Engineering Approach for Computation of the Energy Consumption Needed for Defrosting and Subsequent Heating of Frozen Wood Chips

2016 ◽  
Vol 688 ◽  
pp. 50-56
Author(s):  
Nencho Deliiski ◽  
Anton Geffert ◽  
Jarmila Geffertova ◽  
Veselin Brezin ◽  
Izabela Radkova
Keyword(s):  
Energy Consumption ◽  
Moisture Content ◽  
Wood Chips ◽  
Specific Mass ◽  
Wood Moisture ◽  
Suggested Approach ◽  
Engineering Approach ◽  
Easy Calculation ◽  
Subsequent Heating

An engineering approach for the calculation of the specific mass energy consumption, which is needed for defrosting and the subsequent heating of the frozen wood chips above the hydroscopic range, (in kWh·t-1), has been suggested. Equations for easy calculation of have been derived, depending on the wood moisture content u, on the fiber saturation points of the wood species at 20 °C and at –2 °C (i.e. at 293.15 K and at 271.15 K), and respectively, on the initial chips’ temperature, T0 , and on the final temperature of the heated after their defrosting chips, T1.For the calculation of the according to the suggested approach and equations a software program has been prepared in MS Excel 2010. With the help of the program calculations have been carried out for the determination of the energy consumption , which is needed for defrosting and subsequent heating of oak, acacia, beech, and poplar frozen chips with moisture content in the range from u = 0.4 kg·kg-1 to u = 1.0 kg·kg-1, initial temperature t0 = –20 °C and t0 = –10 °C until reaching of the chips‘ mass temperature of t1 = 80 °C, t1 = 100 °C, and t1 = 120 °C at the end of the heating.

scholarly journals Computing the heat flux required for warming up of frozen wooden prisms for veneer production in the beginning of their autoclave steaming

2021 ◽  
Vol 1208 (1) ◽  
pp. 012021
Author(s):  
Nencho Deliiski ◽  
Dimitar Angelski
Keyword(s):  
Heat Flux ◽  
Moisture Content ◽  
Steam Generator ◽  
Heat Fluxes ◽  
Heat Power ◽  
Wood Moisture ◽  
Medium Temperature ◽  
Suggested Approach ◽  
Loading Level ◽  
In The Beginning

Abstract An approach for computing the heat flux required for warming up of frozen wooden prisms in the regimes for their autoclave steaming at limited heat power of the steam generator, depending on the dimensions of the prisms cross section, wood moisture content, and loading level of the autoclave has been suggested. The approach is based on the use of two personal mathematical models: 2D non-linear model of the temperature distribution in subjected to steaming frozen wooden prisms and model of the non-stationary heat balance of autoclaves for steaming wood materials. For numerical solving of the models and practical application of the suggested approach, a software program was prepared in the calculation environment of Visual FORTRAN Professional developed by Microsoft. Using this program computation and research of the non-stationary change of the processing medium temperature and heat fluxes in an autoclave with a diameter of 2.4 m, length of 9.0 m and loading level of 50% at a limited heat power of the steam generator, equal to 500 kW during the initial part of the steaming in it of frozen beech prisms with different moisture content have been carried out. The suggested approach can be used for computing and model based automatic realization of energy efficient optimized regimes for autoclave steaming of different wood materials.

scholarly journals Sago Bark as Renewable Energy

2014 ◽  
Vol 5 (2) ◽  
pp. 29-34
Author(s):  
Chong K.H. ◽  
Law P.L. ◽  
Rigit A.R.H. ◽  
Baini R. ◽  
Shanti F.S.
Keyword(s):  
Moisture Content ◽  
Waste Product ◽  
Palm Kernel ◽  
Wood Chips ◽  
Paddy Straw ◽  
Biomass Waste ◽  
Heating Value ◽  
Value Determination ◽  
Sago Bark

 Much research has been done on the determination of the heating value of biomass waste, but currently no research is being done on the heating value of sago bark. In Malaysia, sago bark is an abundant waste product from sago starch extraction. This study presents the moisture content and heating value determination of paddy straw, empty fruit bunch (EFB), sago bark, oil palm kernel shell (OPKS), and wood chips. The moisture content and heating value of the investigated biomass were determined according to the British Standard EN 1477-2:2009 and bomb calorimeter, accordingly. It was observed that paddy straw recorded the highest moisture content at 97.75% wt. This was followed by EFB 95.34% wt., sago bark 96.05% wt., OPKS 95.28% wt. and wood chips 11.61% wt. In the dry state, wood chips had the highest heating value, with a value recorded as approximately 22.41 MJ kg-1, followed by OPKS 21.40 MJ kg-1, sago bark 19.56 MJ kg-1, EFB 17.82 MJ kg-1 and paddy straw 15.33 MJ kg-1. Current experimental trials suggest that the heating value of sago bark makes it suitable for use for co-firing with coal power generation.

scholarly journals Improved method based on dual-energy X-ray absorptiometry for nondestructive evaluation of solid wood moisture content

Holzforschung ◽  
2015 ◽  
Vol 69 (9) ◽  
pp. 1133-1136 ◽  
Author(s):  
Takashi Tanaka
Keyword(s):  
Moisture Content ◽  
Pure Water ◽  
Solid Wood ◽  
Dual Energy ◽  
Wood Moisture ◽  
Strong Negative Correlation ◽  
X Ray ◽  
Wide Range ◽  
Better Than

Abstract An accurate, rapid, and convenient method is presented for moisture content (MC) determination of solid wood based on dual-energy X-ray absorptiometry (DXA). Poly(methyl methacrylate)-equivalent thicknesses (PMMA-EThs) of sugi (Cryptomeria japonica D. Don) wood blocks and pure water were measured by means of a wide range of X-ray tube voltages (20–100 kV). The ratio of the PMMA-ETh of pure water to that of wood decreased as X-ray tube voltage was increased, suggesting that an appropriate pair of tube voltages for DXA is 20 and 100 kV. According to this result, X-ray images of 30 wood samples were taken at 20- and 100-kV tube voltages, and their average PMMA-Eths from both images was determined. There was a strong negative correlation between the wet-basis MC of the wood sample and the ratio of its PMMA-Eth at 100 kV to that at 20 kV. A regression equation was developed for estimating the dry-basis MC of wood samples from their PMMA-ETh ratios. The standard error of estimate was 2.2%, which is better than those determined for electric moisture meters. This approach may lead to the development of a practical, nondestructive moisture meter for wood.

Numerical Approach for Computation of the Heat and Heat Flux for Covering of the Emission in the Surrounding Air of Subjected to Unilateral Heating Flat Wood Details before their Bending

2016 ◽  
Vol 688 ◽  
pp. 153-159
Author(s):  
Nencho Deliiski ◽  
Neno Trichkov ◽  
Dimitar Angelski ◽  
Ladislav Dzurenda
Keyword(s):  
Heat Flux ◽  
Energy Consumption ◽  
Temperature Distribution ◽  
Moisture Content ◽  
Numerical Solution ◽  
Initial Temperature ◽  
Numerical Approach ◽  
Surrounding Environment ◽  
Unilateral Heating

A numerical approach for the computation of the specific (for 1 m2) energy consumption, qe, and the specific heat flux, dqe/dτ, needed for covering of the emission in the surrounding environment of the subjected to unilateral heating flat wood details aimed at their plasticizing and following bending has been suggested. The approach is based on the integration and differentiation of the solutions of a linear model for the calculation of the non-stationary 1D temperature distribution along the thickness of subjected to unilateral heating flat wood details, suggested by the authors earlier.For the numerical solution of the model aimed at the determination of qe and dqe/dτ software program has been prepared, which was input in the calculation environment of Visual Fortran. Using the program, computations have been carried out for the determination of the change in the energy qe and in the flux dqe/dτ, which are consumed by spruce details with an initial temperature of 20 °C, moisture content of 0.15 kg·kg-1, and thicknesses of 6 mm, 8 mm, and 10 mm during their 10 min unilateral heating at temperatures of the heating metal band of 100 °C, 120 °C, and 140 °C and of the surrounding air of 20 °C. The obtained results are graphically presented and analyzed.

Examination of moisture content variation within an operational wet deck

TAPPI Journal ◽  
2013 ◽  
Vol 12 (1) ◽  
pp. 45-50 ◽  
Author(s):  
LAURENCE SCHIMLECK ◽  
KIM LOVE-MYERS ◽  
JOE SANDERS ◽  
HEATH RAYBON ◽  
RICHARD DANIELS ◽  
...  
Keyword(s):  
Moisture Content ◽  
Southeastern United States ◽  
Forest Products ◽  
Time Domain Reflectometry ◽  
Water Application ◽  
Wood Moisture ◽  
International Paper ◽  
Content Variation ◽  
Moisture Variation

Many forest products companies in the southeastern United States store large volumes of roundwood under wet storage. Log quality depends on maintaining a high and constant wood moisture content; however, limited knowledge exists regarding moisture variation within individual logs, and within wet decks as a whole, making it impossible to recommend appropriate water application strategies. To better understand moisture variation within a wet deck, time domain reflectometry (TDR) was used to monitor the moisture variation of 30 southern pine logs over an 11-week period for a wet deck at the International Paper McBean woodyard. Three 125 mm long TDR probes were inserted into each log (before the deck was built) at 3, 4.5, and 7.5 m from the butt. The position of each log within the stack was also recorded. Mixed-effects analysis of variance (ANOVA) was used to examine moisture variation over the study period. Moisture content varied within the log, while position within the stack was generally not significant. The performance of the TDR probes was consistent throughout the study, indicating that they would be suitable for long term (e.g., 12 months) monitoring.

Determination of grinding parameters of fenugreek seed

1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Feed Rate ◽  
Average Particle Size ◽  
Specific Energy Consumption ◽  
Average Particle ◽  
Fenugreek Seeds ◽  
Fenugreek Seed

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  

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