FI111291B - Heated roller - Google Patents

Description

111291

Heated roller

The invention relates to a heated roll for calenders, polishing plants and the like, with heating rollers extending along the length of the roll, provided at one end with a connection system for introducing the heat carrier and at the other with a connection system for removing it.

10

In known rolls of this kind (EP 0 158 220 A2), the heating channels are implemented as longitudinal bores which are connected at their ends through a connection channel to a common space. The heat carrier is introduced from the passageway through the second roll pin 15 and removed from the passageway through the second pin or roll and the first pin.

This gives a very even heating over the entire roll width. The same applies to the known roller, in which part of the longitudinal bores is used for the inlet flow and 20 parts for the return flow and both connection systems are parallel (DE-tJ 90 14 117.2).

Often the width of the web does not match the length of the roll. As a result, less heat is removed in the roll end areas resulting in overheating. This has undesirable consequences both for the web that dries at its edges and for the roller which has a tendency to increase the temperature at the periphery, resulting in difficulties in achieving uniform loading.

30

It is an object of the invention to provide a heated roll which corresponds to the type of product described above and which, by simple means, has a better temperature distribution.

This object is solved in accordance with the invention so that each connection system has at least two connection channels which depart from a common space and which enter the heating channel at different distances from the end of the roll and can be made operable by separate selector means.

5 The selection apparatus determines at what distance from the end of the roll the heat carrier enters each heating channel. In this way, the area heated by the heat carrier from the roll can be adapted to the width of the web to be treated. In those parts of the duct system where no flow occurs, the heat carrier is damped so that no heat is introduced.

With respect to the selection apparatus, various means are provided, for example closure elements, such as screw plugs 15, which allow only one access channel to be opened from more than one at a time. But it is particularly advisable if the selection apparatus is implemented as a changeover valve. Such a valve is readily available so that the switching operation can be performed quickly when it is necessary to handle a web of different widths.

To this end, care is taken to ensure that the selection apparatus is a slide having a guide aperture and that the diameters of the connection apertures are disposed adjacent the movement path of the guide aperture 25. Such a slide is a simple valve element that can be implemented in a space-saving manner and is easy to use.

It is recommended that the selectors be adjustable depending on the temperature of the roll end-30 cycles. The higher this temperature, the shorter the flow-through length of the heating channels should be. Excessive temperature at the ends of the rolls indicates that the web being processed does not sufficiently remove heat from the ends of the rolls.

It is advantageous here that each selection path is provided with its own temperature transfer circuit. This results in that each dial path is adjusted independently of the other dial devices. This, on the one hand, increases operational reliability and, on the other hand, enables the temperature of the roll shell to be very uniform in the circumferential direction.

5

In a further embodiment of the invention, it is provided that the selection device is adjustable by an expansion agent system having an actuator for positioning the selection device and a sensor space in the end region of the roll. Therefore, for the temperature control circuit 10 different external cables and the like need to be provided.

In this case, it is preferable that the sensor space comprises a bore parallel to the heating channel and in the vicinity thereof. The sensor mode therefore measures the temperature in the immediate vicinity of the heated heating channel so that its temperature effect can be obtained directly.

The invention will now be explained in more detail by means of the preferred embodiment shown in the drawing. Drawing shows

Figure 1 is a longitudinal sectional view of a roll of the invention, 25

Figure 2 is a cross-section along the line A-A in Figure 1, and

Figure 3 is an enlarged view of a dialer.

3 0

The roll 1 shown comprises a roll body 2 having two pins 3 and 4 connected by flanges 5 and 6 to the frame 1 of the roll 35. The peripheral surface 7 of the roll 1 serves as a web guide, for example paper, textile, felt, film, and as a guide for the respective web to heat this web 4111291 and possibly press against the back roll.

The roll has a plurality of heating channels 8 parallel to the roll axis and extending as longitudinal bores 5 in the vicinity of the peripheral surface. Each heating channel has an inlet end having a connection system 9 communicating with a common space 10 connected to a heat carrier inlet 12 by an annular channel 11 having a cross sectional surface, while an outlet system provided with a and through a tube through pin 4 to remove heat carrier 17.

The inlet connection system 9 comprises three connection channels 18, 19 and 20 which end up in the heating conduit 8 at different spaced distances from the roll sheath 21. The selection device 22 selects the currently operable connection channel, here the connection channel 18. Similarly, the connection device 20 has three connection channels 23, 24 and 25. having a different distance from the left roll end 26. Here is a selection device 27 for making one connection channel in each case, here the connection channel 23.

Figure 3 shows one embodiment of the selection device 22 in more detail. The roll shell 2 has an axial bore 28 in which a movable piston-shaped slide 29 is provided with a guide aperture 30 formed as a notch. The openings 31, 32 and 33 of the three connecting channels 18, 19 and 20 are disposed adjacent the bore 28.

The slide 29 is loaded by the second end 34 paisuntasysteemin body 35, and on the other side of the spring loaded 36, which operates in either a return or only the vastajousena. The expansion system 35 includes a detector space 37 schematically shown in a diaphragm end space 37. The entire system is filled with an expansion medium which, in a temperature dependent manner, changes its volume, as occurs with a solid or liquid expansion pool. depending on its pressure, as happens with a gas or a liquid-vapor mixture. The actuator 34 is provided with an accordion tube 38, 5 so that the expansion material system is surely separated from the heat carrier system. The actuator 34 communicates with the identifier space 37 via the space 39 and the compound channel 40. The size of the space 39 is adjustable by the adjusting screw 41. In this way, the volume change agents 10 can be used to adjust the slide 29. With an expansion medium having a pressure change, the same effect can be achieved by adjusting the bias of the spring 36.

In an embodiment, the sensor space 37 consists of a bore 37, 15 extending axially in the end region of the roll adjacent to the associated heating passage 8. This bore is connected via actuator bore 40 and axial bore forming space 39 to actuator.

When in use, the web covers the entire length of the roll, the heat carrier is passed through the access channel 18 and removed through the access channel 23. When handling a smaller width web, less heat is removed from the ends of the roll. The temperature rises. The blowing agent causes the slide 25 29 to move so that the flow is effected to a greater extent through the access passage 19 and at the other end through the access passage 24. The end areas of the roll will become significantly less heated by this time. If the temperature still rises therefrom, the slide 29 will continue to project so that the lo-30 bushing will flow only through the access channel 20 and at the other end through the access channel 25. In this way, the annoying consequences of continuous overheating of the roll end areas are avoided.

The embodiment shown may be departed from in many respects without departing from the spirit of the invention. Thus, instead of a bellows tube, well insulated is also used

Claims (7)

1. A heated roll for calenders, polishing apparatus 15 and the like, having roll passages for heating, each having a connection system for introducing a heat carrier and an outlet system for discharging it, characterized in that each connection system has at least two connection channels 19 ( , 20, 20 23, 24, 25), which start from the common space (10, 14), end up in the heating channel (8) at different distances from the end of the roll (21, 26), and are operable independently by the selection device (22, 27). Roll according to Claim 1, characterized in that the selector device (22, 27) is provided by a selector valve. Roll according to Claim 1 or 2, characterized in that the selection device (22) comprises a slide (29) with a guide opening (30) and that the opening cross-sections (31, 32, 33) of the connecting channels (18, 19, 20) are disposed adjacent to each other. on the track of the pilot opening (30). Roll according to one of Claims 1 to 3, characterized in that the selector strut (22, 27) is adjustable depending on the temperature of the roll end region. 7, 111291 Roll according to Claim 4, characterized in that each selection device (22, 27) is provided with its own temperature control circuit. Roll according to Claim 4 or 5, characterized in that the selection device (22) is adjustable by an expansion device (35) comprising an actuator (34) for adjusting the selection device and a sensing space (37) in the end region of the diaper. 10 6 111291 pistons or expansion parts filled with an expansion medium. All of the slides 29 can also be connected to a common slider which simultaneously controls all access channels of each roll end area and can be adjusted by a single blowing agent actuator. There are other options for adjustment, such as filling the expansion medium through a valve or other sealable opening. 10 Roll according to Claim 6, characterized in that the sensor space (37) comprises a bore parallel to the heating channel (8) and in the vicinity thereof. 15