PDF Publication Title:
Text from PDF Page: 002
FIGURE 1. Picture of RFV kiln . The reduction of pressure inside a vacuum chamber reduces the boiling point of water. This method is commonly called radio frequency vacuum (RFV) drying and the principal attraction is that the drying process temperature can be considerably lower than that used in kiln conventional drying, thus reducing the occurrence of drying defects combined with the considerably faster drying times. RF heating is considered as volumetric heat transfer where thermal energy is produced simultaneously throughout a pile of lumber placed in an electromagnetic field. Because of this phenomenon, there are no steep temperature profiles formed and transfer of moisture from the center areas towards the surface of wood begins immediately upon exposure to the field. There is no need for heating elements (non-contact process) between each layer or lumber stickering, thus reducing handling costs. Furthermore, the rate of heating is a function of the electric field and the lumber dielectric characteristics and not the thickness of individual pieces of lumber. In RFV drying, because of the simultaneous heat generation within the body of a drying piece of lumber and the piling method (no stickers), the temperature and moisture gradients develop from the center to the surface. Furthermore, because of the high vapor pressures reached in a very short time throughout, free water in both liquid and vapor phase is "pushed" primarily along the longitudinal direction of the wood (path of least resistance) which happens to be the length of a piece of lumber, and where bulk flow is very fast due to very high longitudinal permeability coefficients since longitudinal-to- transverse permeability ratio of over 10,000 (assuming zero grain angle). As a result, Western Dry Kiln Association 37 May, 2000PDF Image | COMMERCIAL RFV KILN DRYING
PDF Search Title:
COMMERCIAL RFV KILN DRYINGOriginal File Name Searched:
Commercial_RFV_ocr.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 | RSS | AMP |