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Патент USA US2130665

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Sept. 2o, y1938.
Flled Sept 18 1935
2 sheets-sheet 1
Sept. 20, 1938.
Filed Sept
73 E
nu -/
2 Sheets-Sheet 2
_I 77
18, 1935
¿3 26.70 39
2,5 ‘9
`Z6 Z6
Patented Sept.
Donald B. Brenner, Hamilton, ohio, assigner to
The Champion Paper and Fibre Company,
Hamilton, Ohio, a corporation of Ohio
Application September 18, 1935, S‘erial No. 41,171
14 Claims'.
'I'his invention relates to methods of and ma
chines for drying or conditioning webs of paper
and the like; and it comprises a supporting de
vice such as a foraminous wire belt adapted to
5 supporta moving web of paper, ablower, a duct
connected to the discharge of the blower, said
duct advantageously having converging walls,
and _adapted to discharge air into a diverging
passageway formed by said supporting device and
10 by an impervious member adjacent thereto; and
it further comprises a method of conditioning
more or less diagrammatically, an example of a
specific embodiment of the invention.. In the
Fig. 1 is a perspective view, partly in section,
of the drying machine, showing the air passage
Fig. 2 is a plan view corresponding to Fig. 1
and showing the carrier for the web; and
' Fig. 3 isan end view of the apparatus of Fig. 1
illustrating the air passage system.
In the showings, in which like reference char
webs, including supporting the web on one side acters indicate >like parts throughout, the ma- on ‘a foraminous carrier and blowing air at high _chine is shown as having an endless foraminous
velocity over the other side of the carrier and carrier I0 adapted to support a web 9 and carried
15 adjacent the supported side of the web, while on two large drums Il (Fig. 2) only one of which 15
is shown in Fig, 1. Driving means are shown for
maintaining the static pressure of the high ve
locity air adjacent the web substantially uniform „one drum,'comprising a pulley I2 and belt I3
and slightly subatmospheric; all as morefully driven by power means, not shown. Aswill be
hereinafter set forth and as claimed.
The invention is particularly adapted to >the
drying of paper after it has been coated, gummed
or the like.
It eliminates the necessity of cum
bersome festoons with their attendant dimculties,
and provides apparatus for drying or otherwise
25 conditioning webs rapidly, continuously and
without injury. The webis held flat during the
drying operation. -According to the invention
explained, the
omitted. The
wire mesh, the
eliminates the
_driving means are in some cases
carrier is advantageously of wide 20
wires being wavy, as shown, which
possibility of occurrence `of dead
spots during drying. The apparatus is provided
with supporting columns 50 carrying cross beams
5l on which are supported siderails i9. The
carrier is movably supported on a plurality of
spa-ced roilers I8 mounted in bearings 52 4on the
there is provided a machine having a pervious ` side rails.
Below the carrier are positioned a plurality of
air circulating units. Each unit comprises a 30
double blower it driven by a belt I5v from a power
flow and reduced pressure whereby the web> is » shaft i6„ driven by a motor Il as shown. The
lightly but ñrmly drawn against the support and two outlet conduits 20 of the double blower are
air is passed rapidly> across the entire width of - merged as Yat 2| into a passage of curving shape
22. The top of this passage merges into two 35
35 the web. ‘ The uncoated or dry side of the paper
support for a moving web and an arrangement of
80 air passages for blowing hot air over the support
ed surface of the paper under conditions of rapid
is in contact with the support. In the apparatus
air is‘forced by a blower through a progressively
constrlcted channel and delivered to the paper in
a gradually diverging passageway.. the system
40 Vconstituting in essence, an embodiment of a
Venturi tube. ` Air at relatively ylow velocity and
relatively high static pressure thereby assumes a
condition of relatively high velocity and low static
pressure, and in the latter conditionr it impinges
ß'ßupon the web. It is arranged that the static
pressure of this high velocity‘air shall beapproxi
mately\uniformly less than atmospheric (or less ‘
plates or sheets 23 closely spaced from the carrier
The inner portions of the sheets 23 are sup
ported on longitudinally extending girders 26.
The sheets 23 extend outwardly to the edges of
the carrier and are slightly deiiected downward,
thus providing two narrow passageways. 25 be
tween the plates and the lcarrier `whichy passage
ways progressively -increase `slightly in cross vsec
tional‘area toward the edges of the carrier. The
amount and rate of this increase in` the cross
sectional area of passageways 25 is important` for
reasons’ >hereinafter pointed out. A restricted
than 'that on the opposite side of 'the‘web)` across ' throat portion 24 joins these passageways 25 with
-the entire surface 'of"the,web, thusholding the
the duct 22 from the blower. This throat por
oo‘web flat _against 1 the `supporting screen. Under" tion is the vmost constricted'passage in the system. 50
. thesey conditions diffusion of water or other sol- ‘
vent from'the opposite, freshly _coated side of the
web is very fast -and there results a very rapid
56 \ vIn the accompanying drawings there is shown,
The'air passage arrangement described isin
effect ‘a venturi. Air is delivered by the blower `
into " conduit 2| Aat a given gage pressure and a
given velocity.-` In going through the throat por,
tion‘ 24 the velocity ‘increases and the static head
falls.I The air then enters passageways 25 which,
as héreinbe‘fore pointed out, gradually increase
in cross sectional area.
The' dimensions of the
passageways and the rate of increase of their
cross sectional area are such that the air here is
in a condition of high velocity and approximately
uniformly reducedpressure across the whole web
With a suitable blower the pressure is
slightly subatmospheric.` In practice the‘gage
10 pressure is of the order of magnitude of an inch
of water (.04 pound per square inch) below
atmospheric. This is suiiicientto draw the web
down flat upon the carrier, where it is rapidly
dried by the high velocity hot air blast.
Return air ducts 30 are provided to deliver the
air back to the heater 33 and thence to the
blower intake. Not all of the air is ordinarily
recirculated. Gaps 34 are provided on each side
of the apparatus between the carrier i0 and side
20 walls 43. These allow some leakage of air in and
out of the system. If desired all the air may be
exhausted to .the atmosphere but to economize
heat it is advantageous to recirculate a consid
erable portion.
'I‘he sides of the machine are provided with
impervious heat insulated walls 43.
Figs. 1 and 3 show an air control arrangement
which I have found useful in connection with
this machine. As shown, the restricted throat
30 -portion 24 is provided with an inner pair of
curved deflecting plates 39, forming two. channels
40 dividing the air stream and directing it into
passages 25. The two deflectors also form be
tween them an air passage 4I delivering to the
A longitudinally
35 center axial region of the web.
extending damper 42 is provided by which means
Ait is possible to direct air to the center portion of
the. web in the required proportion, „to secure
.n drying.
'I'he character of the moving carrier is im
portant. It is desirable that there should be
relative movement between the carrier and the
moving web. Sometimes it suilices to keep the
ca1--er stationary and simply movethe web with
chine as it is found that _the web is held ñat
against the carrier and is restrained from tend
encies to curl. In operation the drying of the
web is exceptionally rapid.
'I'he following example illustrates, by way of 5
example, a typical paper drying operation utiliz
ing the present machine.
Paper stock 39 inches wide and of a grade
commonly used for making coated paper, weigh
ing 50 pounds per ream (500 sheets-25 x 38 10
inches) was coated with a typical clay-water
casein coating composition containing 25 pounds
of water per ream of coated paper.
The coated
paper was continuously delivered to one end of
the carrier, which was moved at a speed slightly 15
less than that of the web. Hot air was delivered
to the under side of the paper by the blowers at
a velocity of 175 feet per second. The static
pressure below the web was 3A inch of water be
low atmospheric and the temperature of the hot 20
air blast was 275° F. The paper was completely
dried in 10 seconds.. After leaving the other end
of the carrier it was wound on a reel (not shown).
In case even more rapid drying is desired, the
top face of the web may be subjected to a warm 25
air current. But for manypaper coating opera
tions, I iind that the operation described, ab
stracting water-from the lower surface alone,
gives a superior product.. The drying is sufii
ciently rapid for all ordinary purposes. The ap--_
paratus is well suited for drying uncoated paper.
The apparatus is well adapted for drying other
webs than paper; cloth for example. It can also
be used for other web conditioning operations.
What I claim isz
1. Machine for conditioning webs, comprising
a conduit having walls converging to a narrow
throat, a foraminous carrier for a web, a partl
tion member adjacent said carrier and slightly
inclined with respect thereto, a passageway com
municating with the throat and deñned on oppo
site sides by said carrier and said partition mem
ber, said passageway thus gradually increasing in
cross sectional area in a direction away from the
45 respect to it.
That is, the apparatus may be
provided with a stationary foraminous top.
Usually I find it better to drive the carrier in the
throat, and means for delivering air through said
conduit and throat into said passageway.
2. Machine for conditioning webs comprising a
same direction as the paper but at a slightly> foraminous carrier for a web, a conduit having
different speed, which may be either faster or walls converging to form a narrow throat, an
50 slower than the paper. The object securedxin extension of said walls disposed slightly inclined
each case is to insure movement of the paper with respect to the web carrier and deñning an 50
relative to the carrier so that all portions of the air passage formed on the one side by the carrier
under surface of the'paper are exposed to the member and on the other by the extension of
air current. Otherwise imperfect drying and , the walls of the throat portion, said air passage
The word “carrier” gradually increasing in cross sectional area to
l as used in the specification and claims refers to provide approximately uniformly lowerpressure 55.y
this supporting member regardless of whether it on- the one side of the carrier than on the other,
is stationary or driven as described. The carrier and a. blower adapted to discharge into said
55 other defects might result.
is conveniently made of woven wire of very open
60 mesh. I have found that a screen composed of
wire strands 0.08 inch in diameter with meshes
1- x 2 inches is satisfactory. The carrier can be
made of thin perforated metal or of cloth, if
desired. It is desirable that the longitudinal
-65 Wires of the screen be curved or staggered, as
indicated in Fig. 2, so as to prevent any portion
of the paper from Ibeing continuously in contact
lwith the carrier througout the entire drying
Observations on the behavior of the machine
in operation indicate that in the immediate vi
cinity of ,an individual carrier wire the pressure
is appreciably greater than that between the
wires. These local pressure variations do not
75 interfere with'the proper functioning of the ma
3. Machine for conditioning webs comprising a 60
blower, a foraminous carrier for a web and means
for delivering air over a substantial area of that
surface of the web supported by said carrier at
high velocity and at a pressure substantially uni
formly less than that on the opposite side of the
web, said means comprising a conduit of pro
gressively decreasing cross sectional area leading
from'the blower, a partition member adjacent
the carrier and forming in conjunction therewith
an air passage into which air may-be delivered 70.
through said conduit, said air passage increasing
gradually in cross sectional area in the direction
-of the passage of air therethrough.
4. Machine for conditioning webs comprising a
foraminous carrier for` a web, a blower, an air
prises supporting the web on one~ side of a forami
nous carrier and passing air at high velocity over
the other side of the carrier while maintaining
ally decreasing in cross sectional area from the lthe static pressure of the high velocity air adja
cent thexcarrier substantially uniform and slightly
blower to said carrier and then ‘gradually in
creasing in cross sectional area throughout the subatmospheric.
` duct leading from said blower to said carrier and
returning to said blower, said carrier forming a
part of one wall of said duct, said air duct gradu-h
part of its length bordered by said carrier.
5. Machine for drying web material comprising
10. Method of conditioning webs which com
prises passing air at high velocity over one side
of the web, supporting this side of the web on a
foraminous carrier and holding the web against 10
carrier by maintaining the static pressure
to a constricted throat, means for forcing heated
a foraminous carrier for supporting a web, means
' air through said conduit and throat, a partition
member connecting with a wall of the throat,
and forming in conjunction with the carrier a
15 gradually enlarging passageway adjacent the
carrier to carry air at high velocity and sub
atmospheric pressure along the side of the web
in contact with the carrier, return ducts con
necting said passageway with said air forcing
20 means and bleed means putting the system in
communication with the atmosphere.` A
6.“ Machine for conditioning a web comprising
a foraminous supporting device adapted to sup
port a moving web, a blower, conduit means
25 leading from the blower to a zone adjacent the
central portion of the web so as to discharge air
to the supported side of the web in a narrow
path between the two edges thereof substantially
centrally of the web as the web travels over the
supporting device, partition _members closely ad
jacent the supporting device and forming in con
junction therewith gradually enlarging passage
ways adjacent the supporting device through
which the air flows at high velocity and at sub
stantially uniformly lower pressure than that
exi'ting on the unsupported side of the web and
means near the edges of the web for removing
air from the vicinity of the web.
7. Machine for conditioning a web comprising
a foraminous supporting device adapted to sup
port a moving web, a blower, a conduit connected
to the blower and tapering to form a narrow
throat portion substantially centrally of the web,
sheet members spaced from the supporting de
vice, the distance between the sheet members and
45 the supporting device gradually increasing to
wards the edges of said device, and means in
thethroat portion to deñect air along the sup
ported side of the web to each edge thereof
through passageways bounded by the supporting
50 device and by said sheetV members.
8. The apparatus of claim 3 wherein the fo
f raminous carrier for theI web is an endless wire
screen belt and means are'provided for moving
the carrier and for moving the web at diñerent
55 relative speeds.
9. Method of conditioning webs which com
of the high velocity air adjacent thereto sub
stantially uniformly just below the pressure on
the opposite side of the web.
11. Method of conditioning webs, which com is>
lprises imparting velocity to a stream of air;
passing the stream through a contracting pas
sageway to increase its velocity and decrease its
static pressure; then causing it to iiow, at high
velocity and low static -pressure, in contact with 20
and substantially parallel to the surface of the
web, maintaining its static pressure substantially
uniform', by causing it to pass through a gradu
ally enlarging passage, while it is in contact with
the web, and supporting the web on the side
exposed to the stream of air.
12. Machine for conditioning webs, comprising
a conduit having lwalls converging to a narrow
throat, a foraminous carrier for a web, partition
members adjacent said carrier and slightly in 30
clined with respect thereto, two passageways
having a common inlet `communicating with the
throat, said passageways being defined on oppo
site sides by said carrier and said partition mem
bers, and thus increasing gradually in cross sec 25
tional area in a direction away from the throat,
and means for delivering air through said con
duit and throat into both of said passageways.
13. A machine for conditioning web material
comprising a blower, a foraminous supporting
device adapted to support a moving web, a con
stricted throat near the central portion of said
supporting device, a conduit leading from the
discharge side of the blower to said throat, sheet
members near said supporting device and slightly 45
inclined thereto, said sheet members and sup
porting device defining passageways which lead
from `said throat to the edges of said supporting
device and gradually increase in cross sectional
area away from said throat, and means for con
ducting air to the central portion of said sup
porting device between said passageways.
14„The machine of claim 13 in which means
are provided for regulating the amount of air
conducted to the central portion of the supporting
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