Seasoning of Wood by Joseph Bernard Wagner (bill gates best books txt) π
Keeping especially in mind the arrangement and direction of the fibres of wood, it is clear at once why knots and "cross-grain" interfere with the strength of timber. It is due to the structural peculiarities that "honeycombing" occurs in rapid seasoning, that checks or cracks extend radially and follow pith rays, that tangent or "bastard" cut stock shrinks and warps more than that which is quarter-sawn. These same pecu
Read free book Β«Seasoning of Wood by Joseph Bernard Wagner (bill gates best books txt) πΒ» - read online or download for free at americanlibrarybooks.com
- Author: Joseph Bernard Wagner
- Performer: -
Read book online Β«Seasoning of Wood by Joseph Bernard Wagner (bill gates best books txt) πΒ». Author - Joseph Bernard Wagner
The "Box" kiln shown in Figure 39 is an exterior view of a kiln of this type which is 20 feet wide, 19 feet deep, and 14 feet high, which is the size generally used when the space will permit.
Box kilns are used mostly where only a small quantity of material is to be dried. They are not equipped with trucks or cars, the material to be dried being piled upon a raised platform inside the drying room. This arrangement, therefore, makes them of less cost than the other types of dry kilns.
They are particularly adapted to any and all species and size of lumber to be dried in very small quantities.
Fig. 39. Exterior view of the Box Dry Kiln. This particular kiln is 20 feet wide, 19 feet deep and 14 feet high. Box kilns are used mostly where only a small amount of kiln-dried lumber of various sizes is required. They are not equipped with trucks or cars, and therefore cost less to construct than any other type of dry kiln.
In these small kilns the circulation is under perfect control, so that the efficiency is equal to that of the more extensive plants.
These special kilns will readily appeal to manufacturers, whose output calls for the prompt and constant seasoning of a large variety of small stock, rather than a large volume material of uniform size and grade.
SECTION XIII DRY KILN SPECIALTIES KILN CARS AND METHOD OF LOADINGWithin recent years, the edge-wise piling of lumber (see Figs. 40 and 41), upon kiln cars has met with considerable favor on account of its many advantages over the older method of flat piling. It has been proven that lumber stacked edge-wise dries more uniformly and rapidly, and with practically no warping or twisting of the material, and that it is finally discharged from the dry kiln in a much better and brighter condition. This method of piling also considerably increases the holding and consequent drying capacities of the dry kiln by reason of the increased carrying capacities of the kiln cars, and the shorter period of time required for drying the material.
Fig. 40. Car Loaded with Lumber on its Edges by the Automatic Stacker, to go into the Dry Kiln cross-wise. Equipped with two edge piling kiln trucks.
In Figures 42 and 43 are shown different views of the automatic lumber stacker for edge-wise piling of lumber on kiln cars. Many users of automatic stackers report that the grade of their lumber is raised to such an extent that the system would be profitable for this reason alone, not taking into consideration the added saving in time and labor, which to anyone's mind should be the most important item.
Fig. 41. Car Loaded with Lumber on its Edges by the Automatic Stacker, to go into the Dry Kiln end-wise. The bunks on which the lumber rests are channel steel. The end sockets are malleable iron and made for I-beam stakes.
In operation, the lumber is carried to these automatic stackers on transfer chains or chain conveyors, and passes on to the stacker table. When the table is covered with boards, the "lumber" lever is pulled by the operator, which raises a stop, preventing any more lumber leaving the chain conveyor. The "table" lever then operates the friction drive and raises the table filled with the boards to a vertical position. As the table goes up, it raises the latches, which fall into place behind the piling strips that had been previously laid on the table. When the table returns to the lower position, a new set of piling strips are put in place on the table, and the stream of boards which has been accumulating on the conveyor chain are again permitted to flow onto the table. As each layer of lumber is added, the kiln car is forced out against a strong tension. When the car is loaded, binders are put on over the stakes by means of a powerful lever arrangement.
Fig. 42. The above illustration shows the construction of the Automatic Lumber Stacker for edge piling of lumber to go into the dry kiln end-wise.
Fig. 43. The above illustration shows the construction of the Automatic Lumber Stacker for edge piling of lumber to go into the dry kiln cross-wise.
Fig. 44. The above illustration shows a battery of Three Automatic Lumber Stackers.
Fig. 45. The above illustration shows another battery of Three Automatic Lumber Stackers.
Fig. 46. Cars Loaded with Lumber on its Edges by the Automatic Lumber Stackers.
After leaving the dry kilns, the loaded car is transferred to the unstacker (see Fig. 47). Here it is placed on the unstacker car which, by means of a tension device, holds the load of lumber tight against the vertical frame of the unstacker. The frame of the unstacker is triangular and has a series of chains. Each chain has two special links with projecting lugs. The chains all travel in unison. The lug links engage a layer of boards, sliding the entire layer vertically, and the boards, one at a time, fall over the top of the unstacker frame onto the inclined table, and from there onto conveyor chains from which they may be delivered to any point desired, depending upon the length and direction of the chain conveyor.
With these unstackers one man can easily unload a kiln car in twenty minutes or less.
Fig. 47. The Lumber Unstacker Car, used for unloading cars of Lumber loaded by the Automatic Stacker.
Fig. 48. The Lumber Unstacker Car and Unstacker, used for unloading Lumber loaded by the Automatic Stacker.
The experience of many users prove that these edge stacking machines are not alike. This is important, because there is one feature of edge stacking that must not be overlooked. Unless each layer of boards is forced into place by power and held under a strong pressure, much slack will accumulate in an entire load, and the subsequent handling of the kiln cars, and the effect of the kiln-drying will loosen up the load until there is a tendency for the layers to telescope. And unless the boards are held in place rigidly and with strong pressure they will have a tendency to warp.
Fig. 49. The above illustration shows method of loading kiln cars with veneer on its edges by the use of the Tilting Platform.
A kiln car of edge-stacked lumber, properly piled, is made up of alternate solid sheets of lumber and vertical open-air spaces, so that the hot air and vapors rise naturally and freely through the lumber, drying both sides of the board evenly. The distribution of the heat and moisture being even and uniform, the drying process is naturally quickened, and there is no opportunity or tendency for the lumber to warp.
In Figure 49 will be seen a method of loading kiln cars with veneer on edge by the use of a tilting platform. On the right of the illustration is seen a partially loaded kiln car tilted to an angle of 45 degrees, to facilitate the placing of the veneer on the car. At the left is a completely loaded car ready to enter the dry kiln.
Gum, poplar, and pine veneers are satisfactorily dried in this manner in from 8 to 24 hours.
In Figure 50 will be seen method of piling lumber on the flat, "cross-wise" of the dry kiln when same has three tracks.
Fig. 50. Method of Loading lumber on its Flat, cross-wise of the Dry Kiln when same has Three Tracks.
In Figure 51 will be seen another method of piling lumber on the flat, "cross-wise" of the dry kiln when same has three tracks.
In Figure 52 will be seen method of piling lumber on the flat, "end-wise" of the dry kiln when same has two tracks.
In Figure 53 will be seen another method of piling lumber on the flat, "end-wise" of the dry kiln when same has two tracks.
In Figure 54 will be seen method of piling slack or tight barrel staves "cross-wise" of the kiln when same has three tracks.
In Figure 55 will be seen another method of piling slack or tight barrel staves "cross-wise" of the dry kiln when same has three tracks.
In Figure 56 will be seen method of piling small tub or pail staves "cross-wise" of the dry kiln when same has two tracks.
In Figure 57 will be seen method of piling bundled staves "cross-wise" of the dry kiln when same has two tracks.
Fig. 51. Method of loading Lumber on its Flat, cross-wise of the Dry Kiln when same has Three Tracks.
Fig. 52. Method of loading Lumber on its Flat, end-wise of the Dry Kiln by the Use of the Single-sill or Dolly Truck.
Fig. 53. Method of loading Lumber on its Flat, end-wise of the Dry Kiln by the Use of the Double-sill Truck.
Fig. 54. Method of loading Kiln Car with Tight or Slack Barrel Staves cross-wise of Dry Kiln.
Fig. 55. Method of loading Kiln Car with Tight or Slack Barrel Staves cross-wise of Dry Kiln.
Fig. 56. Method of loading Kiln Car with Tub or Pail Staves cross-wise of Dry Kiln.
Fig. 57. Method of loading Kiln Car with Bundled Staves cross-wise of Dry Kiln.
In Figure 58 will be seen method of piling shingles "cross-wise" of dry kiln when same has three tracks.
In Figure 59 will be seen another method of piling shingles "cross-wise" of the dry kiln when same has three tracks.
Fig. 58. Method of loading Kiln Car with Shingles cross-wise of Dry Kiln.
Fig. 59. Method of loading Kiln Car with Shingles cross-wise of Dry Kiln.
In Figure 60 will be seen method of piling shingles "end-wise" of the dry kiln when same has two tracks.
In Figure 61 will be seen a kiln car designed for handling short tub or pail staves through a dry kiln.
Fig. 60. Car loaded with 100,000 Shingles. Equipped with four long end-wise piling trucks and to go into dry kiln end-wise.
Comments (0)