Fabric insertion unit for fiber web machine and frame thereof

Abstract

The invention relates to a fabric insertion unit for a fiber web machine and a frame thereof. The frame (20) has internal channels (22) for the fluid, and one or more channels (22) are equipped with apertures (23). The frame (20) has an outer block (28) comprising an aperture (23) and a portion of a channel (22).

Description

Technical Field

[0001] The invention relates to a frame for a fabric insertion unit in a fiber web machine, the frame having an internal channel for a fluid, and one or more channels being provided with orifices. The invention also relates to a fabric insertion unit for a fiber web machine. Background Art

[0002] Chinese patent application publication number CN108221451 discloses a fabric insertion unit, which is a device for changing fabric in a fiber web machine. The fabric insertion unit comprises two relatively arranged transfer devices, which transfer devices comprise lifting means. The transfer devices have a frame with an internal channel for a fluid assembled in the lifting means. The channel is formed by several holes from several directions. Perforations are also required. In order to control the flow of the fluid, several orifices are used. Each orifice is installed deep in the channel.

[0003] Drilling the passages in the frame is laborious. In particular, the orifices require special and precise holes. Furthermore, according to the prior art, it is difficult to install the orifices and there is almost no space for the inlet joints. Moreover, when using cast frames, the casting may include pores, which may lead to leakage and pressure loss. In addition, due to the pores and carbides, other processing of the cast frame is also difficult and time-consuming. If any hole is damaged or the frame is damaged to some extent, the entire frame must be replaced. In addition, the perforation from one hole to another can damage the drill bit. Due to the perforation, metal fragments may remain in the passage. Impurities may cause damage to the seal of the lifting device or blockage of the orifice. Summary of the invention

[0004] The object of the present invention is to provide a new frame for a fabric insertion unit in a fiber web machine, which is more durable than before and is also easier and quicker to manufacture and maintain. The features of the frame according to the invention are as follows. With the new structure, fewer holes are required and drilling is easier than before. Furthermore, the installation of the openings is easy and the maintenance of the openings is quicker. Another object of the present invention is to provide a new fabric insertion unit in a fiber web machine, which is more reliable and easier to maintain than before. The features of the fabric insertion unit according to the invention are as follows. Leakages of fluids and pressures can be avoided and the functioning of the fabric insertion unit can be easily corrected if necessary. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The present invention is described in detail below with reference to the accompanying drawings, which show some embodiments of the present invention, in which:

[0006] Figure 1An example of a body of a press section of a fiber web machine, viewed from the side, is shown,

[0007] Figure 2a shows a complete fabric insertion unit ready to be attached to a fiber web machine,

[0008] Figure 2b A partial cross section of the fabric insertion unit is shown,

[0009] Figure 3a shows the framework of the transfer device,

[0010] Figure 3b A cross section of a block according to the invention with three different orifices is shown. DETAILED DESCRIPTION

[0011] Figure 1 An example of a press section of a fiber web machine, viewed from the tending side, is shown. The press section comprises a frame 10, which has several beam structures 11 and 12. The load is supported in particular by vertical beams, which can also be inclined. Here, the press section has two presses 13, each of which has two fabrics 14. The fabrics 14, which form an endless loop, are supported by rolls 15. The rolls are supported on the frame 10. Each fabric has to be replaced from time to time. Fiber web machines are, for example, paper machines, cardboard machines and pulping machines and belt calenders with replaceable fabrics. For example, the closed fabric loop comprises a wire on the web forming part and a felt and a belt on the press section of a fiber web machine.

[0012] In the embodiment shown, several fabric insertion units 16 are arranged on the operating side in the frame 10. A "fabric insertion unit" will be referred to as a "unit" in the following. The unit is used to change fabrics on a web forming machine and the unit is intended to be installed in the frame 10 of a web forming machine. Figure 1 In general the cells 16 are shown. In addition to the cells 16, the frame 10 also comprises spacers 17 which are removed when the fabric 14 is replaced.

[0013] Figure 2aA unit 16 according to the invention is shown disassembled from a frame of a fiber web machine. The unit 16 comprises two oppositely arranged transfer devices 18 for moving a fabric 14. Furthermore, the unit comprises a lifting device 19 for forming a transfer channel for the fabric 14 between the transfer devices 18. In practice, the transfer channel enables the fabric to pass through the frame of the fiber web machine. Furthermore, each transfer device 18 comprises a frame 20, which is adapted to be part of the lifting device. Furthermore, each frame is attached to the fiber web machine with a plurality of bolts 21. The lifting device functions by means of a pressurized fluid. For this purpose, the frame 20 has an internal channel 22 for the fluid, as provided in the lifting device 19. Figure 2b In addition, in order to control the flow of the fluid, one or more channels 22 are equipped with orifices 23 ( Figure 3b ).

[0014] exist Figure 2a In the embodiment shown in Figure 1, the units 16 are in production position and the transfer devices 18 are connected to each other on both edges by locking devices 24, here eye bolts. The locking devices prevent the frames from moving relative to each other during production and keep the frames together despite vibrations and loads. During production, an intermediate structure 25 is located between the frames, carrying the load from one frame to another.

[0015] When the fabric is changed, the locking device 24 is released. Then, the distance between the transfer device (more specifically, the frames of the transfer device) is increased using the lifting device. In practice, a sufficient lift is 0.5 mm to 10 mm. In this case, the frames are separated from each other, so that the intermediate structure 25 can be removed. In this way, a transfer channel is formed between the frames, so that the fabric can be transferred using the transfer device.

[0016] As mentioned above, the lifting device is arranged as part of the frame of the transfer device. More specifically, the lifting device comprises a pressure chamber located in the frame and defined by a pressure water seal. The seal has a rectangular perimeter with rounded corners and defines the pressure chamber together with a metal belt ring supported by a deflection roller. The deflection roller is attached to the frame and has a drive in one or more of the deflection rollers.

[0017] Advantageously, a fluid (for example water) is fed into the pressure chamber, which fluid simultaneously lubricates the seal sliding against the metal strip without contaminating the environment. Figure 2a As shown in , both frames have the same kind of channels and the lifting devices function identically. Figure 2b2 shows three channels 22 for pressurized water at the upper frame 20 and one channel 22 for leaking water at the lower frame 20. The first channel ends in a pressure chamber and the second channel ends in a groove 26 for a seal. The pressurized water pushes the seal against the metal band ring. The third channel ends in another groove 27 for the leaking water seal. The fourth channel is located between the above grooves 26 and 27. A portion of the fluid leaks and flows out of the frame. As the same structure, both frames include the above four channels.

[0018] According to the invention, each frame 20 has an external block 28 comprising the orifice 23 and a part of the channel 22. In this way, the holes provided to the frame can be simple and without any thread. In practice, the channel can be optimized without taking into account threads and holes. In addition, the block itself is small and easy to process. Moreover, the material of the block can be freely selected. Here, the block is attached to the frame by four bolts 21. In other words, the block 28 is detachably fixed to the frame 20. If necessary, each orifice can be easily changed when the block is removed.

[0019] Figure 3b A cross section of a block 28 is shown. Advantageously, the block 28 is arranged as a manifold comprising one main channel 29 for several channels 22. Thus, fluid can be supplied to several channels via a single inlet 30. In practice, the block 28 comprises one inlet 30 and one outlet 31. Figure 3b In the embodiment of the invention, the inlet 30 has no coupling for the pressurized fluid. Here, there are three different orifices 23. Thus, the fluid flow in each channel can be controlled independently. The basic structure of the orifices is the same, only the diameter of the central hole 32 is different. The larger the hole, the greater the flow. There is a thread 33 between the channel 22 and the hole 23. Thus, the orifice remains in place and is easy to release with standard tools.

[0020] like Figure 3a As shown, the surface of the frame 20 can be flat in the area of ​​the channels. This makes the processing of the frame easier. Then, there is a seal 34 for each channel 22 between the block 28 and the frame 20. Here, the seal is an O-ring seal. The seal can be a standard seal and each channel is firmly sealed. Using the external block according to the present invention, the number of cross bores can be reduced when the throttling regulation of the flow is achieved inside the external block forming the manifold. The block significantly reduces the processing of the frame and the assembly time of the unit. Now, the orifice is screwed onto the surface of the external manifold. Therefore, the orifice is easy to install and replace. At the same time, the entire unit is more reliable and easier to maintain and adjust. The same manifold can be used in units of different sizes.

[0021] In addition to the unique blocks, the structure of the frame is also new. Now, the frame 20 consists of two plates 35 arranged one above the other. First of all, the plate is cheap, but has a uniform quality and it is easy to process. Advantageously, all channels 22 are contained in one plate 35. Here, the channels are located in the thicker plate. In addition, the grooves for the seals of the pressure chambers are located in the same plate. Each plate can be processed independently. However, the final processing is completed when the plates are fixed to each other. In general, the frame can consist of one, two or more plates. Here, a frame consisting of two plates is shown as an advantageous embodiment.

[0022] In practice, the plate 35 is made of stainless steel or acid-resistant steel. Steel is easy to process, the material is strong and corrosion-resistant. In addition, one or more channels can consist of grooves machined on the surface of the plate. Therefore, even fewer holes are needed. Similar to iron, aluminum is also a feasible material with a suitable anti-corrosion coating. In addition, the plate can be a 3D printed part. Composites with fiber reinforcement can also be used.

[0023] In the illustrated embodiment, the panels 35 are bolted together using ten bolts. Figure 3a In the figure, the joints between the plates are represented by dotted lines. Other fixing methods may also be used, such as welding, interference fit, riveting or bonding. In addition, the friction between the plates is increased in one or more ways (for example, by using chemicals or coatings in one or more metal parts). The surfaces may also be processed to increase roughness or even to form a form fit. In addition, friction pads or the like may be used, and the plates may be made of different materials in the first place. With the increase in friction or other structures, sliding between the plates may be reduced or even prevented. In this way, the plates will not bend as much. Therefore, smaller or fewer bolts are required.

[0024] Figure 3a Two keys 36 are shown, which are arranged in the joint between the plates to prevent sliding between the plates. More generally, there are one or more keys 36 between the plates 35. Advantageously, the one or more keys 36 are oriented parallel to the interface between the plates 35. Thus, the strength of the key can be utilized. One or more round pins 37 can be used to replace the rectangular key shown sideways.

[0025] By using plates, there are no pores or fractions inside the frame. Therefore, machining of the frame is fast and easy without damaging the drill. Furthermore, casting of the frame would take months, while machining of the plates would take only weeks. Furthermore, the quality is improved and the manufacturing cost will be lower than before.

Claims

1. A frame for a fabric insertion unit in a fiber web machine, said frame (20) having an internal channel (22) for a fluid, and one or more of said channels (22) being provided with an orifice (23), characterized in that The frame (20) has an outer block (28) which includes the aperture (23) and a portion of the passage (22).

2. The frame according to claim 1, characterized in that The block (28) is detachably fixed to the frame (20).

3. The frame according to claim 1 or 2, characterized in that: A seal (34) is provided between the block (28) and the frame (20) for each channel (22).

4. The frame according to any one of claims 1 to 3, characterized in that The block (28) is arranged as a manifold comprising one main channel (29) for several channels (22).

5. The frame according to any one of claims 1 to 4, characterized in that A thread (33) is provided between the passage (22) and the orifice (23).

6. The frame according to any one of claims 1 to 5, characterized in that The block (28) includes an inlet (30) and an outlet (31).

7. The frame according to any one of claims 1 to 6, characterized in that The frame (20) is composed of two or more panels (35) stacked one above the other.

8. The frame according to claim 7, characterized in that All of the channels (22) are included in one of the plates (35).

9. The frame according to claim 7 or 8, characterized in that One or more of the channels (22) are formed by grooves machined into the surface of the plate (35).

10. A frame according to any one of claims 7 to 9, characterized in that One or more keys (36) are provided between the plates (35).

11. The frame according to claim 10, characterized in that One or more of the keys (36) are oriented parallel to the interface between the plates (35).

12. A frame according to any one of claims 7 to 11, characterized in that Each plate member (35) is made of stainless steel or acid-resistant steel.

13. A frame according to any one of claims 7 to 12, characterized in that The panels (35) are bolted together.

14. A fabric insertion unit for a fiber web machine, the fabric insertion unit (16) being arranged to be mounted in a frame (10) of the fiber web machine, and the fabric insertion unit (16) comprising two oppositely arranged transfer devices (18) for transferring a fabric (14), and further comprising a lifting device (19) for forming a transfer channel for the fabric (14) between the transfer devices (18), wherein the transfer device has a frame (20) having internal channels (22) for a fluid provided in the lifting device (19), and one or more of the channels (22) are provided with orifices (23), characterized in that Each frame (20) has an outer block (28) which includes the aperture (23) and a portion of the channel (22).

15. The fabric insertion unit according to claim 14, characterized in that Each frame (20) is a frame according to any one of claims 2 to 13.

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