2 edition of Drying rates of Douglas fir veneer in superheated steam found in the catalog.
Drying rates of Douglas fir veneer in superheated steam
George Harry Atherton
Written in English
|Statement||by George Harry Atherton.|
|The Physical Object|
|Pagination||67 leaves, bound :|
|Number of Pages||67|
Two Common Wood Movement Disasters quartersawn face grain flat-sawn face grain (arched cathedral) flat sawn: growth rings are less than 45° to face quartersawn: growth rings growth rings are 45° to 90° are 45° to 90° to face All you need to do is multiply three num-bers together. Here's how to find Size: KB. difference,however,appearedinthecoalconsump- tion,for it required a muchlargerquantity of coa-l to evaporate the water and superheat the steam thanitdidtosimply evaporate. 38 p., illus., plans, 28 cm. [Commercial Standards (such as CS, ¡®Douglas Fir Plywood.¡¯] Panels are stamped with a grade mark, unless such a stamp would deface a high quality surface that might be given a natural finish. Such grades are marked on the edges. Dimensions; Veneer grades; Species group number.
Shadows & Substance
Psychiatry and criminal law
D. L. Moody at home.
Doses of diet and drugs
Chemical treatment of acid mine drainage: workshop notes
The interrelatedness of playfulness, communion, and human transcendence
Substance Use Among Young People in Urban Environments
List of lieutenants of counties of England and Wales, 1660-1974
Structure of Modern Commerce
Temperatures above ° F to a controlled final moisture content. The equipment to do this must precisely control the temperature, steam pressure, and superheat in the steam.
Nevertheless, the technical advantage of being able to control the final moisture content of the veneer are important enough so that it isFile Size: KB. A superheated steam fluidized bed drying system has been designed on an industrial scale [5, 6].
Detailed specifications of a SSFBD, however, must be fixed in accordance with a certain grade of. This paper presents a comprehensive overview of state-of-the-art of design aspects, energetic performances, and mathematical modeling on superheated steam drying (SSD).
In fact, SSD is presented as an efficient drying method because of its high energy efficiency, safety, high drying rate, and high quality of final by: Impingement drying rates can be about twice as high for drying in superheated steam as in air. A hybrid cycle was developed in which drying is partially by superheated steam impingement drying and.
The Canadian Journal of Chemical Engineering, published by Wiley on behalf of The Canadian Society for Chemical Engineering, is the forum for publication of high quality original research articles, new theoretical interpretation or experimental findings and critical reviews in the science or industrial practice of chemical and biochemical processes.
Green Veneer. Douglas Fir – The vast majority of the veneer that we manufacture is Douglas Fir due to the quality of the species’ wood fiber. Our preferred peel thicknesses in Douglas Fir are 1/10” and 1/8”.
Green veneer grades include CD, AB, Utility, and Natural (N) or High Density (HD). • SS drying relies on: – saturated steam equilibrium – superheat of steam P=P a+P v ΔS= ΔQ T 30oC s T dp T 1 oC t sat Wet steam Super- Heated Steam 1 2 1 2 50°C s • Conventional air drying depends on: – psychrometric equilibrium.
However,the drying rate in superheated steam is lower than in dry air if the temperature is below the inversion temperature.
Above the inversion temperature, superheated steam is a more effective drying agent than humid air or even than dry air (3). The period of drying at a constant rate is longer for superheated steam drying. There are two methods of drying at temperatures above F: in drying with superheated steam, the kiln is filled with steam to the exclusion of air; high-temperature drying requires a mixture of air and - steam and resembles conventional drying where relative humidity is controlled.
High-temperature drying is not a new process; as early as Title: Kiln drying douglas fir common lumber Author: Forest Products Laboratory Subject: no; ; year: January 20 Keywords: Kiln drying; Douglas fir. LPSSD — low pressure superheated steam drying, SSD — superheated steam drying, VD — vacuum drying, HAD — hot air drying, FIR — far infra-red, redness (a*), yellowness (b*).
Drying of potato slices was carried by SSD (– °C) and HAD (– °C) Cited by: superheated steam mixtures gained industrial acceptance in Germany and later spread outside of the country (Kollmann ). Today, besides for the increased drying rates, drying of lumber in superheated steam at sub-atmospheric to high pressures may provide additional benefits.
These. SUPERHEATED STEAM/VACUUM DRYING TIMES FOR THICK LUMBER Luiz C. Oliveira J.F.G. Mackay Forintek Canada Corp. Vancouver, B.C. Background Superheated SteamNacuum (SS/V) drying is a process in which the lumber is dried under a vacuum and. Drying has a number of close synonyms. Dehydration is the process of depriving a material of its water or the loss of water Drying rates of Douglas fir veneer in superheated steam book a constituent.
The term is often used in food-drying operations to describe processes which strive to expel moisture but retain other volatile constituents in the original material, and which are responsible for valuable aromatic and flavoring properties.
Douglas-fir Shrinkage and Dimensional Stability Douglas-fir is an important building timber in North America, particularly in the Pacific north West, where it has a reputation for being naturally dimensionally stable – the ability to “season well in position” and retaining its shape during use (WWPA, ).File Size: KB.
Effects of superheated steam on the drying of rubberwood Yamsaengsung, R. and Buaphud, K. unity for tannins to oxidize, the color of the wood is maintained through steam drying. Douglas () used steam to dry paper. He found that for paper made from mechanicals pulps, drying in superheated steam produced better-bonded sheet.
Superheated steam drying needs to be performed at reduced pressure when drying heat-sensitive products, as this lowers the boiling point of water and thus the thermal damage. The drying system is more complex with regard to feeding and discharge of products as air leaking and steam leaking out, respectively, need to be prevented.
Model# X2-DMC. Free delivery with $45 order. Set your store to see local. Alexandria Moulding Douglas Fir S4SE4E 1 in. x 3 in. Mixed Grain Board (Actual: in.
x in. x 96 in.) Model# X3-DMC. Free delivery with $45 order. Set your store to see local. Microllam in. x in. x 17 ft. E LVL with Watershed • Drying medium (steam) > oC Features of the drying systems Wolfgang Gard, EDG Conference Riga/Latvia, @ 12 The Netherlands 0 20 40 60 80 0 5 10 15 20 25 time (h) air temperatur [°C] wetbulb temperatur [°C] wood temperature [°C] moisture content [%] EMC [%] Drying schedule Warming up Drying above File Size: 4MB.
Information from N.S.W. veneer producers, with discussion 14 Drying rates Screened driers Continuous driers Shrinkage Flooded gum Scribbly gum Blackbutt White gum Messmate Silvertop stringybark Tentative allowances for.
This paper presents comparison and analysis of thermal-dynamic characteristics of air-drying and superheated steam drying under vacuum. The result reveals that for both convective heat transfer coefficient and resistance of mass transfer on the surface, superheated steam drying under vacuum is superior to air-drying under the same by: 3.
Steam Tables: Properties of Saturated and Superheated Steam Paperback – January 1, out of 5 stars 2 ratings See all 3 formats and editions Hide other formats and editions/5(2).
I took some trees down around Feb of this year, so got them split and stacked at the same time. Today I split some of the logs to check the moisture content, on the inside it is around 22% and outside is under 15%. The question is in another. the drying medium temperature.
Dust collection in superheated steam drying is much simpler by passing the excess vapour through condensers (Trommelen & Crosby, ). Deventer and Heijmans () gave some examples in regards to steam drying benefits and restrictions of superheated steam drying.
Pronyk et al. Douglas-fir 15 A actual time to % MC was hours B as carbon NCASI Method ISS/FP-A was used to measure the MACT HAP emissions. The results are shown in Table 2. The sum of the HAPs emitted was lb/mbf for Douglas-fir. TABLE 2. Summary of HAP results for moisture content and time in Table 1 for charge 2 only.
Fir, Douglas-Quartered, Vertical Grain Veneer Veneer Description: The heartwood of this veneer is a light reddish-brown shade with a prominent growth ring figure. The wood is straight grained. Scientific Name: Pseudotsuga menziesii.
Family: Pinaceae. Other Names: British Columbian pine, Oregon pine. Published information on estimated air-drying times of lumber is of limited usefulness because it is restricted to a specific location or to the time of year the lumber is stacked for drying.
At best, these estimates give a wide range of possible times over a broad range of possible locations and stacking dates. In this paper, we describe a method for estimating air-drying times for specific. Veneer Drying and Measurement All the test veneer was dried in conventional steam-heated driers during the same working day it was peeled.
The dry veneer was graded by company graders underthe supervision of a Douglas Fir Plywood Association supervisor. The grading was done in ac- cordance with Commercial Standard CS 55 for Douglas -fir ply.
Drying rates of douglas fir veneer in superheated steam Comercio de tecnologu00eda New colleges of further education Earth sheltered buildings Selected bibliography Fuel cells energy utilization act.
SUPERHEATED STEAM DRYING (SSD) • Proposed over years ago; received serious attention only during the past years • Uses superheated steam instead of hot air or combustion/flue gases in a direct (convection) dryer • More complex equipment than hot-air drying system;leak- proofing needed; feed/discharge can be difficult.
Steam Tables: Properties of Saturated and Superheated Steam [Combustion Engineering-Superheater Inc] on *FREE* shipping on qualifying offers. Steam Tables: Properties of Saturated and Superheated SteamAuthor: Combustion Engineering-Superheater Inc.
thespecificheatofsuperheated steam by arthirsariailgrossberg1 thesisforthedegreeofbachelorofscience inmechanicalengineering inthe collegeofengineering ofthe.
FormWood Industries is a North American manufacturer of custom veneer faces, flexible veneer, NBL wood-on-wood laminates, architectural veneer plywood, and edgebanding.
Producers of furniture, casegoods, cabinets, store fixtures, perimeter walls, doors, dash boards, and boat interiors have relied on our products and technical assistance since Drying with superheated steam is evaluated in lumber from different Spanish softwoods (Pinus pinaster, radiata, sylvestris andnigra) and hardwoods (Eucalyptus globulus andPopulus sp.).
Major problems with softwoods seem to be related to high resin content and encased knots. Problems with hardwood drying are related to permeability, collapse and checking by: 6. Douglas-fir A actual time to % MC was hours B as carbon NCASI Method ISS/FP-A was used to measure the MACT HAP emissions.
The results are shown in Table 2. The sum of the HAPs emitted was lb/mbf for Douglas-fir. Table 2. Summary of HAP results for moisture content and time shown in Table Size: 1MB.
Re: Steam-drying wood Your first couple of planks will probably have a good bit of twist in them so the bit of extra moisture in there to help transfer the heat will allow them to bend easier. If you are worried about being too wet, just re-saw them now and it would only take a little while for the timber to dry at that thickness.
Douglas fir is very dimensionally stable and has a moderate resistance to shock, high stiffness and crushing strength, and high bending strength. It takes well to lamination but isn't recommended for steam bending.
At 12% moisture content it has a specific gravity of. Plywood in Retrospect The Aircraft story is the 15th in a chronological series of historical monographs on the early Douglas fir plywood mills. Aircraft faced ruin soon after starting when a favorable contract with a large automobile body manufacturer was canceled.
Bill Bailey, Aircraft’s General Manager, salvaged theFile Size: KB. Been poking around various threads looking for info on the best time to tip over Douglas fir. I want to rough mill them next summer into boards and beams for air drying, and am of the understanding that they should be cut during winter months when the sap has dropped into the roots, thereby decreasing drying time.
Quick Tips to Use Douglas Fir Flooring in the Bathroom (Octo ) Texture, Coloring, and Authenticity: Breaking Down the Rustic Hardwood Flooring Trend (Octo ) How to Use Douglas Fir Flooring in the Kitchen (October 9, ) The Heart of the Home: How to Use Douglas Fir Flooring in the Living Room.
Figure 1 and table 3 showed that the EMC values of alder, beech and spruce panels decreased significantly with high temperature veneer drying. Spruce plywood panels had the highest EMC values followed by alder and beech panels. The highest average EMC value (11,79%) was obtained for spruce plywood panels manufactured from veneers dried at 20°C, while beech panels manufactured from Cited by: 2.Full text of "List of publications on kiln drying, physical properties of wood, wood structure" See other formats.Steam is commonly used in industrial environments for power generation and in heating and drying applications.
On a paper or board machine, steam is used to dry the sheet of paper or board to a target moisture content before it is wound up on large rolls that can be transported, stored, or shipped.