Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
  • D21F1/00—Wet end of machines for making continuous webs of paper
  • D21F1/32—Washing wire-cloths or felts
  • D21F1/325—Washing wire-cloths or felts with reciprocating devices

Definitions

• the invention relates to conditioning equipment for the fabric of a fiber web machine including - at least one cleaning head adapted to be moveable back and forth in the transverse direction to the fabric by means of guiding means,
• - discharge means connected to the cleaning head for transferring the supplied fluid and the matter detached from the fabric and collected by the suction effect away from the cleaning head.
• the flow provided with the ejector firstly creates a suction effect in the cleaning head and secondly removes the matter, collected by the suction effect, and the cleaning water from the cleaning head.
• the ejector makes the matter and fluid move fast and blows them out to the discharge means composed of an open tray.
• impurities consisting of the matter and fluid mist out from the saveall to the environment. That is, not only the fabric but also the equipment itself soils.
• a large channel extends over the entire width of the fiber web machine. In practice, it is difficult to find a sufficient installation space for a relatively large channel.
• the cleaning head must be installed against a roll. Also, the flow through the cleaning head is imperfect because the cleaning nozzles are located in the middle of the flow channel.
• the object of the invention is to provide novel conditioning equipment for a fabric of a fiber web machine, the conditioning capacity of which is better than earlier but requires less energy than before. Thus fabrics maintain their operating condition longer than before as resoiling is non-existent.
• discharge means include a functional separator for separating matter and fluid from air.
• the separator can collect matter and fluid controllably without detrimental misting. Thus soiling of the conditioning equipment and its environment as well as that of the fabric are avoided.
• the use of a separator leads to other benefits as well, which are described in more detail in connection with the application examples.
• the conditioning equipment can be made compact and small, yet efficient. Using reliable conditioning equipment, fabrics of a fiber web machine maintain their appropriate operating condition. In this way known problems are avoided whereby it is possible to achieve a higher production rate than before for the fiber web machine. At the same time, web grades that have been problematic earlier can be included in the production.
• Figure 1 is a side view of the equipment according to the invention
• Figure 2a is a diagonal top view of the equipment according to
• Figure 2b is an enlargement of a part of Figure 2a
• Figure 3 is a cross-sectional view of a part of the equipment according to the invention
• Figure 4 shows a basic diagram illustrating the operating principle of the equipment according to the invention.
• Figures 1 and 2a show a part of a fiber web machine provided with conditioning equipment according to the invention.
• Fiber web machines include, for example, paper and board machines, which have several fabrics that require conditioning.
• Tissue machines and pulp drying machines are also fiber web machines.
• a lot of water is used for conditioning press felts and the water is removed together with the matter that causes soiling using felt suction boxes, for example.
• the conditioning equipment is arranged in the vicinity of the fabric to be conditioned.
• FIG. 1 shows a side view of the conditioning equipment ac- cording to the invention.
• the conditioning equipment includes at least one cleaning head 10 adapted to be moveable back and forth in the transverse direction to the fabric 12 by means of guiding means 11.
• the surface area of the cleaning head is relatively small compared to the width of the fabric.
• the cleaning head 10 has additionally nozzle elements 13 arranged therein for supplying fluid to the fabric 12.
• the fluid is usually fresh water which is sprayed at a high pressure toward the fabric. Using high pressure, even a small amount of water can provide a shower that efficiently conditions the fabric.
• steam for example, can be used as fluid.
• the conditioning equipment also includes air flow means 14 for creating a suction effect in the cleaning head 10.
• discharge means 15 are connected to the cleaning head 10 for transferring the supplied fluid and the matter detached from the fabric 12 and collected by the suction effect away from the cleaning head 10.
• This matter usually consists of fibers and fillers used in the web production.
• the cleaning head conditions the fabric continuously or periodically ensuring that the fabric maintains its operating condition and web attachment problems are avoided.
• the discharge means 15 surprisingly include a functional separator 16 for separating matter and fluid from air.
• a functional separator 16 for separating matter and fluid from air.
• the separator 16 includes an inlet connection 17 and an air exhaust connection 18.
• the cleaning head 10 is connected to the inlet connection 17 while the air flow means 14 are connected to the air exhaust connection 18.
• the air flow means are located only after the separator, which means that mainly air only flows through the air flow means. It is also possible to refer to a kind of a suction box prior to which the matter conveyed with the air flow is mainly separated.
• the air flow means can be composed of different components and the air flow means remain unsoiled both inside and outside.
• the separator 16 is advantageously supported to guiding means 11.
• the separator 16 is adapted to be moveable back and forth together with the cleaning head 10 in the transverse direction to the fabric 12.
• the flow connection 19 between the cleaning head 10 and the separator 16 is advantageously short and it can be provided with a virtually invariable structure.
• a con- trol possibility is arranged in the guiding means 11 and/or the flow connection 19, in which case the cleaning head 10 can be positioned relative to the fabric 12 in a way required by each installation position geometry.
• the separator can also be located fixedly, in which case only the cleaning head moves. Then the air flow from the separator to the cleaning head is led via a hose, and a vacuum is generated with a blower, for example .
• the separator 16 includes a discharge connection 20, provided with closing means 21, for removing the separated matter and fluid.
• the closing means are advantageously so adapted that the operation of the separa- tor remains uninterrupted even during the discharge.
• Gravitational discharge is advantageously used together with closing means that operate according to the vacuum valve principle.
• Such closing means can be composed, for example, of two flexible membranes 22 adapted face to face, which separate due to the weight of the matter and fluid thus opening the discharge connection 20 ( Figure 1) .
• the separator always contains some matter and fluid ensuring that an air flow through the discharge connection is prevented and the operation of the separator remains undisturbed.
• an actuator can be adapted in the closing means, whereby the separator can be emptied in a desired point, if required.
• the discharge means 15 further include a collector 23 adapted underneath the discharge connection 20. From the collector, the matter and fluid are led to a sewer or to recycling, for example.
• a collecting pit 24, located at the edges of the fiber web machine, is advantageously used ( Figure 2a) .
• the separator 16 is led above the collecting pit 24 and emptied.
• a saveall tray connected to the separator in which case the separator can be optimally dimensioned without increasing its volume in vain. Therefore, a saveall channel 25 extending across the fiber web machine is advantageously used as the collector 23 ( Figure 1) .
• the separator can empty at any time and it is possible to use simple but automatic closing means, such as the above mentioned membrane closure.
• a collecting pit can be used as well.
• the collecting pit which is used during the separator cleaning, for example.
• the separator is above the collecting pit.
• the collecting pit is so large that the separator can be flushed even externally and the water flows to the collect- ing pit.
• the collecting pit is provided with a suitable gradient for removing the matter gravitationally . If necessary, cleaning showers or a bottom flow are used in the saveall channel.
• the functional separator can be implemented in various ways.
• a cyclone 26 is advantageously used as the separator 16. With a cyclone, a good separating capacity and a compact structure are achieved. In addition, high flow speeds can be used with a cyclone without reducing the separating capacity. A cyclone is also easy to keep clean and, above all, it is easy to empty.
• the air flow means can be implemented in various ways. According to the invention, the air flow means 14 are advantageously composed of an air amplifier 27, which is adapted as the air exhaust connection 18 of the cyclone 26. Such a construction further simplifies the design of the conditioning equipment as well as reduces pressure losses.
• Figure 3 shows a cross-sectional view of the cyclone 26.
• the various parts of the cyclone are dimensioned mainly based on the size and amount of particles as well as the desired separating capacity.
• the air amplifier 27 can be connected directly to the top part of the cyclone 26.
• Figure 3 shows also the access hole 29 to the cyclone 26 for the flow connection 19 and, in the bottom part of the cyclone 26, a mixture separated from air, which consists mainly of matter and fluid.
• the flow connection 19 is so adapted that the air flow arrives tangentially .
• FIG 4 shows the operating principle of the cyclone 26.
• the air flow forms a spiral-shaped path toward the bottom of the cyclone 26.
• the peculiar path is mainly due to the geometrical construction of the cyclone 26.
• the air flow being cleaned forms a new vortex at the bottom, at the center of the cyclone 26, rising upward and exiting the cyclone 26 via the air exhaust connection 18. It has been noticed in tests that the separating capacity of the cyclone is so good that the air exiting from the air amplifier is almost perfectly dry. Thus separate exhaust filters are unnecessary, which further reduces pressure losses.
• the capacity of the air ampli- bomb can be utilized in the best possible way to create a suction effect and to generate an efficient air flow.
• the air flow means are so arranged that the flow speed is at least 10 m/s at the cleaning head. In this way the matter and the fluid sprayed to the fabric can be reliably collected. At the same time, a sufficient flow speed is obtained in the cyclone whereby its separating capacity can be maximally utilized.
• FIG. 1 shows the principle of the energy line assembly 30 of the conditioning equipment.
• high-pressure fluid such as fresh water
• the supply line of fluid is represented here by a broken line.
• the air amplifier 27 requires air pressure.
• the air pressure supply line is represented by a dot-and-dash line.
• the energy line assembly is so formed that various lines permit moving the cleaning head from one fabric edge to the other.
• the energy line assembly also includes means for providing the traversing movement. As the traversing mechanism, any known technique can be used.
• the air blow device such as an air knife/air comb 31, which, according to the invention, is arranged outside the suction effect zone of the cleaning head 10, after the cleaning head 10 in the travel direction of the fabric 12.
• the air blow device advantageously an air knife 31, prevents the matter from spreading out from between the cleaning head 10 and the fabric 12. In most cases an air knife is unnecessary and it is used only when required, such as in problem conditions. For example, in the unsupported part of the fabric, an air knife is advantageous because it prevents mist from spreading forward in the fabric cycle.
• the cleaning head 10 is arranged in the unsupported part of the fabric 12, which is impossible in most known apparatuses.
• the fabric 12 is a dryer fabric
• the cleaning shower can be di- rected through the wire in this application.
• the conditioning equipment still includes a saveall tray 32, which is adapted to be located on a different side of the fabric 12 relative to the cleaning head 10.
• a saveall tray 32 which is adapted to be located on a different side of the fabric 12 relative to the cleaning head 10.
• the cleaning head needle or fan nozzles or combinations of these can be used as nozzle elements. Particularly, a good separating capacity can be achieved with a cyclone when clean and dry air is removed from the top part of the cyclone.
• a cyclone that moves along with the cleaning head and an air amplifier, a separate vacuum system is avoided as well as long pipelines and large channels.
• the conditioning equipment according to the invention has a simple construction and allows fast installation. In addition, the conditioning equipment is almost non-soiling and the separated matter and water are removed by the gravitational force. The efficiency of the conditioning equipment is also clearly better compared to known devices. Based on tests, earlier cleaning capacity can be achieved with a lower compressed air consumption than earlier.
• the fabric can be conditioned by spraying water through it. In known devices, conditioning is possible only against a roll to avoid splashing. When utilizing a separator, large amounts of air and high flow speeds can be used without the risk of misting.
• the height of a cyclone according to the invention designed for the conditioning of a conventional fabric can be in the range of about 300 - 1000 mm while the diameter is in the range of about 100 - 300 mm.
• needle nozzles of 0,1 - 0,3 mm could be used supplying water at a pressure of 100 - 500 bar. In practice, the water consumption would then be less than one liter per minute.
• the separator collects about thirty liters of water per one fabric width.
• Figure 2b shows an enlarged view of the cleaning head 10 according to the invention.
• nozzle elements 13 are connected to the frame of the cleaning head 10 by quick clamping. Thus the nozzle elements can be replaced in less than a minute.
• the cleaning head according to the invention is small in size whereby its positioning is easier than before.
• the flow connection is completely unrestrained as the nozzle elements are located immediately before the flow connection in the travel direction of the fabric. The movement of the fabric transports the matter detached from the fabric surface naturally toward the flow connection.
• a cyclone utilizes a high air flow calming it down at the same time and providing thus separation of the matter and fluid from air.
• the consumption of compressed air in the earlier equipment of the applicant is about 800 standard liters per minute while the pressure is up to 5 bar.
• the conditioning equipment presented now operates equally efficiently with a much lower compressed air consumption.
• the pressure requirement is smaller than before so that the conditioning equipment can be installed in old mills as well.
• the cleaning capacity of the conditioning equipment according to the invention is better than earlier.
• another suitable vacuum generator can be used, such as .an ejector, a pressure amplifier, a venturi pipe or a vacuum blower.

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• Treatment Of Fiber Materials (AREA)

Applications Claiming Priority (2)

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Citations (3)

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• 2009
  • 2009-03-09 FI FI20095231A patent/FI121386B/fi not_active IP Right Cessation
• 2010
  • 2010-02-24 CN CN2010900007684U patent/CN202766909U/zh not_active Expired - Fee Related
  • 2010-02-24 EP EP10750414A patent/EP2406426A4/de not_active Withdrawn
  • 2010-02-24 WO PCT/FI2010/050132 patent/WO2010103169A1/en active Application Filing

Patent Citations (3)

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