Dry kiln operators manualintro, glossary, index publication. If we say that wood moisture content is 10%, it means that in peace of that wood which would weight g when absolutely dry there is 100 g of water. United states agriculture dry kiln forest service operators. It is, therefore, the responsibility of the kiln operator to control temperature, humidity, circulation and ventilation to achieve the best drying rate without creating kiln degrade. As an example, an 18wheeler can haul about 7500 bf of green oak without exceeding the load limits, but can haul 12,500 bf of dried lumber. Dry kiln operators manual agriculture handbook ah188. Fundamental aspects of kiln drying lumber oklahoma state. A welldesigned and properly operated dry kiln can in a few days or weeks turn green lumber fresh from the. Dry kiln operators manual treesearch forest service usda. Table 2 shows the optimum load capacities for the ld800. Dry kiln operators manual enter your mobile number or email address below and well send you a link to download the free kindle app. It is important to remember that the dehumidification system and the chamber together form a dry kiln, and that successful and efficient drying will depend on an air tight, wellinsulated and properly designed chamber. Solar kiln operation started by tree feller on drying and processing. Kiln baffles after the kiln has been loaded, all top, side, and bottom baffles must be set in place so that air will be forced through the lumber packages.
Dry kiln operator s manual agricultural handbook no. Dry kiln operators manual mississippi state university. Introduction, glossary, and index pdf 424 kb chapter 1properties of wood related to drying pdf 750 kb chapter 2kiln types and features pdf 3. Agricultural quarantine inspection monitoring aqim handbook pdf. Lumber drying begins at mild conditions followed by a series of speciesspecific temperature increases and lowering of relative humidity, termed the kiln schedule. Figure 1 is a schematic of a typical conventional kiln. Below is a selection of controllers once fitted to woodrow kilns. At the end of the drying runs, additional pieces of these same boards were cut and ovendried 215 f to determine the final moisture content.
I dont see how someone drying wood could do without a book like this. It covers wood structure, moisture in wood, moisture movement and stress development on kilnseasoning lumber boards. The purpose of this manual is to describe both the ba sic and practical aspects of kiln drying lumber. These reports are produced annually by the wisconsin department of natural resources division of forestry, utilization and marketing program and with the u.
Timber processing quality control in lumber purchasing. Drying too slow is also costly since it will tie up a kiln for too long. The operators manual 1991 is available in pdf format, with the introduction and individual chapters. In the original dry kiln operators manual written in the early 1950s, some species were not used in high quality products.
Hot, moist air should be continuously exhausted while cooler air from the outside is introduced into the kiln. Cost and operation of a small dehumidification dry kiln. It is, therefore, the responsibility of the kiln operator to control temperature. Search our extensive pdf library for kiln maintenance, kiln assembly, kiln installation, kiln specifications and much more. The manual is intended for several types of audiences. Chapter 9 operating a dry kiln kiln samples 207 selecting a drying schedule 208 schedules for homogeneous charges 208 schedules for mixed charges 208 starting the kiln 209 prestart checks 209 steamheated kilns 209 directfired kilns 210 dehumidification kilns 210 warmup period 210 spray during warmup 210 time needed for warmup 210.
Additional fans could be added to the dry kiln to alleviate this, but that would add to the construction and operating cost of the dry kiln. As humidity in the kiln is reduced, the lumber will dry faster. It will have value for the beginner as well as experienced kiln operators and with super. If larger quantities than those shown in table 2 are dried, drying speed will be proportionately slower. Your kiln, with the proper care, will provide you many years of dependable firings. Solar kiln basics scott weikert penn state extension forest county. The exact procedures are presented in the dry kiln operators manual. The modified kiln schedules maintained equilibrium. The procedures and treatment schedules in this manual are administratively authorized for use by aphis to prevent the movement of agricultural pests into or within the united states. Moisture content of raw wood depends on the type of wood and can reach 200%. It is also intended for mill managers, so that they can see the importance and complexity of lumber drying and thus be. To download the file, right click the respective link. Full text of kiln drying handbook internet archive.
Information on current conditions and trends in forest resources and the forest products industry in wisconsin. For many wood products, kiln dried lumber is essential. Lippincott company, philadelphia, pa, 1917 at fpl established lumber kiln drying technology and the first lumber dry kiln design. The dry kiln operators manual 5 outlines an equalization procedure using kiln sample boards when drying to a final desired average mc of 8 percent. First and foremost, it is a practical guide for the kiln operatora reference manual to turn to when questions arise. Daytoday kiln operation started by ckwoodcutter on drying and processing.
Several other fpl drying manuals followed before the 1961 manual by rasmussen. Pdf cost and operation of a small dehumidification dry kiln. When properly loaded, this kiln can dry approximately 600 board feet of 44 lumber. Temperature, humidity and air circulation depend upon the climate conditions of the ambient where the wood is stored, so the drying is extremely slow, and lasts for a year or more. A comparison of kilndrying schedules and quality outcomes. Total hydrocarbon and hap emissions from the drying of. Ventilation also is an important element influencing the quality of drying of the lumber.
For many species, dry wood is nearly half the weight of wet wood. Manufacturer requirements excerpt from the working. Next, insulate all walls with the insulation vapor barrier facing the inside of the dry kiln. When it is impossible for the normal kiln baffles to prevent short circuits of air movement, auxiliary load baffles made from plywood or sheet metal should be used. For questions or problems with your specific application please contact north american kiln for assistance. Dry kiln 2014 operators dry kiln operators short course.
Find the user manual and the help you need for the products you own at manualsonline. Since kiln samples generally are not used in our western mills, equalization of lumber to a final average mc from 6% to 12% mc follows a different procedure. Please click on the blue links for a current manual. Chapter 9 operating a dry kiln usda forest service. Tiemanns book can really he considered the first drying manual. Introduction, glossary, and index pdf 424 kb chapter 1properties of wood related to drying pdf 750 kb chapter 2 kiln types and features pdf 3. Kiln drying in accordance with the schedules prescribed for the regulated article in the dry kiln operators manual, agriculture handbook 188. This plan allows for flexibility in the design of the kiln. Dry kiln operators manual forest products laboratory. Calculating the equilibrium moisture content for wood based. At osu, the 8foot 2x4s were cut to 4 feet and sorted into three 33board units on may 2. Dry kiln operator s manual enter your mobile number or email address below and well send you a link to download the free kindle app. O equals weight of absolutely dry wood in gramm for instance. Casehardening dryshell tension wet core compression dry shell compression.
Introduction, glossary, and index 424 kb chapter 1 properties of wood related to drying 791 kb chapter 2 kiln types and features 3. Pdf dehumidification drying for small woodworking firms and. Dry kiln operators manual forest products laboratory usda. United states agriculture dry kiln forest service operator. You should keep a close watch when firing for the first time to ensure everything is working correctly. If you are new to lumber drying, start by reading the following resources. Chapter 1properties of wood related to drying pdf 750 kb. You have every reason to be proud and to feel you have the very best kiln. Dry wood is nearly twice as strong and twice as stiff as green wood. If smaller quantities are dried, the controls can be adjusted to allow for this. Department of agriculture, forest service, forest products laboratory.
Basics of solar lumber drying oklahoma state university. The modern dry kiln is a unique product of research, development, and. Regardless of rotary kiln size or configuration the basic principles outlined in this manual govern the reliable operation of every rotary kiln, calciner, dryer, incinerator, digester and cooler application. Dry kiln operators manual a publication of the forest products laboratory. Apply caulk to the seams between the sheets of plywood. It covers wood structure, moisture in wood, moisture movement and stress development on kiln seasoning lumber boards.
Forest resources annual report and publications wisconsin dnr. It is also intended for mill managers, so that they can see the importance and complexity of lumber drying and. The emc rh relationship compiled in table 16 of that publication has been used to construct and adjust lumber dry kiln schedules and serves as the basis of comparison for this work. First and foremost, it is a practical guide for the kiln operator a reference manual to turn to when questions arise. The emphasis on general principles, rather than specific procedures, enables the reader to apply these principles to any species of interest. Please beware that settings can be changed on controllers that may make the manual incorrect. The dry kiln operators manual is twice as large 274 pages and includes the softwood and imported woods. Hardwood lumber is usually dried below the fiber saturation point before kiln drying, but occasionally green lumber from hardtodry species is placed directly into the kiln.
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