PDF Publication Title:
Text from PDF Page: 040
Drying Schedules The combination of temperature, relative humidity (or EMC), and velocity - that is, the schedule - that is correct is the combination that dries the lumber at the correct, safe rate without causing degrade. As mentioned earlier, there are many combinations that will work well with a given species and thickness. So there is no one correct schedule. However, the U.S. Forest Products Laboratory in the 1950's developed a systematic approach to schedule development. This systematic approach has many advantages, when compared to a random schedule development process. The advantage today from their approach is that every recommended schedule has been used for over thirty years to dry millions, if not billions, of board feet of lumber successfully. There is something comforting about that, especially when a kiln has $50,000 (or more) worth of lumber in it. U.S. Forest Products Laboratory Schedules The philosophy of the U.S. FPL schedules is based on the four Stages of drying mentioned earlier. • • • • • The schedules also were developed with the assumption that there may be slight variations in equipment and conditions. This necessitated building in a safety factor. Therefore, almost all of the schedules are conservative. With better, more accurate and more reliable controls possible today, this conservatism is no longer necessary. In other words, the old schedules can be accelerated safely with today's modern equipment. All the U.S. FPL schedules have a four character code, such as T4-D2. A master code listing is given in the book Kiln Schedules for Commercial Woods, available from the U.S. Forest Products Laboratory at no cost. The coding system works as follows: Keep an initial mild condition for the loss of the first 1/3 of the moisture, the degree of mildness depending on the likelihood of surface checking. Slowly lower the relative humidity, beginning after the first 1/3 of the green moisture is lost. Keep the temperature low until average MC is below 30%, the actual temperature depending on the species and its degrade risk. Slowly raise the temperature after the average MC is below 30%. Equalize and condition at the end of drying. 40PDF Image | Principles and Practices of Drying Lumber
PDF Search Title:
Principles and Practices of Drying LumberOriginal File Name Searched:
DryingLumber.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)