close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2135627

код для вставки
Nov. 8, 1938.
H, J. SMITH
_
2,135,627
TEMPERATURE CONTROL FOR PAPER MILLS AND THE LIKE
Filed June 24, 1955
a Sheets-Sheet 1
, INVEN
R,
ATTORNEY.
NOV. 8, ‘1938.
_
H, J, sMlTH
2,135,627
TEMPERATURE CONTROL FOP. PAPER MILLS AND THE LIKE
Filed June 24, 1935
'
3 $heets—$heet 2
/
'3
4g
.50
.
Q
a:
59‘ 'im
a;
%k S.‘ INVEKOR.
ATTORNEY.
Nov. 8, 1938.
H, J, SWTH ’
2,135,627
TEMPERATURE CONTROL FOR PAPER MILLS AND THE LIKE
Filed June 24, 1935
‘ 3 Sheets-Sheet 3
7
T
m‘
.
‘(/1913 .
I151
v
g
424
121'
'
i
_
:
25a
_
-
122
g
~~JZ7
[12g
160’? i
I05 103
106
9?
l0
a,‘
‘
107
10
o 0
‘/@''Q
108
| I
'
‘L 409
|
I
1&9
|
I
"1‘
‘
110
1/414
11
x _ _
4
1147
'
150
112
140
145
131
148
125
-
>140
_
> 151
v
-
-
111' ,1
I
‘152
136‘ .129 <
-_
_
.
130
'
1'53
H_OV.A.C.
% /WM
ATTORNEY.
Patented Nov. a, 1938
2,135,621
A
UNITED STATES PATENT’ OFFICE‘
' ausszr
ram-saunas common roa Paras mans
also m use
I‘ Razor 1. Smith, Longmeadow, Mara, assignor, by
mesne assignments, to General Motors Corpo
ration, Detroit, Mich, a corporation of Dela
ware
.
Application June 24-, 1935, Serial No. 28,056
“Claim. (CI. 34-48)
\v
This invention relates ‘to temperature¢control
In accordance with the present invention, the
systems, and more particularly to- a system for
controlling the temperature of the drying rolls
in paper mills and the like.
_
'
movement of a steam supply valve by means of
a reversible motor-control unit.
In order to '
An object of the invention is to ‘provide an
automatic control for the moisture content of the
provide means for adjusting the "range of control 5
sheet which is discharged from the drying rolls
changes in stock. a second motor-control unit is‘
provided which ‘is operated by a hand control or
of a paper mill.
Another object is to provide an'accurate and
automatic system, controlled by variations in the
moisture content of the sheet which is received by
the drying rolls, for varying the temperature of
the rolls so as to discharge the sheet with a uni
_ form moisture content.
i
position of the tensioning roll is translated into
I
\.
Another object is to provide a system of the
above type which-maybe readily adjusted to ac
commodate diiferent types of sheet, or stock hav
ing different moisture contents.
Another object is to provide .a system of the
above type which is adapted to operate in con
junction with present‘ equipment, whereby the
‘cost of installation is reduced to a minimum.
Another object is to provide a system for main
taining the rolls at a predetermined temperature
of the motor-control unit in accordance with
by an automatic thermostat.
The ratio of con
trol eifected by the first and second motor-control 10
units may be varied in order to provide the de
sired result. The automatic thermostat may be
controlled in accordance with the steam conden
sate temperature at a selected roll, for the pur
pose of maintaining the temperature of the rolls ll
substantially uniform when the control of the
first unit is interrupted, as, for example, in re
sponse to a break in the sheet. Means is pro
vided for manually connecting either the hand
control or the thermostat into the circuit, as de
sired.
_
'
' Other features of the invention consist in the
various details of construction and combination
during periods when no sheet is being received -
of parts as hereinafter more fully set forth.
The broader aspects of the invention will be
thereby.
better understood by referring to the following
.
Another object is to provide a simple, conven-'
lent and dependable device of the type above in
dicated.
_
v
'
Other objects will be apparent from the fol
lowing description.
7
~
able temperatures ' by heating means,- su‘ch as
steam, and are adapted to discharge the sheet
with a predetermined moisture content. A fea
ture of the present invention consists in fstillsll ing the variations of moisture content of the in
coming sheet to control the steam supplied to the
rolls in such manner as to compensate for said
variations.
._,,
>
'
description, taken in connection with the accom
Danying drawings in which a preferred embodi
ment has been disclosed for purposes of illus
trationonly.
_
; In the drawings,
The invention is primarily intended for use in
connection with the drying rolls of a paper mill.
In such mills the sheet is passed successively over
a plurality of rolls which are maintained at suit
‘
»
In one embodiment, the tension of the incom
5 ing sheet is used as a measure of the moisture
content. A tensionlng roll, such, for example, as
a Stickies roll, is held against the incoming sheet
' >
'
Figure 1 is a ditic view of a temper
ature-control system embodying the present in-'
vention;
.
‘
>
Figure 2 is a‘ front elevation of the automatic
control switch.
'
‘
'
-'
Figure 3 is a side view thereof;
I
A
' Figure 4 is a detail view of the ‘automatic con
trol mechanism;
'
‘
Figure 5 is a front’ elevation of the control 40
panel;
~
.
Figure 8 is a wiring diagram showing the 6011-!
nections of the signal lights;
Figure 7 is a section of the indicating unit,
taken along the'line ‘I-‘--‘l of Figure 8;
' Figure 8 is a side view of the indicating unit;
and
-
-
. in' such manner that the position of the roll is
- determined by the moisture content of the sheet
Figure 9 is a ‘wiring diagram showing the con
nections between the‘ hand control; lautomatic
0 at any instant. Inasmuch as the tensioning roll
is responsive to minor changes in moisture con:
tent, means is provided to integrate the move
ment of the roll so as to e?ect a control only in
temperature control and motor-control unit.
In the following description and in the claims,
certain speci?c terms have been used for con
venlence in referring to‘ the various details of the
accordance with the average moisture content of . invention. These terms, however, are to be in
terpreted as broadly as the art will permit.
the sheet over predetermined intervals.
65
2
~
2,185,627
Referring to the drawings more in detail, the
invention is shown in Figure l as applied to the
drier of a paper mill which comprises a plu
rality of rolls in over which a sheet H of paper
is passed in the usual manner for successively
drying the same as it passes over the rolls. The
rolls may be heated by steam supplied from a
header l2 and fed to the individual rolls l0 by
communicatingpipes [3. The condensate from
10 each roll is collected in a well l4 and is removed
through a pipe l5 which connects with a drain
line it. Steam maybe supplied to the header
‘the pulley G2 and turns therewith. The contacts
58 are adapted to alternately engage contacts 1|
carried by a contact arm 12 which is supported
by a sleeve 13 journalled on the shaft 59. The '
contact arm 12 carries a pair of brushes 10 which
are electrically connected, respectively, to the
contacts 1| and are adapted to engage sets of »
stationary contacts 14 and 15 which are mount
ed on a stationary support 15.
The construction is such that rotation of the
pulley 62 in'one direction closes one pair of con
tacts 58 and 1| and transmits a force there
through to cause rotation of the contact arm '
l2 from a main- l1 having a control valve 20
12. Rotation of the pulley 62 in the opposite di
which may be operated by a lever 2 l~ in accord
ance with the automatic control mechanism to , rection breaks the ?rst-mentioned pair 01 con
tacts 68 and 1!, closes the other pair of contacts
be described.
68 and 1!, and causes rotation of the contact
The lever 21 is controlled by a pair of motor
control units 25 and 26 having arms 21 and 28 arm 12 in the opposite direction. The contacts
68 and 1| thus ‘constitute reversing contacts
respectively which are connected by links 29 and
30 to a control lever 3|. The control lever 3i is to complete a circuit to one or the other of the 20
connected to the lever 2| by means of a link 32, brushes 10, depending upon the direction of ro
tation of the pulley 52. The position of the
the point of connection of the link 32 to the con
trol lever 3i being varied by a slider 33 having a brushes 1!) determines the position of the mo~
hand set screw 34. By varying the position of tor-control unit 25 by a circuit, to be described.
For limiting the movement of the pulley 62,
the slider 33, the ratio of the control of the mo
tor-control units 25 and 26 may be adjusted. a stop 11 is provided which is adapted to engage
When one of the control units is stationary, the the belt 59 when the pulley 82 is moved to either
link 29 or so which is connected thereto serves extreme position. A contact 18 may be carried
by the stop 11 to engage one of a pair of con
as a fulcrum about which the control lever 3|
tacts 19 for closing the circuit to the signal 30
30 may pivot in response to movement of the other
motor-control unit. In the form disclosed, the
motor-control unit 26 operates as a master con
lights, to be described.
The various contacts 14 and 1.5 are connected
trol for varying the operating range of the valve
20, whereas the motor-control unit 25 operates
as an automatic control which is actuated in
accordance with the moisture content of the
incoming sheet.
The control device for actuating the motor
control unit 25 is shown more in detail in Figure
40 4. It comprises a tensioning roll 33 which is
mounted upon an arm 39, pivoted as at 40, and
held by a weight 4| against the sheet H of paper
which is being supplied to the drying rolls. The
by a cable 80 (Figure 1) to the motor-controb
arm 39 is connected to a valve 42 which controls
45 the flow of ?uid, such as water, through a pipe
stantaneous variations in the sheet. In so do
ing, it causes the valve 42 to operate in a corre
43 leading to a cylinder 44. The cylinder 44 is
provided with a discharge line 45 regulated by
a valve 46. The cylinder 44 carries a piston
41, the position of which is determined by the
50 quantity of ?uid within the cylinder.
The piston 41 carries a piston rod 48 which is
connected to a belt 49 passing over pulleys 50
and 5| and having stops 52 and 53 adapted to
engage the lever 2| for controlling the position
55 of said lever in accordance with the movement ,
of the belt 49. The spacing'between the stops
52 and 53 permits a certain amount of move
ment of the belt 49 without actuating the lever
2!. Suitable weights 54 and 55 may be asso
60 ciated with the belt 48 for maintaining the same
in operating condition and to determine the
operating characteristics of the device.
A belt 59 may also be connected to the piston
rod 48, as by an» arm 50. Said belt 59 may be
unit/25 in such manner that the arm 21 of the
motor-control unit, is caused to take up a posi~
tion corresponding to the position of the brushes
10 on said contacts.
In the operation of the control device illus
trated in Figure 4, the tensioning roll 38 presses
against the sheet I l and causes movement of the 40
arm 39, dependent upon the moisture content
of the sheet. Innormal operation, the arm 39 is
caused-to oscillate in accordance with the in
sponding manner. If the valve 42 admits water
to the cylinder“ at a rate equal to the rate of
discharge of water through the discharge line
45, no movement of the piston 41 will take place.
If the valve 42 admits water to the cylinder 44
at a rate in excess of or less than the rate of dis
charge through the discharge line 45, the water
level will rise or fall, respectively, in the cylin
der 44 and will cause corresponding movement
of the piston 41, which is transmitted by the
belt 59 to the control switch 53. The control
switch 63 actuates the motor-control unit 25 to
progressively open or close the valve 20.
The manner of connection is such that an in
crease in the moisture content of the sheet II
causes the valve 20 to be opened so as to supply
additional steam to the rolls 10, whereby the
temperature of said rolls is raised an amount
pulley 52 of a control switch 53 which is adapt
adapted to compensate for the extra moisture
contained in the incoming sheet. If the moisture
content of the incoming sheet decreases, a re
ed, by its position, to determine the operating
verse operation takes place, the piston 41 being
66 passed around a pulley GI and thence over a
position of the motor-control unit 25. A weight
64 may be hung on the end of the belt 59 to
70 hold the same in frictional engagement with the
pulley 52.
The control switch 63 is shown more in detail
in Figures 2 and 3 as comprising the pulley 82,
over which the belt 59 passes, and a pair of con
76 tacts 68 mounted upon a shaft .59 which carries
raised or lowered in accordance with the aver
age opening of the valve 42 which, in turn, is
determined by the average moisture content of
the sheet H over a given interval.
The contacts 19 may be connected to heating
coils 82 which are associated with thermostatic
switches 83. Each switch 83 is adapted to close
a contact 84 to a signal light 85 which may be
45
,
' 2,185,627’
a
mounted,,for example, on the control panel 86, gear. train I 26 from a pinion I26 carried by a
as illustrated in Figure 5. The connection is‘ reversible motor I21. A plurality of sets of sta
such that, when one of the contacts 19 is closed
a su?icient length of time to actuate the switch
83, the signal light 85 is lighted so as to indicate
to the operator that an extreme change is taking
tionary contacts I28,‘ I29 and a contact I30 are
mounted on a support I3I in position to engage‘
the commutator I23 as the commutator is rotated 5
bythe motor I21.
_
The motor~control units 25 and 26 and the
place. The switch 83, however, is su?iciently
slow-acting as to prevent the signal light 85 from . indicating unit I20 maybe of similar construc
tion with the exception of the indicator I2I,
being energized in response to momentary clos
.10 ing of the contacts 19. When the pulley 62 is
moved to either of its extreme positions, the stop
. 11 engages the belt 59 to limit the movement of
which, in the case of the motor-control units 25 10
and 26, is” replaced by the arms 21 and 28. The
units may, for example, be of the type described
the pulley. If further movement of the piston in my copending application, above-mentioned.
A suitable control‘ circuit for the indicating unit
41 takes place, the belt 59 slips about the periph
15 cry of the pulley 62. The stop 11 also provides ‘ . I20 is illustrated, for example, inv Figure 9, In 16
manual means for adjusting vthe pulley 62 with this ?gure, the reversible motor I21 is shown as >
a reversible shaded pole motor having a ?eld
respect to the belt 59.
'20
The second motor-control unit 26 may be con
nected to a hand switch 89 (Figure 1) or to an
winding I32 which may constitute the secondary
of the transformer I33, the primary I34 of which
automatic thermostat 90, both of which may be
may be connected to a source vof A. C. supply.
The motor is provided with a pair of shading
mounted upon the control panel 86. ,
The hand switch 89 may be of the type de ~' coils I35 whichuwhen energized, are adapted to
scribed in my copending application Serial No. cause rotation of the motor in one direction, and
657,237, ?led February 17, 1933, for Control by another ‘pair of shading coils I36 which are
25 integration. It may comprise, for? example, a adapted to cause rotation ofv the motor in the
shaft 9| (Figures 7, 8 and 9). carrying an arm 92 opposite direction. These coils I35 and I36 may
having apair of contacts 93 adapted to engage be connected to a double-pole, double-throw
contacts 94 mounted on a contact arm 95. The switch I31 having a set of poles I38 connected
contact arm 95 is mounted for rotation on a
30 sleeve 96 which is journalled eccentrically about
the shaft 9|. .A control handle 91 may be con
nected to the shaft 9|. The contact arm 95
by leads I39 to the contadts 9a of the hand switch
carries a pair of brushes 98, 99 which engage sets
tacts II2 of the thermostat 90 maybe connected
oi’ contacts I00, I0! in accordance with the posi
35 tion of the control handle 91. ' The contacts I00,
IOI are connected to the motor-control unit 26
in the manner to be described.
The thermostat 90 may be of the type shown in
0 my Patent No. 1,952,571, dated March 27, 1934.
.40 It may comprise, for example, an ‘arm I 03_piv
oted, as at I04, and actuated by any expansible
bellows I05 in accordance with the temperature
of the ?uid therein. A spring I06 may be used
' to adjust the operating range of the thermo
89 and a set of poles I40 connected by leads I“
to the contacts I01 of the thermostat 90. The
contacts I00 of the hand switch 89 and the con
by cables I45 and I46, respectively, to a junction
box I41 which is connected by a cable I48 to the ;
contacts I28 of the indicator unit I20. The con
tacts IOI of the hand switch 89 and the contacts
II 3 of the thermostat 90 may be connected by
cables I49 and I50, respectively, to a junction box.
I5I which is connected by a cable I52 to the con- i .
tacts I29 of the indicatorunit I20; ‘The contact
I30 of the indicator unit I20 is connected by a
line I53 to the field winding ‘I32 of the motor I21.
The above connections are such that when the
switch I31 is in one position, the hand-control
stat. The arm I03 carries a pair of contacts I 01
which are adapted to engage contacts I08 car
riedon a contact arm I09 which is pivoted, as
at H0, to the arm I03. The contact arm I09
carries a pair of brushes III which are adapted
to engage sets of contacts II 2 and H3. The con
tacts I I2 and I I3 may be connected to the motor
control unit 26 in the manner to be described,
switch 89 is connected in the circuit. If then
the handle 91 is turned in one direction, for ex
ample, in' a counter-clockwise direction, as viewed
in Figure 9, the pair of contacts 93 and. 94 at the
left is closed, thereby completing the circuit from I
the shading coils I35>through the switch I 31 and
one lead I39 to the selected contacts 93 and 94,
whereby, the motor-control unit may be operated
in accordance with the position of the thermo
thence to the brush 98, one of the contacts I 00,
through the cables I45 and I48 to one of the
stat.
‘
.
The bellows I05 may be connected by a ?exible
tube II4 to a bulb II5 which may be mounted in
a suitable well in the return condensate line of
one of the rolls I0.‘ The thermostat accordingly
60 is responsive to the temperature of the steam
contacts I28, thence through vthe commutator
I23, the contact I30 and the return line I 53 to
the ?eld winding I32 of the motor I21. The mo
tor is then caused to operate in agiven direction '
until the circuit is broken. by the commutator
I23 leaving the contact I28 which is energized
at that moment.‘ If the handle 91 is moved in
,
I49, I52 to a contact I29 and energizing the op-
5
condensate in the selected roll I0 and is adapted
to actuate the motor-control unit 26 so as to', the opposite direction, the opposite pair of cone
tacts 93, 94 is ‘closed, thereby completing a cir
control the steam supplied to the roll in-a man
cuit through the brush 99, a contact I III, cables
ner adapted to maintain the roll at a predeter
mined temperature.
In order to indicate to the operator the posi
- posite coils I36, which causes a reverse move-‘
' tion of the motor-control unit 26, an indicating
ment of the motor until the commutator I23
unit I20 is provided (Figures 5, '1 and 8) having
breaks contact with‘ the contact I29" which is
an indicator I2I moving over a scalell9, cali
, vbrated to show the angular position of the arms
28 of the motor-control unit 26. This indicat
ing unit I20 may comprise a‘shaft I22 carrying
the indicator I2I. A commutator I23 and a worm
gear I24 mayvalso be connected to the shaft I22.
75 The worm gear I24 may be driven through a
energized at that moment. The motor I 21 is
thus reversibly and progressively operated in ac- ‘(0
cordance with the position) of the handle 91.
The contacts I28 and I29 may be relatively dis- I
placed to provide di?erent positions of the motor- I
control unit in‘opening and closing the valve 20.
I When the switch I31 is thrown into the oppo- 76
4
2,135,627
site position, the hand-control switch 89 is dis
connected and the thermostat 90 is connected in
the thermostat 90 to the motor-control unit 26.
The thermostat 90 is adjusted to actuate the
the circuit. The control of the motor I21 by
the thermostat 96 is then the same as that above
motor-control unit 26 so as to maintain the rolls
described in connection with the hand switch, the
motor being reversibly and progressively actu
ated in response to temperature variations regis
tered by the thermostat 90.
It is to be understood that the connections be
10 tween the contacts 14 and ‘I5 of the control
switch 63, and the motor-control unit 25 are
similar to those above described. This connec
tion is illustrated in Figure 1 as comprising a
cable 80 connecting the control device 63 with
15 the motor-control unit 25. It is also to be noted
that the motor-control unit 26 and the indicat
ing unit I20 are connected in parallel so that
the indicator I2I shows at all times the position
of the motor-control unit 26. The switch I3‘!
20 is connected to a junction box I55 which is con
nected in parallel by cables I56 and I51, respec
tively, to the motor-control unit 26 and the indi
cating unit I20. The switch I31 may be operated
by a handle I58 mounted upon the control panel
86. The control panel may also carry a suitable
temperature recorder I59, a steam pressure re
corder I66 and a chart IBI.
In the operation of this system, the handle
I58 is normally in a position such that the hand
control switch 89 is connected in circuit, whereby
the position of the motor-control unit 26 and the
indicator unit I20 are governed by the position
of the handle 91. Assuming a paper having'pre
determined characteristics to be passing over the
various rolls ID, the tensioning roll 38 will take
up a position depending upon the moisture con
tent of the paper, thereby causing the piston 41
and the belts 49 and 59 to take up corresponding
positions. The motor-control unit 26 is then
actuated by manipulation of the handle 91 so as
to bring the lever 2! into engagement with the
stop 53 of the belt 49, whereby the control of the
steam supply is taken by the belt 49. The stop
'I'I of the control switch 63 is then adjusted to
45 the central position by causing the pulley 62 to
slip with respect to the belt 59. Thereafter, the
steam supply will be under the control of the
tensioning roll 38 and the motor-control unit 25.
Said unit operates to produce minor variations
50 in the steam supply in accordance with the in
stantaneous positions of the control switch 63
caused by changes in the average moisture con—
tent of the sheet.
If the moisture content of the sheet changes
55 suddenly or becomes such that the control switch
63 is actuated to the limit of its'movement, there
by closing one of the contacts ‘I9, one of the in
dicating lights 85 on the panel 86 will be ener
gized to indicate to the operator that a change
is taking place. If the control device does not
soon correct the change, the operator may make
suitable manual adjustment of the steam supply
by actuation of the handle 91 of the hand switch
89. The hand switch 89 is also used when the
stock is changed and to adapt the system for use
with different grades of paper.
In the event of a break or between runs when
no sheet is passed over the rolls I0, the control
device 63 becomes inoperative. It may be desired
70 to maintain the temperature of the rolls I0 sub-,
stantially constant during this period so that the
rolls will be ready for use when a sheet is again
supplied thereto. For this purpose, the lever I58
is thrown to the opposite ‘position, thereby dis
75 connecting the hand switch 89 and connecting
I0 at a predetermined temperature.
When changing from the thermostat control
to the hand switch, it is necessary to know the
position of the motor-control unit 26 in order to
make a corresponding setting of the hand switch.
The indicating unit I20 is used for this purpose,
since it operates in conjunction with the motor 10
control unit 26 and shows at all times the posi
tion thereof. It is obvious, however, that this
unit may be omitted if such indication is not
required in any particular instance.
It will be noted that the above device is adapted 15
to maintain the drying rolls at suitable tempera
tures to stabilize the moisture content of the ?n
ished sheet. In certain instances, the moisture
readings were stabilized with a variation of 0.2%.
The device also permits the rapid change-over
between different types of stock and eliminates
waste due to improperly dried paper or due to
breaks which are often caused by faulty drying.
The adjustments are such that they may be read
ily adapted to any desired operating conditions,
and the controls are arranged on a panel suited
to give a visible record of the operation of the
system.
The position-indicating unit I20 shows at all
times the position of the motor-control unit 26.
After a paper break or on change of orders, the
operator sees instantly just where to position the
handle 91 to pick up where the thermostat leaves
off.
Under the close control herein provided, it is
possible to readjust the distribution of heat in
the various rolls and to provide for balanced paper
‘shrinkage across the mill, thereby reducing the
breaks and improving the general quality of the
paper. The ability to maintain a uniform and 40
correct drying roll temperature with proper dis
tribution of the shrinkage across the whole mill
permits increasing the speed, and therefore the
tonnage, up to the limit of capacity of the mill.
The hand switch 89 may constitute a master
control for adjusting the system for different pa
pers. The master control can position the valve
in any one of twelve positions. The control
switch 63 can position the valve in twenty-six
different positions. The relative control can be 50
adjusted by varying the position of the slider 33
on the control lever 3I. It is to be noted, there
fore, that an extremely accurate control is ef
fected.
.
The signal lights 85 may, for example, com 55
'prise red and green lights, and are adapted to
call the operator’s attention to the fact that the
sheet is too wet or too dry and that connection
at the master control is required.
Although a preferred embodiment has been dis 60
closed for purposes of illustration, it is evident
that various changes and modi?cations may be
made therein without departing from the scope
of the invention, which is to be limited only in
accordance with the following claims when inter
preted in view of the prior art.
I claim:
1. A temperature-control device for paper mill
drying rolls over which a sheet of paper is passed
to be dried comprising, in combination, a source 70
of heat supply to said rolls, a valve adapted to
control said supply, a pair of reversible motor
control units adapted to jointly control the posi
tion of said valve, means responsive to variations
in tension of the sheet due to variations in mois
2,135,027
ture content thereof to actuate one of said units,
'a hand control, means responsive to the roll tem
perature, and means to actuate the second unit by
either said hand-control or said temperature
_
5
sheet to automatically actuate one ot'said units ‘
and a second control means adapted to actuate
the other of said units.
‘1
‘
-
drying rolls over which a sheet of paper is passed
to be dried comprising, in combination, a source
7. A temperature-control device for paper mill
drying rolls over which va sheet of paper is passed“
to be dried comprising, in combination, a source
of heat supply to said ‘rolls, a valve adapted to
control said supply,'a-pair of reversible motor
of heat supply to said rolls, a valve adapted to
control units adapted to jointly control the posi
responsive means.
'
2. A temperature-control device for paper‘mill
10 control said supply, a pair of reversible motor
_control units adapted to jointly control the posi
tion of said valve, means responsive to variations
in tension of the sheet due to variations in mois
ture content thereof’ to actuate one of said units,
a hand control, means responsive to the roll tem
perature, means to actuate the second unit by
either said , hand-control or said temperature
responsive meanshand an indicator unit adapted
to indicatev the position of said second unit so as
20 to assist the operator in making manual adjust
ments‘by said hand control.
3. A device for controlling ,the temperature of
drying rolls over which a sheet of paper is passed
to be dried, which comprises means responsive to .
tions in moisture content thereof, a progressive
successive multi-step reversible switch actuated
by said means, a reversible motor-control unit
actuated in accordance with the movement of said
30 switch, a source of heat supply to said rolls, means
actuated by said unit to control progressively said
supply, means to limit the movement of said
switch, a pair of signal circuits, and means oper
able when the switch remains in its‘ respective
.35 limit positions for a, given time to energize said
circuits.
4. A device for controlling the temperature of
drying rolls over which a sheet of paper is passed
to be dried, which comprises means responsive
40 to variations in tension of said sheet due to varia
tions in moisture content thereof, a progressive
reversible switch actuated by said means, a' re
versible motor-control unit actuated in accord
vance with the movement of said switch, a source
45 of heat supply to said rolls, means actuated by
said unit to control progressively said supply,‘
.means to limit the movement of said switch, a
, pair of signal circuits, thermostatic switches to
control said circuits, a heating ‘resistance asso
50 ciated with each of said thermostatic switches,
and means to energize said heating resistances
when said reversible switch is at the respective
_
5. A device for controlling the temperature of
drying rolls over which a‘ sheet of paper is passed
to be dried, which comprises a member adapted
to press against-the sheet for tensioning the same,
a fluid cylinder, means responsive to movement of
said member to control "the supply of ?uid to
said cylinder, a piston actuated by said ?uid, a
‘--'progressive reversible control switch actuated by
movement of said piston, a reversible motor con
trol unit actuated in accordance with said control
switch, a source of heat for said rolls, and means
actuated by said motor-control unit to control
said source.
,
_~
I
8- Atemperature-controlfdevice for paper mill 15
drying rolls over which a sheet of paper is passed
to be dried comprising, in combination, a source
of heat supply to said rolls, a valve adapted to
control said supply‘. a pair of reversible motor
control units adapted to jointly control the posi
'
6. A temperature ‘control device for paper mill
drying rolls over which a sheet of paper is passed
to be dried comprising, in combination, a source
70 of heat supply to said rolls, a valve adapted to
control said supply, a pair of motor-control units,
a variable ratio linkage connectingrsaid units to
said valve wherebythe ratio of control effected by
the respective units may be adjusted, means re
75 sponsive to variations in moisture content of said
20.
tion of said valve, a progressive reversible switch
adapted to controleach of said units, means ac
tuating one of said switches in accordance with
the tension of said sheet,‘ and manual means to
actuate the other of said‘switches.
25 variations in tension of said sheet due to varia
limits of its movement.
tion of said valve,'means responsive to variations 10
in tension of the sheet due to variations in mois
ture content thereof to actuate one of said units,
and a second control means adapted to actuate
the other of said units.
'
25
9. A temperature-control device for paper mill
drying rolls over which a sheet of paper is passed
to be dried comprising, in combination, a source
of heat supply to said rolls, a valve adapted to
control said supply, a pair of reversible motor 30
control units adapted to jointly control the posi
tion or said valve, a progressive reversible switch
adapted to control eachof said units, means ac
tuating one of said switches in accordance with
the tension'of said sheet, and thermostatic means
responsive to the roll temperature adapted to ac~
tuate the other of said. switches.
10. A temperature control device for paper mill
drying rolls over which a sheet of paper is passed
to be dried, comprising, in combination, a source 40
of heat supply to said rolls, a, valve adapted to
control said supply, a lever adapted to control
said valve, amember‘ adapted to press against
said sheet for tensioning the same, integrating
means responsive to the average position of said 45
member over given time intervals, a belt actu
ated by said integrating means to control said
lever between limits, and a motor-control unit
adapted to control said lever within said limits,
said motor-control unit also being actuated by 50
said integrating device.
'
.
‘
11. A temperature control device for paper mill
drying ‘rolls over which a sheet of paper is passed
to be dried, comprising, in combination, a source
of heat supply to said rolls, a valve adapted to 55.
controlsaid supply, a lever adapted to control
said valve, 9. member adapted to press against
said sheet m tensioning thesame, integrating
means responsive to theaverage position of said
member over given time intervals, a belt actuated
by said integrating means to control said lever
between limits, a motor-control unit adapted to
control said lever within said limits, said motor»
control unit also being actuated by said inte
grating device, and a master control adapted'to
change the range of control of said motor-con
trol unit.
12; In a paper mill, in combination, a drying
roll adapted to receive a sheet ofv paper to be
dried, a source of steam supply therefor, a con
trol valve for said steam supply, a pair of motor
control units adapted to independently control
said valve, means automatically operating one of
said units in response to variations in the mois
ture ‘content of said sheet, and a second control
76
means actuating the other of said units.
6
2,185,627 '
13. A device for controlling the temperature of
drying rolls over which a sheet of paper is passed
passed to be dried, whichcomprises a source of
heat for said rolls, a proéressive reversible con
to be dried, which comprises a member adapted
to press against the sheet for tensioning the same,
a ?uid cylinder, means responsive to movement of
said member to control the supply of ?uid to
said cylindena piston actuated by said ?uid, a
source of heat for said rolls, and means actuated
in accordance with the position of said piston to
10 control said source for varying the temperature
trol means for controlling said source, means
of said rolls so as to compensate for variations in
adjustment of said control means with respect
to said belt.
moisture of the incoming sheet.
14. A device for controlling the temperature
of drying rolls over which a sheet of paper is
responsive to variations in the moisture content
of the sheet, a belt actuated by said last means,
said belt passing over said control means for
actuating the same, means to limit the movement
of said control means, said belt being adapted to
slide thereover when the limit of movement 01’
said control means has been reached or to permit 10
'
RAZOR J. SMITH.
Документ
Категория
Без категории
Просмотров
0
Размер файла
1 091 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа