US1468932A - Reversing blower kiln - Google Patents

Description

oooooooo 0o 1 moJ/o/oJ/No QMWM v 2 Sheets-Sheet 1 R. THELEN ET AL REVERSING BLOWER KILN Filed March 20. 1925 I I F WW \m MUOOO O O0 O0 .v oooooooooo vl\ Sept. 25 1923.

INVENTORS ROLF THELEN HARRY D TIEMANN fi M: W

A TTORNEYI.

FIG, 3)

FIG. 2

D T D T D T r &5

IN VEN TORS ROLF TH ELEN ATTORNEYB.

2 Sheets-Sheet 3 HARRY D. THEMANN R THELEN ET AL REVERSING BLOWER KILN I Filed March 20. 1923 i. it v H Sept. 25, 1923.

Patented Sept. 25, 1923.

MADISON, WISCONSIN, DEDICATED, BY THE UNITED STATES OF AMERICA.

REVERSING BLOWER KILN.

Application filed March 20, 1923. Serial No. 626,419.

(TILED UNDER THE ACT OF MARCH 3, 1883, 22 STAT. L, 625.)

To all whom it may concern:

Be it known that we, ROLF THELEN and HARRY D. TIEMANN, citizens of the Umted States of America, andemployees of the Department of 'Agriculture, residing in Madison, Wisconsin (whose post-oflice address is Madison, Wisconsin), have jointly invented a new and Improved Reversing Blower Kiln.

This application is made under the act of March 3, 1883, chapter 143 (22 Stat. 625), and the invention herein described and claimed may be used by the Government of the United States,-its officers and employees, and by any person in the United States without the payment tons of any royalty thereon. We hereby dedicate the same to the free use of the Government and the people of the United States. I

Our invention consists in an improvement in the design of forced circulation kilns or chambers for drying and conditioning lumber or similar material. However, its use is not limited to wood or wood products. It 25 consists in the adaptation of fans of the disk type, or similar types, to the production of a unique internal circulation of the air and the vapor in the kiln combined with the production and regulation of the heat and the humidity within the kiln. This apparatus is illustrated in Figures 1 to 4. Figure 1 represents a cross-sectional elevation. Figure 2 represents a lan of one of the fans with its housing an a portion of the shaft. The UK) ofthe housing is broken away to show the fan. Figure 3 is a side elevation of one of the fans with its housing and a portion of the shaft. The side of the housing is broken away to show 40 the fan. Figure 4 represents a horizontal cross-section of the kiln taken directly beneath the lumber-supporting platform.

The principal feature which we claim as novel and an improvement over existing kilns is the use and arrangement of the fans within the kiln. This arrangement is such that a very fast and uniform circulation of the air and vapor through the pile of lumber may be secured and that the direction of this movement may be reversed periodically by reversing the direction of rotation of the fans. This improved circulation causes drying or conditioning to take place uniformly in all portions of the lumber pile and eliminates the drying lag which occurs in kilns of types in which the circulation is not re versible. The arrangement of the fans upon a single shaft extending throughout the length of the kiln provides a simple means of producing a brisk circulation; and the elimination of comparatively small ducts such as those used in external blower kilns reduces very appreciably the work required to produce a given circulation. The pressure required to produce the circulation is correspondingly small, and the disk fans operate very efficiently at these lowpressures. It is possible, therefore, by the use of this invention. to produce a very great circulation of airtand vapor within the kiln with a small expen of power.

While the drawings indicate a narrow kiln with a series of fans mounted upon a single shaft and the description applies specifically to this form, we do not limit ourselves to this one arrangement. It is obvious to anyone skilled in the art that several rows of fans can be used in wide kilns to produce results similar to those secured b the use of one shaft in a narrow kiln. It is also evident that the principles of this invention can be carried out by locating the shaft in places other than the one indicated.

Any well-known means of heating the air and the Vapor in the kiln may be used in conjunction with this invention. steam pipes are used they may be concentrated towards the center or axis of the kiln beneath the lumber-supporting platform and directly in the air current from or to the fans. Any convenient form and arrangement of heating coils or radiators may be used.

The drawings show and the specification describes steam jet pipes for increasing the humidity, and air inlet fines and air outlet flues with suitable dampers for decreasing the humidity.

WVhile we show in the drawings andde. scribe in'the specification specific means for heating the air and vapor in the kiln and for regulating the humidity of the air in the kiln, we do not limit ourselves to the arrangement described, but may make use of any other suit-able means for accomplish ing the same purposes. While the drawings When illustrate and the specification describes a specific form of flat piled lumber with a specific type of circulation of air and vapor, we do not limit the scope of the invention to this particular form since the improvement is equally applicable to other well-known forms of piling, such as single piles with an upwardly restricted central chimney; double piling wih or without chimneys in each pile; inclined piling, both single track and double track; vertical piling, both single track and double track; and other forms.

Referring to Figures are correspondingly lettered: AA represents the fan housings. These housings entirely surround their respective fans, and each is provided with two ducts, one of which is bifurcated. The single duct is arranged verticalwl y and the bifurcated one horizontally. hen the direction of the circulation of the air and vapor is downward'through the central chimney V, the air and vapor enter the vertically arranged ducts of the housings AA. passing downwardly through the fans BB, and then horizontally outward through the bifurcated ducts. The arrows show the general direction of the circulation of the air and vapor throughout the kiln when the fans are rotated so as to produce an upward circulation through the central chimney. When the rotation of the fans is reversed the circulation is in the opposite direction to that indicated. BB are the fans producing the circulation. The housings in all of the illustrations have been broken away to show the location of the fans. Disk fans are preferable. Any type of fan, however, in which the reversal of the direction of rotation of the fan produces a reversal in the direction of the air current passing through the fan can be used. C is the shaft upon which the fans are mounted. Provision is made to take care of the expansionand contraction of this shaft with changes in the temperature in the kiln. DD are air inlet dampers used to regulate and control the amount of air entering the kiln from the outside. EE are the heating coils. The coils illustrated in the drawing and described in the specification are of the return bend type. We do not, however, limit ourselves to this type in the claims. FF are the steam jet pipes used to increase the. humidity of the air in the kiln. The lower palr is used when the circulation of air and vapor is downward through the central chimney V, and the upper pair is used when the circulation is in the reverse direction. G is the lumber-supporting platform. Rails and trucks or other suitable means may be used for this purpose. HH are baffies to control the direction of the air circulation. II are bearings for the shaft C.

J J are curtains to assist in controlling the 1, 2, 3, and 4, whicn circulation of the air and vapor. KK are the side walls of the kiln. LL is the lumber to be dried. Mlvl are running boards to enable the kiln operator to walk along the side passages \VVV when the kiln is loaded. They also assist in controlling the direction of the circulation. N is the shaft pulley. 00 are air outlet dampers for controlling the amount of air being exhausted from the kiln. P is a belt passing over pulleys N and Q. Q is the motor pulley. R is the motor which furnishes the power to drive the fans. S is a. switch for controlling the speed and direction of rotation of the motor armature. While the drawings show and the specification describes an electric motor, any other suitable motor or driving means may be used. TT are air inlet flues in which the dampers DD are fitted. UU are air outlet flues in which the dampers 00 are fitted. V is the central chimney in the lumber pile. While the drawings show and the specification describes a chimney with vertical sides, chimneys of other shapes, such, for instance, as A shaped chimneys in which the cross section diminishes toward the top, may be used. WW are the side air passages which may likewise be of any wellknown form as well as of the form illustrated in the drawings and described in the specification. X is a distributing duct, connecting the vertical ducts of the housing; AA with the bottom of the central chimney V. The bottom of this duct has been broken away in Figure 4 to permit details of the shaft and other parts to be shown. This duct is in the form of av trough with an open top and a solid bottom except where the vertical ducts of the housings AA enter.

The operation of the kiln is briefly as follows: The lumber is placed into the kiln, the doors and all of the dampers are closed, and the motor started. Steam is turned into the coils and one set of steam jets is turned on. Suitable regulating devices are provided to control and regulate the supply of steam to the heating coils and the supply of steam to the steam jets. If it is found impossible to reduce the humidity to the desired point with the steam jets all turned off, the dampers DD and 00 are opened to allow fresh air to enter and moist air to escape. These dampers are adjusted so that a humidity below that desired will be secured. The steam jets may then automatically supply a sufiicient amount of steam to bring the umidity up to the desired point. If the direction of rotation of the motor, the shaft, and the fans is such that the air and vapor pass upward through the central chimney V, the air and vapor through the lumber into the side passages WW, downward through these passages, across the heatin coils, and into the bifurcated ducts of t e housings, through the will pass laterally outward.

fans, and again upward through the vertical ducts in the housings. When operated in this manner the lumber near the central chimney V will dry more rapidly than that near the side passages WW. To overcome this the direction of rotation of the fans, shaft, and motor may be reversed, thus reversing the direction of the circulation of the air and vapor so that it is now upward in the side passages WW and downward through the central chimney V. This reversal may take place periodically once every two or three days or oftener, the exact period being determined by the condition of the lumber in the kiln.

Having fully described the construction and operation we claim as original:

1. In a dry kiln, a series of fans placed near the base of the kiln, a shaft on which the fans are mounted for rotation, means for rotating said shaft in either direction to cause reversal of the circulation of the air and vapor in said kiln, fan housings with intake and discharge ducts, and a distributing duct.

2. In a dry kiln, a series of fans placed near the base of the kiln, a

shaft on which the fans are mounted for rotation, and means for rotating said shaft in either direction to cause reversal of the circulation of the air and vapor in the kiln.

3. In a dry kiln, a series of fans placed near the base of the kiln, a shaft on which the fans are mounted for rotation, means for rotating said shaft in either direction, damp- Ered air inlet flues and dampered air outlet ues.

4. In a dry kiln, a series of fans placed near the base of the kiln, a shaft on which the fans are mounted for rotation, means for rotating said shaft in either direction, dampered air inlet flues, dampered air outlet flues, and means for heating the kiln.

5. In a dry kiln, a series of fans placed near the base of the kiln, a shaft on which the fans are mounted for rotation, means for rotating said shaft in either direction, dampered air inlet flues, dampered air outlet flues, means for heating the kiln, and means for humidifying the kiln.

March 9, 1923.

ROLF THELEN. HARRY D. TIEMAN N.

Images