Dryer stationary syphon adjustment mechanism

A mechanism for drying a traveling web such as employing a steam heated dryer drum in a papermaking machine with the drum being supported on end bearings in journals in a frame and a rigid condensate removal tube extending through one of the journals with its inner end adjacent the inner surface of the drum and the drum having a rotary steam seal through which the tube passes with a pivotal mount for the rigid tube and a micrometer adjustment which adjusts the pivotal position of the tube so that the inner end of the tube being cantileverly supported can be adjusted accurately relative to the inner surface of the drum.

BACKGROUND OF THE INVENTION 
The invention relates to improvements in dryer drums, and more particularly 
to an improved paper machine dryer drum with a condensate removal adapted 
and constructed for accurate adjustment for improved condensate removal 
from the drum. 
Such dryer drums are heated by live steam directed into the interior and a 
continuous web of paper is threaded in serpentine fashion over a series of 
dryer drums. As the heat energy from the steam within the dryer drum 
transfers as heat through the shell of the hollow cylindrical drum to the 
paper web, condensate is formed within the drum. This condensate tends to 
collect on the inner cylinder surface of the drum or to "rim" as the drum 
rotates, and the condensate is removed by a condensate removal syphon 
tube. Because the condensate provides an insulation effect, the layer of 
condensate must be maintained at minimum thickness for the most effective 
heat transfer. The effective removal of the condensate is directly related 
to the spacing between the inner end of the syphon tube and the inner 
surface of the drum. 
In devices heretofore available, different arrangements were employed for 
adjusting the spacing between the inner end of the syphon tube and the 
drum. This creates difficulties because with heat expansion and 
contraction of the drum, the spacing can change, and it is desirable that 
the adjustment can be accomplished during operation inasmuch as it would 
be completely impractical to have to shut down the operation of the paper 
machine for this adjustment. One arrangement for adjusting the end of the 
condensate tube relative to the drum surface is shown in U.S. Pat. No. 
1,953,525 wherein it is necessary to provide a flexible condensate syphon 
tube which can pivot within the drum. Structures of the type shown in this 
patent encounter disadvantages in that there is an instability in having 
to provide a flexible tube, and mechanism and equipment is required which 
operates inside of the dryer drum and is subject to vibration, going out 
of adjustment, and inaccessibility for repair and observation. 
Accordingly, an object of the present invention is to provide an improved 
dryer drum and syphon for condensate removal which is of an improved 
simplified construction and which is more reliable in operation. 
A further object of the invention is to provide an improved adjustment 
mechanism for the syphon tube of a steam dryer drum where it provides a 
minute and accurate control of the position of the inner end of the tube 
relative to the drum wall and which adjustment can be effected at anytime 
during operation of the drum. 
A still further object of the invention is to provide an improved 
adjustment mechanism for locating the inner end of the condensate syphon 
tube of a steam drum relative to the inner wall of the drum which makes 
possible minute adjustment and wherein the operating portions are outside 
of the dryer drum where they can be easily reached and serviced. 
Other objects, advantages and features will become apparent with the 
teaching of the principles of the invention in connection with the 
disclosure of the preferred embodiments in the specification, claims and 
drawings, in which:

DESCRIPTION 
The drawings show a rotatable steam dryer drum 10 which has a cylindrical 
hollow shell for receiving steam therein and for carrying a paper web on 
its outer surface to be dried. The drum is supported on journals 13 and 14 
at its ends which are mounted in stationary bearings 12 and 15 carried on 
a frame member 11. Suitable means may be provided for rotating the drum, 
or the drum may be rotated by engagement with the web or with felts 
carrying the web. 
For delivering steam to the inside of the drum, a coaxial steam delivery 
tube 16 leads through the journal 13 and opens into the interior of the 
drum. Steam is supplied from a supply pipe 18 connected by means of a 
flange 17. The supply piping will have sufficient flexibility to permit 
slight movements of the flange as will later appear. 
For removal of the condensate, a condensate removal tube 23 is provided 
which extends coaxially within the steam tube 16. A pivotally mounted head 
30 provides a cantilever support for the tube 16. The condensate syphon 
tube 23 is fully rigid in the tube 16 and has an inner extending portion 
25 within the drum which is cantileverly supported on the tube 16. The 
outer extending portion 24 is supported at its outer end on a hub 21 and 
also supported further inwardly on syphon tube 23. 
The syphon tube has an inner radially extending end 26 with a head end 27 
for receiving the condensate. The head end is adjacent the inner surface 
28 of the drum and has only a slight clearance 29 between the inner smooth 
surface of the drum and the head. While the drum is illustrated as having 
a smooth surface, in accordance with the principles of the invention, the 
position of the head is accurately and minutely adjustable relative to the 
surface 28, and it will be understood that the structure may be used with 
the dryer drum having a grooved inner surface or other configuration where 
the stationary head 27 must be maintained in close adjacency to the 
relatively rotating surface of the drum. The condensate is removed by a 
syphon action through a pipe 20 which connects to a fitting 19. The piping 
to fitting 19 will have sufficient flexibility to permit slight movement 
of the fitting. 
A steam seal is provided to prevent the escape of steam from the drum, and 
this rotary seal is shown at 31 having a rotating annular face 31a and a 
stationary face 31b. The stationary part is self-aligning and held in 
sealing contact by a compression spring 32. The stationary part also has a 
smooth outer annular tubular surface 31c. The surface coacts in a sealing 
fashion with a flexible annular ring 33 carried in the head. The seal as 
illustrated is constructed so as to accommodate slight changes in angular 
position of the head relative to the drum which has a constant axis. In 
other words, the outer surface 31c of the sleeve portion of the seal is 
constantly coaxial with the drum whereas the flexible ring 33 changes its 
horizontal axial alignment slightly. The pivotal movement of the head 
which occurs with adjustment of a bolt 37 effects the change in axial 
alignment which is sufficiently small so that no disruption of the seal 
results. 
For pivoting the head 30 and thereby changing the cantilever supported head 
end 27 of the syphon tube, the head is mounted on a pivot 34 supported on 
the rigid frame 11. The head has an adjustment arm 35 which has at its 
outer end the adjustment bolt 37. The bolt threads into a portion 36 on 
the rigid frame which is threaded at 39 to receive the lower end of the 
bolt. The arm 35 is also threaded at 38 to receive the bolt 37. The lower 
end of the bolt 41 coacts with the threaded opening 39, and the upper end 
40 of the bolt coacts with the threaded opening 38. The threaded openings 
38 and 39 and the threads of the bolt portions in the openings are 
threaded to a differential lead so that with rotation of the bolt, the 
bolt advances faster in one of the openings than in the other opening, 
i.e., at a different speed so as to obtain very minute pivotal movement of 
the arm 35 with rotation of the bolt. The bolt is readily accessible to 
the operator, and indexing means may be provided to show the bolt's 
position. 
The steam tube which provides support for the condensate removal tube is 
adequately supported in the head with the saddle 22 and is prevented from 
rotation by a locking pin 43 which is threaded into the saddle 22 and 
which projects into an opening 45 in the steam tube. This antirotation pin 
43 provides for alignment of the syphon tube relative to the drum. 
At startup, steam is directed into the interior of the drum through the 
tube 16, and the syphon tube 23 removes condensate. The operator adjusts 
the adjustment bolt 37 to pivot the head 30 until the inner head end 27 of 
the syphon tube just touches the inner surface of the drum and this is 
backed off a matter of a few thousandths of an inch. With changes in 
expansion of the drum and expansion of the condensate tube, and movement 
of the frame, adjustments may be necessary, and these can be running 
adjustments since the adjustment bolt 37 is fully accessible to the 
operator during operation without affecting the continued rotation and 
operation of the steam drum. 
An advantage over available prior art structures is that you do not have to 
shut down and cool the dryer and enter the drum in order to adjust the 
clearance, and in operation, the clearance can be adjusted on the run. 
There is less time required to readjust the clearance. Since adjustment 
can change with minor operational differences, due to wear or temperature 
change, the foregoing are important factors. 
Thus, it will be seen that we have provided an improved micrometer 
adjustment attainable by the bolt 37 and its differential threading for 
adjusting the position of the head end 27 of the syphon tube. The 
structure and its operation achieves the objectives and advantages above 
set forth and provides improvements over devices heretofore available.