FI119069B - Arrangement with press section of web forming machine - Google Patents

Description

I 1 s 119069

ORGANIZATION IN THE CRIMPING MACHINE PART

The invention relates to an arrangement on a press section of a forming machine comprising at least one nip and at least one belt adapted to pass through a netting machine with a press section, and comprising an arrangement for restoring the belt.

The press section of the web forming machine uses press felts 10 to which water is transferred from the web in the press nip. The press felt may be on either side of the web or on one side only. Nowadays, dense, water-impermeable belts are also used, particularly as a belt for a long nip roll and a conveyor belt for use therewith. The conveyor belt is usually repaired with 15 scrapers, which are further combined with water-jet lubrication.

Known recovery equipment is often inadequate. In practice, dirt and water remain on the belt surface despite repair. In addition, the belts are soft, which requires a soft scraper blade to be scraped at a slight angle. The tip of the soft scraper blade quickly rounds or forms a ... Γ fast wide chamfer, which is subjected to water transfer.

• ·: .V In this case, the dirt and dewatering capacity of the scraper will be substantially reduced. ”Ϊ 25 ti. This reduces the dry solids content of the web after the press section and • reduces the moisture profile of the web when water remains ·· * · • j *; unevenly on the belt surface. At the same time, the material builds up on the belt ·· *. * · *. surface, which limits the production of the forming machine and • • e adversely affects the quality of the end product. Weak and quite-. . Also, uneven remanufacturing also restricts the press section's travel speeds, and even causes downtime. Similarly, a poor moisture • • * ··· * profile of the web reduces the quality of the final product and causes • · ϊ / .j. and production costs: ***: The use of inexpensive paper chemicals (especially AKD and ASA) ··· 35 is limited because they contribute to the speed of the belt • · *. *. is difficult due to the life of the belt diaper and maintaining the scraping power requires a short interval between changing the scraper blade.

The object of the invention is to provide a new arrangement on the press section of the forming machine 5, whereby the belt can be rehabilitated more efficiently and the water removed more evenly than before. Characteristic features of the present invention will be apparent from the appended claims. In the arrangement according to the invention, the belt can be repaired in various ways. Good cleaning performance 10 is achieved by better cleaning and more accurate dewatering. This way, the strap going into the nip is clean and evenly moist. For example, more abundant water can be used for cleaning, as excess water can be easily and surely removed before the nip. On the other hand, the amount of water can be reduced by arranging for more efficient water use and only for a part of the strap at a time. In addition, the performance of the rehabilitation equipment remains unchanged despite use, which reduces maintenance and downtime costs. Rehabilitation devices can also be positioned more freely and used with even soft belts without the risk of belt damage.

The invention will now be described in detail with reference to the accompanying drawings, which illustrate some embodiments of the invention, in which: 1 2 3 * ··· 1; Figure 1 illustrates an arrangement of the invention fitted to a press section of a ··· web forming machine,

Fig. 2 is a side elevation view of a rehabilitation device in the arrangement of the invention, ··· ·. · 1 ·. Figure 3 is a side elevational view of another embodiment of the repair tool of the invention.

2 • · • · · · ·· · · 3

Figure 1 shows, by way of example, the applicant's OptiPress press · 1 »1; tin with two press nipples 10 and 13 in a row. Here, ensimmäinen 1: 35, the first press nipple 10 is a so-called roll nipple through which two press felts 11 and 12 are arranged to pass.

3, 119069

The second press nip 13 is a so-called long nip using an upper press felt 14 and a lower impermeable transfer belt 15 · This press section achieves a good dry matter content and a symmetrical web. In addition, 5 runnability is good thanks to the closed export. In practice, the first press nip may also be a long nip. In practice, the belt can also be adapted to pass through, for example, a transfer nip. In other words, the nip is not necessarily a press nip.

10

The invention thus relates to an arrangement on a press section of a forming machine. Generally, the press member comprises at least one nip and at least one belt adapted to pass through the nip.

The belt is mainly used to support the web 15 to be manufactured by the forming machine because the belt itself is impermeable to water. In addition, the arrangement includes means for restoring the belt. For example, Figure 1 shows a conventional scraper 18 as a conveyor belt remover, with an additional lubricating jet 19. As previously mentioned, this scraper 20 is ineffective in terms of rehabilitation and requires replacement of the scraper blade. often. In addition, use a particularly gentle blade angle and * · · • ** | soft blade materials due to soft transfer belt.

• · · • * · • · * * *

According to the invention, the rehabilitation means 17 include a forward scraper 20, · · · · · 25 with a scraper blade 21. In a new and surprising way, • · jt | This scraper blade remains functional without damaging the belt.

The tight fit of the scraper blade also prevents the scraper blade from barking on the surface of the belt. In addition, considerably thinner, though harder, scraper blades can be used, which is still M * ·. ···. 30 improves scraping performance and extends service life. In practice, the Φ · *! * Thin doctor blade sharpens as it wears. The resulting wear bevel will remain · *. Due to the small thickness of the scraper blade, the water transfer situation can be avoided. Thus, the scraping result remains good even if the scraper blade is worn. According to the invention, the thickness of the scraper blade ·,; 35 is 0.1 to 2 mm, more preferably 0.2 to 0.8 mm. The · ·· doctor blade 21 is supported so that its contact point 41 with the belt 4 119069 16 is in the direction of movement of the belt 16 after the projection point 42 of the support point 22 of the doctor blade 21 (Figures 2 and 3). while adjusting to the movement and deformation of the 5 belts, the projection point of the unloaded straight scraper blade is almost the same as the point of contact of the scraper blade, but in the operating position, the blade deflects by acting as it moves.

10, the arrangement according to the invention is arranged in connection with a conveyor belt 15 arranged to pass through a press nip 13. Equally, the strap may be the belt wrap of the long nip of the press nip. The arrangement of the invention can also be used on other belts, such as a calender, where, however, the fouling problem is less than that of the press member.

In the first embodiment of the forward scraper according to the invention, the length of the scraper blade is substantially the same as the width of the belt.

In this case, a full-width scraper blade scrapes the belt throughout the entire 20 minutes. This solution provides a uniformly dry belt.

. Particularly in the case of a transfer belt, it is advantageous to install the **** at the end of the belt cycle, ie as close as possible to the clamp nipple. In this case, a large part of the water will, for example, be able to exit with gravity. On the other hand, • • • ·:: 25 the belt is prevented from being dirty due to the surrounding water mist. Fig. 1 shows two preferred locations for the · ·, · · · · · · · · · · · · · · · · · · · · · · · · For functionally similar parts, like reference numerals are used.

··· ·. ** ·. 30 * · • · ·, * # Instead of a full-width scraper blade, a short • * · ** scraper blade can be used. In other words, according to the invention, the length of the scraper blade ··· * * · · · · is substantially smaller than the width of the belt. In this case, the rehabilitation power may be adjusted locally as desired. For example • *. '. J 35 short scraper blades can be fitted to both edges of the belt. On the other hand, the doctor blade can be fitted with suitable supporting members for moving in the transverse direction of the forming machine. This provides a traversing forward scraper which can be used to repair the belt despite its short width.

5 The newly inserted scraper blade will further improve the performance of the restoration equipment. On the other hand, the doctor blade can be inserted into a normal blade holder, especially when using a full-width doctor blade. Rehabilitation power can be further increased by a washing head 25 fitted to the support members 24 for washing the belt 16 (Fig. 3). In this case, the washing head is also traversing, whereby the entire width of the belt can be restored. In addition, the movement of the scrub head can be adjusted, which, for example, allows for further rehabilitation of problem areas. In practice, the washing head may be moved more slowly at a certain point than 15 elsewhere, or the head may be moved several times at that point. This allows the belt to be completely refurbished and, if necessary, subjected to cleaning. Unlike Fig. 2, the scrub head 25 can be operated without the need for a scraper 20, if necessary, so that the scrub head can easily be positioned even on the unsupported portion 20 of the belt 16 (Fig. 1).

Iti * · *! Figure 3 shows a traverse downstream scraper • Il * · * · * 20 according to the invention with supporting members 24. Supporting members 24 include, for example, a beam having a carriage fitted with guides. The carriage is moved • ♦ · 25 across the machine by any suitable actuator (not shown).

• ♦ j The structure of the support members may also vary from application to application.

: '** · For example, the washing head 25 can be placed in existing structures (· ι ·, such as the beveled water cutter beam 30: (Figure 1). In Figure 2) the support members 24 include a beam with ··· e. ···. as such a conventional blade holder with a doctor blade 21.

• ♦ * · * "Other support means and blade holders may also be used to provide a forward scraper according to the invention.

• Φ · 9 · • ♦ M »

Figure 3 also shows the washing head 25, • ·. · Connected to the scraper 20. · 35 which according to the invention is arranged in the direction of movement of the belt 16

• M

before the scraper blade 21. In this case, in practice, the washing head is first washed with the 6,119,069 belt, followed by a scraper to remove loose dirt and water. At the same time, the forward scraper removes any material remaining on the belt surface. This provides a clean and dry belt surface despite efficient washing. According to the invention 5, high pressure needle and fan nozzles 31 and 32 are used in the scrub head 25, whereby an effective but comprehensive wash jet is obtained by suitably positioning the nozzles. The position of the scrub head can also be changed. The fan nozzles form a fan-shaped or conical jet, while the needle jets 10 provide a jet-shaped jet. In addition to the fan nozzles, the spreading nozzles also include hollow cone nozzles. According to the invention, the washing head 25 has a total of 2 to 12, more preferably 3 to 10, needle nozzles 31 and fan nozzles 32, the width of the resulting wash area being about 40 to 100 mm. Correspondingly, the length of the scraper-15 blade is about twice the width of the wash area, whereby the surface of the belt can be sure to be dried. In practice, high-pressure nozzles use needle nozzles with a nozzle size of 0.15 to 0.4 mm and fan nozzles with a nozzle size of 0.15 to 1 mm, respectively. Water is supplied to the nozzles at a pressure of 15 to 200 bar. In practice, pressurisation is mainly dependent on the belt type and the pressurized water equipment used.

In addition to the scraper, the efficiency of the arrangement according to the invention can be further improved. Rehabilitation means according to the invention may include low pressure lubricating jets of a scrub head or means for heating the belt prior to the pre-scraper or both. In addition, means for supplying 33 detergents and / or antifouling • to the surface of the belt 16 may be combined with the lubricating jets ·· # 19 of the restoration means 17. By ··· ·. ***. In 30 ways, the supply of the anti-fouling chemical is ···. *. possible. It is advantageous to feed the detergent as soon as possible • ♦ · * · *: after detaching the web, allowing the detergent to effect • · * ··. * Before the scrub head. Preferably, the means 33 are adapted to an existing one; ***; grease jets 19 (Figure 1). A simpler • · • * .J 35 detergent dispenser (not shown) is attached to any lubrication jet tube.

7 119069

According to the invention, the washing head 25 may further be provided with means 34 for raising the temperature of the detergent. In this case, hot water is used in the high- and / or low-pressure nozzles, which improves the rehabilitation efficiency. At the end of the wash, water consumption is relatively low, 5 which keeps operating costs reasonable. According to the invention, the elevated temperature of the water is about 20-100 ° C. Devices for heating water are selected on a case-by-case basis and their design may vary from application to application. Figure 1 also shows means 43 for heating the belt 16 prior to the step scraper 10 20. The belt may be heated, for example, by steam using, for example, a steam box.

Figure 3 shows in more detail the structure of the traverse forward scraper according to the invention. Here, the forward scraper 20 includes, in addition to the doctor blade 21, a second doctor blade 35 having substantially the same characteristics as the first doctor blade 21. This ensures that the surface is clean and even moisture after the doctor blade. At the same time, a smaller load can be used than with one scraper blade. According to the invention, in the scrub head 25 20, the doctor blades 21 and 35 are arranged at a distance s from each other. which s is less than 60 mm here. Thus, both scratch blades ··· ** "scratch at approximately the same point, which prevents problems with the life of the belt. The scratch blades thus function essentially the same, so that they wear at the same speed.

Figure 3 also clearly shows a guide fitted to the scrub head 25, which limits the amount of water entering the scraper 20.

• · ·

The position of the guide relative to the scrub head is adjustable and is substantially as long as the scraper blade. •; *; a trough for collecting wash water can also be used.

• · ·. · * ·, 30 The tray can be full-width, fixed or use a narrow tray attached to the support members.

Thus, the forward scraper according to the invention employs a conventional · '*: thinner doctor blade, which is preferably straight. In the embodiment of Fig. 3 * * 35, one example is provided to support one or more scraper blades. Here, the doctor blades 21 and 35 are inserted between 8 119069 two pairs of tubes 38. Pipe pairs 38 are mounted on threaded rods 39 and are tightened to their respective positions by nuts 40. This solution is easy to implement and the position of the doctor blades can be varied. The press bracket of the type shown in Figure 3 5 is particularly advantageous in an application where the downstream scraper is supported on a traverse wash head. Conventional blade holders can also be used (Figure 2).

When a scraper is introduced, the scraper blades are almost perpendicular to the belt. As the belt moves, the doctor blades are slowly driven onto the belt, causing the doctor blades to bend in the direction of movement of the belt (Figures 2 and 3). In this case, each scraper blade only touches the belt at its narrow edge. In addition, the edge of the thin doctor blade remains sharp due to wear on the doctor blade. Delayed scraper blades are also flexible if material is deposited on the belt surface without the need for wash jets. However, with retaining power and the sharpness of the scraper blade, the material gradually releases from the belt surface. In the use of Fig. 3, the angle α of the doctor blade 21 with respect to the tangent and the angle of the second doctor blade 35 with respect to the tangent β is approximately 33 °. In addition, the doctor blades 21 and 35. are 35 mm apart. Generally, the blade angles are 10 · · · '*** - 70 °, preferably 20 - 50 ° and the distance between the doctor blades is 20 * · * · * - 100 mm.

··· • e • · ··· m: 25 In the embodiments shown, the doctor blade is substantially straight.

According to the invention, the doctor blade may also be inclined with respect to the belt. In other words, the ends of the scraper blade are at different heights. In this case, the scraper blade effectively plows water without • water seeping behind the scraper blade. In addition, the water can be controlled ··· ·. ···. 30 guide the strap aside. Such an application is particularly advantageous when using a full-width doctor blade. Various scraper blades can be used in the • * · * · * ϊ scraper according to the invention. The material of the scraper may be plastic, fiber reinforced plastic or · * · *. metal, preferably stainless steel. Contribute to the formula • ·, ·. : 35 allows the scraper blade to be even hard metal.

• 1 ·

The wear resistance can be further improved by using a coating on the material of the scraper 9119069. The coating may be a ceramic, metal ceramic or metal, preferably tungsten carbide metal.

In practical experiments, the arrangement according to the invention has been found to prevent belt contamination or even to clean an already soiled belt. In addition, the forward scraper, in particular, allows the transfer belt to be uniformly dried. As a result, the moisture profile of the web after the press is improved and the dry matter content is increased at the same time. The arrangement according to the invention achieves higher production and better quality of the final product. The arrangement is also inexpensive in terms of investment and operating costs and is easily retrofitted. In practice, the restoration power is adjustable on a case-by-case basis, and the 15 scraper blades are long-lasting, remaining sharp throughout their life without the risk of belt damage.

Usually, the transfer belt consists of a woven core coated on at least one side with an impermeable and wear-resistant multicomponent polymer. Siirtohih-. The use of a knife prevents open spacing when the web is pressed • • e · ** · from the tin section to the drying section. In addition, a smooth transfer belt smooths the surface of the web, which improves the quality of the end product. The impermeable · 1 · *. ·. * Coating also prevents re-wetting in the press nip and thus contributes to a good moisture profile. The transfer belts are about 5 mm thick, as are the belt diapers.

However, the webbing is coated on both sides and may have a groove on its outer surface.

• · • * * • · · · · · • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 9 • 99 • 9

Claims (19)

An arrangement in the press portion of a sheet forming machine, said press portion comprising at least one nip (13) and at least one impermeable belt (16) arranged to pass through the nip (13) to support in the press portion the web produced in the sheet forming machine, and which arrangement comprises repair means (17) for the belt (16), characterized in that the repair means (17) comprise an iron shaker (20), in which the input sheath blade (21) is supported so that it bends under load, whereby its contact point (41) with the belt (16) is located after the projection point (22) of the blade (21) in the direction of movement of the belt (16). Arrangement according to claim 1, characterized in that the belt (16) is a long nip roller shoe press belt and / or conveyor belt (15) which is included in a press nip arranged as a nip (13), which is arranged to run via a press nip or another nip. 20 Arrangement according to claim 1 or 2, characterized in that the thickness of the blade (21) is 0.1 - 2 mm, more preferably 0.2 - 0.8 mm. • · • · ··· a · • a · • · · 4. Arrangement according to any one of claims 1-3, characterized in that, at the point of contact (41), the cutting angle (α, β) between the • a *** blade (21) and band (16) 10 - 70 °, more preferably 20 - 50 °. • · · • · a • · a a a * * * ·; · * 30 Arrangement according to any of claims 1-4, characterized in that the material of the blade (21) is plastic, fiber-reinforced • plastic or metal, presumably stainless steel. • * • · · • ·· * ·. ···. 6. Arrangement according to claim 5, characterized in that the material of the cabinet blade (21) has a coating which is of ceramic, metal ceramic or metal, probably tungsten carbide. 119069 Arrangement according to any of claims 1-6, characterized in that the length of the blade (21) is substantially the same as the width of the band (16). Arrangement according to any one of claims 1-6, characterized in that the length of the blade (21) is substantially smaller than the width of the belt (16). Arrangement according to any of claims 1-8, characterized in that the blade (21) is arranged obliquely in relation to the belt (16). Arrangement according to claim 8, characterized in that the blade (21) is arranged to be movable in the transverse direction of the sheet forming machine by means of support means (24). Arrangement according to claim 10, characterized in that a washing head (25) for washing the belt (16) has been provided for the support means (24). 20 Arrangement according to claim 11, characterized in that the washing head (25) is arranged in the direction of movement of the belt (16) before the blade (21). • · • · • · · • · • · * · **, * 25 Arrangement according to Claim 12, characterized in that • the washing head (25) comprises hose nozzles (31) for high pressure • or spreading nozzles (32) or, moreover, presumably hose and spring nozzles. · · ♦ · · * ♦ · * ··· * 30 Arrangement according to claim 13, characterized in that in the wash head (25) there are snake nozzles (31) and solar spring nozzles ([**: pieces (32) in total 2-12, more preferably 3-10 pieces). · · · · · · · · Arrangement according to any one of claims 1 to 14, characterized in that the repair devices (17) comprise washing or lubricating showers (19), to which have been connected devices 119069 (33) for supplying detergent and / or a soiling limit. -substance to the band (16). Arrangement according to claim 15, characterized in that devices (34) for raising the temperature of the detergent have been connected to the wash head (25) and / or the washing or lubricating showers (19). Arrangement according to any one of claims 1 to 16, characterized in that the arrangement comprises means (43) for heating the belt before the iron maker (20). Arrangement according to any one of claims 1-17, characterized in that the ironing cup (20) comprises, in addition to the blade (21), one or more additional blade blades (35), the characteristics of which are substantially the same as for the first blade (21). 19. Arrangement according to claim 18, characterized in that in the iron maker (20) the blade blades (21, 35) are arranged on 20. - 100 mm distance from each other. • · · · · · · · 1 · »1 ♦» ·· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · • · • · ··· • »• · *« ♦ • · ··· ♦ 1 • · ··· ··· «2» ··· • · • ♦ • · · «• · ♦ · · • · • 1 • t • · • 2