD. Patterns 1 and 3 retained the color better, but were not cost-effective and profitable. Flavor and bioactives were higher in SCD than CESCD dried onion shreds.

Experimental Study on Heat Recovery of Air Dryer from Waste Heat Energy of Condensing Unit from VCRS Air Conditioner

Heating, Ventilating, and Air Conditioning (HVAC) is a system to condition indoor air by cooling or heating to achieve thermal comfort for a human being. The HVAC system operates based on the refrigeration cycle, where heat is dissipated from the condensing unit in the warm air arrangement. This represents an ironic foundation of heat that might be recovered for further schemes or applications. In this paper, experimental work was developed to validate the proposed heat recovery system using heated air released from the condenser unit of the HVAC system as a source for the air dryer for the drying rack. Four different output parameters are to be observed in this research: the dry-bulb temperature of the air exit from the condenser unit, the dry-bulb temperature of the air inflowing the dryer, and the drying time and the relative humidity of the air leaving the dryer. These experimental works were conducted using a domestic application of a 1.0 hp air conditioning (AC) system with R-22 refrigerant gas and based on the following factors: The three-variant mass of wet clothes, the three-stage of mechanical fan speed for releasing warm air from the condenser, and the effect of variable ambient or surrounding air dry-bulb temperature were studied. A physical prototype of the dryer was constructed for proof-of-concept purposes. The experimental output was then analyzed to obtain precision and accurate data. To determine the system behavior, a refrigeration cycle analysis was conducted. It has been shown that an AC system of 1.0 hp can cover wet clothes drying of weights 1950 g, 4255 g, and 6350 g at 55, 80, and 110 min with a constant air velocity of 0.34 m-3.s-1 in an ambient temperature of 33°C. The significant contribution of this research is the proposed heat-recovery-based air dryer system with the capability to increase the Coefficient of Performance (COP) of the AC unit from 2.36 to 2.70. Hence, the energy-saving was received using the heat-recovered-based air dryer instead of a commercial electric air dryer system that uses high power consumption from their heater element.

Life cycle assessment, energy and exergy analysis in an indirect cabinet solar dryer equipped with phase change materials

This study investigated the effect of using phase change materials (PCMs) in a cabinet dryer on thermal and drying efficiency. Three positions related to PCM inside the cabinet were considered, including the bottom, middle and upper trays. The specific energy consumption for drying tomato slices was 11.32–14.87 MJ/kg. PCMs on the lower tray of the cabinet dryer resulted in shorter drying times for the pieces compared to other methods. The overall thermal efficiency of the cabinet dryer varied from 35.23 to 38.92 %. Simulations were conducted using computational fluid dynamics (CFD). As a result, it was possible to predict the cabinet dryer's thermal performance with high accuracy (R2 > 0.95). Evolutionary Polynomial Regression (EPR) is used to predict the output temperature and efficiency of the cabinet dryer. The Life Cycle Assessment (LCA) method was used and compared with that of a thermal electric dryer to estimate the environmental effects of a solar dryer. The results showed a significant difference between the effects of the electric thermal dryer and the solar dryer on all of the above categories.

Design of a Friendly Solar Food Dryer for Domestic Over-Production

Solar drying is one of the many ways of efficiently making use of solar energy to meet the human demand for improved sustainability. In this study, we describe the construction and testing of two indirect solar dryer prototypes, especially designed for vegetables and fruits. The dryers had two compartments: a solar panel and a drying chamber. The dryers were mainly made of wood (Prototype 1) and styrofoam (Prototype 2) and both used recycled aluminum cans. The calculated yield of solar panels was 82% and 77% for Prototype 1 and 2, respectively. The drying tests performed with different fresh products showed that it was possible to dry all of them until less than 10% of their initial weight, at different times, depending on the type of product. As regards the apple slices, the solar dryers were able to remove 95.7% and 95.0% of initial moisture on a wet basis for Prototype 1 and 2, respectively. Comparative tests were conducted with an electric commercial dryer using the same product to explore the drying dynamics and costs. The cost of the final dry product, excluding the purchase of fresh goods, was 6.83 €/kg for the electric dryer, 1.78 €/kg for Prototype 1 and 1.72 €/kg for Prototype 2. Dehydrated apple slices are currently available on the market for around 34.50 €/kg. Our solar dryers can dry quality products at a very low cost for their entire life span, which allows them to compete with electric systems to prevent food waste in a cheaper and environmentally friendly way.

Analysis of the kinetic parameters of clothes drying in an electric vented dryer. Part II: Influence of the type of fabric

In this experimental study, we quantified the impact of four factors of the drying process (power supplied to the heater coils, airflow, amount of clothes, and type of fabric) at two levels (low and high) on energy consumption (EC), total cycle time (TCT), and drying efficiency of an electric vented dryer. A numerical model previously developed was used to analyze some kinetic parameters of the drying process, such as evaporation rate, dehydration profile, water activity, and saturation pressure on the textile surface, among others. The two types of fabric used were 100% polyester and 100% cotton. This study concluded that polyester drying consumes less energy (29% evaluated with parameters at the low level and 6% assessed at the high level) than cotton with the same evaluated parameters.

Techno-economic analysis of greenhouse solar dryer for drying agricultural produce

The numerous benefits of solar drying over open sun drying have resulted in extensive research in the field of solar dryers. This research paper describes the development and analysis of a 100 kg capacity greenhouse solar dryer designed to produce high-quality dried products. The greenhouse is effective in raising the temperature within it to 10–14 °C higher than ambient temperature and the tested products dry at a much shorter duration when compared to drying in the open sun. Detailed economic analysis was conducted through annualized cost, life cycle savings, and payback period methods. According to annualized cost method calculations, the cost of drying products by using a solar dryer is much lesser than when an electric dryer is used. Calculations also reveal potential savings of up to 10 times the value of current-day investment within the dryer lifetime, depending on the product to be dried. The dryer also has a short payback period of 1.5–2.1 years for the considered agricultural products.

Airflow Drying Licking Countercurrent of Mango (Mangifera Indica L): Experimental Determination of Drying Parameters

Abstract: This work focused on the experimental determination of drying parameters during airflow drying licking countercurrent of Mangifera Indica L. The samples were dried in a modular electric dryer operating in forced convection. The data collected made to draw the different drying kinetics of the mango at 40, 50 and 60°C. The solution of the Fick equation and the exploitation of the experimental data by the slope method have used.

Analysis of mango drying methods and effect of blanching process based on energy consumption, drying time using multi-criteria decision-making

Fruits are considered one of the healthiest foods, but their high moisture content makes them perishable; they must be dried to improve shelf life. Given India's dominance in mango fruit production, the purpose of this paper is to evaluate the effects of drying conditions on mango physical properties, as well as for blanching pre-treatment. Statistical analysis evaluates seven thin layer drying models for the drying kinetics analysis. The effect of blanching on drying kinetics is investigated at predetermined time intervals, along with the moisture ratio. For determining the fit quality of the proposed models, the coefficient of determination (R 2 ), Root Mean Square Error, and Sum of Squared Errors are used. Subsequently, five different drying methods (Open Sun Dryer, Controlled Solar Box Dryer, Hot Air Oven Dryer, Microwave Oven Dryer, and Electric Oven Dryer) are used to optimize the drying of mango samples using Multi-Criteria Decision Making methods. The Analytical Hierarchy Process, Multi-Objective Optimization by Ratio Analysis and Complex Proportional Assessment methods, along with fuzzy sets, determine the best drying method with the lowest energy consumption, cost and drying time. Finally, sensitivity analysis is performed to validate the results. It can be concluded that the mathematical models Page, Two-term, Diffusion, and Weibull provide a better fit to the experimental data than other models. Blanching affects on drying because it shortens the drying time. According to optimization results, the electric oven dryer and microwave oven dryer produced the best results and are regarded as the best drying methods for both controlled and blanched samples considering energy consumption, dryer cost, drying time.

Analysis of the kinetic parameters of clothes drying in an electric vented dryer. Part I: Validation of a model and influence of power

Experimental and numerical models were used to analyze the kinetic parameters that affect the clothes drying process in an electric vented dryer. The numerical model was derived from a thermodynamic analysis of a dryer using mass and energy balances. The experimental study used a prototype of a dryer that was instrumented with data acquisition equipment. A textile made from 50% polyester and 50% cotton was used in the tests; the results were used to validate the model. The temperature and relative humidity of the air at the drum inlet and outlet, the evaporation rate, and the residual moisture in the clothes were analyzed. A procedure to calculate the mass and heat transfer coefficients inside the drum was presented. The numerical and experimental results showed that the behaviors of coefficients obtained at heating powers of 1300 W and 2000 W were almost constant during the drying period.

Substantiation of modes of drying alfalfa pulp by active ventilation in a laboratory electric dryer

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Evaluation of the Drying Characteristics of Coffee Grounds with Electric and Gas Combustion Heat Sources

The water content of the coffee grounds discharged from coffee beverage production facilities and coffee stores is about 75 wt.%. When the coffee grounds is used as solid energy source, drying technology is important because the high water content of the coffee grounds causes lower heating values reduction and combustion deterioration. In particular, it is necessary to maintain a constant water content of the dried coffee grounds with low energy consumption. In this study, two types of coffee ground batch dryer were tested: an electric heating and a gas burning system. After coffee grounds were injected into each dryer, vapor evaporation, drying rate, specific moisture evaporation rate, and drying efficiency were measured. The drying systems applied the moisture intensity (pulse, P) sensor and an automatic control program to maintain the moisture content of the dried coffee grounds. The drying performance and efficiency of the electric heating dryer were 21% and 33% higher than the gas burning dryer, respectively. The water content of dried coffee grounds is about 2.1 wt.%, and the ash content is 1.5 wt.%. The lower calorific value of dried coffee grounds is 5,710 kcal/kg, satisfying Bio-SRF (solid refuse fuel, Korea) quality standard. Therefore, when the dried coffee grounds is used as a solid energy source, it is advantageous to reduce the amount of greenhouse gas and save fossil fuels compared to the case of landfilling the dried coffee grounds.

Development of a forced convection electric fish drying machine

A forced convection electric fish dryer was developed in this study to provide an efficient means of drying fish in urban and rural areas and serve as a substitute for the largely inefficient local means of drying fish. The machine was designed to accommodate 126 kg of fish distributed accordingly within the drying chamber. Six flat electric coils of 3 kW capacity each and a fan blower were provided to induce a saturating forced convective current within the drying chamber. The machine was evaluated at a drying temperature of 60oC with a total of 126 kg catfish, 21 kg on each tray. The result showed that percentage moisture contents of 81.8%, 72.7%, 62.7%, 54.1%, 47.7%, and 40.9 % were evaporated from the fish on the sixth to the first tray respectively in one hour. The mean percentage of moisture evaporated from all the trays was 60 %.

Improving the thermal efficiency and energy consumption of convective dryer using various energy sources for tomato drying

High energy consumption and low thermal efficiency are the main problems associated with convection hot air dryers. The effect of various energy sources on tomato drying in a convective dryer was performed. In particular, drying experiments were performed on a convection dryer at two types of heat energy sources, electric and butane-gas, air velocity 1.0, 1.5, and 2 m/s, and air temperature 40, 50, and 60 °C. The rising temperature from 40 to 60 °C caused a reduction of the drying period by 24.8, 22.1, and 21.5% at 1.0, 1.5, and 2.0 m/s, respectively. Minimum energy consumption of 3.83 kW.h was recorded using the electrically heated system while minimizing energy consumption of 0.82 kW.h was detected for the convection gas dryer at 60 °C and 1.0 m/s. The lowest SEC was recorded at 17.44 kWh/kg using gas dryers, while a maximum SEC (112.05 kWh/kg) was observed at the electric dryer under 60 °C and 2.0 m/s. The gas dryer had a thermal efficiency ranging from 50.32 to 78.77%, while the electrically heated dryer had a thermal efficiency ranging from 34.86 to 50.34%. Moreover, applying the butane gas as a heat source for drying had various advantages over the conventional electric system, such as less overall energy consumption with more effectiveness under all conditions.