scholarly journals Effect of tray dryer’s independent variables (drying temperature and air velocity) on the quality of olive pomace and system’s energy efficiency

2018 ◽  
Author(s):  
Mehmet Koç ◽  
Ulaş Baysan ◽  
A. Güngör ◽  
Figen Kaymak-Ertekin
Keyword(s):  
Energy Efficiency ◽  
Specific Energy Consumption ◽  
Oxidation Stability ◽  
Extraction Rate ◽  
Olive Pomace ◽  
Air Velocity ◽  
Drying Time ◽  
Drying Temperature ◽  
Moisture Extraction

In this study, the effects of drying temperature (70, 80, 90°C) and air velocity (0.5, 1.8 m/s) of hot air drying (tray drying) on quality of dried 2-phase olive pomace and system’s energy efficiency were investigated. The drying experiments were carried out in a tray dryer. The effects of drying conditions were evaluated with analyzing drying time, the primary and secondary oxidation and calculating specific moisture extraction rate (SMER), moisture extraction rate (MER) and specific energy consumption (SEC). The results showed that increase in drying temperature and decrease in air velocity led to decrease in quality of dried olive pomace. Keywords: Waste valorization, 2-phase olive pomace, Tray dryer, Energy efficiency, oxidation stability  

Experimentation and performance analysis of solar-assisted heat pump dryer for intermittent drying of food chips

2021 ◽  
pp. 1-35
Author(s):  
A Singh ◽  
Jahar Sarkar ◽  
Rashmi Sahoo
Keyword(s):  
Energy Efficiency ◽  
Economic Analysis ◽  
Heat Pump ◽  
Payback Period ◽  
Extraction Rate ◽  
Maximum Enhancement ◽  
Drying Time ◽  
Moisture Extraction ◽  
And Performance ◽  
Drying Efficiency

Abstract A solar-assisted heat pump dryer is fabricated for intermittent drying. The experiment is performed for different intermittency ratios for radish drying using future refrigerant R1234yf. The effects of total drying time (on-period + off-period) on various energetic, exergetic, and economic performances are investigated. Radish chips were dried to extract moisture from 92.4% to 11.9%. Energy efficiency and drying efficiency are estimated higher for a lower intermittency ratio. The moisture extraction rate and specific moisture extraction rate are higher for intermittent drying as compared to continuous drying and increase with a decrease in intermittency ratio. The economic analysis concludes that the payback period is lower for a lower intermittency ratio. The payback period for intermittency ratio of 1, 0.66, 0.33 and 0.2 are estimated as 1.617 years, 1.459 years, 1.384 years, and 1.347 years, respectively. Present experimental thermo-economic analysis reveals that intermittent drying is much better (maximum enhancement of specific moisture extraction rate is 60.6%, that of energy efficiency is 56.4% and maximum reduction of drying cost is 37.9% with studied conditions) than continuous drying.

scholarly journals Effect of Pretreatments on Convective and Infrared Drying Kinetics, Energy Consumption and Quality of Terebinth

2021 ◽  
Vol 11 (16) ◽  
pp. 7672
Author(s):  
Yousef Abbaspour-Gilandeh ◽  
Mohammad Kaveh ◽  
Hamideh Fatemi ◽  
Esmail Khalife ◽  
Dorota Witrowa-Rajchert ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Bioactive Compounds ◽  
Specific Energy Consumption ◽  
Moisture Diffusion ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Drying Time ◽  
Time And Energy

This study is focused on the influence of convective drying (50, 60, and 70 °C) and infrared (IR) power (250, 500, and 750 W) on the drying kinetics, the specific energy consumption of terebinth drying as well as quality and bioactive compounds upon various pretreatments such as ultrasound (US), blanching (BL), and microwave (MW). Compared to convective drying, IR drying decreased more the drying time and energy consumption (SEC). Application of higher IR powers and air temperatures accelerated the drying process at lower energy consumption (SEC) and higher energy efficiency and moisture diffusion. Terebinth dried by a convective dryer at 60 °C with US pretreatment showed a better color compared to other samples. It also exhibited the polyphenol and flavonoid content of 145.35 mg GAE/g d.m. and 49.24 mg QE/g d.m., respectively, with color variations of 14.25 and a rehydration rate of 3.17. The proposed pretreatment methods significantly reduced the drying time and energy consumption, and from the other side it increased energy efficiency, bioactive compounds, and quality of the dried samples (p < 0.01). Among the different pretreatments used, microwave pretreatment led to the best results in terms of the drying time and SEC, and energy efficiency. US pretreatment showed the best results in terms of preserving the bioactive compounds and the general appearance of the terebinth.

scholarly journals Influence of Different Hot Air Drying Temperatures on Drying Kinetics, Shrinkage, and Colour of Persimmon Slices

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 101 ◽  
Author(s):  
Senadeera ◽  
Adiletta ◽  
Önal ◽  
Di Matteo ◽  
Russo
Keyword(s):  
Moisture Content ◽  
Quadratic Model ◽  
Drying Process ◽  
Air Velocity ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Drying Characteristics ◽  
Drying Temperature ◽  
Hot Air

Drying characteristics of persimmon, cv. “Rojo Brillante”, slabs were experimentally determined in a hot air convective drier at drying temperatures of 45, 50, 55, 60, and 65 °C at a fixed air velocity of 2.3 m/s. It was observed that the drying temperature affected the drying time, shrinkage, and colour. Four empirical mathematical models namely, Enderson and Pabis, Page, Logarithmic, and Two term, were evaluated in order to deeply understand the drying process (moisture ratio). The Page model described the best representation of the experimental drying data at all investigated temperatures (45, 50, 55, 60, 65 °C). According to the evaluation of the shrinkage models, the Quadratic model provided the best representation of the volumetric shrinkage of persimmons as a function of moisture content. Overall, higher drying temperature (65 °C) improved the colour retention of dried persimmon slabs.

scholarly journals Energy efficiency and physical integrity of maize grains subjected to continuous and intermittent drying

2021 ◽  
Vol 25 (10) ◽  
pp. 710-716
Author(s):  
Geraldo A. Mabasso ◽  
Valdiney C. Siqueira ◽  
Wellytton D. Quequeto ◽  
Rodrigo A. Jordan ◽  
Elton A. S. Martins ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Moisture Content ◽  
Energy Demand ◽  
Air Flow ◽  
Specific Energy Consumption ◽  
Fixed Bed ◽  
Membrane Integrity ◽  
Drying Time ◽  
Cell Membrane Integrity ◽  
Tempering Time

ABSTRACT Grain drying is a common process, due to its need for the maintenance of quality, but it is the activity with the highest energy demand among the postharvest stages. Thus, this study aimed to evaluate the effect of different tempering times on the energy efficiency of drying process and maintenance of cell membrane integrity of maize grains harvested with moisture content at 0.34 ± 0.01 d.b. The grains were dried in an experimental fixed-bed dryer with control of temperature and air flow conditions. The experiment was conducted in a completely randomized design with five tempering times (0, 4, 8, 12 and 16 hours) and four repetitions, where zero corresponds to continuous drying, while the remaining times correspond to the intermittent dryings. The grains were dried at the temperature of 100 ºC and air flow of 15.4 m3 min-1 t-1 until reaching moisture content of 0.16 ± 0.03 d.b. For intermittent drying, the process was interrupted with 0.22 ± 0.02 d.b. and restarted after the tempering time. The increase of tempering time led to reductions in effective drying time, specific energy consumption, electrical conductivity and damage and increase in the drying rate and overall energy efficiency. Intermittent drying reduced the drying time, being 30.25% more efficient than continuous drying.

scholarly journals Drying characteristics and quality evaluation in convective drying of Cissus quadrangularis Linn.

2018 ◽  
Vol 192 ◽  
pp. 03041
Author(s):  
Setthawat Thanimkarn ◽  
Ekkapong Cheevitsopon ◽  
Jiraporn Sripinyowanich Jongyingcharoen
Keyword(s):  
Quality Evaluation ◽  
Moisture Diffusivity ◽  
Convective Drying ◽  
Total Phenolic ◽  
Drying Time ◽  
Drying Characteristics ◽  
Drying Temperature ◽  
Cissus Quadrangularis ◽  
Lower Bulk Density

This study aimed to investigate the effect of drying temperature (40, 60, 80, and 100°C) on drying characteristics of Cissus quadrangularis Linn. (CQ) undergoing convective drying. Physical properties and phytochemicals of the dried CQ were also evaluated. CQ with the thickness of 5 mm was dried from about 10 to 0.1 g water/g dry matter. The results showed that increasing drying temperature increased drying rate (DR) and effective moisture diffusivity (Deff) and consequently decreased drying time. The drying time, maximum DR, and Deff were in the ranges of 85-1920 min, 0.0059-0.0248 g water/g dry matter·min, and 0.7302-9.1281×10-9 m2/s, respectively. Lower drying temperature could preserve quality of the dried CQ. Decreasing drying temperature resulted in greener and lower bulk density and shrinkage. The greatest total phenolic content (TPC) and quercetin content were obtained by drying the CQ at 60°C.

scholarly journals Effect of drying temperature on the content and composition of hop oils

2018 ◽  
Vol 64 (No. 10) ◽  
pp. 512-516 ◽  
Author(s):  
Rybka Adolf ◽  
Krofta Karel ◽  
Heřmánek Petr ◽  
Honzík Ivo ◽  
Pokorný Jaroslav
Keyword(s):  
Moisture Content ◽  
Essential Oils ◽  
Experimental Chamber ◽  
Drying Time ◽  
Drying Temperature ◽  
Different Temperatures ◽  
Traditional Manner

In terms of content, the paper is aimed at analysing and comparing the quality of fresh green hops and hops dried at two drying temperatures – 55°C (in the traditional manner) and 40°C (using the so-called gentle drying), regarding the maximum preservation of hop essential oils. Comparative experiments were carried out in an experimental chamber dryer with two Czech hop cultivars Saaz and Harmonie. The moisture content of hops at the beginning of drying was 75% and at the end of drying it was 9–10%. By lowering the drying temperature from 55°C to 40°C, the drying time in cv. Saaz prolonged from 8 to 10 h and for the cv. Harmonie from 9 h to 12 h. Compared to fresh hops, the amount of hop oils decreased by 10% when dried at 40°C and by 36% (cv. Saaz) and 43% (cv. Harmonie) when dried at 55°C. These losses can be considered significant, especially for hops intended for late and dry beer hopping. However, by drying the hops at different temperatures, the ratios between various components of the essential oils and thus also their sensory character remained approximately unchanged. Due to the reduced amount of essential oils, the drying effect reduces the intensity of hop aroma depending on the drying temperature.

scholarly journals Drying characteristics of eggplant (Solanum melongena L.) slices under microwave-convective drying

2016 ◽  
Vol 62 (No. 4) ◽  
pp. 170-178 ◽  
Author(s):  
R.A. Chayjan ◽  
M. Kaveh
Keyword(s):  
Air Temperature ◽  
Microwave Power ◽  
Specific Energy Consumption ◽  
Solanum Melongena ◽  
Moisture Diffusivity ◽  
Moisture Ratio ◽  
Convective Drying ◽  
Air Velocity ◽  
Drying Time ◽  
Thin Layer Drying

A laboratory scale microwave-convection dryer was used to dry the eggplant fruit, applying microwave power in the range of 270–630 W, air temperature in the range of 40–70°C and air velocity in the range of 0.5–1.7 m/s. Six mathematical models were used to predict the moisture ratio of eggplant fruit slices in thin layer drying. The results showed that the Midilli et al. model had supremacy in prediction of turnip slice drying behavior. Minimum and maximum values of effective moisture diffusivity (D<sub>eff</sub>) were 1.52 × 10<sup>–9</sup> and 3.39 × 10<sup>–9</sup> m<sup>2</sup>/s, respectively. Activation energy values of eggplant slices were found between 13.33 and 17.81 kJ/mol for 40°C to 70°C, respectively. The specific energy consumption for drying eggplant slices was calculated at the boundary of 86.47 and 194.37 MJ/kg. Furthermore, in the present study, the application of Artificial Neural Network (ANN) for predicting the drying rate and moisture ratio was investigated. Microwave power, drying air temperature, air velocity and drying time were considered as input parameters for the model.

scholarly journals Reconstruction of Turbomachines on the Basis of the Flow Structure Visual Diagnostics

2020 ◽  
Vol 22 (2) ◽  
pp. 405-414
Author(s):  
Vasyl Arsiri ◽  
Oleg Kravchenko
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Flow Structure ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Dynamic Processes ◽  
Hydraulic Efficiency ◽  
Different Types ◽  
Increase In Productivity

AbstractThe indicator of the quality of modern turbomachines is only the coefficient of efficiency, which characterizes the ratio of the useful work of compressors or fans to the energy expended on the drive. For the analysis of the quality of the motion, processes in flow parts, the values of resistances are used which are difficult to be considered as an indicator of the efficiency of dynamic processes. The report presents the results of visual diagnostics of the structure of flows during the movement in the elements of turbomachines, as well as options for improving the geometry of the flow parts - in the inlet pipes, impellers.For the analysis of the efficiency of the motion of liquids and gases in flowing parts, a calculated index is proposed - the coefficient of hydraulic efficiency of dynamic processes. The joint use of two indicators - the efficiency of transformation of different types of energy (efficiency of turbomachines) and the efficiency of dynamic processes in flowing parts allows us to develop and to analyze the results of reconstruction of turbomachines. Reconstruction of turbomachines with the purpose of improving the geometry of the flow parts provides an increase in productivity of turbines, compressors, fans and pumps, while reducing the specific energy consumption for the processes of compression and transport of liquids and gases. Optimization of turbomachines flow parts based of flow structure visual diagnostics allows to reduce noise and vibration, as well as to solve other problems.

scholarly journals Heat pump drying of industrial wastewater sludge

2020 ◽  
Vol 15 (2) ◽  
pp. 404-415
Author(s):  
Gang Yuan ◽  
Khim Hoong Chu
Keyword(s):  
Heat Pump ◽  
Industrial Wastewater ◽  
Closed Loop ◽  
Energy Savings ◽  
Specific Energy Consumption ◽  
Extraction Rate ◽  
Wastewater Sludge ◽  
Loop Layout ◽  
Moisture Extraction ◽  
Exhaust Treatment

Abstract The popularity of heat drying of wastewater sludge has increased over the past several years because it can reduce sludge mass and volume, and hence disposal costs. However, drying sludge using conventional combustion-heated dryers is energy-intensive. Heat pump dryers can be efficient and offer significant energy savings by recycling the drying heat. This paper describes a heat pump dryer designed for continuous drying of industrial wastewater sludge. The dryer constructed was essentially a closed-loop air system. The air used for drying is dehumidified to recover the latent heat of vaporization, re-heated using the recovered heat, and recirculated in a closed environment. The closed-loop layout eliminates emissions of dust, malodorous gases, and volatile compounds, obviating the need for exhaust treatment otherwise required to meet environmental regulations. Data on the moisture extraction rate, specific moisture extraction rate, and specific energy consumption are presented and discussed.

scholarly journals The effect of drying temperature on cup quality of coffee subjected to mechanical drying

2021 ◽  
pp. 35-41
Author(s):  
T.N. Sandeep ◽  
B.B. Channabasamma ◽  
T.N. Gopinandhan ◽  
J.S. Nagaraja
Keyword(s):  
Drying Methods ◽  
Drying Time ◽  
Drying Temperature ◽  
Sun Drying ◽  
Robusta Coffee ◽  
Temperature Regimes ◽  
Quality Rating ◽  
Drying Rates ◽  
Cup Quality

The objective of the work was to study the effect of drying temperature on cup quality of the robusta coffee subjected to mechanical drying in comparison with conventional sun drying. The robusta coffee processed by wet (parchment coffee) and dry (cherry coffee) methods were subjected to drying at different temperature regimes (40 oC, 50 oC and 60 oC) in a rotary mechanical dryer. The results of the study indicated that as the drying temperature increased, the time of drying reduced. Sun drying of parchment coffee took 48 hours (approximately seven days) to attain the desired moisture content of 11-12 per cent, while mechanical drying reduced the drying time to 16 to 24 hours. Similarly, cherry coffee subjected to sun drying took 88 hours (approximately 15 days), while mechanical drying reduced the drying time to 32 to 48 hours. The cup quality rating of coffee dried by different drying methods revealed that sun-dried robusta parchment coffee scored the highest cup rating. As the drying temperature increased, the cup quality ratings decreased. A similar cup quality rating was also observed with cherry coffee. These results indicate a considerable reduction of drying time when coffee beans are dried in a mechanical dryer. However, there is a need to regulate the drying temperature, which otherwise would negatively impact the quality of coffee. The drying temperature should not exceed 40oC for preserving the innate quality of robusta coffee because the high drying rates provoked by high temperatures can cause damage to the coffee quality due to the damage caused to the cell membranes. Overall, mechanical drying is more advantageous to sun drying in-terms of drying hours (indirectly reduces dependency on manpower) and preservation of innate quality of the coffee.

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