PDF Publication Title:
Text from PDF Page: 049
kT rl kR rl kL rl =(S )3, w =kT, rl =(S )8. w (55) The relative gas permeability is defined respectively in the tangential, radial and longitudinal directions as: kT rg kR rg kL rg =1+(2S −3)(S )2, w w =kT , rg =1+(4S −5)(S )4. w w (56) Intrinsic Permeability Intrinsic permeability values are essential wood properties for the development of an accurate wood drying model and were therefore, measured as part of this study. We measured the gas permeabilities for each species as detailed in section 3.4 Drying modelling - Measurement of essential wood properties. The liquid permeability values were given the same values as for the gas permeabilities as pit aspiration does not apply for hardwoods. Gaseous Diffusion (Deff) The gaseous diffusion is defined respectively in the tangential, radial and longitudinal directions as (Perré and Turner, 2008): DT =10−3×kT×D, eff rgv D R = 2 × DT , , where Dv is the mass diffusivity of vapour in the air phase. eff eff DL =100×DT eff eff Diffusivity of vapour (Dv) (57) The diffusivity of vapour in gas is defined as (Perré and Turner, 2008, Bird et al., 1960): 1.013×105 T 1.75 (58) Dv =2.2×10−5 P 273 Bound Water Diffusion (Db) – Theory Initial simulations used theoretical bound liquid diffusivities, detailed by Perré and Turner (2008) and summarized below. In this section, we assume the gradient of bound water is the driving force. This allows two pseudo-diffusivities to be defined (bound water in the cell wall and air in the pores): (59) 42 Evaluation of super–heated steam vacuum drying viability and development of a predictive drying model for Australian hardwood species – Final report ˆ Db =ρsDb, M ∂P Dv=vDv v, ˆ RT ∂Xb ˆ 4300 Db =ρs exp−12.8183993+10.8951601Xb −T+273.15 Using homogenisation results, we propose the following correlations:PDF Image | Evaluation of super-heated steam vacuum drying
PDF Search Title:
Evaluation of super-heated steam vacuum dryingOriginal File Name Searched:
PN08_2047_Vacuum_Drying_Reviewed_Report.pdfDIY PDF Search: Google It | Yahoo | Bing
5,000 BF Shipping Container Lumber Dry Kiln For Quality Lumber The 5,000 BF container kiln consists of one 40 foot high-cube aluminum shipping container... More Info
Shipping Container Lumber Dry Kilns by Global Energy Global Energy designed and developed the container kiln back in 1991. The purpose is to give access to portable sawmill owners, furniture makers, and small business the value added profit of dry kiln lumber and quality hardwoods... More Info
Vacuum Kiln Conversion Kit for Lumber and Wood Dry Kilns Convert your existing conventional dry kiln into a fast drying vacuum kiln. Similar to vacuum bagging in the boat building and aircraft industry, we have come up with a proprietary process which allows you to build a very simple vacuum kiln at a fraction of the price, and without the intensive conventional metal chamber structure... More Info
Vacuum Pump Cart System for Bagging Clamping Wood Drying and more Vacuum Cart with 2HP Pump and Dual Pistons with multiple multiplex vacuum ports and liquid reservoir... More Info
Vacuum Bagging Basics Vacuum bagging is a method of clamping, which has traditionally been used in the composites industry, but can also be used for vacuum drying materials, including wood products... More Info
CONTACT TEL: 608-238-6001 Email: greg@globalmicroturbine.com (Standard Web Page)