FI107398B - Heated roller - Google Patents

Description

107398

Heated Roll, Upphettbar Vals 5

The invention relates to a heated roll, in particular a calender roll, which comes into direct contact with a paper or board web comprising a hollow tubular roll shell which is rotatably mounted on its machine body by bearings and equipped with a drive motor or the like to roll the roll. .

Hot rollers are required in paper machines and paper finishing equipment in a variety of applications. The most common applications of hot rollers are calendars and presses and super calendars. In particular, the calendering process increasingly utilizes elevated molten roll surface temperatures to plasticize paper and improve calendering performance. The most common solution for heating the roll has been to apply heat to the roll by means of a suitable heat transfer medium, which has traditionally been water. In these solutions, water is circulated through a separate heating unit to the roll. With the proliferation of soft calendars, hot oil heat transfer medium 20 has become very popular. The hot oil is heated in a separate boiler plant and pumped into a roll.

Various methods and solutions for heating rolls are known in the patent literature. The oldest known solution is one in which a through hole is drilled in the center of the massive roll 25 into which the heat transfer medium is rotated. However, a major disadvantage of such a solution is that the distance of the heat transfer from the medium to the surface of the roll is very large, whereby efficient and economical heating is not achieved by this solution. Another and more sophisticated solution is one in which the roll comprises a non-rotating blasting body 30 on which a roll shell is rotatably mounted. In this solution, a heat transfer medium, such as water or oil, is introduced into space 2 107398 between the displacement body and the roll mantle to heat the roll mantle. One such solution is disclosed, for example, in European Patent Application Publication No. 0 188 238. However, a major disadvantage of such a solution is that the amounts of liquid to be treated are very large. This causes eg. the fact that the power consumption of the roll is very high. Other heated rolls of a similar construction, in which however the soldering element rotates with the roll jacket, have been previously disclosed e.g. U.S. Patent Nos. 4,607,420,4,730,374 and 4,734,966 and EP Application Publication No. 0 158 220. These rolls also have a very poor heating efficiency because the heating medium must be separately heated before being introduced into the roll.

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One known solution for heating a roll is one in which a plurality of axially extending bores are formed in the roll through which the heating medium is rotated. Such solutions have previously been presented e.g. U.S. Patent No. 1,223,763, EP-A-0 597 814 and FI-15, Publication No. 88 632. In connection with the prior art described above, for example, a solution is known in which hollow roll casing is provided with axial bores. A non-rotatable soldering member is further imaged within the roll casing which directs the heating medium supplied to the roll to circulate in the space between the roll casing and the roll casing and in the bores formed in the roll casing head.

The latest development in roll heating is inductive heating of the roll. The inductor may be located either inside or outside the roll. Examples of internal induction heating can be found in U.S. Patent Nos. 5,553,729 and 5,895,598.

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The major problems with current solutions are related to the complexity of rigid systems, the need for maintenance, and poor efficiency. Heating methods using a heating medium have the inherent disadvantage mentioned above, namely that the quantities of liquid to be treated are very large. Another disadvantage is that, in any case, the heat transfer medium must first be heated in some suitable way, e.g. by means of electricity, after which the heat transfer medium is introduced into the roll. The heating efficiency of such rolls is poor and the power consumption is considerable.

It is an object of the present invention to provide a heated roll, in which the heating efficiency of the roll 5 is improved and which provides a uniform heating of the roll shell. To achieve these objectives, the roll according to the invention is essentially characterized in that the roll shell heating apparatus is a roll-in, friction-based apparatus adapted to provide internal roll friction work in an amount substantially equivalent to the thermal energy consumption and loss of the roll contact with the roll.

The invention provides several significant advantages over the prior art, of which the following may be noted. First of all, the essential advantage is that the roll has a simple construction and a very high heating efficiency. The energy required for heating is preferably taken from the electric motors and mechanically transmitted to the roll. The efficiency of the electric motor and the mechanical transmission are known to be very good. In roll replacement situations, mechanical parts are easier to remove and handle than rotating fittings and fluid hoses. In connection with the roll of the invention 20, there is no need to use external, obstructive and expensive devices. Other advantages and features of the invention will become apparent from the following detailed description of the invention.

The invention will now be described by way of example with reference to the examples shown in Fig. 25 of the accompanying drawing.

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Figure 1 shows a preferred embodiment of a roll according to the invention in partial longitudinal vertical section.

Figure 2 illustrates an alternative embodiment of a roll according to the invention as shown in Figure 1.

4, 107398

In Fig. 1, the roll is generally denoted by reference numeral 10. The roll 10 comprises a hollow roll casing 11 with ends thereof fitted with roll ends 12, 13. The roll ends 12, 13 still have shaft pins 14, 15 of which roll 10 is supported by bearings 16, 17. 5 be attached to the machine frame. The shaft pins 14, 15 may be identical to the roll ends 12, 13 and, as shown in Figure 1, the shaft pin 14 of the first roll end 12 is hollow. The roller 10 is further provided with a drive motor 18 which rotates the roller 10 through a suitable force transmission member 19. The drive motor 18 is most preferably an electric motor which provides the best advantages of the invention. It is also conceivable to use a hydraulic-10 motor.

Inside the roll sheath 11 is a soldering member 20 which is concentric with the roll 10. The sputtering body 20 is provided at its ends with shaft pins 21, 22 or the like with a continuous through shaft of which the sputtering body 20 is rotatably mounted within the roll 10 by bearings 23, 24. The shaft pin 21 at the first end of the blasting body 20 is, as shown in Figure 1, long enough to extend through the first roll end 12 and the hollow shaft pin 14. The sputtering body 20 is further provided with a drive motor 25 coupled to the first shaft pin 21 for rotating the sputtering body 20. Most preferably, the drive motor 25 of the blasting piece 20 is an electric motor that provides the most desirable benefits. The drive motor 25 can also be a hydraulic motor. The roll 10 and the blasting member 20 are thus each provided with separate drive motors 18, 25, so that they can be rotated independently of one another.

The heated roll according to the invention is intended in particular to be a calender roll and the heating of the roll is implemented in such a way that the frictional work inside the roll 10 is produced in an amount substantially equivalent to the thermal energy consumption and losses in the environment. Losses to the environment, particularly due to convection, are considerable and can be up to 30% of the roll power 30 consumption. More specifically, the solution of the invention is implemented by rotating the roller 10 and the blasting body 20 mounted inside the roller shell 11 by means of drive motors 18, 25 at different speeds. The space S between the roll shell 11 and the blasting body 20 is filled with high viscous heat transfer oil and the gap is dimensioned such that when there is a speed difference between the roll shell 11 and the blasting body 20, heat is generated by the viscous resistor 5 of the heat transfer oil. The amount of heat generated can be easily controlled by adjusting the relative velocity, i.e. the velocity difference, between the roll shell 11 and the blasting member 20. If the blasting body 20, and in particular the outer surface thereof, is still properly shaped, a strong oil flow is provided inside the roller 10, which ensures uniform heat distribution over the roller shell 11. To improve flow, the outer surface of the syrup 10 may be suitably roughened or provided with various blades or the like.

Figure 2 shows another embodiment of a roll according to the invention, generally referred to in this figure as reference numeral 110. In this embodiment, roll 110 comprises a hollow roll casing 111 with roll ends 112, 113 fitted with shaft pins 114, 115. bearing via bearings 116, 117 to machine frame. 1, the shaft pin 114 of the first roll end 112 is also provided with a hollow through hole. The roller 110 is provided with a drive motor 118 which, via a transmission means 119, rotates the roller 10. The drive motor 118 is preferably an electric motor. A hydraulic motor can also be used.

Injection body 120 is coaxially disposed within roller sheath 111. Shearer body 120 is provided at its ends with shaft pins 121, 122, 25 of which are rotatably mounted with respect to roller 110 through bearings 123, 124. Instead of the shaft pins 121, 122, a single shaft passing through the blasting member 120 may also be used. The shaft end 121 of the first end of the actuator 120 is so long as to extend through the first roll end 112 of the roll 110 and the hollow shaft pin 114. The throttle body 120 is further provided with a drive motor 125, 30 coupled to a first shaft pin 121 for rotating the throttle body 120. As stated previously, the drive motor 125 is most preferably an electric motor, although a hydraulic motor may also be used. In this respect, the embodiment of Figure 2 corresponds to that shown in Figure 1.

In the embodiment of Fig. 2, the roll shell 111 is provided with substantially axial-to-end bores 131 which extend from the end of the roll shell 111 to a plurality of said bores 131 and are spaced circumferentially. Further, radial bores 132, 133 extending from the inner surface of the roll shell 111 to axially bore 131 are formed in the roll envelope 111 at each end region of the roll shell 111, thereby engaging the first radial bores 132 of the first from the area through second radial bores 133. Furthermore, the outer surface of the blasting body 120 is shaped or provided with a shaped body 135 which, when the blasting body 120 rotates, provides an oil flow in one direction in the axial direction of the roll 15 in the slot S between the blasting body 120. Only one shaped member 135 is shown. The shape members 135 may also be multiple and may have a shape different from that shown in Figure 2.

When the rotational movements of the blasting member 120 and the roll 110 have a difference in speed, the shape of the outer surface of the syr-20 freezing member 120 causes the oil to flow between the blasting member 120 and the roll shell 111.

«♦ axial velocity component in one direction. Thus, as stated above, in the intermediate space S, axial flow occurs. Because the axial bores 131 communicate with the interior of the roll shell 111 via the radial bores 132, 25 133, the axial flow in the intermediate space S causes the oil to flow through the first radial bores 132 into the axial bores *. to the bores 131, where the flow therefore takes place in the axial direction in the opposite direction to the intermediate space S. From the axial bores 131, the oil returns to the intermediate space S via second radial bores 133 in the region of one end of the roll. This solution provides a very even distribution of heat throughout the roll shell, since the heating oil flows in two directions axially, on the inner surface of the roll shell 111 in one direction and in the axial bores 131 in the opposite direction.

The invention has been described above by way of example with reference to the embodiments shown in the figures of the accompanying drawings. However, the invention is not limited to the examples shown in the figures, but different embodiments of the invention may vary within the scope of the inventive idea defined in the appended claims.

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Claims (10)

8 107398 A heated roll, in particular a calender roll, which comes into direct contact with a paper or board web, the roll (10; 110) comprising a hollow tubular roll 5 (11; 111) rotatably mounted at its ends on the machine frame by bearings (16, 17). ; 116, 117) and stolen by a drive motor (18; 118) or the like for rotating the roll, to which roll (10; 110) is provided apparatus (20-25; 120-125, 131-135) for heating the roll jacket (11; 111), wherein the roll mantle heating apparatus (20-25; 120-125,131-135) is a roll-mounted, friction-based apparatus configured to provide an internal frictional action of the roll mantle (11; 111) substantially equivalent to the roll mantle (11; 111). 11; 111) thermal energy consumption by the contacting web and losses from the roll to the environment. Roll according to Claim 1, characterized in that a soldering element (20; 120) which substantially rotates and is centered on the roll with respect to the roll (10; 110) and having its own drive motor is inserted inside the roll shell (11; 111). (25; 125) or the like for rotating the blasting body (20; 120) independently of the speed of rotation of the roll (10; 110), and wherein the space (S) between the blasting body (20; 120) and the roll shell (11; 111) is filled with a fluid viscous heat transfer medium wherein the difference in rotational speeds between the roll mantle (11; 111) and the blasting member (20; 120) is adapted to heat the heat transfer medium and thus the roll mantle (11; 111) due to the viscous resistance of the heat transfer medium. 25 Roll according to Claim 2, characterized in that the amount of heat produced by the heating apparatus 'i' (20 to 25; 120 to 125, 131 to 135) is monitored to adjust the relative speed between the roll casing (11; 111) and the soldering element (20; 120). adjusting. 30 9 107398 Roll according to Claim 2 or 3, characterized in that, in order to achieve uniform heat distribution on the roll casing (11), the sputtering body (20) is shaped such that the shape of the sputtering piece (20) causes a strong flow of heat transfer medium inside the roll. 5 Roll according to Claim 4, characterized in that the outer surface of the blasting body (20) is provided with roughening, fins or the like. Roll according to Claim 2 or 3, characterized in that the roll jacket (111) 10 is provided with substantially axial bores (131) extending from the end of the roll to the end of the roll, communicating with the interior of the roll (11) at radial through radial bores (132, 133) extending from the inner surface of the roll shell (11) to the axial bores (131). 15 Roll according to Claim 6, characterized in that the outer surface of the blasting element (120) is provided with a shape element (135) or the like which causes the blasting element (120) to flow substantially axially due to the velocity difference between the roller sheath (111) and the blasting element (120). ) and 20 in the intermediate space (S) between the rollers (111). Roll according to Claim 6 or 7, characterized in that the axial flow in the intermediate space (S) between the discriminating body (120) and the roll shell (111) is forced to force the heat transfer medium to pass into the axial bores (131) at the first end of the roll shell. through the first radial bores (132) and axially respectively! from the bores (131) back to the intermediate space (S) through the second radial bores (133) at one end of the roll shell so that the heat transfer medium in contact with the roll shell (111) flows in the opposite space (S) and axial bores (131). ίο 10 / ό 9 8 Roll according to one of the preceding claims, characterized in that the drive motor (25; 125) of the soldering iron (20; 120) is an electric motor. Roll according to one of Claims 1 to 8, characterized in that the drive motor (25; 125) of the priming body (20; 120) is a hydraulic motor. u 107398