U.S. patent number 3,612,170 [Application Number 04/813,127] was granted by the patent office on 1971-10-12 for thermal treatment roll.
This patent grant is currently assigned to Societe Rhodiaceta. Invention is credited to Paul Juppet, Robert Konopatsky, Jean Ruetsch.
United States Patent |
3,612,170 |
Juppet , et al. |
October 12, 1971 |
THERMAL TREATMENT ROLL
Abstract
The specification describes a thermal treatment roll, e.g. for
heating or cooling a textile yarns etc., wherein a rotor is mounted
on a stator which is provided with a heating or cooling means.
Between the stator and rotor is a connecting element of a solid,
heat-conducting lubricating material, e.g. a ring or rings of
sintered metal impregnated with a lubricating oil.
Inventors: |
Juppet; Paul (Lyon,
FR), Konopatsky; Robert (Lyon, FR),
Ruetsch; Jean (Tassin, FR) |
Assignee: |
Societe Rhodiaceta (Paris,
FR)
|
Family
ID: |
8648552 |
Appl.
No.: |
04/813,127 |
Filed: |
April 3, 1969 |
Foreign Application Priority Data
Current U.S.
Class: |
165/89; 219/619;
165/DIG.139; 28/240; 72/200; 219/469; 28/241; 126/410; 384/92;
100/330 |
Current CPC
Class: |
D02J
13/005 (20130101); D02G 1/00 (20130101); H05B
3/0095 (20130101); Y10S 165/139 (20130101) |
Current International
Class: |
D02G
1/00 (20060101); D02J 13/00 (20060101); H05B
3/00 (20060101); F28d 011/02 (); F28f 005/02 () |
Field of
Search: |
;28/62 ;62/345
;72/200,201,202 ;165/64,86,89,90 ;219/469,470,244-471 ;308/77,DIG.5
;29/116 ;100/93RP ;126/410 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: O'Dea; William F.
Assistant Examiner: Ferguson; P. D.
Claims
We claim:
1. A thermal treatment roll comprising, in combination:
a. a hollow rotor having an inner and an outer periphery;
b. a stator disposed inside said rotor and having an outer
periphery;
c. a heating means in said stator; and
d. a connecting element composed at least partly of a solid heat
conducting, lubricating material in direct contact with the greater
part of the outer periphery of the stator and in direct contact
with the greater part of the inner periphery of the rotor,
effective to provide a conductive heat path between said stator and
rotor.
2. A roll as defined in claim 1, wherein the connecting element
forms at least part of the external periphery of the stator.
3. A roll as defined in claim 1, wherein the connecting element
forms at least part of the internal periphery of the rotor.
4. A roll as defined in claim 1, wherein the connecting element is
a sintered metal ring impregnated with a lubricating oil.
5. A roll as defined in claim 1, wherein said connecting element
comprises an inner, an outer and central coaxial sintered metal
rings, impregnated with a lubricating oil, said inner ring
contacting said outer periphery of said stator and said outer ring
contacting the inner periphery of said rotor.
6. A roll as defined in claim 1, and further comprising a
temperature sensitive probe located within said connecting element,
and regulating means connected to said probe effective to control
said heating means in response to temperature variations sent by
said probe.
7. A thermal treatment roll comprising, in combination:
a. a hollow rotor having an inner and outer periphery;
b. a stator disposed inside said rotor and having an outer
periphery;
c. a cooling means in said stator; and
d. a connecting element composed at least partly of solid heat
conducting lubricating material in direct contact with the greater
part of the outer periphery of the stator and in direct contact
with the greater part of the inner periphery of the rotor,
effective to provide a conductive heat path between said stator and
rotor.
Description
The present invention concerns a thermal treatment roll for
treating a material running thereon, such as continuous filaments,
yarns formed of fibers, ropes, tows, strips of continuous material
or sheets formed of discontinuous elements.
In various treatments, notably in the textile field, it is
necessary to bring such a material to a temperature which is both
uniform and precise, for example 100.degree. or 200.degree. C., and
to correct rapidly any variations which may be caused by any
disturbing element, such as a current of air.
In a first type of known roll, heat is supplied to the longitudinal
structure by injection of a fluid at appropriate temperature into
the rotor. The heat transmission is good, but the supply of fluid
at a precise temperature to the roll is difficult to effect. Such
feeding complicates the installation of the roll and creates a
danger of leakage of fluid through the rotating packing or
packings. It has not hitherto been possible to eliminate this
danger satisfactorily. In addition, the control of the temperature
of the rotating part is difficult to effect and is unsuitable in
practice for a precise temperature regulation.
The danger of leakage is obviated if, in accordance with a second
type of known roll, the heat is supplied to the roll by radiation
between the external periphery of a fixed stator disposed inside
the rotor and the internal periphery of the rotor. However, it is
then difficult to effect a good heat transmission from the stator
to the rotor, and a precise control of the temperature of the
rotor.
According to the present invention there is provided a thermal
treatment roll, such roll comprising a hollow rotor, a stator
disposed inside said rotor, heating or cooling means in said stator
and a connecting element, composed at least partly of a solid,
heat-conducting, lubricating material, in contact with at least
part of the outer periphery of the stator and with at least part of
the inner periphery of the rotor.
With a roll according to the present invention, the material is
heated or cooled in contact with the external periphery of the
rotor, the latter being brought to the appropriate temperature
mainly by conduction of the heat produced by the stator through the
connecting element. The element is therefore advantageously so
shaped and disposed as to be in contact with the greater part of
the internal periphery of the rotor and the external periphery of
the stator, or at least of their useful part, i.e. of that part of
the rotor which is in contact with the material to be treated and
of that part of the stator which produces the heat.
These two parts are advantageously disposed opposite to one another
and the connecting element disposed between them is advantageously
of small thickness. Thus, the losses of heat through the ends in
the course of the conduction are reduced, as also is the time
necessary for the heat transmission, whereby both the output and
the speed of reaction of the roll to any modification in adjustment
of the quantity of heat produced by the stator are improved.
Advantageously, the connecting element may serve as a means for
centering the rotor, which avoids the use of any ball bearing or
like centering device and considerably simplifies the design of the
roll. In addition, when the connecting element is in contact with
the greater part of the internal periphery of the rotor, the latter
is also advantageously of small thickness, whereby the inertia of
the rotating part of the roll is reduced and the heat transmission
to the material to be treated is further improved.
The connecting element may be secured to the rotor or with the
stator or independent of both of them. It may be composed of a
number of independent parts of the stator and of the rotor or of
parts of which at least one is fixed to the rotor or with the
stator. As required, the connecting element may be formed entirely
of a solid heat-conducting lubricant or it may comprise one or more
heat-conducting supports, of which the surfaces in contact with the
rotor, with the stator and with one another, respectively, are
formed of a solid-heat-conducting lubricant.
By "solid lubricant" is meant a solid material having a low
coefficient of friction which is comparable to that of a liquid
employed for lubrication.
Such a solid lubricant may consist of a homogeneous solid material,
for example graphite or suitable heavy metal salt, such as
MoS.sub.2, WS.sub.2, NbSe.sub.2 or TaSe.sub.2. It may also consist
of a heterogeneous solid material comprising either exclusively
appropriate solid materials (antifriction alloy on sintered mass
based upon metal powder and ethylene polytetrafluoride, for
example) or at least one liquid combined with at least one
appropriate solid, the combination being such that the material
obtained has the characteristics of a solid. This is the case, for
example, with a sintered metal or alloy impregnated with a liquid
lubricant retained by capillarity in contact with the sintered
mass, and hence incapable of separating from it under the normal
conditions of use.
When the solid lubricant is in the form of a thin layer distributed
over a part of the surface of the connecting element or elements,
it may consist, for example, of a heavy metal salt of the type
mentioned above, distributed in the form of fine colloidal
particles which spontaneously adhere to such surface or are
attached thereto by means of an appropriate resin. The lubricant
and the mode of attachment must obviously be chosen with due
regard, more particularly, to the stability of the connecting
element at the service temperature of the roll and of its thermal
conductivity in the temperature range reached by the roll.
The connecting element or elements and the rotor are advantageously
mounted on the stator by simple fittings. The clearance which must
be provided between the elements depends mainly upon the expansion
coefficients of the materials of which these elements are made. It
is advantageously a few hundredths of a millimeter at the service
temperature chosen for the roll.
Rotation of the rotor may be effected by a shaft mounted along the
axis of the roll, by driving it by means of a pinion on its
periphery or by any other appropriate means. The speed at which the
rotor may be driven may vary within wide limits, and it is
generally higher in proportion as the load applied to the
intermediate element is lower. In particular it should be noted
that with the roll of the present invention, it is possible to
carry out readily a continuous treatment of chemical filaments
travelling at the highest speeds at present known.
The service temperature of the roll may be measured, if necessary,
by any known means. Preferably, a temperature measuring probe is
fixed in relation to the stator, advantageously in the connecting
element or in that fixed part of the connecting element which is
closest to the rotor, at a very short distance from the latter,
whereby it is possible to detect very precisely the temperature of
the internal periphery of the rotor. When the rotor is a cylinder
of a very small thickness, the temperature probe is therefore
disposed at a short distance from the material to be treated. Since
the space corresponding to this short distance is occupied by
materials of good thermal conductivity, the probe is therefore
subject to excellent conditions for an accurate detection of the
temperature of the material and for a rapid detection of the
temperature variations thereof.
Simultaneously, it is possible to dispose the probe at a short
distance from the heating element, under excellent conditions for
an accurate detection of temperature variations of the latter.
Thus, the probe is capable of reacting very rapidly to any
modification in the adjustment of the heating element or to any
thermal disturbance emanating from the outside.
It may therefore with very great advantage be associated with a
regulating device of high gain without incurring any danger of
hunting. A roll according to the invention thus has remarkable
temperature stability, so that it is possible to obtain an
excellent regularity in the thermal treatment of the material and
consequently an excellent constancy of the characteristics of the
latter. Such a result is particularly appreciable where the
treatment is applied to continuous thermoplastic filaments, for
which the constancy of the characteristics which may be influenced
by thermal treatment, namely dynamometric characteristics, dyeing
affinity and contraction, is essential.
The present invention will be more readily understood from the
following description, given merely by way of example, reference
being made to the accompanying drawings, in which:
FIG. 1 is a longitudinal section through one form of roll according
to the invention;
FIG. 2 illustrates the roll of FIG. 1 mounted for testing
purposes;
FIG. 3 is a view similar to FIG. 1 of a second embodiment of roll
according to the present invention;
FIG. 4 is a fragmentary view of a portion of a third embodiment
and;
FIG. 5 shows a suitable control arrangement.
As illustrated in FIG. 1, a frame 1 supports the stator, the
external periphery of which is formed of a ring 2 consisting of a
self-lubricating and sintered bronze containing 25 percent of tin.
The ring is impregnated in known manner with a mineral oil having
good stability at a temperature of 130.degree. C.
Disposed inside the ring is a heating member formed of an
electrical resistor 3 capable of developing a power of 600 watts at
an alternating voltage of 220 volts. The resistor 3 is wound upon
an insulating support 4 with a turns density which varies along a
generatrix of the support, so as to obtain in operation a constant
temperature equal to 100.degree. C. along the whole length of any
generatrix of the external periphery of the rotor. The ring 2 is in
contact at its external periphery with the internal periphery of
the rotor 5, which is in the form of a stainless steel tube of a
length of 120 mm., of a thickness of 1.5 mm. and of an external
diameter of 51 mm. The clearance between the ring and the rotor is
0.06 mm. in the cold and 0.03 mm. at 100.degree. C., taking into
account the thermal expansion difference between these two
elements. Secured to the rotor 5 is a pinion 6, which can drive the
rotor at a speed of 4,000 r.p.m., i.e. at a peripheral speed of
about 600 meters per minute.
The rotor 5 is maintained in position along the axis of the roll by
a shoulder 7 at the driving end and at the other end by an end
plate 8 fixed to the ring 2. In operation, no trace of oil appears
in the gap between the rotor 5 and the plate 8.
A heat-resistant platinum probe 9 is disposed in a cylindrical bore
in the connecting element and includes two thermocouples (FIG. 5)
which are connected to a temperature recording device 24 and to an
amplifier and control device 25 for adjusting the current across
the resistor 3, the amplitude and control device including a
regulator for this purpose. In operation, at a temperature of
100.degree. C. and at 4,000 r.p.m., it is found that the
temperature indicated by the probe is constant to within less than
0.1.degree. C.
According to FIG. 2, the stator of the roll of FIG. 1 is mounted on
precision ball bearings and the torque necessary for preventing the
stator from turning when the rotor is driven by the pinion 6 is
measured. It is found that this torque decreases when the driving
speed of the rotor increases and that, at 4,000 r.p.m., this torque
is distinctly lower than that necessary to rotate the stator
mounted on precision ball bearings.
When a roll identical to that illustrated in FIG. 1, but with the
connecting element impregnated with a silicone oil which retains
good lubricating properties at a temperature of 200.degree. C. was
used it was found that the temperature can readily be raised to
this value and that the roll could simultaneously be rotated at
12,000 r.p.m., which corresponds to a speed of travel of the
material to be treated of about 1,950 meters/min. The temperature
variations detected by the probe under these conditions remained
lower than 0.1.degree. C. Since the load on the self-lubricating
ring was very low, the roll could be rotated at much higher
speeds.
In FIG. 3 there is illustrated a heating roll having a diameter of
100 mm. and a length of 140 mm. and including a rotor 10 of a
thickness of 2.5 mm. in contact over its entire internal periphery
11 with a ring 12 of oil-impregnated sintered bronze, of the same
type as that described with reference to FIG. 1, mounted on a
tubular support 13 bolted to a frame 14. The internal periphery of
the ring 12 is in contact with a cylindrical heating element 15
comprising a coiled resistor (not shown) which developes a power of
1,000 W at a voltage of 220 volts.
The rotor 10 is driven, from the pinion 16, through the shaft 17
and the disc 18, by means of a screw 19 threaded to the disc, of
which the shoulder 20 is adapted to slide in the elongate aperture
21 radially cut in the rotor. Thus, the rotor can turn freely about
the axis of the periphery of the ring 12, which axis is not
necessarily identical with that of the shaft 17. The device for
holding the shaft in position along its axis, which is of a known
type and is not shown, axially maintains the rotor.
A cylindrical recess of a diameter of 2.5 mm. and of a depth of 70
mm., in the ring 12, contains a thermocouple 22 substantially
midway along the length of the roll. The said thermocouple is
connected to a regulator of a type known per se (not shown), the
proportional band of which is 1.degree. C.
This roll was experimentally operated at a peripheral velocity of
3,000 meters/min. and at a temperature of 130.degree. C. The
combination of the above-described regulation with this type of
roll makes it possible to limit the temperature variations
indicated by the probe to an amplitude of 0.1.degree. C.
In FIG. 4, the construction is similar to that of FIG. 1 and like
reference numerals have been used for like parts. The connecting
element includes an outer ring 2A, a central ring 2B and an inner
ring 2C, the rings being coaxial and each formed of an oil
impregnated sintered material. The ring 2A is secured to the rotor
5 and the ring 2C is secured to the stator mounting member 30.
In the foregoing, reference has been made to a single roll and to a
single operating temperature of this roll. It is obvious that it is
possible, for applying more complex treatments, to employ in
association a number of rolls at various temperatures or even to
produce a number of staggered temperature zones along the axis of
the same roll. Likewise, rotors having various external surface
conditions may be employed, and also stators comprising heating
elements or cooling elements of very different natures.
* * * * *