Design Of Dryer Research Articles

THERMAL AND ENVIRONMENTAL ANALYSIS OF DEVELOPED SOLAR DRYER ENHANCED BY PV MODULE AND HEAT STORAGE UNIT FOR DRYING CANTALOUPE

A developed design of solar dryer with water storage heat unit was conducted to can operate the drying process continually at day and night using the stored heat. It is used to avoid the problems of sun drying as dust, pests, poor quality for dried products and long time for process. This design could provide also further improvement for the performance of the pervious same type of solar dryers. It has the following advantages such as: movable to can be directed according to sun’s angle, besides it could connect to photovoltaic modules and batteries to can store energy and operate dc fan and dc water pump in the drying system.It is found suitable for drying agricultural products as Cantaloupe. The average of daily PV efficiency during daytime was 9.1%, collector efficiency 54.38% and dryer efficiency was 23.32%. The energy payback time was 1.21 years and CO2 mitigation over the lifetime was 36.48 tons. The time of the dried cantaloupe from this solar dryer is shorter than the dried products in the open sun. This system is useful for farmers in arid areas, and non-electrical zones.

Design and Development of Solar Crop Dryer Integrated with Oil Bath

Design and Development of Solar Crop Dryer Integrated with Oil Bath

Simulation of Grain Quantity, Fan and Solar Collector Sizes for an Experimental Forced Convection Grain Dryer

Forced convection grain dryers are more efficient and achieve greater drying rates than natural convection dryers. However, it is necessary to dry an appropriate grain layer thickness in such a dryer for the drying process to occur efficiently and at an appropriate rate. A well sized fan is also essential if the drying process is to proceed effectively. An oversize fan will be unnecessarily expensive to buy and operate due to high fan power, while an undersized one will not be able to supply adequate air flow. The solar collector must be properly sized if it is to heat the air to the required temperature. All these factors need to be addressed during the design of a grain dryer. Lengthy and expensive trial and error processes can be avoided by applying simulation in the design process. This study developed an experimental grain dryer, addressing the above mentioned issues in the process. Simulation of air flow within an initial model of the dryer was done and the results used to size the fan and drying cabinet. The solar collector was also sized. The experimental grain dryer developed consisted of a drying cabinet of dimensions 0.5 m x 0.5 m x 1.0 m and was equipped with a 0.039 kW centrifugal fan. The solar collector area was of dimensions 1.2 m x 1.8 m.

Proposal for a solar fruit dryer design with organoleptic properties recovery system

With the passing of time, the demand for dehydrated organic products has increased, ranging from vegetables to fruits, however in the latter efforts to achieve a quality product have led to the use of industrialized systems which depend on the use of fossil fuels or systems that use electric current which greatly increase production costs. At present, various solar dryer models have emerged, having achieved an optimal performance in what corresponds to the processing of vegetables, however in the processes of dehydration of fruits the results have not been satisfactory, due to the loss of its color, taste, aroma and texture (organoleptic properties). Faced with this problem, an innovative design of solar fruit dehydrator is proposed, which has two objectives, the first related to recovering the organoleptic properties through a system of condenzation, cyclic dehydration and the synchronization of the calorific balance, and the second one focused on the improvement of thermal efficiency, through the use of some heat piles and a trombe wall. The heat transfer fluid was improved, adding silver nanoparticles (silver nanospheres), which were synthesized using the green chemistry method; the efficiency of the heat transfer fluid was increased by 30%.

Design of a solar dryer for small-farm level use and studying fig quality [pdf

Design of a solar dryer for small-farm level use and studying fig quality [pdf

Design of a solar dryer for small-farm level use and studying fig quality.

In the mountain areas of south-east Morocco, farmers are engaged in the solar drying of figs using traditional processes. However, this practice leads to losses in quality. This study aims to improve this drying method by designing and studying the performance of a natural convection solar dryer and the quality of fresh and dried figs. An indirect solar dryer was designed and its performance was studied. The TSS content, moisture, firmness and morphological parameters of fresh and dried figs were determinated. The average difference (inside/outside) in the temperature of the dryer is +8.3°C. This will allow  a decrease in the mean drying duration from 10 days (traditional drying) to 4 days. This duration is signifi- cantly correlated with air humidity (R2 = 0.84) and temperature (R2 = 0.63). The relationship between the degree of dehydration (%) and time follows a polynomial model with a determination coefficient of 0.98. Fig-drying yield is 38.7% and dried figs have a high (TSS) content with 63.7% and a firmness of 6.03 kg/cm2. The water content was approximately 25.6%. The solar dryer with natural convection designed in this study can be an alternative to traditional drying practised by small farmers in the mountainous regions of Errachidia.

Computational fluid dynamics simulation and energy analysis of domestic direct-type multi-shelf solar dryer

Solar food drying is a well-established food-conserving process in India. Various researchers had developed solar dryer models which were usually validated using experimental observations and numerical simulation processes that are time-consuming and money-consuming. Computational fluid dynamics (CFD) simulation software facilitates the simulation of the models and gives same results in a comparatively small frame of time. This research paper is focused on CFD simulation, validation of design, energy analysis and numerical computation for domestic direct-type solar dryer for which experimental observations were performed at Ludhiana in November 2006. The design and simulation of the domestic direct-type multi-shelf dryer at no load condition are performed using ANSYS Fluent 14.0 software. The temperature of the air inside the dryer is found to be 326 K, which validates the design and purpose of the domestic direct-type multi-shelf dryer. The embodied energy of the constituents used in the construction of dryer is obtained as 339.015 kWh, and the energy payback time and carbon credit are found to be 7.57 years and INR 2055, respectively. The convective heat transfer coefficient for the dryer varies from 2.4 to 2.8 W m−2 °C−1. Coefficient of determination is estimated to be 0.98 under no load condition which shows the fare agreement between predicted and experimental value.

CFD modelling of almond drying in a tray dryer

Drying is important in many food processing applications, and particularly so in the dry fruits industry. This work is focused on developing computational models for simulating the drying of almonds in a tray dryer. It is important to quantitatively understand heat and mass transfer within and around a single almond particle as well as the particle‐particle interactions and their implications for dryer design. In this work, we have developed a systematic CFD modelling framework for modelling almond drying in a tray dryer. A single tray filled with almonds (∼2 kg) were dried at three set temperatures viz., 55, 65, and 75 °C. Air relative humidity at the inlet and outlet locations, and the weight of almonds were measured during drying for each experiment. An additional set of experiments were conducted in which almonds were filled only in the half section of the tray, keeping the other half empty. The same amount of almonds were used, to have multiple layers of almonds in the tray, and the set temperature for the experiment was 75 °C. Flow, heat, and mass transfer in the tray dryer were simulated using commercial CFD software Ansys Fluent. The validated computational model was used to simulate various cases including larger and more trays. The developed approach and models will be useful to select the appropriate dryer configuration and optimize its design. The developed models will also be useful to identify suitable operation conditions for the drying of almonds as well as other food products.

Design, Construction, and Analysis of a Passive Indirect Solar Dryer With Chimney

The growing demand for alternative technologies, of clean and sustainable nature, has fostered the development and improvement of equipment that uses solar energy for the dehydration of seeds and fruits. Such equipment has been used worldwide for hundreds of years; however, it remains uncommon in Serra Gaúcha, a region of great production of grapes and apples for natura consumption in the state of Rio Grande do Sul—Brazil. In order to investigate the economic and technical viability of solar dryers in the Serra Gaúcha, this work has as target the design, simulation, construction, and experimental analysis of an Indirect Passive Solar Dryer with Chimney. The prototype, divided into three parts: solar collector, dehydration chamber, and chimney, was built prioritizing materials of low cost, but that did not compromise its performance. The device was submitted to experiments, which observed: solar collector behavior very close to the simulated one; obtaining a coefficient of performance of 87% in the equipment; satisfactory rise in temperature at the collector outlet comparing to its inlet; and dehydration of apples with a reduction of 89% in mass with 32.78 MJ of energy delivered to the system. The prototype payback period was estimated in two years.

Numerical and experimental characterization of the hydrodynamics and drying kinetics of a barbotine slurry spray

Spray drying is a basic unit operation in several process industries such as food, pharmaceutical, ceramic, and others. In this work, a Eulerian-Lagrangian three-phase simulation is presented to study the drying process of barbotine slurry droplets for the production of ceramic tiles. To this end, the simulated velocity field produced by a spray nozzle located at the Institute of Ceramic Technology in Castelló (Spain) is benchmarked against measurements obtained by means of laser Doppler anemometry in order to validate the numerical model. Also, the droplet size distribution generated by the nozzle is obtained at operating conditions by means of laser diffraction and the data obtained are compared qualitatively to those found in the literature. The characteristic Rosin-Rammler droplet size from the distribution is introduced thereafter in the three-phase simulation to analyse the drying kinetics of individual droplets. The model predicts the theoretical linear evolution of the square diameter (D2-law), and the temperature and mass exchange with the environment. The proposed model is intended to support the design and optimization of industrial spray dryers.

Design and performance test of a batch system rotary vacuum dryer with a 50-liter capacity to dry basidiomycota classmushrooms

The community’s most common drying process is drying under the sun for at least two to three days, depending on the weather. Research aimed to resolve the weather dependency of this drying process by drying mushroom in the oven at 40-degrees Celsius and drying process using tray dryer under a vacuum condition and obtained optimum cap and stalk drying results at 60-degrees Celsius under 20 kPa vacuum pressure. However, the shelf drying process resulted in differences in the moisture content. To resolve this problem, a dryer that can operate at a low temperature by vacuuming. The objectives of this research were to design and test the performance of a rotary vacuum dryer with a batch system for drying mushrooms from the Basidiomycota class. The results of functional test and performance tests using 1000 g of mushrooms were obtained: vacuum pressure 16 cmHg, temperature of drying chamber (60 ± 1) oC, drying time 16 hours, rpm drying cylinder 6-8 rpm, and final mushroom moisture content: 13% wb.

Design of Automatic Dryer for Smartphone Controlled Seaweed Production

In the majority of the seaweed drying process is still using the traditional method by drying it in the sun on a waring. Based on these problems, it is necessary to have a combination of energy in the drying process of seaweed so that drying of the seaweed can be more efficient and save time. The results of designing and testing the tool as a whole can run and the sensor can detect the value of temperature and humidity. The android application can run and activate the dryer system and turn off automatically when it reaches a humidity below <28%. Conclusion in testing the accuracy of the DHT22 sensor with a hygrometer measuring instrument, the average temperature value during the day is 30,365 ° C hotter than the nighttime temperature of 27.75 ° C. The average value of humidity at night is 66.35% cooler than the humidity at daytime of 60.45%. So it can be concluded that the temperature during the day is hotter than the temperature at night. And the humidity at night is cooler than during the day. For the delay is higher at 18:00 at night using the Indosat operator, which is 1.0545ms than the Axis operator, which is 1.0185ms. Meanwhile, throughput is greater at 12:00 noon when using the Axis operator, which is 7,497 Kbit / Sec than the Indosat operator, which is 1.7245Kbit / Sec.

Intensification of the Plant Products Drying Process by Improving Solar Dryer Design

The article presents the rationale for production of dried fruits and vegetables using a solar drying unit. To intensify the drying process, convection of drying agent flow in the proposed drying chamber is studied using Navier–Stokes equations. Numerical methods are used for solving equations describing the process of convective heat transfer. As a result, graphical interpretations of isolines of drying agent flow are obtained and location of passive zones in the dryer chamber are identified. Uniformity of the temperature zones in the chamber is ensured by supplying additional drying agent into the passive zones. Temperature values at various levels of the drying chamber are experimentally obtained. Results for drying cut-up mass of vegetables and fruits are presented.

Experimental Study of Drying Parameters of Ginger at Different Temperature and Moisture Content

Drying provides extended shelf life to agricultural crops in general and thus proper design of dryer will assist in drying them to acceptable level and quality. To design adequate dryer, necessary drying parameters of drying materials is necessary. This work involves experimental determination of effective drying parameters such as moisture content, moisture diffusion coefficient, density (true and bulk), specific heat, thermal conductivity and thermal diffusivity of ginger and to analyze these parameters in relation to each other. Fresh ginger rhizomes were washed to remove soil from the field, peeled and washed again in clean water and sliced into thin pieces. The sliced ginger was heat-treated by adding 200ml of clean water and steaming for 5–8 minutes in an aluminum pot, to a temperature of 85–90 oC, and a light brown colour. Microwave oven, calorimeter, desiccators, thermometers, triple beams balance, micrometer screw gauge were used to determine the drying parameters of ginger. Effect of temperature and moisture content on some thermal properties was determined. The results of the experiments shows that average initial moisture content for the ginger samples was 72.31%, the true and bulk densities of the sample increased linearly from 0.5809 to 0.6338g/cm3 and 0.7405 to 0.7972 g/cm3 respectively between the temperatures of 45 – 75 °C. The specific heat capacity of ginger varied from a minimum of 1.568kJkg-1K-1 to a maximum of 2.026kJ kg-1K-1, with temperature in the range of 45oC to 75oC and moisture content in the range of 24.43 to 46.19 % (d.b). The thermal conductivity of ginger samples varied from 0.316×10-3 to 9.763×10-4 Jm-1S-1 oC; as the moisture content and temperature increased. Thermal diffusivity of the ginger increased linearly from 3.149×10-8 to 4.438×10-8 m2s-1 for ginger with increase in moisture content and temperature. Conclusively, the experimental study analysis show that specific heat of ginger varies with temperature. Also, there is variation in length, breath and thickness of ginger when subjected to temperature. Therefore, it can be said that ginger do shrinks when it is subjected to heat.

Experimental Study of Drying Parameters of Ginger at Different Temperature and Moisture Content

Drying provides extended shelf life to agricultural crops in general and thus proper design of dryer will assist in drying them to acceptable level and quality. To design adequate dryer, necessary drying parameters of drying materials is necessary. This work involves experimental determination of effective drying parameters such as moisture content, moisture diffusion coefficient, density (true and bulk), specific heat, thermal conductivity and thermal diffusivity of ginger and to analyze these parameters in relation to each other. Fresh ginger rhizomes were washed to remove soil from the field, peeled and washed again in clean water and sliced into thin pieces. The sliced ginger was heat-treated by adding 200ml of clean water and steaming for 5–8 minutes in an aluminum pot, to a temperature of 85–90 oC, and a light brown colour. Microwave oven, calorimeter, desiccators, thermometers, triple beams balance, micrometer screw gauge were used to determine the drying parameters of ginger. Effect of temperature and moisture content on some thermal properties was determined. The results of the experiments shows that average initial moisture content for the ginger samples was 72.31%, the true and bulk densities of the sample increased linearly from 0.5809 to 0.6338g/cm3 and 0.7405 to 0.7972 g/cm3 respectively between the temperatures of 45 – 75 °C. The specific heat capacity of ginger varied from a minimum of 1.568kJkg-1K-1 to a maximum of 2.026kJ kg-1K-1, with temperature in the range of 45oC to 75oC and moisture content in the range of 24.43 to 46.19 % (d.b). The thermal conductivity of ginger samples varied from 0.316×10-3 to 9.763×10-4 Jm-1S-1 oC; as the moisture content and temperature increased. Thermal diffusivity of the ginger increased linearly from 3.149×10-8 to 4.438×10-8 m2s-1 for ginger with increase in moisture content and temperature. Conclusively, the experimental study analysis show that specific heat of ginger varies with temperature. Also, there is variation in length, breath and thickness of ginger when subjected to temperature. Therefore, it can be said that ginger do shrinks when it is subjected to heat.

Kinetic changes of antioxidant parameters, ascorbic acid loss, and hydroxymethyl furfural formation during apple chips production

In this study, the kinetic change of the antioxidant properties were determined during apple chips production using three different cultivars. Using a rotary forced-air dryer, apple slices were dried at three different temperatures (65, 70, and 75°C). The ascorbic acid content, total phenolic content (TPC), total flavonoid content (TFC), Oxygen Radical Absorbance Capacity (ORAC) and Trolox Equivalent Antioxidant Capacity (TEAC), and hydroxymethylfurfural content were analyzed. Phenolic compounds of apple chips were also identified by chromatographic separation. Thermal degradation of ascorbic acid was fitted to first-order reaction kinetics. TPC, TFC, ORAC, and TEAC values, and hydroxymethylfurfural content increased with drying time and temperature where the data were fitted to first-order and zero-order reaction kinetics. Reaction rate constants were influenced by temperature, based on the Arrhenius model. The primary phenolic compounds of apple chips were gallic acid, chlorogenic acid, catechin, caffeic acid, epicatechin, and rutin. Practical applications Dietary antioxidants with health benefits have increased attention on fruit and vegetable products. The processing of fruits and vegetables affects their antioxidant properties as well as their quality. Apple chips are dehydrated, ready to eat, fruit-based snacks with desirable sensory properties. The results of this article will contribute to an understanding of the thermal kinetics of antioxidant properties and phenolic content during apple chip production. The kinetic results may be useful for the design of dryers and optimization of the drying conditions.

Design and Thermal Analysis of an Air Source Heat Pump Dryer for Food Drying

In this study, an experimental heat pump dryer was designed. The specific moisture extraction rate and moisture extraction rate were used as performance indicators to explore the influence of environmental factors and the style of the hot air cycle on heat pump drying. The average temperature and humidity in Nanjing’s summer, winter, and throughout the whole year were taken as the experimental ambient temperature and humidity. Garlic slices 3 mm thick, with an initial moisture content of 66.714% w.b., were dried until the end moisture content was 10% w.b. Experimental results and thermal analysis showed that the open and semi-open heat pump dryers were greatly affected by ambient temperature and humidity. The closed heat pump drying system was greatly affected by the bypass air rate.

Drying Kinetics, Quality and Economic Analysis of a Domestic Solar Dryer for Agricultural Products

In this study, design, development and testing of an indirect solar dryer for rural domestic use is reported. Qualitative and quantitative methods have been deployed to derive the appropriate design for the solar dryer, based on the local expectation and drying requirements. Local materials and resources have been used to construct the dryer, making it portable, affordable, and accessible, thus, promoting a do-it-yourself (‘DIY’) model. Bitter gourd (Momordica charantia), okra (Abelmoschus esculentus), raw mango (Mangifera indica) and hirda (Terminalia chebula) have been tested for the performance evaluation, as these items are typically openly sun dried for using them in later seasons or as sellable products. Results show that moisture content of the food products is brought down to acceptable limits, while retaining the color using this solar dryer. The functioning of the fabricated solar dryer has been demonstrated to the local people of the selected villages to encourage them to use the dryer and to receive their feedback.

Design and Analysis of Solar Paddy Dryer by Natural Convection

Design and Analysis of Solar Paddy Dryer by Natural Convection

Energy Effective and Green Drying Technologies with Industrial Applications

Heat pump drying is a green technology with zero global warming potential and zero ozone depletion potential when operating with natural fluids. A well designed heat pump dryer can be several times more energy efficient and less costly than conventional dryers. This dryer beneficially contributes to a sustainable society while providing superior products at competitive cost. It is an advanced engineered drying technology ready for implementation by modern industries wishing a return of investment while contributing to a sustainable society. This paper covers the advances in heat pump and superheated steam drying technologies. These drying processes are in the category of green technologies because they are highly effective and advantageous for the environment and climate change. Descriptions and layouts are given covering design of heat pump and steam dryers. Details are provided in their beneficial operation in single and multistage with vapor compression and drying chambers placed in series. The drying modes covered are atmospheric sublimation and evaporation for improved capacity and superior characteristics of dried materials. The future trend is heat pump drying with natural fluids and superheated steam drying complying with proper industrial practice and with regulations reducing damage to sea, soil and water as well as zeroing contribution to global warming and to climate change. These technologies have been built and extensive R&D has been done at Norwegian University of Science and Technology in Trondheim. The technology has progressed to pilot scale and industrial applications indicating a small but real contribution to a better society today and tomorrow. Lastly, this is an advanced engineered drying technology ready for implementation by modern industries wishing a return of investment while preserving the environment.