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Патент USA US2122362

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June 28, 1938.
A_ H, STANTON
“
2,122,362
CONTROL MECHANISM FOR PAPER MAKING MACHINES
Filed April 30, 1935
I mue/zfors
Patented June 28, 1.938
2,122,362 ‘
UNITED STATES PATENT OFFICE
2,122,362
CONTROL MECHANISM FOR PAPER MAKING
‘
MACHINES
'
Avery H. Stanton, Dedham, Mass, assignor to
Eldon Macleod, Frank A. Morrison, Cameron
Maeleod, Leslie Soule, and Sullivan A. Sargent,
Jr., trustees, doing business as Mason-Neilan
' Regulator Company, Boston, Mass.
Application April 30, 1935, Serial No. 18,979
7 Claims. (Cl. 34-487)
This invention relates to moisture control
mechanism for paper making machines, wherein
the paper is passed around steam heated drying
cylinders, and relates more particularly to appa
ratus for automatically controlling the supply of
steam to the cylinders, whereby their tempera
ture and consequently the moisture content of the
paper is regulated. It is, of course, of great im
portance in paper making that the moisture con
tent of the paper be closely regulated to maintain
a small but uniform moisture content as the pa
per is delivered from the machine. Heretofore
the many variable factors aiiecting moisture con
25
30
_
35
40
45
50
.
the downstream side of the valve.
It is also to _
be understood that moisture control may be ef
fected in any suitable manner, tension roll con
trol merely being one of several suitable methods. 10
Before explaining in detail the present inven
tion it is to be understood that the invention is
not limited in its application to the details of con
struction and arrangement of parts illustrated
in the accompanying drawing, since the inven
tion is capable of other embodiments and of be
weight of the paper sheet, change in density and ing practiced or carried out in various ways. Also
freeness of stock, change in air humidity, change it is to be understood that the phraseology or
terminology employed herein is for the purpose of
in the machine speed, as well as change in tem
perature of the drying cylinders due to previous description and not of limitation, and it is not 20
change in pressure or rate of ?ow of the steam intended to limit the invention claimed herein
supplied to the cylinders or to change in the rate beyond the requirements of the prior art.
In the drawing:
of condensate removal from the drying cylinders.
Fig. 1 is a diagrammatic view of my control
It is also important in moisture control that the
control mechanism be instantly responsive to' mechanism in a paper making machine.
25
In the drawing, Ill represents a mechanism for
changes in conditions, for if there is time lag in
resetting the temperature control point in the maintaining an adequate and constant pressure
of air or other suitable ?uid for operating the
dryers, the mechanism may be re-setting for con
ditions which no longer exist a few minutes later. independent pressure system, and as this device
Similarly it is important that the mechanism forms no part of the invention claimed it need 30
not be described in detail. The operating air
does not over-control or go too far in ‘each direc
tion, as this ‘produces “hunting”.or undesirable pressure is supplied through pipe H and is suit
?uctuation in the range of moisture content.
ably ?ltered through the ?lter Hill, the pressure
My invention comprises brie?y the utilization gauge l5 indicating the operating pressure. The
of two instruments, one a tension roll responsive air passes through pipe II to a pilot valve mech
to changes in tension of the paper sheet due to anism 20. The branch pipe I‘! having a restricted
moisture content, and the other a temperature ori?ce I8 by-passes the stream of air and ordi
bulb responsive to changes in temperature in the narily exhausts it to the atmosphere through ex
drying cylinder, which instruments operate the haust ori?ce is at the lower end of branch pipe
control valve governing the supply of steam to H. A ?apper lever 55, as actuated by the three 40
the- cylinders through their separate or joint ac
responsive instruments to be later described con
tion. An independent pressure system, prefer
stitutes an adjustable mounting 80 which oper-j
ably air and ordinarily exhausting to the atmos
ates to close the exhaust ori?ce l9 and thereby
phere is used as an operating pressure to actuate build up pressure in branch pipe I‘! below the re
the control valve governing the steam supply, and stricted ori?ce l8.
45
operates through a pilot mechanism and exhaust
Branch pipe I1 connects with the pilot valve
valve, comprising an exhaust ori?ce and ?apper mechanism 20 through the pipe 2| below the re
lever. Compensation to prevent over-control or stricted ori?ce l8 which leads into a central dia
"hunting” is provided from the operating air phragm chamber 22. A stem 24 abutting the top
pressure, which operates to check or compensate side of the diaphragm chamber 22 forms a valve 50
the action of the exhaust valve in one direction between pipe II and chamber 25. A similar stem
in response to changes in moisture content or 26 abutting the bottom side of the diaphragm
temperature of the cylinders by providing a slight chamber 22 forms an exhaust valve between the
movement of the exhaust valve in the opposite chamber 21 and the atmosphere. Both cham
direction. It is to be understood that instead bers are connected on the outside by pipe 28 55
trol have prevented the close regulation desired.
15 For instance the factors which may a?ect the
moisture content of the paper are .changes in
20
of joint tension roll and temperature control, the
joint control may be taken from tension roll and
the pressure of the heating medium, or from ten
sion roll and from rate of ?ow of the heat
ing medium, across any form of ori?ce, both
pressure and ?ow connections being taken from
2
2,122,362
’
which leads through pipe 23 to the controi valve by regulating the amount of steam supplied to
36. A gauge 3| connected to the pipe 29 indi- - the drying cylinders. 'The degree of sheet mois
cates the pressure in said pipe, and permits read
ing the amount of opening of valve 30, whichiisv
calibrated within de?nite pressure limits. Pipe
32 connects the operating pressure in pipe 29 to '
I ‘the Bourdon tube 65 of the adjustable mounting
80 for'providing compensation, as later described.
Control valve 30, which is preferably a diaphragm
motor valve, controls the admission of steam to
the drying cylinders 36, and is shown for purposes
I of illustration as normally closed, opening on ap
plied air pressure to diaphragm 36a. ‘
The drying cylinders 36 may be one or more,
15 but are here shown as a battery of three with one
at the top and two arranged below on either side
on asuitable frame 34.
Steam is supplied to the drying cylinders 36
through pipe 35, having connections 3511 leading
20 to each cylinder 36.
It is understood that the
sheet of paper 33 passes around the rotating dry
ing cylinders 36, and that any form of heating
medium, as hot water, hot air, in addition to
steam may be used.
Onthe closing of exhaust ori?ce l9, pressure in
diaphragm chamber 22 builds up, forcing valve
26 closed and valve 24 open allowing pressure
from pipe II to enter directly into chamber 25,
?ow through connecting pipe 28 into chamber 21
30 and equalize the pressures therein.
When pres
sure in chambers 25 and 21 balances the force in
central chamber 22, the valve 24 closes to prevent
pressure in chamber 25 from increasing. Air
pressure in pipes 28 and 29, in a closed chamber,
immediately reacts on diaphragm 30a. to par:
tially open control valve 30, permitting more
steam to flow into the drying cylinders 36. .t
the same time air pressure reacts through pipe 32
on the Bourdon tube segment 85 to provide com
40 pensation, as later described.
A thermostat 31 or other temperature respon
sive instrument containing an expansible ?uid is
provided in one of the drying cylinders 36 pref
erably in a dryer subsequent to the tension roll
45
location, and preferably located inside the dryer
from the “front" end or in the steam inlet to the
dryer. In the drawing, however, for cenvenience
of illustration, the connection is shown at the
ture content can be varied as desired by chang
ing counterweight 65. Movement of tension roll
lever 64 compresses or allows to expand a bellows
1| provided in a closed hydraulic pressure system
10 comprising the bellows 1|, tubing 12, a second
bellows 13, spring resisted, and connected to a
Bourdon tube 14, pictured as a segment rigidly
mounted at one end and at its free end connected 10
to an extension 56a. of ?apper lever 56. Bellows
13 is utilized to provide correct de?ection of
Bourdon tube 1.4 by absorbing a portion of the
pressure created by change in position of bel
lows ‘El.
‘
,
.15
'
It will be seen, therefore, that my moisture
control mechanism controls from the separate
or joint action of two instruments, the tension
roll 66 being responsive to changes in tension of
the paper sheet, and the thermostat 31 responsive
to temperature changes in' one of the drying cyl
inders 36. These two instruments operate ,»
through their separate or joint action to control
the supply of steam. to the cylinders through
control valve 30, which is set in operation by reg 25
ulating the amount of exhaust to the atmosphere
of the independent air pressure system through
movement of ?apper lever 56,
In case the paper sheet breaks, I have provided
a shut-off device for the operating air pressure -30
system comp-rising valve 90. As the paper sheet
breaks the tension roll lever 64 drops and oper
ates to close the valve 90. This in turn shuts off
the air pressure operating control valve 30 and
allows it to close, thereby, shutting oh the steam 35
supply to the cylinders. .
.
The operation of my device is as follows:
As the-temperature in the cylinder 36 carrying
the thermostat 31 rises, the expansive ?uid in
the thermostat 31 increases its pressure and un
winds the Bourdon tube 39 which acting through‘
arm 40 lowers ?apper lever 56.partially opening
exhaust ori?ce l9. Air pressure in pipe I 1 below
the restriction l6 then decreases in diaphragm
chamber 22 to release the pressure from chamber 45
21 and pipe 29 through valve 26 from the dia
phragm 30a of motor valve 36, to partially close
valve 30. This decreases the ?ow of steam
through pipe 35 and branch pipes 35a and fur
ther increase in temperature in‘cylinders 36 is '50
at one end and at its free end connected to arm prevented. On a decrease in temperature in cyl
40 which in turn transmits motion to ?apper inder 36 carrying the thermostat 31, the action
lever 56. The coil 39 may be helical, spiral or isv the opposite. Likewise if the paper sheet be
a segment of a Bourdon tube or other device re
.comes excessively dry, because of any one of the
sponsive to pressure (i. e. pressure responsive variable factors which affect its moisture content, 55
thermostat 31 contains expansible ?lLid).
the paper sheet passing between two of the cyl
A tension roll device 60, of suitable construe
inders will tend to straighten, and this increase
tion, as known in the art, is mounted ‘adjacent of the paper sheet tension will cause the tension
one of the cylinders 36, to bear yieldingly‘ against roll 60 to yield slightly, thereby elevating lever
the travelling sheetef paper. As is well known 64 and‘ compressing bellows 1| in the closed hy
the tension roll device may comprise a roller 6|, draulic pressure system 16, and increasing the
a bell crank lever 62 pivotally supported at point pressure therein which unwinds Bourdon tube
63 to the frame 34, and a lever 64 also pivotally 14, thereby moving ?apper lever 56 away as to
supported at 63 and'movable as a unit with lever partially open orifice l9. Again the independent
62 and having the counterweight 65 attached to air pressure system operates in the same manner 65
one end. By this device the roller 6| is yield
as with the increase of temperature of thermo
ingly held against the face of the paper sheet 33 stat 31, and allows control valve 30 to partially
between’two of the cylinders 36, where the paper close, thereby diminishing the amount of steam
is subject to slight sag when its moisture con
supplied to the cylinders 36. Likewise on an in
steam inlet to the dryer. The thermostat 31 con
50 nects through tubing 38 to coil 39 rigidly ?xed
55
.60
65
'
70 tent exceeds a predetermined amount and tends
to straighten when the moisture content is re
duced below that amount. This alternate sag
ging and stiffening or straightening of the paper
sheet in response to its moisture content is used
75 ’for controlling the moisture content in the paper
crease in moisture content in the paper sheet, "
decrease in the tension of the paper sheet pro
duces an opposite action, to increase the amount
of steam supplied to the cylinders.
Because there will be a substantial lapse of
time before a change in temperature in the cyl
2,122,862
3
inders or the moisture content in the paper can
be re?ected through thermostat 31 or tension
roll 60 to re-set the motor valve 30, I have pro
pendent source of pressure for operating said
control valve and ordinarily exhausting to the at
mosphere, an exhaust valve governing the exhaust
vided compensation through the operating pres
from said pilot mechanism, an instrument actu
ated by varying tension of the paper, another
instrument responsive to a variable character
istic of said drying cylinder, joint means operated by the action of said instruments for ac-.
tuating said exhaust valve, and means respon
sive to the operating pressure afforded by said 10
(Pl sure, which works in an opposite direction to the
thermostat 31 or tension roll 60, and whose ac
tion is immediately effective on the setting of
?apper lever 56. The setting of ?apper 56 as
actuated by changes in temperature of the cyl
1O inders 36 and changes in tension in the paper
sheet is immediately compensated or counter
acted by the operating pressure without wait
ing for the impulse to go through the thermo
stat 81 or tension roll 60. For instance as tem
perature in cylinder 36 rises and ?apper 56 moves
downward through the action of the helical coil
39 to partially open exhaust ori?ce l9 and the
operating pressure decreases to partially close
control valve 30, the decrease in the operating
20 pressure is immediately re?ected in the Bourdon
tube segment 85, which tends to wind and raise
?apper 56, thus partially closing exhaust ori?ce
l9. On a decrease in temperature in cylinder
36 the action of Bourdon tube 85 is opposite.
25 Likewise changes in the position of ?apper lever
56 induced by changes in the tension of the
paper sheet re?ected through the tension roll 60
are likewise opposed by the action of Bourdon
tube 85 acting in opposite direction thereto.
It is to be observed that the effect from the
30
operation of the Bourdon tube 85 is to decrease
the effect from either tension roll 60 or ther
mostat 31 in repositioning the control valve.
The effect from tension roll 60 less the effect
from Bourdon tube 85 having been positive and
causing a reposition of control valve 30 then
an opposing action comes from thermostat 31
due to the variation in temperature caused by the
reposition of valve 30 and the effect from 31'
40 is to compensate further thus preventing any
hunting or overtravel. It further should be ob
served that the reactions of thermostat 3‘! occur
as fast as the changes within the dryer. The de
gree of effectiveness is from 85 and 31 and is
45 proportional to the ratio of fulcrum arms 40,
56 and 56a as set for the particular installation
which is adjustable. Thus the compensating ac
tion from the operating pressure stabilizes the
pilot mechanism'for counteracting movement of
said exhaust valve.
2. A moisture control mechanism for paper
making machines comprising a drying cylinder,
the temperature of which is to be controlled, a
source of steam supply for heating said cylinder,
a control valve governing supply of steam to said
cylinder, a pilot mechanism utilizing an inde~
pendent source of pressure for operating said con
trol valve and ordinarily exhausting to the at- '
mosphere, an exhaust valve governing the ex
haust from said pilot mechanism, means for di
Verting. said pressure to operate said control
valve on the closing of said exhaust valve, an
instrument actuated by varying tension of the
paper, another instrument responsive to the tem
perature of said drying cylinder, joint means op
erated by the action of said instruments for ac
tuating said exhaust valve, and means respon
sive to the operating pressure afforded by said
pilot mechanism for counteracting movement of
said exhaust valve.
3. A moisture control system for paper making
machines, comprising a drying cylinder, the tem
perature of which is to be controlled, a source of
steam supply for heating said cylinder, a control
valve governing the supply of steam to said cylin
der, a pilot mechanism utilizing an independent
source of pressure for operating said control valve
and ordinarily exhausting to the atmosphere, an 40
exhaust valve governing the exhaust from said
mechanism, a movable ?apper controlling said
exhaust valve, a lever supporting said ?apper at
one end, a second lever supporting said ?apper at
its other end, an instrument responsive to the 45
temperature of the drying cylinder, a coil actu
ated by the temperature responsive instrument
for moving the ?rst ?apper supporting lever, an
control instrument and ‘prevents the usual wide instrument actuated by the varying tension of
the paper, a coil actuated by said second instru
50 ?uctuation, thereby rendering this type of con
ment for moving said second ?apper supporting
trol extremely accurate.
By means of my device I am able to, obtain lever, and so actuating said exhaust valve through
moisture control of the paper sheet within closer the action of said coils, a third coil responsive
to the operating pressure afforded by said pilot
limits than before possible with tension roll con
mechanism for counteracting the movement of
trol and by eliminating “hunting” and over
control a uniform steam ?ow ‘to the dryers is said exhaust valve as actuated by the ?rst two
obtained, thus providing uniform heat input to coils;
4. A- moisture control mechanism for paper
the sheet under uniform conditions of basis of
weight and effective drying. This uniform ?ow I making machines comprising a drying cylinder,
further aids in boiler plant operation. Because the temperature of which is to be controlled, a 60
of the control from thermostat 31 an anticipatory source of steam supply for heating said cylinder,
action is provided wherein changes in steam a control valve governing supply of steam to '
pressure a?ecting the temperature of the dryers said cylinder, a pilot mechanism utilizing an in
will re-set the valve before such changes can dependent source of pressure for operating said
alter the moisture content of the sheet. Thus a control valve and ordinarily exhausting to the 65
large amount of manual control to meet ‘varying atmosphere, an exhaust valve governing the ex
conditions affecting moisture content of the paper haust from said pilot mechanism, said pilot
mechanism including a casing, a pair of dia
is eliminated.
phragms dividing said easing into two outer
I claim:
1. A moisture control mechanism for paper chambers and an inner chamber, a supply valve 70
making machines comprising a drying cylinder, and a waste valve in said outer chambers govern
the temperature of which is to be controlled, a ing the supply and waste of pressure by which
source of steam supply for heating said cylinder, said control valve is operated; the pressure from
a control valve governing supply of steam to said said independent source expanding said inner
chamber and actuating said supply and waste 75
cylinder, a pilot mechanism utilizing an inde
4
12,122,862
valves to divert said pressure to the control valve pressure afforded by said supply and waste valves
for operating the same on the closing of said ‘ex ,t for counteracting movement of said exhaust valve.
haust valve, an instrument actuated by varying
6. A moisture control‘ mechanism for paper
tension of the paper, another‘instrument respon
making machinescomprising a drying cylinder,
sive to a variable characteristic of said drying the moisture in the paper sheet vpassing over
cylinder, and joint means operated by the action which is to be controlled, a source of heating
of said, instruments for actuating said exhaust medium for heating said cylinder, a control valve
' valve.
governing supply of heating medium to said cyl- '
5. A moisture control mechanism for paper inder, a pilot mechanism utilizing an independ
10 making machines comprising a drying cylinder,
ent source of pressure for operating said control
‘the temperature of which is to be controlled, a valve, an element responsive to the temperature 10
source of steam supply for heating said cylinder, of said drying cylinder, and joint means operated
a control valve governing supply of steam to said by the tension of said sheet and by said tempera
cylinder, a pilot mechanism utilizing an inde
ture responsive element-for controlling said. pilot
pendent source of pressure for operating said to reset the temperature of said cylinder in pro
control valve and ordinarily exhausting to the
atmosphere, an exhaust valve governing the ex
haust from said pilot mechanism, said pilot mech
anism including a casing, a pair of diaphragms
dividing said casing into-"two outer chambers
and an inner chamber, a supply valve and a waste‘
valve in said outer chainbers governing the sup
portion to changes in sheet moisture.‘
15
7. A moisture control mechanism for paper
making machines comprising a drying cylinder,
the moisture in the paper sheet passing over
which is to be controlled, a source of heating me 20
dium for heatingv said cylinder, a control valve
ply and waste of pressure by which said control governing supply of heating medium to said cyl
valve is operated; the pressure from said inde ‘ inder, a pilot mechanism utilizing an independ
pendent source expanding said inner chamber ent sourcelof pressure for operating said control
and actuating said supply and waste valves to valve, an element responsive to temperature of 25
said drying cylinder, any element responsive to
divert said pressure to the control valve for oper
ating the same on the closing of said exhaust
valve, an instrument actuated by varying ten
sion of the paper, another instrument responsive
to a variable characteristic of said drying cylin
der, joint means operated by the action of said
instruments for actuating said exhaust valve, and
- means responsivev to the control valve operating
the operating pressure afforded by said pilot for
partially o?setting a change in said pressure, and
means operated jointly 'by the tension in said
sheet, by said temperature responsive element 30
and by said pressure responsive element to reset
the temperature in said cylinder substantially in
proportion to changes in sheet moisture.
AVERY H. STANTON.
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