JPS59211697A - Drying part of papermaking machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to papermaking technology, and more particularly to a new and improved paper machine drying section drive system.

[Conventional technology]

After the wet paper web has been dehydrated in the paper machine to the extent that it is self-supporting, the wet paper to be dried is placed in cooperating upper and lower tier relationship so that the wet paper is passed around the drying rolls of each tier. A drying section having a plurality of rotatably mounted, unheated drying drums or rolls runs continuously along a tortuous path. The individual drying section felts guide and hold the wet paper web onto the circumferential surface of the drying roll in each stage. Additionally, each dryer section felt is also active in maintaining substantially synchronized the drying rolls of each stage with which the felt is associated.

A typical example of this type of drying section is U.S. Pat.
, No. 815,256.

Although it was customary to drive the entire drying section with a single large drive motor via a long gear train at the back of the machine, the linear speed of about 3000 rt/m, i.e. in the longitudinal direction, was In modern drying stations that operate at high speeds, a single motor drives all of the drying rolls at once, for example as many as 15 in a typical drying station.

This requires a fairly strong and expensive frame/gear box device, but this frame/gear box device has a large area in front of the drying section that is not blocked by the gear box structure.
Not only does it interfere with the removal of damaged products, it also interferes with the lateral moisture profile and symmetrical air flow from the paper machine foundation. Also, due to the large number of gears in the gear train, considerable operating noise may be generated. Conventionally, these gears are lubricated under pressure with oil, so oil leakage can be a problem.

In addition, gears or transmission mechanisms, housings, support devices, pressurized lubrication systems, etc. add considerably to the cost of paper machine equipment.

[Summary of the invention]

An important object of the present invention is to provide a new and improved dryer section drive which overcomes the disadvantages, weaknesses, inefficiencies, shortcomings or problems inherent in conventional dryer section drives. be.

To this end, the present invention provides a plurality of rotatably mounted heated drying rolls on which the wet paper to be dried runs along a winding path, a plurality of rotatably mounted heated drying rolls, which guide the wet paper on the periphery of the drying rolls, and In a paper machine drying section of the type having a drying felt means adapted to hold the drying roll, the drying roll is supported so as to run freely on an anti-friction bearing, and the felt means is driven to drive the drying roll. The present invention provides a drying section characterized by comprising means for.

It should be noted that various changes and improvements may be made to the present invention without departing from the spirit and scope of the novel concepts concretely set forth in the following disclosure. (The first point will become readily apparent from the following description of typical examples shown in conjunction with the accompanying drawings.

〔Example〕

Paper machine drying section strip of the type to which the invention is particularly applicable, first
As shown in the figure and FIG. 4, the drying rolls of the upper stage 7 and the lower stage 8 are arranged in a cooperating staggered relationship, and the wet paper paper W to be dried is continuously passed through the drying rolls of the upper stage 7 and the lower stage 8. It consists of a plurality of rotatably mounted heated drying drums, cylinders or rolls 5 which are wound and arranged to travel along tortuous paths. Although the illustrated drying section has a total of six drying rolls, three rolls on the upper stage 7 and three rolls on the lower stage 8 arranged in a staggered relationship, special drying equipment is required. In order to meet the operational requirements, a larger number of rolls can be used in each stage, and the drying rolls can be arranged in two or more stages;
You should be able to understand that certain counterfeits can be placed vertically, and that the diameter can also be changed. Similarly, the number of drying sections operating in series may be increased as desired to control shrinkage of the wet web as drying progresses. Also, for example, the dryer roll has a diameter of about 72 inches and a length that can handle wet paper about 30 feet wide;
It can travel at around 3000 ft/m.

The drying rolls 5 are each operable in a drying section non-room means 10 which includes an upper beam 11 (only the rear or back beam is shown) along which the rolls 5 extend in the longitudinal or machine direction. A journal 9 (only the back side journal of the drying section is shown) having shaft means projecting oppositely in the axial direction, which is rotatably supported, is fixed to the beam 1. Each bearing hanger bracket structure 12 provides a support for a journal 9 of an upper roll 5.A vertical roll column 13 is mounted on the lower 80 roll 5 and on the base beam means 15. A bearing block structure 1 configured to pivotally support a journal 7 of
4 and extends to support the Henger structure. The journals 9 of the individual rolls 5 in each stage are provided with anti-friction bearings (see Figure 3), which allow the rolls 5 to rotate with the least amount of energy, i.e. the least amount of driving force. is working. The drying air is at the bottom of the device 17.
(See Figure 2) and move upwards.

In a known manner, each drying roll 5 is heated by a heating fluid, such as steam, supplied from a suitable source through a respective steam inlet 18 connected to a backside journal 9, which is preferably hollow for this purpose. It is supposed to be heated. The waste heating fluid may be discharged through the opposite or front journal (not shown), which is also hollow for this purpose. Wet paper W is a web forming device of a paper machine (
From the illustration, it is guided by rollers 19 towards the first of the series of drying rolls 5 in one tier, ie to the first roll 5 in the upper tier 7 in FIG. Next, the wet paper web W is moved downward from the upper drying roll 5 to the adjacent lower drying roll 5 and then upward to the upper drying roll 5 in the appropriate manner until the wet paper leaves the drying section by the guide roller 20. , driving continuously through winding passages.

When running over the upper drying roll 5, the wet paper web W is an endless paper made of a porous material through which air and steam can pass, any type of woven fabric suitable for this purpose, such as It is held on the peripheral surface of each drying roll by the drying section F-1.

For example, the fer) F-1 may be formed from a woven plastic fabric or screen; suitable materials include woven plastics, such as Formex, through which moist steam can be passed by heated air.
) F-1 is a perforated plastic screen or woven fabric of the type known as cloth (commercial name).
It is guided by guide rollers 22 towards the first roll of the series of drying rolls 5 in the upper stage. Between the upper drying rolls 50, the felt F-i sufficiently surrounds each drying roll 5: the felt guiding/tensioning roller 23 is placed between the upper drying rolls 50 so that the wet paper is in sufficient contact with the outer periphery of the drying roll. A song winds around the top to guide you. These guide rollers 23 are located in pockets defined between two adjacent upper rolls 5 and an adjacent lower lower roll 5. Furthermore, the upper roll 5 and the guide roller 23
Fell 1. The turns p l occupy approximately 50 inches of the circumferential surface of each guiding relation obtained by each roll 5 and the felt F=l. From the last roll of the series of drying rolls 5 in the upper stage, the rolls F-1 are guided back to the transfer track by guide rollers 24.

Fer) In the same manner as explained above for F-1,
An endless drying section F-2 winds the lower drying roll 5. The guide roller 25 guides the felt F-2 onto the first roll of the series of lower drying rolls 5. Between the drying rolls 50, the felt guide rollers 27 have a winding or driving torque tension iI acting on the drying section felt F-2. It can be seen that the guide rollers 27 are located in pockets defined between each of the two lower rolls 5 and the upper roll 5 adjacent thereto above. At the end of the lower roll group, the guide roller 28 is F-
2 is guiding Fell) F-2 toward the return track where it travels beyond the guide rollers 29.

Both felt F-2 and felt F-2 should have a width of the full width of the machine, that is, at least dry paper W
O) It has a total length of 11J and has a width equal to or substantially equal to the total length of the drying roll 5. Therefore, by maintaining proper tension throughout each 7.1-rut run, including the return run, both felts have a large torque capacity, i.e., a large tensile force capacity, in each of the upper and lower dryer tiers 7 and 8. have. To selectively tension the upper fer) F-1, use the guide roller 21.
22 or 24 in a known manner by acting as an adjustable tensioning roller 3. Similarly, in order to apply the desired tension to the lower fel F-2, the guide roller 25.28″1.
This can be achieved by powering any one of them as an adjustable tensioning roller. Note that the tensile stress of both felts is much greater than that of the wet paper paper W.

Therefore, since both of these sheets of paper and the windings on the roll 5 are tensioned, the synchronous surface speed of the drying rolls in each stage is sufficiently within the stretchable range of the wet paper W. Able to maintain car.

According to the invention, the drive of the drying rolls 5 of each of the upper and lower stages 7 and 8 is reliably driven for this purpose while the drying rolls 5 are running freely on their anti-friction bearings 17. This is done by each of the drying section felts F-1 and F-2. For this purpose, the drying section felt F-,1
and F-2 are each driven by at least one drive motor, depending on the length of the drying section, drive torque requirements, etc. In this specific example, two drive motors 30 are shown for each upper stage 7 and lower stage 8.

In the upper stage 7, a driving motor 3o is arranged to drive the felt guide roller 23 once. In the lower row 8,
A drive motor 3o is arranged to drive the felt guide roller 27. This arrangement of the drive motor 30 can be said to be the most effective drive arrangement. However, if desired, felt F-1 and felt) F-2
Any one or more of the other guide rollers can be selected to drive each felt.

As best seen in Figures 1 to 3, each motor 3
0, the motor shaft is aligned coaxially with and coupled to the extension 32 of the shaft means or journal 33, from which the ends of the connected rollers 23 or 27 also extend, in this case, by means of the adjacent frame column 13. It is adapted to be installed on a supported motor bracket 31. The journals 33 are each rotatably supported by an anti-friction bearing 34 carried by a bearing support 35 mounted on the adjacent frame column 13 in connection with the support bracket 31 of the coupled motor 3o.

Since the nonyl rollers 23 and 27 are generally significantly smaller in diameter than the drying roll 5, e.g. a 3:1 ratio, the felt rollers 23, 270 speed can be driven directly by the shaft of the motor 3o without the use of a gear reducer. This is sufficiently high.

A coaxial joint 37 may be used to join the outer end of each motor shaft to the connected journal extension 32. however,
If the diameter of the felt roller is large, it may be desirable to use a geared drive coupling between the motor shaft and the journal extension 320.

F-1 and F-2 are maintained by keeping the drying rolls 5 of each stage running synchronously, but due to unavoidable fluctuations, either the upper stage 7 or the lower stage 8 may cause one to be killed. There is a tendency to drift out of sync.

To alleviate this tendency, one of the motors 30 of each of the upper and lower stages 7 and 8 is synchronized with one of the other motors, thereby varying the running speed of each roll stage relative to the other roll stages. Control means are provided for synchronization.

In the practical embodiment shown in FIG. 4, the motors 30 of each stage are each connected to a power supply 38 common to the motors 3o of that stage. One of the motors 3o in each stage is connected to a speed regulator 40 for controlling the speed of the drying rolls in that stage.
It is connected to a power source 38 through a tachometer 39 or other speed sensing device acting through the tachometer 39 or other speed sensing device. power supply 38
may be either a variable voltage DC power supply or a variable frequency AC power supply, but a variable frequency AC power supply is preferred since each drive motor 3o is an induction motor and its voltage can be directly transformed depending on the frequency. Since the motors 30 of each stage are all in a parallel relationship, the connected dryer section felts F-1 or F-2 can in this case provide practical synchronization of the motors and drying rolls in each stage.

In order to obtain constant synchronization for each of the upper and lower stages 7 and 8, a frequency reference device 41 is provided which compares the frequency feedback from the motor 30 of each stage group by valving the speed regulator 40 of that stage group. be.

・By establishing a synchronized relationship between the two drying rolls as shown in 2, the drying section 10 is able to fully function within the enclosure to allow the mixed paper W to stretch, and the wet paper paper W can be stretched in the second tier 1:・near. It will not be damaged when traveling between drying rolls.

The drying section 10 as a whole can start running from a rest state to a low speed synchronous state in order to regulate the insertion of a new wet paper into the drying section, and then the drying section can be accelerated to a high speed. It is possible. It is noted that it is desirable to have the tension adjustment device or speed control device 42 operatively coupled to the frequency reference device 41.

〔Effect of the invention〕

From the foregoing description, it can be seen that the present invention has numerous improvements and advantages, including those described in the elimination of costly and complex gearing, and the installation of a very simple frame structure behind the dryer. It is clear that they were able to provide the This eliminates the need for a gear reduction gear, which significantly reduces the cost of the original equipment. Furthermore, since startup time is not required, savings can also be achieved when the device is started up. The large and heavy drive motor foundation required in conventional practical applications is unnecessary. A highly effective and inexpensive drive system has been created by uniquely driving the dryer roll through the dryer felt by holding the drive motor in direct driving relationship with the dryer felt roller. be. The elimination of the obstruction caused by the conventional drive gear box for the drying rolls allows access to the backside of the drying section, which in particular significantly improves the inflow of air flow. Therefore, even the air distribution inside the drying section hood could be obtained. Very simple oil systems are possible for rollers and roll bearings. The dryer roll spacing is flexible and can be adjusted without disturbing the gear train. Expansion joints and nozzles, which are normally included in the gear train drive of the drying roll, are omitted.

It will be appreciated, however, that various changes and modifications may be made without departing from the spirit and scope of the novel concept of the invention. .

[Brief explanation of the drawing]

FIG. 1 is a partial elevational view of the back side of a paper machine drying section embodying the present invention. FIG. 2 is a longitudinal cross-sectional view taken along the line ■--■ in FIG. FIG. 3 is an enlarged sectional view taken along line 1ff-1 in FIG. 1. FIG. 4 is a diagram showing the drive and control system of the drying section. 5...Drying roll, 7...Upper stage, 8...Lower stage, 9...Journal, 10...Drying section frame means, IL - Upper beam, 12...Bearing...Ninger bracket structure, 13... Vertical frame column, 14...Bearing block structure, 15...Foundation beam means, I Li...Anti-friction bearing,
17... lower part of the device, 18... air intake, 19, 20
．． 21. 22... To guide row' 23... Spring guide and tension roller, 24° 251 Spring guide roller, 27...
Felt guide roller, 28.29... Guide roller, 30
・・Drive motor, 31・・Motor bracket, 32・
・Extension part, 33... Journal, 34... Anti-friction bearing, 3
5... Bearing support (,~J+, 12, U7... Joint, 38...
- Power supply 1.39...Tacomine, 40...Speed regulator, 41...1 Frequency reference 2: N, 42...Speed control device, F-1, F-2...Felt, W...Wet paper. Agent Masami Kimura

Claims (1)

[Claims] (1) A plurality of rotatably mounted drying rolls on which the wet paper to be dried runs along a winding path, and a drying section felt that holds the wet paper on the circumferential surface of the drying rolls. means for supporting the drying roll so as to freely rotate; and means for driving the drying means for driving the drying roll. Paper machine drying section.