Hybrid Drying Research Articles

Hybrid microwave-hot air drying of the osmotically treated carrots

The influence of the hot air drying (HAD) and the hybrid drying (microwave drying followed by HAD) with (MWODHAD) or without (MWHAD) previous osmotic dehydration (OD) was evaluated on the effective moisture diffusivity (Deff), volumetric shrinkage (Sh), rehydration, carotenoid content and color of sliced carrots. The OD was performed with a ternary solution of sucrose and sodium chloride (35 °C; 300 min). The HAD procedure was carried out at 70 °C (1.5 m/s) and the MWHAD was tested using three different power levels (55.7, 167.9, 336.8 W) until the final moisture content of 0.13 ± 0.01 kg H2O/kg dry matter (DM). The results showed that the use of MWHAD with the highest power, reduced (p < 0.05) the total drying time (144 min) and increased the Deff compared to the HAD. Moreover, the MWHAD treatment showed the highest values of Sh, rehydration and carotenoid content. The sliced carrots dried using these three drying arrangements had no significant differences in color. In general, the combined treatment MWHAD could improve the drying rate and the quality.

Design and construction of a hybrid gas and biogas dryer for fruits, vegetables, meat and fish

The problem of food loss due to lack of proper conservation and preservation scheme is pertinent. In an attempt to reduce such losses, the agronomic sector is constantly innovating with technological accessories to solve the related problem. The problem with such accessories lies in the fact that most of them do not consider present global developmental objectives coupled to the fact that they are expensive and have a high cost of maintenance regarding the amount and type of energy needed to run them. As such, local tools were used to design and construct a hybrid biogas/liquefied gas dryer for food products with a wide range of application spanning from fruits and vegetables to meat and fish. The advantage with this dryer lies in its energy sources which are readily more available and the ability of alternative fuel which is biogas can readily be produced even in remote / rural zones for domestic and industrial use. The use of a renewable alternative makes it not only cost effective but also tied to the millennium development goals. The addition of a solar powered fan and an Arduino control unit solves a major problem of temperature and humidity control. The prototype constructed has the following characteristics: A functional hybrid dryer of external dimensions 125 cm × 75 cm × 65 cm; useful volume: 420,000 cm3; number of trays : 10 trays of dimensions : 60 cm × 70 cm; drying surface : 46,200 cm2 ;Volume / surface ratio : 10. The products dried successfully include: White cabbage, Lemon Grass, Bitter leaf and Green Aramanth.

Design and Performance Evaluation of Solar - Infrared Hybrid Dryer for Drying of Anchovy Fish

Design and Performance Evaluation of Solar - Infrared Hybrid Dryer for Drying of Anchovy Fish

Thermal Analysis of Tilapia Fish Drying by Hybrid Solar Thermal Drying System

The present work presents a hybrid solar thermal drying of Tilapia fish to improve the product quality and satisfy the importers. The developed hybrid dryer utilized direct solar drying, a solar air heater and a thermal backup unit which sustains the drying process during the night, cloudy and rainy weather conditions. Besides, a new feature of the developed dryer utilizes the flue gas exhausted from the thermal unit to enhance the updraft in the drying chamber by re-injection of the flue gases in the chimney. The initial moisture content of the Tilapia fish used in the investigation was 246.6% on a dry basis, equivalent to 74% on a wet basis. The investigations were repeated three times on different days. Experimental results showed that the moisture content was reduced to an average final of 17.0% db (5.0% wb) within 17.5 hours, while in the open sun drying, it required around 48-72 hours. Hybrid solar drying required around 72% shorter time than open sun drying. The average overall drying efficiency of the developed system for drying Tilapia fish was 13.0%. The Re-injection technique used in the present hybrid solar-thermal system has excluded the need for an electric source for air extraction from the drying chamber, which is highly desired in the rural and fishery regions.

Model identification and fuzzy control of the temperature inside an active hybrid solar indirect dryer

In this paper, an indirect hybrid solar-electric dryer was used to be able to dry a wide range of agriproducts and to ensure a continuous drying operation. The hybrid dryer is a multivariable system made up of a solar collector, a drying chamber, a fan in the outlet duct, and electrical resistance heaters. To preserve the product quality, the temperature should be kept within a restricted temperature range during the drying process. Temperature control is also required to optimize the conventional energy demand and to achieve better use of the available solar energy. This paper presents the thermal behavior study and the control of the temperature inside a hybrid solar dryer. To predict the temperature evolution in a fairly short time, a state-space model based on the nonlinear least square method was developed. Based on the temperature prediction model, Fuzzy Logic Controller (FLC) was developed and its performances were compared with a Proportional Integral (PI) temperature controller. The experimental tests were carried out under an air mass flow rate of 0.025 kg/s and the temperature was controlled at 60 °C and 80 °C. By using this combination, the static temperature inside the drying chamber remains under 0.8 °C and the relative error remains under 1.04%. The developed fuzzy controller could almost recover the dryer performances in less than 8 min after temperature disturbance. Moreover, for continuous use covering day and night, the temperature controller allows reducing the conventional energy consumption by 11.3%.

UNJUK KERJA PERALATAN PENGERING HYBRID (ENERGI MATAHARI DAN GAS) UNTUK PENGERINGAN BIJI COKLAT

This research was conducted to examine the drying system with a hybrid energy source between solar energy and gas fuel for applying cocoa beans. Solar thermal energy is used as the main energy source for this dryer, while the energy source from gas fuel is the main energy back-up when the intensity of the sun's heat drops (afternoon, evening and cloudy weather). The results of this test indicate that the drying performance of the data plate collector with 3 cm thick black sand can eradicate cocoa beans with an initial air content of 65-75% with a duration of 26-28 hours, while the hybrid dryer with heat and gas energy sources can shorten the time. drying to 17-19 hours. Keywords: Hybrid Energy, Gas Fuel, solar intensity, Temperature

Hybrid drying of ultrasound assisted osmotic dehydration (UOAD) and hot air drying of Eucalyptus deglupta

Eucalyptus deglupta is one of the promising medicinal plants from Mytracea family consisting of bioactive compounds that are to be used in medications. The bioactive compounds present in Eucalyptus deglupta were extracted at the best yield using a hybrid drying method consisting of ultrasound assisted osmotic dehydration (UOAD) and hot air drying in this study. The drying conditions of UAOD were optimised with response surface methodology (RSM) to attain the highest antioxidant activity via of DPPH radical scavenging assay. Four parameters were optimised with response surface methodology, namely concentration of sucrose (v/w), temperature (°C), duration of drying and intensity of ultrasound (%) ranged from 30% to 50%, 20°C to 60°C, 40 min to 100 min and 60% to 100%, respectively. A series of 27 combinations of the UAOD drying conditions were performed and followed by hot air drying performed at 60°C until a constant weight was achieved. A moderate scavenging activity of DPPH assay (56.12%) was achieved at a concentration of sucrose, temperature, duration of drying and intensity of ultrasound of 50%, 40°C, 100 min and 264 W, respectively.

An Innovative Hybrid Drying Technique for Parboiled Rice Production Without Steaming: an Appraisement of the Drying Kinetics, Attributes, Energy Consumption, and Microstructure

An Innovative Hybrid Drying Technique for Parboiled Rice Production Without Steaming: an Appraisement of the Drying Kinetics, Attributes, Energy Consumption, and Microstructure

Effect of carbonation and ultrasonication assisted hybrid drying techniques on physical properties, sorption isotherms and glass transition temperature of banana (Musa) peel powder

Banana peels (Cavendish and Nay poovan) in ripe and raw form were dried using tray drying (T), microwave (M), microwave-convection (MC) and freeze drying (F) with ultrasonication (U) and combined treatment of carbonation and ultrasonication (CU) as pretreatments. SEM analysis showed microscopic channels in samples after U treatment, which were more ravine after CU. Based on bulk density, tapped density, porosity, angle of repose, colour parameters, viscosity, CU + F was found best drying combination followed by CU + MC. For selected samples, relative water sorption changes induced by U and CU were positive as the sorption surface area increased after given pre-treatments. Peleg model fitted best to experimental data for sorption studies. The water plasticizing effect of U and CU treatments on glass transition temperature (Tg) was predicted using Gordon-Taylor model. State diagram predicted critical moisture content (Xc), 0.106 kg H2O/kg dry matter and critical water activity (awc), 0.525 at 16 °C.

Effect of burner’s configuration on the temperature profile inside an innovative solar-gas dryer: Numerical and experimental investigations

The main purpose of this work is the optimization of a novel hybrid solar gas dryer. The hybrid dryer was made up of a drying chamber and an innovative solar-gas collector. The gas system consisted of three gas burners incorporated below the absorber as follows: in the bottom, the middle, and the top sides. Each burner is independently controlled for activation and deactivation. Given this distribution, seven configurations of the burners were possible (Top burner (Tb), Middle burner (Mb), Bottom burner (Bb), Top-middle burners (T-Mbs), Top-Bottom burners (T-Bbs), Middle-Bottom (M-Bbs), Top-Middle-Bottom (T-M-Bbs)). This work aims to figure out the suitable configuration of the burners and to optimize their placements inside the solar-gas collector. Numerical simulations followed by experimental investigations were conducted in a transitory and steady-state. It was concluded that for the same consumed gas power, the highest temperature (95.6 °C) was achieved by activating the middle burner (Mb) while the lowest temperature (74.1 °C) was obtained by activating the top–bottom burners (T-Bbs). Further, it turned out that the highest temperature could be obtained by concentrating the burners in the middle side of the solar-gas collector. The obtained results have helped to enhance the efficiency of the proposed hybrid solar-gas dryer.

홍고추 건조 시 건조기의 건조 에너지에 관한 연구

In the Korean food culture, chili peppers (Capsicum annuum L.) are often used to make spicy seasonings. These peppers are mainly used in the powdered form, obtained as a result of a drying process and chili peppers powders generally have a moisture content of 14-20%. Chili peppers are dried naturally using solar radiation (sunlight) or using dryers. Dryers are used to reduce the drying time as compared to the natural drying method. In this paper, a membrane-heat pump hybrid dryer was developed in order to find efficient drying methods by controlling the membrane and heat pump. Furthermore, the drying energy calculation method was proposed in the drying process. The results showed that the cross over control method used 20.5% more drying energy as compared to the time control method.

Design and development of resistance heating apparatus‐cum‐solar drying system for enhancing fish drying rate

AbstractResistance heating is unique to thermic food manufacturing applications, particularly getting popularity across the food sector. Here, a prototype ohmic heating device over a capability of 6.25 kg/hr has been developed to process fish. The developed device was used combined with PID‐controlled solar dryer, and the parameters have been optimized by using central composite rotatable design and artificial neural network (ANN). During the processing of hybrid drying (ohmic heating with solar drying), the selected input variables were voltage (160–200 V), salt concentration (0–2%), solar drying temperature (40–72°C), and loading density (109–190 g) to improve the drying rate (drying time, overall temperature, and final moisture content). The designed ohmic heater reduced the moisture in fish muscles from 348.5% (db) to 260.91% at the first stage of drying under optimum conditions (180 V ohmic voltage and 1% salt concentration) in the time interval of 165–300 s for all experiments, followed by final moisture content, which was reduced to 12.66% (db), and the overall drying rate was improved to 2.73 g/min at the second stage of solar drying during optimum conditions (72°C temperature and 0.672 cm2 load density). The R2 (determination coefficient 0.96–0.94) values, SSE (sum of square error values 0.15–025) values, and MSE (mean square values 1–8.7) were more significant for RSM than ANN. This developed resistance heating apparatus for enhancing fish drying rate and also reduced post‐harvest losses, and it is considered to be a good technology for drying the fish and making a fish powder that can be further used for value‐added product.Practical ApplicationsThe fish comes readily digestible; on the other hand, extremely spoilable accordingly, and fish cannot be gathered for a longer time below atmosphere circumstance, leading to enormous reap as well as commercial disadvantage. The processing of fish may impede against spoiling before reaching the consumers. Dehydration becomes a more frequent also essential approach to post‐processing conservation. Fish dehydration must be promoted by farmers' stage in addition to micro‐industry scale by way of convenience to frozen food locker. Hybrid or combined drying is an attraction for its nutritive values retention, uniformity of drying, reducing the microbial load, and improving product storage properties. Therefore, the present study aimed to develop an ohmic device accompanied by solar drying for preservation of Rohu fish muscles under ambient condition.

Accelerating and Mitigating Postharvest Losses in Nigeria Through an Automated Hydrid Dryer

Africa has the world's biggest population of people without access to electricity, with an estimated 600 million people without access today and 700 million by 2030. Currently, almost two-thirds of Nigeria's population lacks access to reliable energy, and the majority of rural regions are not connected to the national grid. Given these staggering statistics, farmers in Nigeria, especially those in the production section are exposed to postharvest losses annually. Every year, Nigeria loses N3. 5 trillion in post-harvest losses due to a lack of suitable storage facilities and bad road conditions across the country. To mitigate this trend and help accelerate the adoption and acceptability of technology that will solve these postharvest problems, a hybrid dryer is developed. This research involved the development of an automated passive, hybrid dryer developed in the Federal Polytechnic Auchi, Edo State Nigeria with a research grant from TETFUND. A detailed AUTOCAD model for the dryer is developed and validated through experimentation. Energy and environmental analysis of the proposed dryer system were equally evaluated. Two crop produce, yam and tomatoes were used in evaluating the machine. One of the major highlights of the machine is that it is an automated dryer with power sources from both solar and mains supply. The drying process was conducted during the day, and it was compared with open sun drying and oven drying. The highest solar drying temperature obtained under the same condition for both yam and tomatoes were 38 0 C. At the average solar radiation of 2462 W/m 2 and air flow rate of 19.74 kg/s, the thermal efficiency of the hybrid dryer was obtained at 23.74 %. It was observed that the thermal efficiency of the collector was high when compared to similar dryers from literatures. Further analysis to established the commercial scalability of the system is however, recommend. Keywords: Postharvest losses, Hydrid, Automated, Accelerate, Mitigate DOI: 10.7176/ISDE/12-4-02 Publication date: October 31 st 2021

Fabrication of solar hybrid dryer and drying charecteristics of Simarouba glauca

Drying natural with help of direct solar energy is tedious, time-consuming, and risky depending on the climatic condition of the day. The development of this hybrid dryer was done based on the conditions and requirements of the farmer to perform a flexible operation. The farmer with AC/DC supply can use this dryer for powering if not a solar panel with a battery is sufficient. The drying characteristics of a Simarouba gluca was studied in the developed hybrid drier. The drying characteristics are performed in three different temperatures like 40, 45 and 50ºC and took 6h, 5h 30 min and 5h, respectively. Therefore, the solar hybrid dryer is an efficient and reliable dryer for the farmers who requires drying operations on the field for getting longer shelf life and higher-value products.

Enhancement of Convection Heat Transfer in Air Using Ultrasound

The use of ultrasound is a new method to enhance convection drying. However, there is little information in the literature on the improvement of convective heat transfer caused by ultrasound. Therefore, the heat transport during ultrasound-assisted convective heating of small samples in a hybrid dryer was experimentally examined. A small Biot number regime of heat transfer was considered. The results confirmed a great enhancement of heat transfer due to the application of ultrasound. Due to the use of ultrasound, the convective heat exchange coefficient increased from 45% to almost 250%. The enhancement is a linear function of applied ultrasound power. It was shown that the energy absorption of ultrasound existed, but the thermal effect of this absorption was very small.

Experimental investigations on drying kinetics, modeling and quality analysis of small cardamom (Elettaria cardamomum) dried in solar-biomass hybrid dryer

An indirect active solar-biomass hybrid dryer (SBHD) has been developed to study the drying kinetics, mathematical modeling, and quality of dried small cardamom. The experiments were carried out in hybrid (solar with biomass) and biomass mode to assess the performance of the dryer. Freshly harvested small cardamom with a moisture content of 82.4 % on a wet basis (w.b) was dried to 9.1 % (w.b) in hybrid mode. In biomass mode, moisture content was reduced from 83.2 to 9.5 % (w.b). The drying period of 19 h was sufficient in both modes of drying to attain the required final moisture content. The drying rate curve depicted that the small cardamom drying occurred under the falling-rate drying period in both SBHD and Biomass mode. In this study, non-linear regression analysis was performed to determine the drying behavior of small cardamom. Eleven empirical models were used to determine the coefficients of determination (R2) and model constant for drying characteristics of small cardamom. Midilli model recorded the highest R2 value of 0.992 and 0.988, least chi-square of 0.0001 and 0.0005, and RMSE of 0.0002 and 0.0002 for SBHD and Biomass mode, respectively. The average drying efficiency of 28.63% was observed for the drying of small cardamom in the SBHD while 23.98% was obtained from Biomass mode. The colour analysis showed that the retention of green colour was better in SBHD than biomass mode of drying. The biochemical analysis revealed that the small cardamom dried under SBHD retained the maximum percentage of oleoresin (3.30 %) and volatile oil (7.33 %) compared to biomass mode. The microbial quality of dried small cardamom was within the acceptable limit for both SBHD and Biomass mode.

Modification and the Performance Enhancement of Solar Biomass Dryer

Drying is an important agricultural process, particularly for crops, and shriveled products are used all over the world. The performance of drying green chili was also tested in this article, which created an alternate way of drying agricultural products. The goal of this study is to provide a solar biomass hybrid dryer with improved design, construction, and performance testing. During most hours of the trial, the temperature within the solar collector and dryer was sufficiently higher than the ambient temperature, according to the results obtained during the test period. The temperature of the ambient air at the collector intake ranged from 30 to 35 degrees Celsius. The temperature of the air at the collector's outlet ranged from 54 to 64 degrees Celsius, while the temperature of the drying chamber ranged from 51 to 60 degrees Celsius, making it suitable for drying green chili and a variety of other agricultural products. The collector was found to be 46.54 percent efficient. The findings revealed that the alteration of the collector, which produces turbulent air flow and improves chamber wall insulation, affects drying. Based on the results of this study, the created solar biomass hybrid drier is cost-effective for small-scale crop growers in rural areas of developing countries.

Evaluation of ultrasound‐assisted microwave hot air convective drying Chinese hickory—Drying kinetics and product's quality properties

AbstractThe fresh Chinese hickory nuts (Carya cathayensis sarg.) were exposed to airborne ultrasound‐assisted convective drying and microwave‐assisted convective drying, as well as their combination. We investigated the effect of different drying schemes on process kinetics and quality characteristics. The global model of drying kinetics based on coupled ordinary differential equations was used to describe the moisture and material temperature profiles during drying. Application of ultrasound and microwave in convective drying reduced drying time in the range of 14.0–56.6%, but the maximum savings was found for simultaneous exposure of convection, ultrasound, and microwave with the range of 73.6–84.2%. The globally mathematical model was successfully used to simulate the real drying kinetics processes. The quality properties about the content of heat‐sensitive bioactive substances such as phenolic, flavonoid, proanthocyanidin, individual phenolic compounds, as well as antioxidant capacity in convective drying assisted with microwave (100 W) and ultrasound (200 W; CU2M1) are found to be significantly higher than the other groups. The results allow stating ultrasound increase drying efficiency, as expected by reducing the drying time there is less damage to the product.Practical ApplicationIn this work, we designed an experimental scale hybrid dryer that equipped with hot‐air convective drying, ultrasound generator and microwave drying system to dehydrate Chinese hickory nut and the effect of different drying schemes on the drying kinetics and product characteristics were investigated. This is an innovative technology of microwave and ultrasound hybrid drying to produce dried hickory products. Application of ultrasound and microwave in convective drying reduced drying time in the range of 14–56.6%, but the shortest drying time was observed for simultaneous action of convection, ultrasound, and microwave. The results of qualitative analysis showed a product improvement due to ultrasound as compared to convective drying and microwave‐convective drying.

Effect of hybrid drying on the quality attributes of formulated instant banana-milk powders and shakes during storage.

The present research aimed to evaluate the effect of microwave-assisted conventional drying (hybrid drying) on the physico-chemical and functional characteristics of formulated instant banana-milk powders (IBSPs), and organoleptic attributes of banana-milk shakes during storage. The instant powders were prepared from ripe (IBSP1 (control) and IBSP2) and overripe (IBSP3) bananas using hot-air drying (control) and hybrid (microwave assisted hot-air) drying. The water holding capacity, water solubility index, and viscosity of fresh samples, IBSP1, IBSP2, and IBSP3 were 1.97, 1.53 and 0.60g/g dry sample, 69.48, 75.21 and 76.62g/mL and 82.29, 86.29 and 72.55 mPas, respectively. A significant (p < 0.05) increase in moisture content, water activity (aw), acidity, and non-enzymatic browning was observed in all the variants/samples during storage. Among various treatments, the shakes prepared by reconstitution (IBSP: water ratio, 1:4) of IBSP2 formulation rated highest organoleptically (significant, p < 0.05).

Design Fabrication and Experimental Investigation of Solar Hybrid Dryer with Biomass Burner

Design Fabrication and Experimental Investigation of Solar Hybrid Dryer with Biomass Burner