CN1170982C - Method and apparatus for draining oil from a shoe press assembly - Google Patents

Abstract

The invention relates to a device and a method for oil evacuation from a shoe press unit, which shoe press unit comprises a beam (1), a shoe element (2) arranged movably on said beam (1) by means of a pressing unit (3, 5) and having a pressing surface (21), an oil evacuation arrangement (4) with at least one inlet opening (41) which is moved with the shoe element (2), a number of evacuation ducts (48) and an outlet pipe (49), and also a flexible belt (6) interacting with said shoe element (2), oil being supplied during operation to lubricate between said pressing surface (21) and said belt (6), an oil excess with kinetic energy being pressed out at an upstream edge region (21A) of said pressing surface (21), and an oil excess being evacuated from said shoe press unit by said oil evacuation arrangement (4), in which said inlet opening (41) is arranged in such a manner in a container (43A, 43B, 44, 45, 46) connected firmly to the shoe element (2) that a large part of said oil excess is squirted directly into said inlet opening (41), said outlet pipe (49) is connected firmly to said beam (1), and at least a first part of said evacuation duct (48) is arranged movably in relation to said outlet pipe (49).

Description

Method and apparatus for draining oil from a shoe press assembly

technical field

The invention relates to a method for draining oil from a shoe press assembly comprising a beam, a shoe movably arranged on said beam by a press assembly, and There is a pressing surface, an oil drain having at least one inlet, a plurality of oil drain pipes and an outlet pipe, and a flexible belt interacting with said shoe. During operation, oil is fed between the press surface and the belt to lubricate them, excess oil with kinetic energy is pressed out at an upstream edge region of the press surface, and excess oil passes through the drain The oil means is drained from the shoe press assembly and at least some of the excess oil is sprayed directly into the inlet. The invention also relates to a device for a shoe press assembly.

Background technique

Methods and apparatus for a shoe press assembly as described above in the technical field are known from earlier eg US Pat. No. 5,935,385. In order to reduce the friction and thus the heat generated between the belt and the shoe, during operation oil is fed between the pressing surface and the belt to lubricate and cool them. The excess oil is squeezed out at an upstream edge region of the press surface (on the inlet side of the belt) and the excess oil is drained from the shoe press assembly by an oil drain. According to US Pat. No. 5,935,385, the inlet of the oil drain device is arranged on the beam and has a certain distance from the shoe. Therefore, the drain device cannot move together with the shoe.

During the shoe press operation, excess oil is pressed out of the junction area formed between the edge area of the press surface and the belt. If the shoe press has an oil drain with an inlet located in a region other than the region where the direct oil injection occurs during operation, the kinetic energy present in the oil can never be utilized. Oil may accumulate inside the shoe press assembly if the oil drain is not provided with a mechanism to prevent the oil from flowing in different directions. This in turn causes the oil and air that accumulates inside the shoe press assembly to mix, which makes draining the oil more difficult, and means that additional adjustments must then be made to separate the air from the oil before it can be used again come out. Additionally, heat may be released from pressing excess oil before the oil is drained, which would result in an undesirable temperature increase within the shoe press assembly. From an economical operating point of view, the presence of oil accumulation inside the shoe press assembly is undesirable because it requires increased input power.

Contents of the invention

It is an object of the present invention to eliminate or at least reduce one of the above-mentioned drawbacks by a method for draining oil from a shoe press assembly. Wherein, the shoe-shaped pressing assembly includes a beam, a shoe-shaped member, which is movably arranged on the beam through a pressing assembly and has a pressing surface, and an oil draining device, and the oil draining device has at least one An inlet movable with the shoe, drain pipes and an outlet pipe, and a flexible belt interacting with the shoe. During operation, oil is fed between the press surface and the belt to lubricate them, excess oil with kinetic energy is pressed out at an upstream edge region of the press surface, and excess oil passes through the oil drain A device is drained from the shoe press assembly. It is characterized in that said inlet is arranged in a container tightly connected to the shoe in such a manner that a large amount of said excess oil is sprayed directly into said inlet, said outlet pipe is firmly connected to said On the beam, at least a first portion of the drain pipe is movably arranged relative to the outlet pipe.

The present invention has many advantages. Firstly, the location and arrangement of the inlet means that the large amount of kinetic energy present in the pressed oil is useful for the relief of excess oil; secondly, the structure of the oil relief device results in more effective relief; thirdly, The invention makes it possible to keep the temperature in the shoe press assembly at a low level, because a large amount of hot oil is released inside the shoe press assembly without having time to release its heat; This will reduce energy consumption during the operation of the shoe press assembly because no or only a minimal amount of excess oil will accumulate inside the shoe press assembly.

The method according to the invention also comprises further features:

- said oil drain pipe comprises a first pipe portion tightly connected to said device having an inlet, preferably this pipe portion is substantially rigid.

- the pipe portion is movably arranged inside a through hole in the beam and has a sufficient length to protrude from the other end of the through hole.

- The end of the first pipe portion is arranged movably in a sealed manner relative to the outlet pipe.

- The sealing is provided using a flexible mechanism, preferably a rubber bellows.

- One end of said flexible mechanism is connected to said movable first pipe part and its other end is connected to a second pipe part tightly arranged on said output pipe.

- The shoe press assembly comprises a hermetic shoe press provided with an internal high pressure of between 10-500 mbar, preferably below 200 mbar, more preferably below 50 mbar.

- The outlet pipe is connected to a low pressure application from the outside of the shoe press, for the purpose of making it easier to drain the excess oil.

The invention also relates to a device for a shoe press assembly, wherein the shoe press assembly comprises a beam, a shoe movably arranged on said beam by a press assembly, and having A pressing surface comprising an upstream edge region, an oil drain having an inlet fixedly arranged relative to the shoe, a plurality of oil drain pipes and an outlet pipe, and with the shoe A flexible strap that interacts. It is characterized in that said inlet is arranged in a container firmly connected to the shoe in such a manner that a large amount of said excess oil is sprayed directly into said inlet, said outlet pipe is firmly connected to said A portion of at least one oil drain pipe is movably disposed relative to the outlet pipe on the beam.

The device according to the invention also comprises further features:

- said device having an inlet arrangement is in the form of a container to which the movable part of said drain pipe is firmly connected in a sealed manner, and which preferably contains on all sides and bottom a surrounding wall pieces.

- The movable part of said drain pipe interacts with a sealing mechanism forming a substantially sealed connection between said inlet and said outlet pipe.

- said sealing mechanism comprises a flexible tube, preferably a rubber telescoping tube, one end of which is sealingly connected to the periphery of said movable part of the drain pipe and the other end of which is connected firmly to said outlet pipe on the attachment.

- said accessory comprises a tubular connection, preferably a metal tube, which is connected in a sealed manner to said output tube.

- Said movable part of the oil drain pipe interacts directly at its end through its outer surface with a sealing mechanism, preferably comprising at least one O-ring, arranged on the inlet side of the oil drain pipe.

- said sealing means are arranged between two retractably arranged parts so as to be able to interact in a sealed manner.

- A guide plate is provided in the area between the lower limit surface of the inlet and the shoe, the means preferably extending substantially in a rectilinear direction.

- The shortest distance between the upper surface of the inlet and the inner surface of the belt is between 0-10mm, preferably less than 5mm.

- said container extends in the longitudinal direction to a length comprised between 500-1500 mm.

- The diameter of the first oil drain pipe is between 30-100mm, preferably 50-70mm.

- At least two such containers are arranged adjacent to each other inside said shoe press assembly.

Description of drawings

The present invention will be described in more detail below in conjunction with accompanying drawing, wherein accompanying drawing is:

Figure 1 is a cross-sectional view of a preferred embodiment of the present invention.

Figure 2 is a partial cross-sectional view of the preferred embodiment of the present invention disposed within a closed shoe press assembly.

Figure 3 is a perspective view of a preferred assembly in accordance with the present invention.

Fig. 4 is a sectional view of another embodiment of the oil drain pipe according to the present invention.

Detailed ways

Figure 1 shows the principle of a shoe press assembly according to the invention in a sectional view. From known principles per se, the shoe press assembly consists of a support beam 1 in which recesses are provided to receive a press assembly 3 , 5 for a shoe 2 . The pressing assembly 3, 5 itself comprises in a known manner a hydraulic piston which is arranged in a sealed manner inside a hydraulic cylinder 5 so that the shoe 2 can be moved in a direction perpendicular to the longitudinal extension of the shoe 2. Hydraulically driven back and forth. A support seat 9 is arranged on a short end of the shoe-shaped part 2 . An endless flexible belt/cover 6 is itself arranged in known manner so that it interacts with a pressing surface 21 of the shoe 2 via its one side surface 6A, and with its other side surface 6B and an opposing roller 10 interactions. As shown in the figure, the endless belt 6 rotates in the counterclockwise direction, therefore, the support base 9 is arranged at the downstream end of the shoe 2 . Arranged on the left in the figure at the upstream end of the shoe is a distribution chamber 7 which supplies oil to the pressing surface 21 via a delivery pipe 71 in a known manner. Simultaneously, an oil drain device 4 is also shown, which includes an inlet 41 disposed in a trough container (see Fig. 3), a first pipe portion 48A of an oil drain pipe, a rubber telescoping tube 48C, an upper connection pipe (second pipe portion) 48B, and an output pipe 49 . It can be clearly seen that the rubber telescoping tube can provide good flexibility in multiple directions, not only for vertical movement between the two tube parts 48A and 48B, but also for certain operating conditions that may occur Deviating from or deviating from its cross-sectional direction at an angle. The two tube parts 48A and 48B are suitably made of a dimensionally stable material, such as a metallic material, so that they cannot be compressed by external high pressure. It is also shown in Figure 1 that the shoe press assembly is provided with a second oil drain means 11 adapted to serve as an oil drain system in the event of a stoppage of operation. It is also shown that the shoe press assembly is provided with a belt guide 12 mounted on a support plate 13, the purpose of which is to facilitate the installation and removal of the belt/overcoat 6.

Figure 2 shows in more detail a portion of a shoe press assembly according to the invention. According to the preferred embodiment shown, it can be seen that the shoe 2 is designed symmetrically in each edge region of said pressing surface 21 . Marked at the upstream end of the shoe 2 is an edge zone Z1-Z2 which constitutes the zone of a convex surface 21A. It can be seen that the extension L of this edge region is relatively short relative to the concave portion 21 of the pressing surface. In this edge region 21A there is a line X which produces the first contact between the belt 6 and the pressing surface 21 of the shoe.

Set on the distribution chamber 7 is the lower part of the oil drain device 4 , which further includes a guide plate 42 , a container, an oil drain pipe 48 and a grooved inlet 41 . The container comprises a first longitudinal wall member 45, a flat bottom wall 44, a second longitudinal wall member 46 and two end walls 43A, 43B. The upstream longitudinal wall member 46 is divided into a lower wall member 46A and an upper wall member 46B. The lower wall part 46A is arranged at an acute angle with the bottom wall 44 and the plane P containing the bottom surface 44, according to the preferred embodiment, this angle x is about 60-70, and the upper wall part 46B is arranged at a less acute angle with respect to said plane P. In this way, the upper wall part 46B presents an inclination of only a small degree to the tangent to the belt 6 in the region of said upper wall part 46B, so that the upper part converges slightly towards the inner surface of the belt. The end 41B of the upper wall part forms the upper limit surface of the inlet 41, and it is very advantageous if the upper limit surface 41B is located at a position close to, or even in contact with, the inner surface of the belt 6, thus forming as much as possible between them. small gaps. The downstream wall element 45 is also arranged at an acute angle with respect to said plane P, and according to the preferred embodiment it forms an angle β which is substantially the same as the angle x of the other wall element 46A. End walls 43A and 43B are provided at each short end of the container, and the lower limit surface 41A of the inlet 41 is formed by the upper end of the downstream longitudinal wall member 45 . All parts forming the container are made of thin metal sheet, preferably 2mm thick. Extending vertically from said lower limit surface 41A and up to the shoe is a guide plate 42, also made of sheet metal, and adapted to be made of the same sheet metal as the container, The container is formed by first suitably stamping and forming the sheet metal and then bending it into the desired final shape, after which the end walls 43A and 43B are joined in a sealed manner (suitably by welding) to the bent portions . A circular hole 44A is provided on the bottom surface of the container, on which an oil drain pipe is provided in a sealed manner (suitable for welding). The container is secured to the dispensing chamber 7 by means of a screw connection 50 which in turn is connected (usually screwed) to a longitudinal side wall 23 of the shoe. Thus, the drain device 4 is fixed firmly to the shoe so that they can move as a unit. For the purpose of enabling the movement of the shoe and the oil drain device 4, there is a recess 1A in the support beam 1, in which the oil drain pipe can freely move up and down.

As already mentioned above, the oil drain device 4 is arranged on the position of the upper limit surface 41B of the inlet 41 quite close to the surface of the belt, so that the distance S between them during operation is small enough to prevent the leakage between the inlet 41 and The distance S should preferably not allow more than 10 mm for a large amount of oil spillage between the belts 6 . The inlet 41 should further be located in such a position that a large amount of excess oil that is pressed out can be sprayed directly into the inlet 41 . According to the preferred embodiment, due to the above structure, the tangent Tx of the convex surface at the contact line X between the belt 6 and the shoe 2 will extend between the lower limit surface 41A and the upper limit surface 41B. In this case, a geometry should be provided between the edge region 21A and the inlet such that the tangent Tx of the contact line X (which can be considered as the excess oil ejected usually in a divergent form A representation of a central flow direction) is located, from an imaginary straight line Y1 extending between the contact line X and the lower limit surface 41A of the inlet 41, or an imaginary straight line extending between the contact line X and the upper limit surface 41B of the inlet 41 At least one of Y2 deviates by a maximum of 15. Furthermore, the inlet 41 should be located close to the upstream edge area 21A, suitably between 10-150 mm, and more preferably at a maximum of 100 mm from the edge area 21A.

The device shown in Figures 1 and 2 has functions in the following form. When starting to operate the machine, the inner surface of the belt bears a thin layer of oil, which serves to lubricate between the belt 6 and the pressing surface 21 of the shoe 2, but also to cool the shoe pressing assembly. The oil supplied usually occurs at several different locations, notably through the distribution chamber 7 to lubricate the central area of said pressing surface 21 (see FIG. 1 ), and also usually directly at least somewhere on the inner surface of the belt. In other respects, the shoe press assembly itself operates in a known manner, the shoe 2 exerting pressure via the press assemblies 3, 5 against a counter-roll 10, in order to subject the web located therebetween to the Desired treatment, such as dehydration treatment. In this connection, excess oil supplied with the belt 6 to the upstream end of the shoe will be forced out of the joint zone formed between the inner surface 6A of the belt and the upstream edge region 21A of the shoe. The excess oil O acquires kinetic energy in this way and is sprayed into the inlet 41 in the direction opposite to the direction of belt movement to be collected in a container. When using a closed shoe press assembly, due to the slight high pressure inside the shoe press assembly, the oil collected in the container will be forced out through the first tube portion 48A of the oil drain line, through the rubber bellows 48C and through the The connecting pipe (ie, the second pipe portion) 48B enters into the outlet pipe 49 and finally reaches a collection container (not shown). In certain applications, the output line is connected to a low pressure to ensure proper oil drainage. Typically a closed shoe press assembly is used with an internal high pressure of less than 50 mbar.

A portion of the oil will not be carried away but will flow along the surface of the shoe edge region 21A down the end wall 23 of the shoe. However, due to the action of the guide plate 42 pressed against the end wall 23 of the shoe, this part of the oil will also be directed into the inlet 41 . In the embodiment shown in Figure 1, in such a connection, gravity will assist the flow of this additional oil into the container. It should however be pointed out that this is not essential, since a low pressure can be produced in the area adjacent to the inlet 41, so that such an influx of excess oil can be produced even without the influence of gravity. The fact that the oil drain pipe is arranged vertically in the oil drain device does not therefore constitute a limitation of the shown invention.

The above-mentioned container integrated with a guide plate 42 and drain pipe is shown in perspective view in FIG. 3 . It can also be seen that the guide plate 42 is provided with a plurality of holes 47 for installing the fixing screw 50 . Since the oil drain is preferably disconnected, in this case a plurality of containers of limited length are arranged adjacent to each other on the shoe 2, preferably with an inlet 41 of each container extending along the entire width of the container , is always set ideally with respect to the spray oil, irrespective of the inclination of the beam 1. According to a preferred embodiment, each container is approximately 1 meter in length. The length of the container should not be less than 500mm or not more than 1500mm to obtain the best discharge function. For the same reason, the diameter of the drain pipe should not be too small, suitably around 60mm. The diameter should preferably not be less than 10 mm and not exceed 50 mm.

Figure 4 shows a first alternative embodiment according to the invention, where the drain pipe 48 is provided with two telescopically arranged pipe sections 48A and 48B. The first tube portion 48A of the oil drain tube provides a relatively larger diameter D1 in this connection, while the second tube portion 48B of the oil drain tube provides a relatively smaller diameter D2. The two tubular portions are arranged to overlap each other by a substantial length 1 in the rest position, which length is preferably at least as large as the diameter of the first tubular portion 48A. According to the preferred embodiment, disposed in the annular gap 60 formed between the overlapping tubes is a seal 61 secured to the end of the second tube portion 48B. It is thus possible to move between this seal 61 and the first tube portion 48A, the sliding taking place in the cylindrical contact area 62 between the seal 61 and the inner surface of the first tube portion 48A.

According to another alternative embodiment of the present invention, the drain pipe fixed to the container should be long enough so that it can enter the interior through the inlet 49A of the outlet pipe 49 . In this case, seals such as one or more O-rings are provided directly in the inlet 49A of the outlet pipe 49, these seals interacting directly with the outer surface of the drain pipe. Since the outlet pipe 49 can be made of a larger diameter pipe, suitable between 100-200 mm, the end of the oil drain pipe can move freely inside the outlet pipe 49 because the maximum stroke length of the shoe 2 is usually No more than 50mm, usually between 20-35mm.

In many applications, it is very important if the sealing connection between the first pipe portion 48A and the adjacent portion of the oil drain device is flexible in multiple directions so that the connection is also flexible in the transverse direction. Advantageous; because during operation, there is a possibility of causing some lateral movement of the shoe by lateral force and/or thermal deformation, and the first tube portion 48A must be able to follow this movement without complicated Danger.

The invention is not limited to what has been disclosed above, but various modifications can be made within the scope of the following claims. It is therefore clear that, for example, the oil drain can be made of many other materials than sheet metal, such as a polymer material; it can also be clearly seen that the inlet 41 of the oil drain can be separated (for example due to strength reason) to form a plurality of enlarged or reduced extension openings adjacent to each other; it is also clear that the components of the oil drainage device do not have to be made of the same material, it can be made of a variety of different components/ It is self-evident to those skilled in the art that they can be arranged/connected to each other in other ways; it can also be clearly seen that the oil drainage device is arranged in one place only for demonstration purposes. On the distribution chamber, the oil drain device can of course be arranged directly on the shoe 2 , for example along its side surface 23 . Furthermore, it is also clear that the container may comprise a device different from the above design, for example with a considerably smaller "container space" and/or with a completely different cross-sectional shape (e.g. oval), as long as it is in accordance with the The space available in the intended shoe press will suffice; it is also clear that other means than the rubber bellows 48C can also be provided as a flexible part, i.e. a seal between the two pipes in the oil drain Connections, such as fibre-reinforced flexible materials and impermeable polymeric materials other than rubber, or liquid-impermeable textile materials.

Claims (31)

1. A method for draining oil from a shoe press assembly, wherein the shoe press assembly comprises a beam (1), a shoe (2), which passes through a press assembly (3, 5) Movably arranged on said beam (1) and having a pressing surface (21), an oil drain (4) having at least one inlet (41) movable together with the shoe (2) ), a plurality of oil drain pipes (48) and an outlet pipe (49), and a flexible belt (6) interacting with the shoe (2), during operation oil is supplied to the pressing surface ( 21) and the belt (6) to lubricate them, excess oil with kinetic energy is squeezed out at an upstream edge region (21A) of the pressing surface (21), and excess oil passes through the oil drain (4) is released from the shoe press assembly, characterized in that the inlet (41) is set in a container tightly connected to the shoe (2) in such a way that a large number of The excess oil is sprayed directly into the inlet (41), the outlet pipe (49) is firmly connected to the beam (1), at least the first part of the drain pipe (48) is opposite to the The output pipe (49) is movably arranged. 2. The method according to claim 1, characterized in that the oil drain pipe (48) comprises a first pipe portion (48A) tightly connected to the inlet (41). 3. The method of claim 1, wherein the first tube portion is rigid. 4. The method according to claim 2 or 3, characterized in that the first pipe part (48A) is movably arranged inside a through hole (1A) on the beam (1), and has a sufficient length to Extend the other end of the through hole (1A). 5. A method according to claim 4, characterized in that the end of the first pipe portion (48A) is arranged movably in a sealed manner relative to the outlet pipe (49). 6. A method as claimed in claim 5, characterized in that a flexible sealing element is used to provide said sealing. 7. The method of claim 5, wherein said sealing element is a rubber shrink tube. 8. The method according to claim 6, characterized in that one end of the sealing element (48C) is connected to the first pipe portion (48A), and the other end is tightly arranged on the outlet pipe The second pipe portion (48B) on (49) is connected. 9. The method of claim 1, wherein said shoe press assembly comprises a closed shoe press provided with an internal high pressure, said internal high pressure being between 10-500 mbar. 10. A method according to claim 9, characterized in that said internal high pressure is lower than 200 mbar. 11. The method of claim 9, wherein the internal high pressure is lower than 50 mbar. 12. A method according to claim 9, characterized in that said outlet pipe (49) is connected to a low pressure acting on the outside of the shoe press in order to easily drain said excess oil. 13. A device for draining oil from a shoe press assembly, wherein the shoe press assembly comprises a beam (1), a shoe (2) passing through a press assembly (3, 5) is movably arranged on said beam (1) and has a pressing surface (21) comprising an upstream edge region (21A), an oil drain (4) with an inlet (41), said inlet ( 41) Arranged securely relative to said shoe (2), a plurality of drain pipes (48) and an outlet pipe (49), and a flexible belt (6) interacting with said shoe (2) ), characterized in that said inlet (41) is arranged in a container firmly connected to the shoe (2) in such a way that a large amount of said excess oil is sprayed directly into said inlet (41) , the output pipe (49) is firmly connected to the beam (1), and the first pipe portion (48A) of at least one oil drain pipe (48) is movably arranged relative to the output pipe (49). 14. The device according to claim 13, characterized in that the inlet (41) is arranged in a container, and the first pipe portion (48A) of the oil drain pipe (48) is firmly connected in a sealed manner onto the container, 15. Device according to claim 13, characterized in that the container comprises mutually enclosing wall elements on all sides and bottom (44). 16. The device according to claim 13, characterized in that said first pipe portion (48A) of said oil drain pipe (48) interacts with a sealing mechanism (48C), which seals at said inlet ( 41) and said outlet pipe (49) form a substantially airtight connection. 17. The device according to claim 16, characterized in that the sealing mechanism comprises a flexible pipe (48C), one end of which is sealingly connected to the periphery of the first pipe portion (48A) of the oil drain pipe, and the other One end is connected to an accessory firmly connected to said output pipe (49). 18. The device of claim 16, wherein said sealing mechanism is a rubber bellows. 19. Device according to claim 17, characterized in that said accessory comprises a tubular connection connected in a sealed manner to said outlet tube (49). 20. The device of claim 19, wherein said tubular connector is a metal tube. 21. Device according to claim 16, characterized in that said first pipe portion (48A) of the drain pipe (48) directly interacts at its end with a sealing mechanism via its outer surface. 22. The device according to claim 21, characterized in that said sealing mechanism comprises at least one O-ring, which is arranged on the inlet side (49A) of the oil drain pipe. 23. The device of claim 16, wherein the sealing mechanism is disposed between two retractably arranged parts so as to interact in a sealed manner. 24. Device according to claim 14, characterized in that a guide plate (42) is provided in the area between the lower limit surface (41A) of the inlet (41) and the shoe (2). 25. The device of claim 24, wherein the guide plate extends in a linear direction. 26. The device according to claim 13, characterized in that the shortest distance (S) between the upper surface (41B) of the inlet (41) and the inner surface (6A) of the belt is between 0-10 mm. 27. Device according to claim 26, characterized in that said shortest distance (S) is less than 5 mm. 28. The device of claim 14, wherein the container extends in the longitudinal direction to a length of 500 to 1500 mm. 29. The device according to claim 14, characterized in that the diameter of the first tube portion (48A) is 30 to 100 mm. 30. The device according to claim 29, characterized in that the diameter of the first tube portion (48A) is 50 to 70 mm. 31. Apparatus according to claim 28, characterized in that at least two such containers are arranged adjacent to each other inside said shoe press assembly.

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