Impact of Initial Moisture Content on the Drying Process of Wood Exposed to Infrared Radiation

Drying is a critical point for the exploitation of biomass for energy production. High moisture content negatively affects the efficiency of power generation in combustion and gasification systems. Different types of dryers are available however; it is known that rotary dryers have low cost of maintenance and consume 15% and 30% less in terms of specific energy. The study analyzed the drying process of woody residues using a new prototype of mobile rotary dryer cocurrent flow. Woodchip of poplar (Populus spp.), black locust (Robinia pseudoacacia L.), and grapevine (Vitis vinifera L.) pruning were dried in a rotary drier. The drying cycle lasted 8 h for poplar, 6 h for black locust, and 6 h for pruning of grapevine. The initial biomass had a moisture content of around 50% for the poplar and around 30% for grapevine and black locust. The study showed that some characteristics of the biomass (e.g., initial moisture content, particle size distribution, bulk density) influence the technical parameters (i.e., airflow temperature, rate, and speed) of the drying process and, hence, the energy demand. At the end of the drying process, 17% of water was removed for poplar wood chips and 31% for grapevine and black locust wood chips. To achieve this, result the three-biomass required 1.61 (poplar), 0.86 (grapevine), and 1.12 MJ kgdry solids−1 (black locust), with an efficiency of thermal drying (η) respectively of 37%, 12%, and 27%. In the future, the results obtained suggest an increase in the efficiency of the thermal insulation of the mobile dryer, and the application of the mobile dryer in a small farm, for the recovery of exhaust gases from thermal power plants.

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Cherry Tomato Drying: Sun versus Convective Oven

Horticulturae ◽

10.3390/horticulturae7030040 ◽

2021 ◽

Vol 7 (3) ◽

pp. 40

Author(s):

Vincenzo Alfeo ◽

Diego Planeta ◽

Salvatore Velotto ◽

Rosa Palmeri ◽

Aldo Todaro

Keyword(s):

Moisture Content ◽

Initial Moisture Content ◽

Drying Process ◽

Drying Time ◽

Oven Drying ◽

Sun Drying ◽

Different Temperatures ◽

Final Water Content ◽

Drying Curves ◽

Drying Conditions

Solar drying and convective oven drying of cherry tomatoes (Solanum lycopersicum) were compared. The changes in the chemical parameters of tomatoes and principal drying parameters were recorded during the drying process. Drying curves were fitted to several mathematical models, and the effects of air temperature during drying were evaluated by multiple regression analyses, comparing to previously reported models. Models for drying conditions indicated a final water content of 30% (semidry products) and 15% (dry products) was achieved, comparing sun-drying and convective oven drying at three different temperatures. After 26–28 h of sun drying, the tomato tissue had reached a moisture content of 15%. However, less drying time, about 10–11 h, was needed when starting with an initial moisture content of 92%. The tomato tissue had high ORAC and polyphenol content values after convective oven drying at 60 °C. The dried tomato samples had a satisfactory taste, color and antioxidant values.

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Heat and Mass Transfer during Contact Drying in a Laundry Calender

Proceedings of the Institution of Mechanical Engineers ◽

10.1243/pime_proc_1973_187_045_02 ◽

1973 ◽

Vol 187 (1) ◽

pp. 591-599

Author(s):

J. F. T. MacLaren ◽

A. A. Nicol ◽

R. Wallace

Keyword(s):

Mass Transfer ◽

Moisture Content ◽

Heat And Mass Transfer ◽

Initial Moisture Content ◽

Temperature Profiles ◽

Drying Process ◽

Steam Temperature ◽

Empirical Expression ◽

Contact Drying ◽

Physical Variables

Contact drying of fabric was studied using a two-roll steam-heated laundry calender. The effects on heat and mass transfer of steam temperature, fabric initial moisture content, fabric velocity, contact pressure and steam-side heat transfer coefficient were observed experimentally. Bed and roller surface temperature profiles were measured to assist in interpreting and subsequently analysing the drying process. The experimental results were correlated using dimensionless parameters derived from a dimensional analysis of a drying equation. An empirical expression was obtained that related the final moisture content of the fabric to the initial moisture content and the other pertinent physical variables.

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Ultrasound Drying of Rose Hips: a Process Study

Food Processing Techniques and Technology ◽

10.21603/2074-9414-2020-1-79-86 ◽

2020 ◽

Vol 50 (1) ◽

pp. 79-86

Author(s):

Elena Verboloz ◽

Marina Ivanova ◽

Vera Demchenko ◽

Sergey Fartukov ◽

Nikita Evona

Keyword(s):

Vitamin C ◽

Moisture Content ◽

Quality Indicators ◽

State Standard ◽

Raw Materials ◽

Initial Moisture Content ◽

Raw Material ◽

Drying Process ◽

Resource Saving ◽

Drying Time

Introduction. Rose hips are rich in macro- and micronutrients. Unfortunately, heat treatment destroys most nutrients. Ultrasonic technologies make it possible to reduce the drying time and lower the temperature regime. The research objective was to adjust ultrasound technology to rose hip production in order to reduce the loss of vitamins and improve the quality indicators of the dried product. Study objects and methods. The research featured rose hips of the Rosa canina species collected in the south of Kazakhstan. This subspecies of wild rose is poor in vitamin C. Nevertheless, this shrub is extremely common in Russia and other countries of the Commonwealth of Independent States. The raw material was dried according to standard methods. One group of samples was treated with ultrasound, while the other served as control. Both groups underwent a sensory evaluation and were tested for moisture and vitamin C. Results and discussion. The rose hips were dried in a combination steam oven with a built-in ultrasonic wave generator. The research revealed the following optimal parameters of the ultrasound drying process: frequency of ultrasonic vibrations – 22 kHz, processing time – 2.5 h, temperature in the combination steam oven – +56°C, initial moisture content – 30%. The resulting product met the requirements of State Standard. The loss of moisture was 57%. According to State Standard 1994-93, the initial moisture content should be 15% or less. Time decreased from 360 min to 160 min, and the initial moisture was 13%. The experiment confirmed the initial hypothesis that ultrasonic treatment improves the drying process by improving quality indicators and preserving vitamin C in raw materials using. Conclusion. Ultrasound treatment during moisture removal from rose hips provides a resource-saving technology that fulfills an economically and socially important function.

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Modelling of biomass temperature in the drying process

E3S Web of Conferences ◽

10.1051/e3sconf/202015401004 ◽

2020 ◽

Vol 154 ◽

pp. 01004

Author(s):

Ewa Golisz ◽

Małgorzata Jaros ◽

Szymon Głowacki

Keyword(s):

Moisture Content ◽

Initial Moisture Content ◽

Direct Calculation ◽

Logistic Function ◽

Temperature Model ◽

Drying Process ◽

Drying Time ◽

Temperature Changes ◽

Higher Temperature ◽

Temperature Rate

The goal of the work was to propose and verify the model of temperature changes of the convective dried biomass depending on the drying time. The algebraic temperature model of the convective dried solid, giving the possibility of its direct calculation, was based on the logistic function of growth. Temperature model was verified for convective dried biomass: vegetable and wood (poplar and willow wood chips) significantly differing in initial moisture content. Parameter W in the temperature model, defined as the coefficient of temperature rate changes reaches greater values in higher temperature of drying air and for wood biomass which has lower initial moisture content. Empirically selected parameter W allows to verify the temperature model with the relative error less than 5%.

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Effect of steam thermal treatment on the drying process of Eucalyptus dunnii variables

CERNE ◽

10.1590/s0104-77602013000400014 ◽

2013 ◽

Vol 19 (4) ◽

pp. 637-645 ◽

Cited By ~ 8

Author(s):

Elias Taylor Durgante Severo ◽

Ivan Tomaselli ◽

Fred Willians Calonego ◽

André Luiz Ferreira ◽

Lourival Marin Mendes

Keyword(s):

Moisture Content ◽

Initial Moisture Content ◽

Moisture Gradient ◽

Steam Treatment ◽

Drying Rate ◽

Drying Process ◽

Intermediate Layers ◽

Eucalyptus Dunnii ◽

Electric Oven ◽

Heating Up

The aim of this study was to evaluate the effect of steam treatment prior to drying on the initial moisture content, moisture gradient, and drying rate in Eucalyptus dunnii Maiden wood. Boards were steamed at 100ºC for 3 h after 1 h of heating-up. Part of these boards was dried in a drying electric oven at 50ºC, and part was dried at kiln. The results showed that the steaming prior to drying of wood: (1) significantly reduced by 9.2% the initial moisture content; (2) significantly increased by 6.2% the drying rate; (3) significantly decreased by 15.6 and 14.8% the moisture gradient between the outer layer and the center of boards and between the outer and intermediate layers of boards, respectively. Steamed boards when dried in an oven showed drying rate of 0.007065 whereas in kiln were 0.008200 and 0.034300 from green to 17 and 17 to 12% moisture content, respectively. It was demonstrated that the steaming prior to drying can be suitable for reduces the drying times of this kind of wood.

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Loss of desiccation tolerance in Copaifera langsdorffii Desf. seeds during germination

Brazilian Journal of Biology ◽

10.1590/1519-6984.19712 ◽

2014 ◽

Vol 74 (2) ◽

pp. 501-508 ◽

Cited By ~ 6

Author(s):

WVS. Pereira ◽

JMR. Faria ◽

OAO Tonetti ◽

EAA. Silva

Keyword(s):

Moisture Content ◽

Desiccation Tolerance ◽

Cell Damage ◽

Cell Structure ◽

Initial Moisture Content ◽

Phase 2 ◽

Drying Process ◽

Dry Process ◽

Germination Process ◽

Copaifera Langsdorffii

This study evaluated the loss of desiccation tolerance in C. langsdorffii seeds during the germination process. Seeds were imbibed for 24, 48, 72, 96, 120 and 144 hours and dried to the initial moisture content, kept in this state for 3 days after which they were submitted to pre-humidification and rehydration. Ultraestructural evaluations were done aiming to observe the cell damage caused by the dry process. Desiccation tolerance was evaluated in terms of the percentage of normal seedlings. Seeds not submitted to the drying process presented 61% of normal seedlings, and after 24 hours of imbibition, followed by drying, the seeds presented the same percentage of survival. However, after 48 hours of imbibition, seeds started to lose the desiccation tolerance. There was twenty six percent of normal seedlings formed from seeds imbibed for 96 hours and later dried and rehydrated. Only 5% of seeds imbibed for 144 hours, dried and rehydrated formed normal seedlings. At 144 hours of imbibition followed the dry process, there was damage into the cell structure, indicating that the seeds were unable to keep the cell structure during the drying process. Copaifera langsdorffii seeds loses the desiccation tolerance at the start of Phase 2 of imbibition.

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Effects of Fabric Parameters and Initial Moisture Content on the Smoothness Appearance of Woven Cotton Fabrics in Dryer

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.671.466 ◽

2015 ◽

Vol 671 ◽

pp. 466-472 ◽

Cited By ~ 2

Author(s):

Wei Wei Hu ◽

Yu Hui Wei ◽

Xue Mei Ding ◽

Xiong Ying Wu

Keyword(s):

Moisture Content ◽

Surface Density ◽

Initial Moisture Content ◽

Cotton Fabrics ◽

Drying Process ◽

Drum Drying ◽

Washing Process ◽

The Difference

The effects of fabric parameters and initial moisture content in dryer on the smoothness appearance of woven cotton fabrics have been determined. In this study, 11 kinds of cotton fabrics were selected to evaluate their smoothness appearance after drum drying. The results indicated that the fabric parameters---surface density, thickness and warp density--- had a certain correlation with the fabric smoothness appearance, which wasn’t significant. The initial moisture content affected smoothness appearance positively. With the increasing of initial moisture content, the grade improved and the difference between the max and the mini is about 0.5grade. This study can provide a reference for the design of the dryer program and make fabric washing process achieve the coordination with drying process to obtain a best fabric appearance.

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Performance Evaluation of Solar Tunnel Dryer for Drying of Garlic.

Current Agriculture Research Journal ◽

10.12944/carj.5.2.09 ◽

2017 ◽

Vol 5 (2) ◽

pp. 212-218 ◽

Cited By ~ 1

Author(s):

Arjoo Arjoo ◽

Yadvika Yadvika ◽

Y.K. Yadaadav

Keyword(s):

Performance Evaluation ◽

Moisture Content ◽

Thermal Efficiency ◽

Initial Moisture Content ◽

Drying Process ◽

Tunnel Drier ◽

Drying Time ◽

Tunnel Dryer ◽

Safe Level ◽

And Performance

This paper presents dying efficiency and performance of the solar tunnel dryer for drying of garlic. The dryer is a tunnel like semi-cylindrical in shape, poly house made up of UV-stabilized polyethylene sheet. The capacity is large enough that it can be used to dry 400 kg of garlic under controlled environmental conditions. The temperature inside the dryer was always higher than the ambient and the variation varied from 8-30 ºC. Initial moisture content of garlic was reduced from 66 % (w.b.) to about 9 % (w.b.) in 9 days which is considered to be a safe level. During the drying process the average thermal efficiency of the drier was estimated to be about 13.45 %. Drying time was considerably reduced with the use of a solar tunnel drier and pressing of the sample. Also, the final dried garlic was found to be good in terms of quality and sensory evaluation shows that it is highly acceptable.

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Purwarupa dan Kinerja Pengering Gabah Hybrid Solar Heating dan Photovoltaic Heater dengan Sistem Monitoring Suhu

Jurnal Teknik Elektro ◽

10.15294/jte.v12i1.24028 ◽

2020 ◽

Vol 12 (1) ◽

pp. 24-32

Author(s):

Usman Usman ◽

Akhyar Muchtar ◽

Umar Muhammad ◽

Nunik Lestari

Keyword(s):

Moisture Content ◽

Initial Moisture Content ◽

Electrical Energy ◽

Temperature Monitoring ◽

Solar Panels ◽

Drying Process ◽

Grain Moisture ◽

Measurement Tools ◽

Drying Efficiency ◽

And Control

Grain drying is a process to reduce grain moisture content to certain conditions, so the grain can last longer in storage. The grain dryer model used in this research was Indirect Type Solar Dryer (ITSD). In order to make this dryer can work at night, heating element that used electrical energy from solar panels was added. This energy is a renewable and environmentally friendly energy. This dryer was equipped with a temperature monitoring system and control of the photovoltaic heater. The results of temperature monitoring and voltage sensors to controlling photovoltaic heaters based on validation are categorized as work measurement tools, because they have an error of 0.5% – 2%. Whereas the relay works when the battery voltage is 11 - 10.9 V. This dryer can dry grain to reach a moisture content of 14.90% from initial moisture content of 48.46%. The drying process lasts for 11 hours, which is 7 hours using solar energy and 4 hours using photovoltaic heaters. The average temperature produced by dryer system during the drying process is 35.28 °C with a drying efficiency of 60.14%.

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