FI121386B - Rehabilitation equipment for fiber web machine fabric - Google Patents

Description

RENOVATION EQUIPMENT FOR FIBER MACHINE TISSUE

FIELD OF THE INVENTION The present invention relates to a device for repairing tissue of a fiber web machine, the device comprising 5 - at least one washhead adapted to be moved transversely back and forth with the guide means, for removing the removed and sucked-up material from the scrub head, and the means for removing includes a functional separator for separating the material and fluid from the air.

During production, fibers and fillers, in particular, adhere to the fabrics of the dryer parts of fiber web machines, which hinder 20 production. Particularly on board machines, fouling of the edges of the fabric has been observed, which causes edge ribs in the wire gaps, which eventually lead to web breaks. Other areas of the tissue are also contaminated, causing adhesions and a general decrease in drying efficiency. The problem is further exacerbated when the dirt accumulating in the tissue 25 becomes tacky as a result of warming and the web tends to adhere to the tissue. With the use of recycled material, and in particular board production lines, and more particularly corrugated board grades, the aforementioned contamination of the drying section fabrics has become a significant problem for increasing the susceptibility to breakage.

To avoid the problems caused by fouling, the tissues are repaired with various devices. Current equipment is primarily an online scrubber, with a scrub head crossing the fabric in 35 transverse directions. In other words, the tissue is continuously regenerated in small areas at a time during production. However, the rehabilitation power of known devices is insufficient to keep tissues clean enough. In prior art devices, tissue 2 and fluid, such as wash water, are discharged to a vacuum system via long pipelines, which are expensive to build and operate. In the applicant's own device, marketed under the name OptiCleaner Dry, the suction effect is formed by a 5 ejector integrated in the wash head. In other words, long pipelines are unnecessary. The flow provided by the ejector firstly creates a suction effect on the scrub head and secondly removes the material collected by the suction effect and the wash water from the scrub head. With the ejector, the material and fluid are rapidly circulated and blown into open venting means. However, dirt consisting of material and fluid is polluting the trough. In other words, in addition to the tissue, the device itself becomes soiled. In addition, the large trough extends over the entire width of the fiber web machine. In practice, it is difficult to find sufficient installation space for a larger trough. 15 In addition, the washing head must be mounted against the roll. Also, the flow through the scrub head is incomplete, since the scrub nozzles are in the middle of the flow channel.

The object of the invention is to provide a new type of rehabilitation apparatus for the fabric 20 of a fiber web machine, which has a better rehabilitation capacity but which requires less energy than before. This will allow the tissues to remain functional for a longer period of time, with non-replication. Characteristic features of the rehabilitation apparatus according to the present invention are that the separator is supported on guide means and thus fitted with the washing head for reciprocal movement with respect to the tissue. The separator allows the material and fluid to be collected in a controlled manner without harmful dusting. This prevents contamination of the rehabilitation device and its environment and tissue. 30 There are other benefits of using a separator, which are described in more detail in the application examples. With the right component choices, the rehabilitation equipment provides a compact and compact yet efficient solution. With a reliable recovery device, the fabrics of the fiber web machine remain in working order. This avoids the known problems of increasing the production rate of the fiber web machine. At the same time, previously problematic web species can be brought into production.

3

The invention will now be described in detail with reference to the accompanying drawings, in which: Figure 1 is a side view of the device according to the invention,

Figure 2a is a top plan view of the device of Figure 1,

Fig. 2b is a partial enlarged view of Fig. 2a, Fig. 3 is a sectional view of a part of the device according to the invention,

Figure 4 is a schematic drawing showing the operation of the device according to the invention.

Figures 1 and 2a show a part of a fibrous web machine equipped with a rehabilitation apparatus according to the invention. Fiber web machines are, for example, paper and board machines and have a number of fabrics that require repair. Tissue and pulp drying machines are also fiber web machines. 20 The press felts are refurbished with a large amount of water, which is removed together with the fouling agent, for example with felt cleaners. Instead, only a limited amount of water can be used to repair the drying linings of the dryer section, so high-pressure water jets are commonly used. Regardless of the operating principle, the rehabilitation equipment is arranged in connection with the tissue to be rehabilitated.

Figure 1 is a side view of a rehabilitation device according to the invention. The rehabilitation apparatus includes at least one washing head 30 10 arranged with guide means 11 to be moved transversely relative to the fabric 12. The surface area of the scrub head is relatively small compared to the width of the fabric. In this case, in order to repair the entire tissue, the washhead is slowly moved back and forth while moving rapidly in the transverse direction with respect to the washhead. The washing head 10 is further provided with nozzle members 13 for supplying fluid to tissue 12. Usually, fresh water is used as the fluid, which is sprayed at high pressure per tissue. Using high pressure, even a small amount of water provides an effective tissue repair shower. For example, steam may be used as a fluid instead of or in addition to water.

5

Preferably, the rehabilitation device also includes airflow means 14 for effecting suction on wash head 10. In addition, suction head 10 is provided with suction means 15 for transferring the feed fluid and material removed from tissue 12 and tissue surface. The material is usually fibers and fillers used in the manufacture of the web. During production, the washing head continuously or intermittently repairs the tissue, which thus retains its functionality while the web adhesion problems remain.

According to the invention, the removal means 15 surprisingly include a functional separator 16 for separating the material and the fluid from the air. In practice, only air is removed from the separator as material and fluid accumulate in the separator. This prevents water-mixed dirt that is usually dripping around the washing head. There are different separators and their location may vary from application to application. Regardless of the application, the separator 16 includes an inlet duct 25 and a duct 18. According to the invention, the washing head 10 is connected to the inlet 17 while the airflow means 14 is connected to the duct 18. The airflow means are only after the separator. It is also possible to speak of a kind of vacuum cleaner, before which the material entrained in the air stream is essentially separated. Hereby, the air flow means may be formed of different components and the air flow means will remain unpolluted both internally and externally. 1

According to the invention, the separator 16 is preferably supported on the guide means 11. Thus, the separator 16 is arranged together with the washing head 10 to be moved transversely to the fabric 12. In this case, the flow connection 19 between the washing head 10 and the separator 16 is advantageously short and its structure can be made almost constant. Advantageously, the guide means 11 and / or the flow connection 19 are provided with an adjustment means whereby the scrub head 10 5 may be positioned relative to the fabric 12 as required by the geometry of each mounting position. The separator can also be fixed so that only the scrub head moves. The air flow is then led from the separator to the washing head by a hose and a negative pressure is created, for example, by a blower.

10

With the continuous operation of the retreading device, the separator continuously accumulates material and fluid. Thus, the separator 16 includes, in addition to the inlet 17 and the vent 18, an outlet 20 for removing the separated material and fluid, which is provided with a closure means 21. According to the invention, the closure means are preferably arranged such that during operation the separator remains uninterrupted. Preferably, gravity evacuation is used in conjunction with the shut-off means operating on the principle of a vacuum valve. Such sealing means may, for example, consist of two oppositely arranged flexible membranes 22 which separate from the weight of the material and the fluid to open the outlet 20 (Figure 1). When the separator is sufficiently drained, the membranes again face each other to seal the outlet. Thereby, there is always some substance and fluid in the separator, whereby the flow of air through the outlet connection is prevented and the operation of the separator remains undisturbed. On the other hand, an actuator can be fitted to the closing means, whereupon the separator can be emptied at a desired point. To achieve controlled and clean emptying, the discharge means 15 further includes a collector 23 disposed below the outlet connection 20, from which the material and fluid are discharged, for example, to a sewer or recycle.

The controlled drainage preferably utilizes a manhole 24 positioned at the edges of the fiber web machine 35 (Figure 2a). The separator 16 is then guided above the collection well 24 and emptied. It is also possible to use a collecting container connected to the separator, whereby the separator 6 can be optimally dimensioned unnecessarily without increasing its volume. Preferably, therefore, a collection trough 25 extending across the fiber web machine is used as the collector 23 (Figure 1). In this case, the separator can be emptied at any time, whereby simple but automatic closing means, such as the membrane closure mentioned above, can be used. A collection well can also be used with the collection chute. In this case, for example, from the collection chute, the material and the fluid are led to a collection well, which is used, for example, for cleaning the separator. During cleaning, the separator is located above the well. The collection well is also so large that the separator can also be flushed from the outside as water flows into the collection well. Preferably, the collection trough has a suitable slope for gravity removal. If necessary, rinsing showers or dripping troughs are used in the collection chute.

15

The functional separator can be formed in different ways. Preferably, 16 cyclone 26 is used as separator. The cyclone provides good resolution and compact structure. In addition, high flow rates can be used with the cyclone without loss of resolution. The cyclone is also easy to keep clean and above all to empty. Correspondingly, the air flow means may be formed in different ways. Preferably, according to the invention, the air flow means 14 consist of an air amplifier 27 which is arranged as a deaeration connection 18 of the cyclone 26. This structure further simplifies the structure of the rehabilitation means and reduces the pressure losses. Figure 3 is a sectional view of cyclone 26. The various parts of the cyclone are sized mainly on the basis of particle size and particle size and the desired resolution. The air amplifier 27 can be mounted directly on the top of cyclone 26. Figure 3 also shows the inlet port 29 of the flow connection 19 to the cyclone 26 and the lower part of the cyclone 26 contains an air-separated mixture consisting mainly of material and fluid. Further, the flow connection 19 is arranged such that the air flow is tangential. 1

Figure 4 shows in principle the operation of cyclone 26. The airflow forms a spiral trajectory towards the bottom of cyclone 26. The special motion path is mainly due to the geometry of cyclone 7 26. In the helical flow of air, the separating material and fluid are ejected into the walls of cyclone 26 and run to and from the bottom of cyclone 26 to the outlet 20. The purifying air stream forms a new vortex 5 in the middle of cyclone 26 ascending up and exiting cyclone 26 In tests, it has been found that the cyclone resolution is so good that the air amplifier becomes almost completely dry air. In this case, separate exhaust filters are unnecessary, which further reduces pressure losses. In other words, the power of an air amplifier can be best used to create a suction effect and provide efficient airflow. According to the invention, the air flow means are arranged so that the flow rate at the scrub head is at least 10 m / s. In this case, the material and the fluid injected into the tissue can be assuredly collected. At the same time, a sufficient flow rate is obtained for the cyclone so that its resolution can be maximized.

Figure 1 shows, in principle, the energy line 30 of the purification apparatus 20. First, a high pressure fluid, such as fresh water, is supplied to the washing head 10 for the nozzle members 13. The fluid feed line is shown here by a dashed line. Second, the air amplifier 27 requires compressed air. Here the compressed air supply line is represented by a dotted line. In practice, the energy array 25 is formed such that the various lines allow the washing head to be moved from one edge of the tissue to the other. The energy line also includes means for effecting a traversing motion. Any known technique may be used as a traversing time canis. Another object requiring compressed air is a blowing device such as, for example, an air knife / air comb 31, which according to the invention is provided outside the suction action area of the scrub head 10 in the movement direction of the fabric 12 after the scrub head 10. A blowing device, preferably an air knife 31, prevents material from spreading between the scrub head 10 and the fabric 12. In most cases, an air knife is unnecessary and is only used when needed, such as in problem situations. For example, on an unsupported tissue portion, an air knife is advantageous because it prevents the spread of pollination in the tissue cycle.

In the embodiments of Figures 1 and 2a, the washing head 10 is disposed on an unsupported portion of the fabric 5, which is impossible in most prior art installations. Especially when the fabric 12 is a drying fabric, in this embodiment, the washing jet can be directed through the fabric. In this case, the rehabilitation apparatus further comprises a collecting basin 32 which is arranged to be positioned relative to the washing head 10 on different sides of the fabric 12. Thereby, a significant portion of the fluid and at least a portion of the material passes through the wire into a collection basin 32 by the remainder of the material and fluid into the separator. In this situation, a surprisingly small separator can be used. Flushing showers or dipsticks are also used in the collection pool. In addition, the collecting basin has a suitable slope and can be lowered into, for example, the aforementioned collection well.

For example, needle or fan nozzles or combinations thereof may be used as nozzle members at the wash end. In particular, cyclone 20 provides good resolution when clean and dry air leaves the top of the cyclone. The use of a cyclone and air amplifier that moves with the scrub head avoids a separate vacuum system as well as long piping and large troughs. The rehabilitation apparatus according to the invention is simple and quick to install. In addition, the rehabilitation equipment is virtually uncontaminated, and the separated material and water are removed by gravity. The performance of the rehabilitation apparatus is also clearly better than that of known known apparatuses. Tests have shown that earlier cleaning performance is achieved with less consumption of pressurized nails. In addition, the tissue can be repaired by spraying water through it. In known devices, it is only possible to roll against the roll to avoid splashing. When using the separator, large volumes of air and flow rates can be used without fear of dusting.

35

The height of the cyclone according to the invention for conventional tissue repair may be from about 300 mm to about 1000 mm with a scavenger of about 100 mm to about 300 mm. 0.1 to 0.3 mm needle nozzles could be used at the washing head, which are supplied with water at a pressure of 100 to 500 bar. In practice, water consumption would then be less than a liter per minute. If the scrub head moves ten meters across a 5-wide tissue at a speed of ten millimeters per second, the thinner will collect about thirty liters of water per tissue width. Fig. 2b is an enlarged view of the washing head 10 according to the invention. Here, the nozzle members 13 are fastened to the body of the washing head 10 by means of a quick attachment. The nozzle members can then be replaced in less than a minute.

In addition, the washing head according to the invention is compact, making it easier to position. In addition, the flow connection is completely obstructed since the nozzle members are located in the direction of travel of the tissue just prior to the flow connection. The movement of the tissue naturally directs material removed from the surface of the tissue towards the flow connection. In particular, the cyclone takes advantage of the high airflow while moderating it, causing material and fluid to separate from the air.

20

Applicant's previous device consumes compressed air of about 800 standard liters per minute at pressures up to 5 bar. The rehabilitation equipment we are presenting is just as efficient at much less compressed air consumption. At the same time, the pressure requirement is lower than 25, so the retrofit device can also be installed in old factories. However, despite the clearly lower power requirement, the cleaning efficiency of the rehabilitation equipment according to the invention is better than before. Instead of an air amplifier, another suitable vacuum generator can be used, such as an ejector, a pressure amplifier, a venturi or a vacuum fan.

Claims (8)

1. Fabric adjustment equipment in a fiber web machine, comprising equipment 5. at least one wash head (10), which is arranged to move forward and eat transversely in relative to the fabric (12) arranged on the wash head (10) (13) for supplying a fluid to the fabric (12), air flow means (14) for providing a suction effect on the wash head (10), and removal means (15) associated with the wash head (10) for removing the fed fluid and the detached from the fabric (12) and ice collected by the suction power from the wash head (10) and the removal means (15) comprise a functional separator (16) for separating material and fluid from the air, characterized in that the separator (16) is supported by guiding devices (11) and thus arranged together with the wash head to be able to move forward and eat transversely in relation e to the fabric (12). 2. Aggregation equipment according to claim 1, characterized in that the separator (16) comprises an inlet connection (17) and a vent connection (18), and the wash head (10) is connected to the input connection (17) when the air flow devices (14) are connected. the vent connection (18). Cutting equipment according to claim 2, characterized in that the separator (16) comprises, in addition to the inlet connection (17) and the vent connection (18), also an outlet connection (20) for removing the input fluid and the released material, to which the outlet connection shut-off devices (21) have been provided. 35 4. An assembly device according to claim 3, characterized in that the removal means (15) further comprise a collector (23) arranged on the underside of the outlet connection (20), which is a collection channel (25) extending across the fiber web machine and / or The edges of the fiber web machine are placed in the collection well (24). 5. An assembly device according to any of claims 1-4, characterized in that the separator (16) is a cyclone (26). 10 6. Aggregation equipment according to claim 5, characterized in that the air flow devices (14) are an air amplifier (27), which is arranged as the vent connection (18) of the cyclone (26). 15 7. Aggregation equipment according to any one of claims 1 to 6, characterized in that a blowing device (31) is arranged outside the suction area of the wash head (10), in the direction of movement of the weave (12), of the web (10). 20 8. An assembly device according to claim 7, characterized in that the blower (31) is an air comb or an air knife. An assembly equipment according to any of claims 1 to 8, characterized in that the insertion equipment further comprises a collection vessel (32), which is arranged to be positioned relative to the wash head (10) on the other side than the fabric (12).