DE2121295A1 - Heatable roller for heat treatment of synthetic fibers and tapes - Google Patents

Description

Dipl. Ing. R. Mertens

Patent attorney
Frankfurt / Main 1, Ammelburgstr. 34: 2121295

Frankfurt am ^Main, April 28, 1971

H 31 P 263 -

HONEYWELL INC.
2701, Fourth Avenue South Minneapolis, Minnesota / USA

«Heatable roll for heat treatment of synthetic fibers and • Ribbons "

The invention relates to a rotatable and heatable roller for Heat treatment of synthetic fibers and ribbons with one a sealed, rotationally symmetrical chamber in the role only partially filling the heat transfer medium, which can be heated up to above the boiling point by a stationary heating device opposite a part of the chamber wall is.

For the heating of rotating rollers, it is known to transfer the heat generated, for example by an electrical heater arranged inside the roller jacket, uniformly to the roller jacket by means of a liquid or vaporous heat transfer medium. For example, German patent specification 718 0 ^ 5 shows a heating roller with an electrical heating tube arranged in the interior, the remaining cavity of the roller between the heating tube and the roller jacket being filled with a liquid, low-evaporating heat conductor such as oil or glycerine. From the French patent 1 2 ^ 5 827 a heating godet for the treatment of synthetic fibers and tapes is known, which has a ring-cylinder-shaped cavity, which is filled with a vaporous or liquid heat transfer medium and which is bounded on the outside by the roll jacket, in which electrical heating rods carried by the roll protrude. From the German patent specification 833 ^ 16 as well as the German utility models 1 804 125 and 1 9βΗ 320 heating rollers are

109849/1636 BAD οπ, Ο, Ν «.

knows, the interior of which only partially with a liquid heat transfer medium which can be heated by means of one or more heating devices is filled. Located in the part of the cavity not occupied by the liquid and the heating device the heat transfer medium is in the vapor phase, is deposited on the free cavity wall and thus gives its Heat of evaporation, according to the heat demand of the roller, on its outer surface. This creates a uniform tempera door of the roll shell is reached over almost the entire length of the roll.

Furthermore, the German Offenlegungsschrift 1 953 692 shows a device for heating a rotating roller with an annular space adjoining the roller shell, in many cases a liquid heat transfer medium is filled in such an amount that it is close to the outer surface of the roller as a result of the centrifugal force acting on the medium is in contact with the entire inner surface of the roller. By the interior of the roller fixedly arranged heating device, the heat transfer medium is maintained in the boiling state, so that the vapor phase is separated of the medium in the annular space through the liquid phase of the W to be heated inner surface of the roll. Even at high speeds of the V / alze, at which the liquid phase of the medium is pressed against the roll shell with so great a centrifugal force that when the roll shell is locally cooled, the liquid film is deposited / precipitated at the relevant point of the liquid film due to an external thermal load The heating device according to German Offenlegungsschrift 1 953 692 provides for the attachment of alternating webs and grooves to the inwardly directed jacket surface of the orphan within the annular space, in such a way that the webs protrude inward from the liquid phase adjacent to the outer wall and are thus directly exposed to the vapor phase of the medium.

BATH ORIGINAL

'■ ^ Cifio.c:; - .. 109849/1638

If one takes into account that, due to the high speeds and Temperatures, any imbalance in the roll has an extremely detrimental effect on its storage and as a result of its simultaneous use a large number of such rolls, for example in a draw twisting machine, the failure of even a single roll interrupts the entire production process and becomes too significant It can be seen that both the production of these grooves and webs and the balancing the role has to be done with the utmost care and is therefore tedious and is expensive. In addition, there is the disadvantage that the heating device, which is arranged concentrically within the annular space, is stationary their heat not directly to the positive phase of the heat transfer medium to be heated, but initially gives off in the form of radiant heat to the vapor phase.

The object of the invention is therefore to avoid the above Disadvantages of creating a rotatable and heatable roller suitable for the heat treatment of synthetic fibers and tapes, which are as simple as possible in their structure and in their production and as favorable as possible with regard to their degree of efficiency is and at the same time a both in the circumferential direction as the same temperature of the roll outer jacket also guaranteed in the axial direction.

rf ..

Starting from a role of the type mentioned at the outset, the invention provides for the solution of the problem that the inner surface the outer wall of the chamber is tapered and the heating device is arranged in the area of the largest chamber diameter is.

This is due to the Einr on the heat transfer medium acting! centrifugal force a constant heat cycle this Medium forced, at the same time the heating device is effective where the liquid phase of the medium to be heated is is located, close to the area of the largest chamber diameter. In

109849/1636 ORIGINAL BATHROOM

- Ii -

With regard to the desired temperature equality over the entire Rolüe, the heat transfer by means of a heat transfer medium that is partly in the liquid and partly in the vapor phase shows a self-compensating effect in such a way that in each case where most of the heat is withdrawn, ie at the coldest spot of the roller, the vapor condenses on and releases its heat of vaporization to that location of the roller shell. the concentration of the heater at the point in which the Flüsnigphase of the medium is accumulated, also leads to a reduction in the required heating power and dor losses and z \\ Advantages in terms of the required space.

A particularly favorable heat transfer from the heating device on the medium results., - If the heating device is ring-shaped encloses the area of the largest chamber diameter from the outside. Further advantageous refinements emerge from the subclaims.

The invention is illustrated below with reference to two in the drawings illustrated embodiments explained. Here shows

Figure i shows schematically a section along the roller axis through a first embodiment and

Figure 2 shows a corresponding partial section through a "second Execution? Form of the roll with heating device »

The heatable roller 10 - often also called Helzgalette has an essentially cylindrical outer shape, the. Cylinder jacket 12 during operation is usually very often wrapped in a synthetic that is to be subjected to a heat treatment!? Eden 13 is wrapped _{around 5} which runs at one end onto the GaIs b-ss svu wnö runs from the other end, Der Faüen 13: outside ■; ■■■ - .: ./- yJ .- ": - lB" 7siss rau "sine! ⁵ temperature ¹ salary we: give ₂ weloh-i nahs i: 5P ■; * ■" ■ ^ niels'äs ^ - "oerafcur lies ₅ unc sv-ar about äi ^: s said ^ aie ^ iy.l ^. ^ 'iiauhli ;: ¹ = gende length of the thread * Scmio it is oriOr-l · -:. ^!: λ-: .κϊο Ji3

BATH

Surface 1? is kept at a uniform temperature over the entire useful length of the godet. The inner surface I ^ of the godet is bevelled in the shape of a truncated cone, the inner diameter 15 a: n free end 16 being the smallest and the inner diameter 17 at the l'-gerende 20 being the largest. The galette is overhung with its drive shaft 26 in the machine frame 30 by means of a ball bearing vl. The end plate 20 has for this purpose a stepped approach 25 against which the inner ring of the. Ball bearing 27 is supported. The two end plates 16 and? O bili-on together with the roller shell 11 a completely sealed number 21, -which contains a heat transfer medium 22, which is in operation in the area ^l \ 6 of the largest inner diameter of the chamber, , ie in the immediate vicinity of the end plate 20, accumulates. The type of heat transfer medium 22 used depends on the operating temperature of the roller 10 and is selected such that when the roller is operated at the desired temperature, the vapor pressure in the chamber 21 is slightly below atmospheric pressure, so that the external atmospheric pressure shrouds the jacket 10 holds under a slight pressure. This makes it possible to design the jacket 11 with a minimal wall thickness, as a result of which the heat transfer from the inside of the jacket to the outer useful surface of the jacket is promoted and, in particular, a rapid temperature equalization is ensured. The wall thickness of the roller and the steam pressure can be selected over a wide range depending on the desired mode of operation. The vapor pressure can be either higher or lower than atmospheric pressure.

The heat transfer medium is introduced into the chamber 21 through a conical filling hole 23, which is then closed by a ball 2k . The chamber 21 is evacuated beforehand. The transmission modium 22 is normally liquid and is partially evaporated by the supply of heat. After filling, the ball ? J \ is pressed into the filling hole 23 and then closes the chamber Pl liquid *; - and vapor tightly.

BATH ORIGINAL

109849/1636

The carrier 30 for 'the bearing 27 and the godet 10 has in the present Case in the form of a bow or cup and is fastened to the machine frame 33 with its wall parts 31 and 32. The machine frame can carry several roles. The drive shaft 26 is driven by a motor or transmission, not shown set in rotation, either by a single drive or by coupling with the drives for additional rollers. A synchronous motor is normally provided for each roller, which drives the cantilevered godet 10 via the shaft 26 drives.

For the supply of the heat required to evaporate the heat transfer medium 22, the primary winding 35 of an induction heater is connected to an alternating current source by means of the lines 36 and 37 connected. The primary winding 35 has a toroidal core 40 of magnetic material which is U-shaped in cross section surround. As a yoke piece for closing the magnetic circuit, a coil 4l made of magnetic material is on the roller shell 11 attached, which closes the magnetic circuit of the stationary core 40 via the air gaps 43 and 44. Immediately on the ring 4l sits a copper ring 45, which as a secondary short-circuit winding des through the magnetic core 40, 4l and the primary winding 35 formed heating transformer is used. The magnetic flux circulating in the magnetic core 40 and the ring 4l encloses the secondary Short-circuit ring 45 and thereby induces considerable in this Currents which lead to excessive heating of the short-circuit ring 45. This generated heat is in the area 46 by the Transferring the roller jacket 11 through to the heat transfer medium 22, which begins to boil and evaporates in the chamber 21. The steam precipitates at the coldest point on the chamber wall and leads through the evaporation heat that is generated This. Provide the heat required to keep the temperature of the entire chamber wall at an even level To maintain level. The thermal load on the roller is made up of several components, namely the ventilation losses as a result of the high speed when the roller rotates.

- ■ "■ *" ■ - * ^y * ^d 109849/1636

BAD ORfQINAL

speed-forming air flow, the heat dissipation losses, in particular via the shaft 25, 26, and the actual hat üw / irrceab drove to the fadon 13 wrapping around the roller jacket 11 · As soon as the steam of the i-iecHumo settles on the inner conical beveled surface l'l of the roller jacket 11 precipitates as a liquid, the centrifugal force generated by the rotation of the roller causes the resulting liquid to try to flow off into that area of the chamber which has the largest internal diameter. The liquid flying Lan alco ~ s of the conical inner wall I ^ toward the area ^, is surrounded by the soft Kurzschlußi'ing k ^l j>. Here the liquid is evaporated again j to turn to the coldest. Knock down place of the role. This creates an intermediate cycle of the heat transfer effii ttelo, which reaches the coldest point of the inner wall of the can in vapor form and in Γi; -.- *? I,. ^ Er? ':: .- ;. aur Heiz-sone surücki'lieät. In AbhangSksit from äs: 'ti :. '■ -' ^: Λ - ι last xinz of the roller rrsantels 11 condensed n-shf or r -: 'txer l2 /, mc? on iar conical inner surface and thus creates. Aehr or v / some-. ¹ 7erda: npfunr.sv; arme. This ensures uniform heat transfer to the thread 13, that is, it is kept at a constant temperature, regardless of fluctuations in the thermal load, for example as a result of changes in the temperature of the thread when the roll runs up or as a result of external cooling influences.

In the embodiment according to FIG. 2, the roller 10 has a roller jacket 11 * made of magnetizable material, whereby the magnetic ring ^ l can be omitted, which in the embodiment according to FIG ^{. 1} closes the magnetic circuit of the core 1JO. The ring made of copper or other electrical conductor material ^ 5 is placed directly on the roller shell 11 'in FIG 11 '.

109349/1636 ΒΑ0 OBtGlNAL

The invention proposes an extremely effective heating godet, which at the same time is extremely simple in terms of its construction, which ensures a uniform temperature along the outer wall of the roller. The arrangement is self-compensating for any fluctuations in thermal load. The speed of circulation of the heat transfer medium in the chamber depends on the inclination of the beveled inner wall, lh . Also, a conventional resistive or Strahlungshei can he ^ defl for heating the transfer medium 22 in the area instead of the illustrated induction heater KSS of the largest diameter of the chamber 21 serve. Such a heater can be attached to the roller itself or, like the illustrated induction heater j, be attached in a stationary manner and then transmit its heating power to the medium 22 by radiation. The chamber 21 does not need to be frustoconical, as in the embodiment shown, but can instead have the shape of an annular chamber with a conically tapered outer wall. In the heating zone, that is to say in the region of the largest diameter of the chamber, the chamber wall can run cylindrically, optionally be offset to form a clearly defined annular heating zone.

109849/1636

Claims (1)

01-4460 Ge Claims 1. Rotatable and heated roller for heat treatment of synthetic Fibers and ribbons with a sealed rotationally syniiTietrische Chamber in the role only partially fills the heat transfer medium, which through a part of the The heating device facing the chamber wall can be heated up to above the boiling point, characterized in that the inner surface (14) of the chamber wall was outer (11) beveled conically and the heating device (35, 40, ^ l5) in the area (46) of the largest chamber diameter is arranged. 2. Role according to claim 1, characterized gekennzeic Hnet that the heating device (35,40,45) is annular the area (46) of the largest Kair.mer diameter of auP> en encloses. " 3. Roller according to claim 1 or 2, characterized in that that the heating device has a stationary magnetic core (40) with an excitation winding (35) and at least one on the roller in the area (46) of the largest chamber diameter in good heat-conducting contact with the roller shell en
(11) attached /, the secondary winding of the induction heater forming short-circuit ring (45). 4. Roller according to claim 3, characterized in that the roller shell (11) in the region of Magnetic core (40) has a ring (41) made of magnetizable material and the short-circuit ring (45) between this Ring (4l) and the stationary magnetic core (40) lying on the Roll shell attached i; 3t. BATH ORIGINAL 109849/1636 -ιοί. Roller according to claim 3, characterized in that that the roller shell (11) made of machinable Material. 6. Roll according to one of claims 1 to 5, characterized characterized as having a kep; truncated elbow Has chamber (21), which is perpendicular to the axis of rotation on both ends by one circular wall (16,20) is closed. BAD ORIGWAL 109849/1636