scholarly journals DEVELOPEMENT OF A VEGETABLE DRYER

2021 ◽  
Vol 5 (11) ◽  
Author(s):  
Iyidiobu Blessing Ngozi ◽  
Awulu John Okanagba
Keyword(s):  
Load Condition ◽  
Heating Element ◽  
Moisture Loss ◽  
Effect Of Temperature ◽  
Drying Time ◽  
Constant Weight ◽  
Final Weight ◽  
Drying Efficiency ◽  
Drying Chamber ◽  
Equal Spacing

A Vegetable dryer of dimension 1.50 m (high) x 0.72 m (wide) x 0.59 m (breadth) was developed using mild steel iron and its performance evaluated. The device consists of a drying chamber with three drying trays; fans incorporated for heat circulation, a heating element of 2000 W, four swivel caster rollers for ease of mobility, a thermostat to regulate the heat generated in the drying chamber and a thermo-gauge inserted to monitor the temperature in the drying chamber. The vegetable dryer has a drying capacity of 34 kg and three compartments of 0.25 m equal spacing. The dryer is partitioned at 0.75 m, 0.1 m and 1.25 m from the heating element, with the first (bottom) tray, the second tray (middle) and the third (upper) respectively. The device performance was evaluated under no-load and load conditions at 50 °C, 60 °C, and 80 °C temperatures with three replications. Results obtained under no-load indicated that temperatures very close to the preset values (by the thermostat) were attained within 5 mins. Under load condition, the dryer was evaluated by drying 16.74 kg of tomatoe slices at 50 °C, 60 °C, and 80 °C. Weight reduction (degree of moisture loss) from the slices was recorded at intervals of 1hour until a nearly constant weight was obtained. The result revealed that the dryer has a mean drying efficiency of 80.6 % and drying rate of 0.02 kg/hr. At a drying time of 10 hours and temperatures of 50 °C and 60 °C, 16.74 kg of tomatoes were reduced to 1.23 kg and 1.13 kg representing 93 % (wb) of removed moisture, while a final weight of 1.08 kg dry matter was obtained from the same starting weight of wet tomatoes at 80 °C representing 94 % (wb) of moisture loss for the same drying time. ANOVA studies indicated that the effect of temperature and tray level on drying of vegetable (tomatoes) were highly significance at (P< 5 %). The dried vegetable (tomatoes) is free from dust and any form of contamination making it healthy for consumption.

Effect of temperature and state of hydration on rate of imbibition in soft seeds of yellow serradella

2004 ◽  
Vol 55 (1) ◽  
pp. 39 ◽  
Author(s):  
G. B. Taylor
Keyword(s):  
Sulfuric Acid ◽  
Free Water ◽  
Negligible Effect ◽  
Moisture Loss ◽  
Effect Of Temperature ◽  
Moisture Uptake ◽  
Constant Weight ◽  
Moist Atmosphere ◽  
Ornithopus Compressus ◽  
Hydration And Dehydration

Seeds were removed by hand from pods of yellow serradella (Ornithopus compressus L.) cvv. Santorini and Charano and accession GRC5045-2-2 that were taken from the field on 26 March after burial treatment to initiate seed softening. Times taken for soft seeds to imbibe were determined at constant temperatures of 8�, 20�, and 30�C. Rates of moisture uptake and loss were measured in seeds held in a moist (76% RH) or dry (over sulfuric acid) atmosphere and the effects of hydration and dehydration on subsequent imbibition times determined at 20�C.Temperature had negligible effect on imbibition times in GRC5045-2-2, in which nearly all soft seeds imbibed within 24 h of wetting. Imbibition times in individual seeds of both Charano and Santorini varied from a few days to more than 200 days and were markedly reduced by increasing temperatures. Times taken to approach constant weight in the moist atmosphere were approximately 75, 165, and 430 days in GRC5045-2-2, Charano, and Santorini, respectively. By contrast the rate of moisture loss in the dry atmosphere was similar in all lines. Imbibition times in GRC5045-2-2 were little affected by state of hydration, but in both Santorini and Charano, imbibition was delayed by dehydration and accelerated by hydration.It is proposed that slow imbibition is attributable to the presence of a minute opening in the seed at an as yet unidentified site (possibly the micropyle or hilum) that restricts moisture uptake until a threshold is reached when seeds in contact with water imbibe rapidly. It is hypothesised that the moisture threshold coincides with the build up of sufficient moisture in tissues associated with the underside of the lens, to cause its rupture, thereby allowing rapid uptake of free water.

Using Microwave Sensing to Investigate Kernel Moisture Content at the Front and Back of Semitrailers during Peanut Drying

2017 ◽  
Vol 33 (5) ◽  
pp. 611-617 ◽  
Author(s):  
Micah A. Lewis ◽  
Samir Trabelsi ◽  
Stuart O. Nelson
Keyword(s):  
Moisture Content ◽  
Real Time ◽  
The Other ◽  
Moisture Loss ◽  
Monitoring Systems ◽  
Moisture Profile ◽  
Drying Time ◽  
Moisture Sensor ◽  
M 10 ◽  
Drying Efficiency

Abstract. Several factors influence the effectiveness of peanut drying. Such factors include temperature and relative humidity of the air used for aeration, air velocity through the peanuts, and the presence of foreign material that could obstruct air flow. All of these factors can vary at any location in a semitrailer holding 20 to 25 tons of peanuts being dried. Therefore, it is highly unlikely that a volume of peanuts &gt;71 m3 (2500 ft3) will dry uniformly. During the drying process, an operator removes samples of peanuts for kernel moisture content testing every 3 to 4 h to validate the estimated drying time determined by peanut-drying models used in the peanut industry. However, if samples are only taken from one location, it is likely that other locations differ in kernel moisture content. To investigate kernel moisture content near the front and back of the semitrailer, two peanut drying monitoring systems, each equipped with a microwave moisture sensor, were deployed at a peanut buying point in central Georgia during the 2014 and 2015 peanut harvest seasons. Each system monitored in-shell kernel moisture content and drying parameters in real-time, every 12 s. In-shell kernel moisture content was determined with a standard error of prediction of 0.55% moisture when compared to the reference oven-drying moisture tests. The two monitoring systems were placed in 13.7-m (45-ft) drying semitrailers, one 3 m (10 ft) from the front and the other 3 m (10 ft) from the back. Data from the measurements were time-stamped and reconciled accordingly, and they were analyzed to compare the moisture loss in real-time at both locations in the trailer. The 12-s resolution provided a continuous moisture profile to analyze rather than the discrete profile currently provided by sampling every few hours. Results show that moisture loss, and therefore resulting kernel moisture content, can vary from one end of the trailer to the other during peanut drying. Therefore, systems that monitor peanut drying at various locations throughout the semitrailer would improve peanut drying efficiency. Keywords: Dielectric properties, In-shell kernel moisture content, Microwave sensing, Peanut drying, Real-time monitoring, Sensors.

scholarly journals Experimental study of infrared – assisted heat pump drying of lime slices

2021 ◽  
pp. 1-10
Author(s):  
Nguyen Minh Ha ◽  
Ha Anh Tung
Keyword(s):  
Heat Pump ◽  
Radiation Intensity ◽  
Infrared Radiation ◽  
Effect Of Temperature ◽  
Air Velocity ◽  
Drying Time ◽  
Infrared Radiator ◽  
Chamber Temperature ◽  
Heat Pump Drying ◽  
Drying Chamber

This paper describes the experimental drying of lime slices using an infrared –assisted heat pump dryer. Experiments were carried out on a heat pump dryer model with a capacity of 1 HP integrated with 2000 W infrared radiator whose power can be varied from 0% to 100%. Experiments have been performed with the drying capacity of 1,2 kg/batch and the drying air velocity of 1,2 m/s. Three evaluations were considered: the effect of material thickness on drying time; the effect of temperature in drying chamber and intensity of infrared radiation on drying time, power consumption and product quality. The results showed that the drying process having 3 mm thickness of lime slices, the temperature in the drying chamber of 42,5¸45oC and the radiation intensity of 110¸300W/m2 was the good effective drying range. In addition, the study formulated a linear regression equation for the drying time relationship with drying chamber temperature and infrared radiation intensity. This mathematical model can be used as reference to determine actual drying time as well as a helpful tool for designing infrared - heat pump dryer.

scholarly journals Drying Kinetics and Mathematical Modeling of Bottle Gourd

2019 ◽  
pp. 1-8
Author(s):  
Murlidhar Ingle ◽  
A. R. Tapre ◽  
Radhika Nawkar
Keyword(s):  
Bottle Gourd ◽  
Moisture Loss ◽  
Drying Process ◽  
Drying Time ◽  
Constant Weight ◽  
Drying Behavior ◽  
Drying Rates ◽  
Drying Curves ◽  
Time Required ◽  
Agricultural Materials

Aims: The aim of this study was to evaluate the drying behavior of bottle gourd slices using tray dryer. Study Design: The bottle gourd slices were dried in a tray dryer at 50, 55, 60, 65 and 70 + 1°C. The moisture loss was determined by gravimetry. Readings were taken at 30 minutes till constant weight was observed. Place and Duration of Study: Experiments were done in Department of Food Science and Technology, MPKV Rahuri and completed within 12 months. Methodology: The drying curves were fitted into four different drying models (Henderson, Logarithm, Page and Modified Page) widely accepted for modeling of agricultural materials drying. The best model describing the drying process was selected based on the low RMSE, low χ2, and high R2. Results: The drying time at 50, 55, 60, 65 and 70ºC drying temperature were 630, 570, 450, 420 and 360 min respectively for bottle gourd slices. By comparing time required at 50ºC and 60ºC temperature and 60ºC and 70ºC there were 28.57% and 20.00% reduction in drying time respectively. At the beginning of a drying process, the moisture content of fresh bottle gourd was 92.09% (w.b.) which is reduced to 7.08% (wb). The drying rate decreased with increase in drying time. The drying rates were as high as 0.89 at 55ºC and as low as 0.1 at almost all the temperatures. The R2 values ranged from 0.788 to 0.954, the adjusted R2 values also ranged from from 0.777 to 0.951, χ2 values between 0.029 and 0.681, and RMSE values between 0.0533 and 0.3742. Conclusion: Henderson and Pabis model was found to be a better model for describing the drying characteristics of bottle gourd at all temperatures. The product quality was found well at all the temperature.

scholarly journals Development of Black Pepper Rotary Drum Dryer System

2020 ◽  
Vol 12 (7) ◽  
Author(s):  
Ana Sakura Zainal Abidin ◽  
◽  
Mohamad Zulhatta Kifli ◽  
Annisa Jamali ◽  
Rasli Muslimen ◽  
...  
Keyword(s):  
Moisture Content ◽  
Heating Temperature ◽  
Chemical Properties ◽  
Practical Method ◽  
Black Pepper ◽  
Drying Time ◽  
Final Weight ◽  
Rotary Drum ◽  
Current Weight

Rotary drum dryer has been identified as hygienic and practical method to dry black pepper. The quality of black pepper is defined based on the chemical properties and moisture content. This research aims to develop a control system for black pepper rotary drum dryer. The dried pepper should meet the specific 12% moisture content while the heating temperature must be kept below 550C. The requirement of 12% moisture content is equivalent to 30% of the remaining weight of the pepper (final weight). The developed system uses Arduino Mega 2560 REV board as a microcontroller. A type K thermocouple with MAX6675 thermocouple amplifier and S-type load cells (TAS501) with HX711 load cell amplifier are used as input sensor to microcontroller. The system keeps measuring the current weight until it hit the targeted final weight. Two set of experiments that are using 500 g and 1500 g of pre-treated pepper were conducted to verify the system. As a result, the dryer was successful to work within the desired temperature and it stop operating just after the samples reached 12% of the moisture content. The finding has proven a shorten of drying time from 4 to 7 days when using the traditional method to the current 3 – 5 hours only when using the developed system. Hence, this is an improved method achieved to a quick drying of the black pepper.

scholarly journals Karakteristik Pengeringan Kulit Melinjo (Gnetum gnemon L) dengan Alat Pengering Tipe Tray Dryer untuk Pembuatan Keripik Kulit Melinjo

2020 ◽  
Vol 4 (4) ◽  
pp. 512-521
Author(s):  
Durry Munawar ◽  
Dewi Sri Jayanti ◽  
Raida Agustina
Keyword(s):  
Weight Loss ◽  
Food Product ◽  
Food Products ◽  
Drying Rate ◽  
Processed Food ◽  
Airflow Velocity ◽  
Drying Time ◽  
The Public ◽  
Gnetum Gnemon ◽  
Drying Chamber

Abstrak. Pemanfaatan kulit melinjo sebagai produk makanan olahan belum banyak diketahui oleh masyarakat. Biasanya kulit melinjo tidak dimanfaatkan lagi dan dibuang begitu saja padahal kulit melinjo dapat diolah kembali menjadi beberapa produk makanan seperti keripik kulit melinjo, manisan, teh, pewarna makanan. Penelitian ini bertujuan untuk mengetahui karakteristik pengeringan dan mutu dalam pembuatan keripik kulit melinjo dengan alat pengering tipe tray dryer pada suhu 35oC dan 45oC. Masing-masing suhu tersebut diulang sebanyak dua kali. Hasil penelitian menunjukkan bahwa pada suhu 35oC kelembaban udara yang diperoleh adalah 70,50% dengan lama pengeringan 390 menit (6,5 jam) dan rata-rata laju pengeringan sebesar 1,08 bk/menit, sedangkan pada suhu 45oC kelembaban udara yang diperoleh adalah 60,72% dengan lama pengeringan 300 menit (5 jam) dan rata-rata laju pengeringan sebesar 1,32 bk/menit. Kecepatan aliran udara ruang pengering pada suhu 35oC dan 45oC adalah konstan (2,4 m/s). Rata-rata kadar air awal kulit melinjo adalah 82,26% sedangkan kadar air akhir adalah 21,36%. Susut bobot pada suhu 35oC adalah 77,56% dan pada suhu 45oC adalah 77,32%. Hasil uji organoleptik terbaik adalah pada suhu 35oC dengan skor 4,28 untuk warna, 4,50 untuk aroma, 4,53 untuk rasa dan 4,40 untuk tekstur.Characteristic Melinjo Peel (Gnetum gnemon L) Drying with Tray Dryer for Making Melinjo Peel ChipsAbstract. The use of melinjo peel as a processed food product is not widely known in the public. Melinjo peel is usually no longer used and thrown away even though the peel could be reprocessed into several food products such as melinjo peel chips, confectionery, tea, and food coloring. This research aimed to determine the characteristics of drying and quality in the making of melinjo peel chips with tray dryer at 35oC and 45oC. Each temperature is repeated twice. The results showed that at a temperature of 35oC, the humidity was 70.50% with a drying time was 390 minutes (6.5 hours) and the average of drying rate was 1.08 dw/minute, meanwhile at 45oC the humidity was 60.72% with a drying time was 300 minutes (5 hours) and an average of drying rate was 1.32 dw/minute. The airflow velocity of the drying chamber at 35oC and 45oC was constant (2.4m/s). The average of initial moisture of melinjo peel was 82.26% and final moisture was 21.36%. The weight loss at 35oC was 77.56% and at 45oC was 77.32%. The best results of organoleptic test was at temperature 35oC with score 4.28 for color, 4.50 for flavor, 4.53 for taste and 4.40 for texture.

scholarly journals Drying Modelling, Moisture Diffusivity and Sensory quality of Thin Layer dried Beef

2018 ◽  
Vol 6 (2) ◽  
pp. 552-565 ◽  
Author(s):  
Eunice Akello Mewa ◽  
Michael Wandayi Okoth ◽  
Catherine Nkirote Kunyanga ◽  
Musa Njue Rugiri
Keyword(s):  
Thin Layer ◽  
Sensory Quality ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Effect Of Temperature ◽  
Slice Thickness ◽  
Drying Time ◽  
Drying Characteristics ◽  
Thin Layer Drying

The objective of the present study was to determine the drying kinetics, moisture diffusivity and sensory quality of convective air dried beef. The effect of temperature of drying (30-60°C) and thickness of samples (2.5-10 mm) on the convective thin-layer drying kinetics of beefdried in a cabinet dryer was evaluated. Five semi-theoretical models were fit to the drying experimentaldata with the aim of predicting drying characteristics of beef and fitting quality of models determined using the standard error of estimate (SEE)and coefficient of determination (R2). Determination ofeffective moisture diffusivity (Deff) from the experimental drying datawas done and sensory quality of the optimized dried cooked and uncookedbeef samplesevaluated. Drying time and rate of drying increased with an increasing temperature but decreased with increased slice thickness. However, there was overlapping of drying curves at 40-50°C. Among the selected models, Page model gave the best prediction of beef drying characteristics. Effective moisture diffusivity (Deff) ranged between 4.2337 x 10-11 and 5.5899 x 10-10 m2/s, increasing with an increase in air temperature and beef slice thickness.Of all the sensory parameters evaluated, texture was the only attribute that gave significantly different (P > 0.05) scores between the cooked and uncooked dried beef samples.

An efficient termination control strategy of air-vented dryer for fabric drying

2018 ◽  
Vol 30 (3) ◽  
pp. 412-427 ◽  
Author(s):  
Yuhui Wei ◽  
Zhaowei Su ◽  
Huashan Lu ◽  
Xue Mei Ding
Keyword(s):  
Energy Consumption ◽  
Control Strategy ◽  
Low Cost ◽  
Drying Time ◽  
Content Type ◽  
Exhaust Duct ◽  
Microscopic Damage ◽  
Novel Strategy ◽  
Drying Efficiency ◽  
Practical Implications

Purpose The purpose of this paper is to develop an efficient termination control strategy of air-vented dryer in term of energy saving, improving smoothness and reducing microscopic damage of fiber. Design/methodology/approach A simple, low cost termination control strategy is developed by testing the instantaneous humidity of exhaust air and then deducing the drying degree of fabric in process. The practicability evaluation of this novel strategy was investigated by using both experimental and mathematical approaches. The effect of termination control strategy on drying efficiency and fabric apparent properties were also discussed. Findings Termination control strategy significantly affects drying time, energy consumption, smoothness and microscopic of fiber. Specially, a novel termination control strategy that the combination of equilibrium moisture content of fabric in ambient environment and relative humidity of exhaust air in exhaust duct is workable and can save 25.2 percent of energy consumption, 26.7 percent of the drying time and improve 0.7 grade of the appearance smoothness, as well as significantly reduce the microscopic damage of fiber compare to the original control strategy of dryer. This indicates possible ways to minimize drying energy consumption and dryer damage by reducing unnecessary migrate out of the water from the clothes. Practical implications The paper is helpful in not only the development of new drying product but also the optimization of appearance smoothness of fabric after drying and reduce the microscopic damage of fiber. Originality/value A novel termination control strategy of dryer is applied to improve drying efficiency of dryer and reduce fabric damage.

Solar Assisted Dehydrator for Decentralized Controlled and Homogeneous Multi-Product Drying

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Waseem Amjad ◽  
Muhammad Waseem ◽  
Anjum Munir ◽  
Abdul Ghafoor ◽  
Furqan Asghar ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Air Distribution ◽  
Drying Time ◽  
Specific Product ◽  
Heating Source ◽  
Batch Type ◽  
Evacuated Tube Collector ◽  
Drying Rates ◽  
Evacuated Tube ◽  
Drying Chamber

Abstract Batch type food dryers are common for drying agricultural produce due to simple in design, but they are prone to nonuniform drying and significant heat cost exclusively if they fall in the medium to large size range. The current study illustrates a solar hybrid food dryer using a gas burner and solar collector (evacuated tube collector, ETC) as heating source along with an inline perforation inside the drying chamber to obtain spatial drying homogeneity. Air distribution was assessed through three-dimensional simulation using computational fluid dynamics (CFD) analysis. Performance trials were conducted under three heating options (ETC, gas, and dual) using green chilies at 60 °C. Throughout drying chamber, under all heating modes, the average difference in drying rates ranged from 0.61 to 1.30 kg water/kg dry matter, demonstrating homogeneous drying. Simulated and experimental results of air distribution were found to be in agreement with each other. Using three options for thermal heating (ETC, gas, and dual) and an overall 58% efficiency for evacuated tube collector, the specific energy for moisture evaporation was found to be 4.5–5.7 MJ/kg and specific product energy 19.2–24.9 MJ/kg. In case of dual heating option, the energy supplied by solar and gas sources for a 20 hours period was 50.64% (160.22 MJ) and 49.35% (156.13 MJ), respectively. Compared with dual heating option, energy cost can be reduced by 68% if only solar energy is used as a heating option but with a protracted drying time.

scholarly journals Effect of pretreatments on drying behavior of eggplant

2019 ◽  
Vol 17 (1) ◽  
pp. 105-109
Author(s):  
Md Junaeid Khan ◽  
Farjana Yeasmin ◽  
Md Nazrul Islam ◽  
Raju Ahmmed ◽  
Pabitra Chandra Das ◽  
...  
Keyword(s):  
Constant Temperature ◽  
Rate Constant ◽  
Hot Water ◽  
Effect Of Temperature ◽  
Constant Thickness ◽  
Drying Rate ◽  
Fresh Sample ◽  
Drying Time ◽  
Preservation Method ◽  
Drying Behavior

Eggplant is a familiar and admired vegetable in Bangladesh. It is a highly perishable vegetable and cannot be preserved long. Drying is an ancient preservation method used to extend shelf-life of fruits and vegetables. Different Pretreatments may affect the drying kinetics of foods. A study was conducted to evaluate how pretreatments affect the drying behavior of eggplant. Proximate composition of fresh eggplant was analyzed. The samples of constant thickness (8 mm) were dried at 50°C, 55°C and 60°C to determine the effect of temperature on drying rate constant, while for determining the effect of thickness on rate constant, eggplant slices of 4, 6 and 8 mm thicknesses were dried at a constant temperature of 55°C. It was observed that, drying rate decreased with the increase in thickness and the index ‘n’ was found to be 0.89 at 55°C. Under similar drying condition at constant thickness (8 mm), drying time showed an inverse relationship with temperature. The activation energy (Ea) was calculated as 3.242 Kcal/g-mole. Eggplant slices having the highest thickness (8 mm) were blanched at 70°C, 75°C and 80°C for 1, 2 and 2.5 minutes, respectively using hot water bath to determine the effective blanching time and temperature. It was observed that the samples blanched at 75°C and 80°C for 2 minute were enough to inactivate the enzymes. Pretreated (blanched, sulphited and blanched plus sulphited) eggplant slices having constant thickness (8 mm) were dried at constant temperature of 55°C. The drying time was influenced by pretreatments. The highest drying rate was observed for eggplant slices with blanched plus sulphited (5% KMS solution) samples while eggplant slices with 5%KMS solution dipped for 10 minutes showed the lowest drying rate. In case of fresh slices, drying time was lower than blanched and sulphited samples but higher than blanched plus sulphited samples. Pretreatment was also found effective on the color changes (preservation or degradation). Blanching gave a bright color compared to fresh sample but less bright compared to sulphited samples. In case of SO2 retention, blanched plus sulphited sample showed higher retention than sulphited sample. Sulphited sample retains 44.8 ppm SO2/100g of sulphited sample, while the blanched plus sulphited sample retains 280 ppm SO2/100 g of blanched plus sulphited sample. J. Bangladesh Agril. Univ. 17(1): 105–109, March 2019

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