Analysis of Wood Combustion Based on the First and Second Laws of Thermodynamics

1987 ◽  
Vol 109 (3) ◽  
pp. 129-141 ◽  
Author(s):  
A. Dadkhah-Nikoo ◽  
D. J. Bushnell
Keyword(s):  
Moisture Content ◽  
Energy Content ◽  
Wood Combustion ◽  
Moisture Contents ◽  
Direct Combustion ◽  
Air Temperatures ◽  
Wide Range ◽  
Laws Of Thermodynamics ◽  
Different Types ◽  
Wood Fuels

Wood is a highly flexible fuel which can be used in a variety of ways for energy generation. Direct combustion of wood is the oldest method of utilization of this renewable energy source. This paper presents an analysis of wood combustion based on the first and second laws of thermodynamics, using a computer program developed for this study. Since the moisture content of the available wood fuels vary over a wide range, special attention is given to the effects of moisture content on the exergy and energy content of the wood. Because of the wide variation in particle size and moisture content of the wood fuels, different types of combustion systems have been designed and are utilized in industry. Each combustion system uses a certain amount of combustion air and is designed for a certain range of combustion air temperatures and wood fuel moisture contents. The effects of these variables on wood combustion and the efficiencies of the process have been studied and are presented in this paper. To point out the importance and differences between efficiencies that are commonly used, several efficiencies based on the first and the second laws of the thermodynamics are calculated and compared. Based on the results presented in this report, it is concluded that, over the range of variables studied, the most efficient conditions for wood combustion can be achieved by using the minimum amount of excess air at highest permissible temperature. It is also concluded that the lower moisture contents result in higher combustion efficiencies.

scholarly journals PHYSICO-CHEMICAL STANDARDIZATION OF A UNANI ANALGESIC FORMULATION HABB-E-SURANJAN

2019 ◽  
Vol 9 (4-A) ◽  
pp. 486-489
Author(s):  
Shahid Suhail ◽  
Shagufta Parveen ◽  
Shazia Jilani ◽  
, Shama
Keyword(s):  
Moisture Content ◽  
Petroleum Ether ◽  
Fluorescence Analysis ◽  
Normal Range ◽  
Moisture Contents ◽  
Loss Of Weight ◽  
Physico Chemical ◽  
Different Types ◽  
Microscopic Features ◽  
Effective Role

Habb-e-Suranjaan is an important compound preparation which is used for a centuries in Unani system of medicine as an effective analgesic for all types of Waj-al-Mafasil (Arthritics). The drug is known for its pharmacological actions such as Mushile-Balgham (Phlegmagogue), Mushile-Safra (Cholagogue), Mushile-Sauda (Melanagogue), Mohallile-Waram (Anti-inflammatory), Musakkin-e-Alam (Analgesic), Dafae Niqris (Anti-gout) Muqawwi-e asaab (Nervine tonic) Munawwim (Hypnotic/Soporific), Musaffi-e-Dam (Blood Purifier). Ingredients of Habb-e-Suranjaan play very effective role in management of different types of Waj-al-Mafasil.  In this article, standardized value of a specimen of Habb-e Suranjaan assessed on physico-chemical and analytical parameters viz Macroscopic and microscopic features, extractive values, moisture contents, Ash values, loss of weight on drying, pH of 1 % and 10 % solution, TLC and  Fluorescence analysis are provided. The moisture content and the ash value were found within the recommended normal range. The value of different hot extracts (Petroleum ether, Methanol, chloroform and Aqueous) is more than the cold extracts of drug. Keywords-  Habb-e-Suranjaan, Waj-al-Mafasil, Analgesic.

Humidity Effects on Fluidic Temperature Devices

1974 ◽  
Vol 7 (12) ◽  
pp. 463-468
Author(s):  
John O. Geremia ◽  
Chih Wu
Keyword(s):  
Moisture Content ◽  
Ideal Gas ◽  
Humidity Effects ◽  
Dry Air ◽  
Moisture Contents ◽  
Air Stream ◽  
Wide Range ◽  
Vapour Mixture ◽  
Thermodynamic Equations ◽  
The Ideal

A fluidic temperature device, designed by and obtained from The Harry Diamond Laboratories, was tested for stability when subjected to a variation of moisture content in an air stream. The device proved highly stable over a wide range of moisture contents. Slight variations in frequency were consistent with the variation predicted by the ideal gas behaviour of an air-water vapour mixture. The device is stable enough to be calibrated with dry air and corrected to any other humidity condition by application of the thermodynamic equations governing ideal gas mixtures.

Evaluation of a Bulk Drying Model for Peanuts1

1992 ◽  
Vol 19 (1) ◽  
pp. 1-7 ◽  
Author(s):  
M. Parti ◽  
J. H. Young
Keyword(s):  
Moisture Content ◽  
Thin Layer ◽  
Flow Rate ◽  
Test Results ◽  
Air Flow Rate ◽  
Moisture Movement ◽  
Moisture Contents ◽  
Air Temperatures ◽  
Thin Layer Drying ◽  
Drying Model

Abstract Results of a peanut bulk drying model, PEADRY8, have been compared with experimental test results for Virginia-type peanuts. The model describes the peanut pod as two separate components with moisture movement in both liquid and vapor form. The Henderson equation was used to describe the equilibrium moisture contents of the kernel and the hull. The following conclusions were drawn: (1) predicted drying times averaged 11% longer than the observed values; (2) predicted kernel moisture contents at the top of the wagons averaged 5% less than the measured values; (3) predicted hull moisture contents at the top of the wagons averaged 17% higher than the observed values; (4) predicted hull final moisture contents at the top of the wagons average 21% higher than measured values and (5) predicted exhaust air temperatures averaged 1% higher than measured values. An attempt was made to improve the fit of the observed and simulated results by changing the equation to describe the equilibrium moisture contents. The Chung-Pfost equation, compared to the Henderson equation, was more accurate in describing the hull moisture content and less accurate in describing the kernel moisture content history. Changing the reference air flow rate of the thin-layer drying relationship did not give a better fit between the observed and predicted data. Several drying simulations were found to be very sensitive to small changes in either wet-bulb or dry-bulb temperature. Small errors in wet-bulb temperature measurement could account for the predicted drying times for six experiments which were excessively long relative to observed values.

scholarly journals Effects of Moisture Content and Grain Direction on the Elastic Properties of Beech Wood Based on Experiment and Finite Element Method

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 610
Author(s):  
Wei-Lian Fu ◽  
Hui-Yuan Guan ◽  
Sawata Kei
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Moisture Content ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Beech Wood ◽  
Wood Products ◽  
Moisture Contents ◽  
Wide Range ◽  
Element Method

Beech wood (Fagus sylvatica L.) is used in a wide range of wood products. However, the influence of the wood’s moisture content on its mechanical functions will affect its structural strength. It would be complicated and time-consuming to experimentally measure wood’s mechanical functions under different moisture contents. Therefore, it is necessary to establish a prediction formula between the moisture content and elastic constants, and then verify whether its mechanical functions within a wide range of moisture content can be studied by using FEM (finite element method). In this study, which was based on experimentation, we studied the influence of a wide range of moisture contents and grain direction on the compressive yield strength, modulus of elasticity and shear modulus of beech wood. The relationship between the moisture content and elastic constants was established; the moisture sensitivities of different elastic parameters were obtained. Ultimately, compression curves under different moisture contents were plotted out, using both FEM and experimentation. According to the results, the interaction of moisture with the grain direction had a significant effect on the elastic constants of wood, with grain direction having a greater effect on the elastic properties than the moisture content. Moreover, the decay function can be used to fit these experimental results well. The elastic constants of beech wood responded differently to the moisture content, depending on whether it was in the longitude or transverse directions. Finally, this study proved the feasibility of using FEM to simulate wood’s compressive performance with a wide range of moisture contents.

USE OF SPIKE MOISTURE CONTENT AS AN ALTERNATIVE TO KERNEL MOISTURE CONTENT AND DAYS TO RIPE IN THE MEASUREMENT OF RELATIVE MATURITY IN SPRING WHEAT

1990 ◽  
Vol 70 (1) ◽  
pp. 99-105 ◽  
Author(s):  
J. B. THOMAS ◽  
P. J. CLARKE ◽  
G. B. SCHAALJE
Keyword(s):  
Triticum Aestivum ◽  
Regression Analysis ◽  
Moisture Content ◽  
Spring Wheat ◽  
Triticum Aestivum L ◽  
Joint Analysis ◽  
Wheat Cultivars ◽  
Moisture Contents ◽  
Wide Range

This study was undertaken to determine if the spike moisture content of ripening spring wheat (Triticum aestivum L. em. Thell.) could provide an accurate measure of kernel moisture content and whether spike moisture content could also substitute for days to ripe in evaluating the relative maturity of spring wheat cultivars. Starting with a large, unreplicated observation nursery, 65 plots were selected to represent a wide range in relative maturity and all parts of the nursery. Spike moisture content and kernel moisture content were determined for each plot as the earliest plots approached a kernel moisture content of about 20% while the latest were at about 50%. Joint analysis of these two variables (regression analysis and other procedures) showed that across this wide range of relative maturity, moisture contents of entire spikes gave virtually the same result as did a measurement of the moisture content of the kernels. This was true for wheats both with and without awns. In replicated cultivar trials, spike moisture content as the earliest cultivars approached maturity had similar normalized errors and was as closely correlated with yield as was days to ripe. Spike moisture content therefore appears suitable for use in the evaluation of relative maturity of different wheat cultivars.Key words: Kernel moisture, maturity, earliness, yield

Effect of moisture content and soil type on self diffusion of 86Rb in soils

1963 ◽  
Vol 60 (2) ◽  
pp. 239-244 ◽  
Author(s):  
I. J. Graham-Bryce
Keyword(s):  
Diffusion Coefficient ◽  
Moisture Content ◽  
Diffusion Coefficients ◽  
Pore Space ◽  
Considerable Effect ◽  
The Self ◽  
Self Diffusion ◽  
Moisture Contents ◽  
Wide Range ◽  
Self Diffusion Coefficient

Self-diffusion coefficients (D) for Rb+ have been measured in a heteroionic Lower Greensand soil over a wide range of moisture contents at three different compactions. The moisture content is shown to have a considerable effect on the value of the self-diffusion coefficient, a rapid rise in the value of D taking place between 5 and 10% moisture content. It is shown that this effect is not simply due to the increased volume of water-filled pore space at higher moisture contents, and other possible factors which could influence the shape of the diffusion coefficient/moisture content curve are discussed. Diffusion coefficients for Rb+ in eight other soils at pF 2 are also reported, but no simple correlation with any of several soil properties measured could be found. A value of 1·0 × 10−7cm2/sec. would seem to be a reasonable generalization for the self-diffusion coefficient of Rb+ in moist calcium-dominated soils.

scholarly journals Artificial drying of safflower seeds at different air temperatures: effect on the physiological potential of freshly harvested and stored seeds

2019 ◽  
Vol 41 (4) ◽  
pp. 397-406 ◽  
Author(s):  
Guilherme Cardoso Oba ◽  
André Luís Duarte Goneli ◽  
Tathiana Elisa Masetto ◽  
Cesar Pedro Hartmann Filho ◽  
Karina Laís Leite Sarath Michels ◽  
...  
Keyword(s):  
Seed Germination ◽  
Moisture Content ◽  
Air Temperature ◽  
Safflower Seed ◽  
Water Removal ◽  
Drying Process ◽  
Moisture Contents ◽  
Air Temperatures ◽  
Physiological Quality ◽  
And Storage

Abstract: The air temperature used in the drying process can determine the initial physiological quality and storage potential of a seed lot, which is the object of this study. Safflower seeds, harvested at a moisture content of 25.8%, were subjected to drying in an experimental dryer at air temperatures of 40, 50, 60 and 70 °C until reaching a moisture content of 6.6 ± 0.6%. Immediately upon drying and every 60 days after that, up to 240 days of storage under uncontrolled conditions, seed samples were collected to determine physiological quality. Increasing drying air temperature resulted in higher water removal rates, promoting immediate and latent damage to seed physiological quality, evidenced by the reduction in the percentage and speed of root protrusion, first count, and germination, mainly at temperatures of 60 and 70 °C. For the maintenance of safflower seed germination and vigor up to 240 days of storage, it is recommended that drying air temperature does not exceed 40 °C, especially when seeds present moisture contents close to or higher than 25.8% at the drying moment.

scholarly journals Temperature and Seed Moisture Govern Storage Duration and Germination of Phlox drummondii

HortScience ◽  
1993 ◽  
Vol 28 (3) ◽  
pp. 185-188
Author(s):  
W.J. Carpenter ◽  
E.R. Ostmark ◽  
J.A. Cornell
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Storage Duration ◽  
Moisture Contents ◽  
Long Term Storage ◽  
Seed Moisture ◽  
Wide Range ◽  
Phlox Drummondii ◽  
Term Storage

Phlox drummondii Hook seed germinated well over a wide range of constant or alternating temperatures. Germination percentages at constant temperatures of 10 to 25C ranged from 94% to 98% for `Light Salmon' and from 83% to 88% for `Deep Salmon'. No seeds germinated at constant 30C. Total germination percentages at alternating temperatures ranged from 93% to 99% for `Light Salmon' and 67% to 82% for `Deep Salmon'. For both cultivars, the number of days to 50% of final germination (T50) and between 10% and 90% germination (T90-T10) decreased as constant temperatures or the median for alternating temperatures rose from 10 to 20C. The seeds had only limited desiccation tolerance. Reducing the moisture content of stored seed from 9 % to 5 % did not reduce total germination significantly, but 5% to 6% seed moisture levels increased the days to T50 and T90-T10 compared with higher moisture contents. The relative humidity and temperature that phlox seed received during long-term storage influenced germination. After seed was stored at 5C, germination generally was higher, earlier, and more uniform than after storage at 15 or 25C. The highest total germination percentages and shortest T50 and T90-T10 occurred following storage for 12 months at 5C and 20% to 40% relative humidity.

Experimental Investigation of Biomass Pellets and Pelletizing Process Using Hardwood and Switchgrass

2014 ◽  
Author(s):  
Kyle Eggerstedt ◽  
Xia Wang
Keyword(s):  
Activation Energy ◽  
Fossil Fuels ◽  
Energy Content ◽  
Energy Resource ◽  
Ash Content ◽  
Combustion Characteristics ◽  
Renewable Energy Resource ◽  
Moisture Contents ◽  
Different Types ◽  
Biomass Materials

Biomass fuel has been utilized as a renewable energy resource to replace or supplement fossil fuels. Combustion characteristics of biomass affect the utilization of biomass pellets. Activation energy, ash content, energy content, moisture content, density, and durability are a few parameters that are analyzed for ideal combustion. An ideal fuel can be created through analyzing multiple biomass materials and pelletizing procedures. The objective of this research is to improve biomass performance by investigating its pelleting parameters and the related combustion characteristics. A lab scale pelletizing process was developed with the pelletizing conditions being 150°C for 150 seconds under a pressure of 4500 psi. A total of 45 different types of pellets with a diameter of 2.5cm and a thickness of 5mm were created using the new pelletizing process. They had five different material mixtures (100% hardwood (HW), 75/25hardwood/switchgrass (HS), 50/50HS, 25/75HS, and 100% switchgrass (S)), three different original moisture contents (15%, 20%, and 25%), and 3 different amounts of binder (1/6, 1/12, and 0). Trends of the combustion characteristics to pelletizing process parameters were found. When the material mixture changes from pure hardwood to pure switchgrass, both activation energy decreases while ash content increases. When the binder decreases, activation energy increases as well as ash content while both energy content and durability decrease.

Vulnerability of sweet cherry cultivars to continuous periods of spring frosts in Plovdiv, Bulgaria

2020 ◽  
Vol 12 (4) ◽  
pp. 348-352
Author(s):  
S. Malchev ◽  
S. Savchovska
Keyword(s):  
Sweet Cherry ◽  
Weather Conditions ◽  
Frost Damage ◽  
Cold Weather ◽  
Bud Burst ◽  
Intermediate Group ◽  
Air Temperatures ◽  
Wide Range ◽  
Group Form ◽  
Sweet Cherry Cultivars

Abstract. The periods with continuous freezing air temperatures reported during the spring of 2020 (13 incidents) affected a wide range of local and introduced sweet cherry cultivars in the region of Plovdiv. They vary from -0.6°C on March 02 to -4.9°C on March 16-17. The duration of influence of the lowest temperatures is 6 and 12 hours between March 16 and 17. The inspection of fruit buds and flowers was conducted twice (on March 26 and April 08) at different phenological stages after continuous waves of cold weather conditions alternated with high temperatures. During the phenological phase ‘bud burst’ (tight cluster or BBCH 55) some of the flowers in the buds did not develop further making the damage hardly detectable. The most damaged are hybrid El.28-21 (95.00%), ‘Van’ (91.89%) and ‘Bing’ (89.41%) and from the next group ‘Lapins’ (85.98%) and ‘Rosita’ (83.33%). A larger intermediate group form ‘Kossara’ (81.67%), ‘Rozalina’ (76.00%), ‘Sunburst’ (75.00%), ‘Bigarreau Burlat’ (69.11%) and ‘Kuklenska belitza’ (66.67%). Candidate-cultivar El.17-90 ‘Asparuh’ has the lowest frost damage values of 55.00% and El.17-37 ‘Tzvetina’ with damage of 50.60%.

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