JPH0440629B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a heating roll for drying various strips such as nonwoven fabric, paper, processed paper, and paperboard.

BACKGROUND OF THE INVENTION It is well known to introduce heated steam into the interior of a rotatably supported cylindrical roll to heat and dry a strip that travels over the outer circumferential surface of the roll. In this case, it is important that the strip is uniformly heated and dried in the width direction. However, due to factors such as the flow of heated steam inside the roll, the ends (edges) on both sides of the roll are generally overheated compared to other parts, and the strip is therefore not uniformly dried in the width direction. There is a tendency not to.

Therefore, the superheated roll disclosed in Japanese Patent Publication No. 39-904 and Japanese Patent Application Laid-Open No. 56-159390 was proposed. These superheated rolls have an annular weir that extends in the circumferential direction near the end of the inner peripheral surface of the roll, so that a certain amount of condensate from the superheated steam accumulates near the end of the inner peripheral surface of the roll. . On the other hand, the condensed liquid at the center of the inner peripheral surface of the roll is discharged to the outside by a suction nozzle. Therefore, since the heat transfer coefficient is lowered at both end portions of the roll by the condensate film layer, overheating is prevented and it is possible to maintain a substantially uniform temperature distribution across the width of the roll outer peripheral surface. can.

Furthermore, in the heating roll disclosed in Japanese Patent Publication No. 39-904, by attaching and detaching a stopper to a hole formed in the weir, on the other hand, in the heating roll disclosed in Japanese Patent Application Publication No. 56-159390, The weir is made up of two plates, each of which has a notch and can be slid relative to each other, and by adjusting the overlap of the notches on each plate, the height of the weir can be changed to reduce the amount of collected condensate. The thickness of the membrane layer can be adjusted.

(Problems to be solved by the invention) However, the conventional heating roll described above has two problems.
There are two major drawbacks. Firstly, the height of the weir and thus the thickness of the condensate film layer cannot be changed during operation of the heating roll. Second, it is impossible to change the state in which condensed liquid is accumulated near both ends of the inner circumferential surface of the heating roll to a constant thickness, and is discharged from the center. As long as these drawbacks exist, it is actually impossible to uniformly heat-dry a strip-shaped article across its width. The reason for this is that the moisture content distribution (moisture profile) of the strip before being transferred to the heating roll is not necessarily uniform across the width, nor is it necessarily constant. As mentioned above, it is true that there is a general tendency for the edges of the heating roll to become heated more easily than other parts, but on the other hand, the moisture profile of the strip is It is also true that there are some problems, and in order to uniformly heat and dry the strip, both facts must be taken into account.

Therefore, an object of the present invention is to make it possible to adjust the thickness of the condensate film layer accumulated inside the heating roll in various ways in the axial direction of the heating roll, thereby reducing the variation in the moisture profile of the strip. The object of the present invention is to quickly respond to such changes by changing the temperature distribution in the direction of the rotation axis of the heating roll, thereby achieving uniform heating and drying across the width of the strip.

(Means for Solving the Problems) According to the present invention, a horizontally disposed structure having a smooth outer circumferential surface for supporting a transition strip and rotatably supported at both left and right ends provided with an end plate. a cylinder; an introduction path for heated steam formed in the cylinder so as to communicate with the inner space of the cylinder; Condensation of heated steam, comprising at least one annular weir partitioning a surface into a plurality of parts along the rotational axis direction, and a suction port opening close to the inner circumferential surface of each portion of the cylinder partitioned by the annular weir. A strip heating roll comprising a plurality of suction nozzles for sucking liquid, the suction nozzles being divided into a plurality of suction nozzle groups along the rotational axis direction of the cylinder, and the suction nozzle groups each consisting of one or more of the suction nozzles, and further, the strip heating roll is connected to a connecting pipe connected to the suction nozzle for each suction nozzle group, and each of the connecting pipes is connected to the outside of the cylinder. A strip heating roll is provided, comprising a lead-out pipe communicating with the cylinder, and a plurality of regulating valves provided in each of the connecting pipes and individually operable from the outside of the cylinder.

(Function) In the heating roll of the present invention, when the end of the roll becomes overheated or the moisture profile of the strip becomes uneven, the respective suction nozzle groups connected to the Adjustment valves installed in the connecting pipes are individually operated from outside the cylinder.
Thereby, the thickness of the condensate film layer on the inner peripheral surface of each portion of the cylinder partitioned by each annular weir is increased or decreased. For example, a regulating valve installed in a connecting pipe connected to a suction nozzle group having a suction port opening on the inner peripheral surface of the part corresponding to the cylindrical part that has become overheated is throttled down, and the condensation sucked out from the suction nozzle group is By reducing the amount of liquid, the thickness of the condensed liquid film layer on the inner peripheral surface of the corresponding portion is increased. Furthermore, with respect to the cylindrical portion with which the high moisture content portion of the strip comes into contact, the corresponding regulating valve is opened wide, and the thickness of the condensate film on the inner circumferential surface of the corresponding portion is reduced. The thicker the condensate film layer, the lower the heat transfer coefficient, which suppresses the amount of heat supplied to the cylindrical part that is at risk of overheating. The amount of heat necessary for sufficient drying will be supplied to the part. In this way, the strip is uniformly heated and dried across its width.

(Embodiment) As shown in FIG. 1, a first embodiment of the belt-like material heating roll according to the present invention has a smooth outer circumferential surface 20 that supports a transition strip material 1, and left and right open ends are mirror plates, respectively. A horizontally arranged cylinder 2 is closed by a cylinder 24 and is rotatably supported by a bearing 250, and a cylinder 2 is formed by penetrating the left rotation shaft 25 and end plate 24 as seen in FIG. a large number of annular weirs 22 rising from the inner circumferential surface 21 of the cylinder 2 and extending in the circumferential direction thereof at intervals l apart from each other in the direction of the rotation axis; a suction nozzle 3 which is opened close to the upper and lower sides of each inner circumferential surface 210 of each portion partitioned by 22 and has a suction port 30 for sucking out the condensate of superheated steam S that has condensed; We are prepared. The suction nozzles 3 are divided into five groups of ten suction nozzles 3 along the rotational axis direction of the cylinder 2, and each suction nozzle group A to E is connected to a respective I-shaped connecting ring 30A to 30E. is connected to. Each of the connecting pipes 30A to 30E connects a signal line 41 and a blind cover 3 at the outer end of the lead-out pipe 31 from outside the cylinder 2 to a lead-out pipe 31 that is provided through the rotating shaft 25 on the right side as seen in FIG.
The current collectors 10 and 10 are connected to each other via regulating valves 4 that are separately operated by signals sent through the rotating current collectors 50 and 10, respectively. The condensed liquid d is combined by a discharge pipe 31 and led out of the cylinder 2 via a rotary joint 32.

In this way, in the first embodiment, the outer peripheral surface 20 of the cylinder 2 is divided into five parts in the width direction, and the heat conduction characteristics of each of the partial outer peripheral surfaces 20A to 20E can be adjusted independently from each other. However, in the belt heating roll of the present invention, the outer circumferential surface of the cylinder is divided into an arbitrary number and intervals in the width direction, and the heat conduction characteristics of each part can be adjusted independently from each other. It is also possible to configure it as follows. Furthermore, the height at which the annular weir protrudes from the inner circumferential surface of the cylinder determines the maximum thickness of the condensate film layer temporarily stored on the inner circumferential surface of the portion where the inner circumferential surface is partitioned by the annular weir. However, it is usually sufficient to set it within a range of 20 m/m or less. The annular weir may be one carved on the inner surface of the cylinder, or one in which a thin annular plate made of stainless steel or other stainless steel or carbon fiber strong heat-resistant synthetic resin material is protruded from the inner circumferential surface. Any material may be used as long as it can dam the condensate within the inner circumferential surface of the portion. In addition, suitable regulating valves include, for example, electromagnetic regulating valves, various motor-driven regulating valves such as pulse motors, and various thermoelectric regulating valves such as bimetal type, but any regulating valve other than these types may be used. There is no problem. Many regulating valves that can be remotely operated in various ways are known. Preferably, the regulating valve is provided within the cylinder so that its center line coincides with the rotation center line of the cylinder as much as possible, and is as symmetrical as possible with respect to the center line. Furthermore, as a rotating current collector, a large number of sliding ring members are supported by a tubular support member in an insulated state in an insulated tube, and carbon, carbon,
It is preferable to have a configuration in which a current collector brush made of mercury or the like comes into sliding contact. Note that the regulating valve is operated from outside the cylinder by a signal flowing through a signal line, the rotary current collector, etc., and the operation may be either manual or automatic, and especially in the case of automatic operation. For example, various known moisture content control devices such as those shown in Japanese Utility Model Application Publication No. 58-92399 can be used.

The superheating roll according to the first embodiment operates as follows. For example, when applied to a paper machine, the moisture profile changes from moment to moment due to the bending of the slicing lip, the blockage of holes in the suction box in the wire mesh section, the wetness of the blanket in the water extraction section, etc. A transition strip 1 made of paper is supported on a smooth outer circumferential surface 20, and an electric motor (not shown) lifts the material every minute.
Superheated steam S of about 10 Kg/cm ^{2 G is applied to the inner space 27 of an airtight cylinder 2 made of cast iron with an outer diameter and a width of about 5 m, respectively, and which is rotated at a high speed at an outer peripheral speed exceeding 1000} m as shown in Fig. 1. Introducing channel 2 in the direction of moistening with the middle arrow S.
The transition strip 1, which is supplied through step 8 and has an average moisture content before heating of about 60% by weight and is in surface contact with the outer circumferential surface 20, is heated and dried to an average moisture content of about 5% by weight after heating. . At this time, the inner space 27
Most of the heated steam S supplied to the cylinder 2 condenses over the entire inner circumferential surface 21, which has a relatively low temperature, radiates heat and becomes liquefied. Because of this, liquefied condensate is stored in the form of a film on the inner circumferential surface 210 of each section partitioned by the annular weir 22. Inner peripheral surface 2 of each part
The condensate d at 10 is supplied by a vacuum pump (not shown)
As a result, suction is sucked from the suction ports 30 that are open close to the inner circumferential surfaces 210 of each part, and the suction nozzles 3, the connecting pipes 30A to 30E, and the outlet pipes 3
1. The connection pipes 30A to 30E are led out to the vacuum pump via the rotary joint 32 and the discharge pipe (not shown) connected thereto, and the connecting pipes 30A to 30E are led to the discharge pipe 31 through the respective regulating valves 4. Each regulating valve 4 is individually connected to a signal line 41 from outside the cylinder 2.
Since the rotary current collectors 50 and the like can be operated individually by signals flowing through them, the amount of condensate d sucked up by each suction nozzle group A to E can be freely varied. In the heating roll having the structure shown in FIG.
The rotating shaft 25 and the end plate 24 adjacent to the 20A are particularly heated, and the heat flow is transmitted through them to reach the side end of the cylinder 2, so that the partial outer circumferential surface 20A is particularly heated to the other partial outer circumferential surface 2.
It becomes overheated compared to 0B to 20E. If none of the regulating valves 4 were provided or if they were all adjusted to the same opening degree, the lug portion of the transition strip 1 that was in surface contact with the partial outer peripheral surface 20A would become overly dry. By narrowing down only the regulating valve 4 connected to the connecting pipe 30A to a desired opening/closing state, the amount of condensed liquid sucked out from the 20 suction nozzles 3 included in the suction nozzle group A connected to the connecting pipe 30A can be reduced. Decrease. Then, the thickness of the condensate film layer on the corresponding partial inner peripheral surface increases, and the heat transfer coefficient decreases, so that the partial outer peripheral surface 20A corresponding to the suction nozzle group A becomes smaller than the other partial outer peripheral surfaces 20B to 2.
Since the heat flow state can be adjusted to be almost the same as 0E, overdrying of the ear portion can be avoided. For example, by narrowing down the regulating valve, the thickness of the condensate film layer on the inner circumferential surface of each corresponding portion is reduced to 0.75.
m/m to 1.50 m/m by just less than 1 m/m, the inner periphery of each part of the cylinder from the transition strip that is in surface contact with the outer periphery of a cast iron cylinder with a peripheral wall thickness of 25 m/m. The overall heat transfer coefficient from the surface to the condensate film surface is significantly reduced by about 28%.

Above, we have described in detail how the belt heating roll of the present invention can avoid overdrying at the edges of the transition belt. Even if the transition band-like material has a localized moisture content unevenness in its width direction due to blockage, wetness of the blanket at the water extraction part, etc., the area with the uneven moisture content can be treated in the same way as described above. By adjusting the corresponding regulating valve to increase or decrease the thickness of the condensate film layer on the inner circumferential surface of each portion, the moisture content unevenness can be quickly eliminated during operation of the paper machine.

A second embodiment of the strip heating roll according to the present invention has a smooth outer circumferential surface 20 for supporting the transition strip 1, as shown in FIG. A horizontally disposed cylinder 2 rotatably supported by a bearing 250 and a heating cylinder 2 formed through a rotation shaft 25 on the left side as seen in FIG. Steam S introduction path 2
8, two annular weirs 22 rising from the inner circumferential surface 21 of the cylinder 2 and extending in the circumferential direction at a distance l from each other in the direction of the rotation axis, and inner circumferential surfaces 210 of each portion partitioned by the annular weirs 22. The suction nozzle 3 is provided with a suction nozzle 3 that is opened close to each of the suction nozzles 3 and has one suction port 30 for sucking out the condensate of the heated steam S that has condensed. The suction nozzle 3 is a cylinder 2
Each suction nozzle 3 along the rotational axis direction of
The suction nozzle groups A, B, and C are connected to connecting pipes 30A, 30B, and 3, respectively.
Connected to 0C. Each connecting pipe 30A, 30
B, 30C are pivotally supported from outside the cylinder 2 by a signal line 41 and a blind cover 310 at the side end of the lead-out pipe 31 in the lead-out pipe 31 provided through the rotation shaft 25 on the left side as seen in FIG. They are communicated with a rotary current collector 50 through regulating valves 4 that are individually operated by signals sent through them. The condensed liquid d is combined by a discharge pipe 31 and led out of the cylinder 2 via a rotary joint 32.

Here, a fluid expansion type thermoelectric valve is used as the regulating valve 4, and this valve includes a fluid such as alcohol, an electric heat source 40 such as a sheathed heater that heats the fluid, and a resistance thermometer that detects the temperature of the heated fluid. A fluid reservoir 44 containing a temperature sensor 400 is connected to the fluid reservoir 44, and a valve stem 45 is attached to the tip thereof, and is movable by the expansion or contraction of the fluid and its vapor, and is loaded by the counterforce of the spring 42. bellows 4
3 and a heat insulating container 47 made of a heat insulating material such as glass wool with a water-resistant surface treatment is housed therein, and a valve seat 48 is attached to one open end, and the other open end is a connection terminal for the signal line 41. A condensate flow path 49 is closed with an end cap 490 having a diameter of 410, and is partitioned internally by a valve stem guide member 491 through which a valve stem 45 with a valve body 46 attached to its tip passes through.
It consists of a valve box 49 having 2 valves. The regulating valve 4 is installed inside a T-shaped pipe joint 311 that connects the outlet pipe 31 and each of the connecting pipes 30A, 30B, and 30C via the regulating valve 4, and is provided between the valve box 49 and the condensate. The outlet flow path 313 is formed, and the regulating valve 4
It is supported by a regulating valve support member 312 and the like and installed inside the T-shaped pipe joint 311 so that the center line of the cylinder 2 and the rotational center line of the cylinder 2 substantially coincide with each other. In addition, a signal is sent to a moisture content manual adjustment device (not shown) or a moisture percentage automatic control device (not shown) in relation to the temperature detected by the temperature detector 400, its target value, and the valve opening degree of the regulating valve 4 related thereto. The rotary current collector 50 connects the signal lines 41 inside and outside the strip heating roll with each other in order to input and output the information. A tubular support member 5 made of brass that is locked to prevent the sliding ring member 521 from rotating.
It consists of a current collector ring 52 consisting of 20 mercury reservoirs 510, and a current collector brush 51 made of a heat-resistant material such as ceramic, which has 10 mercury reservoirs 510 on top, each storing mercury. A part of one sliding ring member 521 is always in sliding contact, and one signal line 41 is connected to the mercury in each sliding ring member 521 and each mercury reservoir 510.
is connected.

In the embodiment shown in FIG. 2, one suction nozzle 3 is provided for each inner peripheral surface 210 of the cylinder 2, and each suction nozzle 3 is connected to each suction nozzle group A,
B and C are respectively configured, but for example, by further providing multiple sets of suction nozzles, connecting pipes, and regulating valves on the inner peripheral surface of the central portion, it is possible to create multiple suction nozzles for one inner peripheral surface of the portion. It is also possible to set groups.

Further, the regulating valve provided in each of the connecting pipes may be provided at the connecting part with the outlet pipe as in the illustrated first and second embodiments,
It may also be provided in the middle.

(Effects of the Invention) According to the heating roll of the present invention, the thickness of the condensate film layer accumulated inside the heating roll can be adjusted variously in the axial direction of the heating roll during operation of the heating roll, so that the outer surface of the heating roll Inhomogeneities in temperature distribution as well as variations in the moisture profile of the strip, etc.
It is possible to quickly respond to and overcome various factors that impede uniform heat drying across the width of the strip, and the strip is uniformly heat dried across the width.

[Brief explanation of drawings]

FIG. 1 shows the first part of the belt heating roll according to the present invention.
FIG. 2 is a partial cross-sectional view showing a second embodiment of the belt heating roll according to the present invention. DESCRIPTION OF SYMBOLS 1... Transition strip, 2... Cylinder, 20... Outer circumferential surface, 21... Inner circumferential surface, 210... Partial inner circumferential surface, 2
2... Annular weir, 24... Mirror plate, 25, 25'...
Rotating shaft, 27...inner space, 28...introduction path, 3...
...Suction nozzle, 30...Suction port, 30A to 30E
... Connecting pipe, 31 ... Leading pipe, 4 ... Adjustment valve, A
~E...Suction nozzle group, S...Heating steam, d...
Condensate, l...interval.

Claims (1)

[Claims] 1. A horizontally arranged cylinder having a smooth outer circumferential surface for supporting a transition strip and rotatably supported at both left and right ends provided with an end plate, and a cylinder so as to communicate with the inner cavity of the cylinder. An introduction path for heated steam formed in a cylinder, and at least one passage provided so as to extend in the circumferential direction on the inner circumferential surface of the cylinder, and partitioning the inner circumferential surface of the cylinder into a plurality of parts along the rotational axis direction. and a plurality of suction nozzles for sucking the condensate of heated steam, each having a suction port that opens close to the inner peripheral surface of each part of the cylinder partitioned by the annular weir. In the material heating roll, the suction nozzles are divided into a plurality of suction nozzle groups along the rotational axis direction of the cylinder, each suction nozzle group consisting of one or more of the suction nozzles, and further comprising: A strip heating roll is provided in each of the suction nozzle groups, a connecting pipe connected to the suction nozzle, an outlet pipe to which each of the connecting pipes is connected and communicating with the outside of the cylinder, and each of the connecting pipe. , a plurality of regulating valves individually operable from the outside of the cylinder.