Water and air separation device for removing air from white water spray

Abstract

The invention relates to a water and air separation device (100) comprising: an intake section (10) having an intake opening (11); a guiding section (20) comprising a housing (24), a separation chamber (40), an inlet (21), a plurality of guiding channels (12) for transporting a white water spray into the separation chamber, a liquid outlet (22), a gas outlet (23), and wherein the guiding section (20) further comprises a first separation plate (41) arranged to divide the separation chamber (40) into a first section (A) and a second section (B), thereby forming a connection passage (46) for allowing white water to enter into the second section (B) below the first separation plate (41) and thereby separate the white water from the air of the white water spray.

Description

Water and air separation device for removing air from white water spray Technical Field

[0001] This invention relates to a water and air separation device for removing air from a white water spray ejected from the forming wire in the forming section of a paper machine. The invention also relates to a paper machine incorporating such a water and air separation device. Background Technology

[0002] Paper, tissue paper, paperboard, and other products are typically made from suspensions (e.g., suspensions of cellulose in water). These suspensions can be described as pulp. The forming section of a paper machine used to manufacture tissue paper, paper, or paperboard typically includes a headbox that injects pulp between the loops of a forming wire (e.g., a perforated wire or cloth) and the loops of a fabric (e.g., felt or another forming wire), the loops of which are driven around guide rolls, and the loops of which are typically driven around forming rolls. Forces applied to the pulp (e.g., via the headbox, forming wire, fabric, or rolls) cause water to pass through the forming wire, trapping the suspended material on the forming wire to form a web (e.g., a cellulose web) between the forming wire and the fabric. Water from the pulp (often referred to as white water) is sprayed through the forming wire. This white water jet or spray is typically collected and reused.

[0003] To reuse this spray of white water, a significant amount of entrained air needs to be removed from the water. Typically, the spray is slowed and collected to create a flowing stream of liquid water in a so-called trough. The trough usually consists of relatively long channels (typically several meters long) through which water flows relatively slowly, allowing air bubbles to rise to the surface before the water is reused. The trough and the adjacent structures designed to calm the water and allow air bubbles to escape are often referred to as the calming section.

[0004] In some paper machines, a turbine is provided to recover the energy from the white water ejected from the forming section. This is advantageous from an energy efficiency point of view, but it also has the following disadvantages: a larger amount of air is mixed into the white water, making it more difficult to stabilize the white water in the water tank of the stabilization section.

[0005] When processing white water spray, an inlet section is typically provided to receive the spray from a forming section (and optionally from a turbine arranged between the inlet and forming sections). The white water is then allowed to enter a guide section through multiple channels from the inlet section, where it is deflected to slow down and discharged into a stabilizing section via an outlet. By providing deceleration in the guide section, the stabilization of the white water in the tank is improved. Several prior art techniques exist that provide a guide section that attempts to further improve the stabilization of the white water by separating air from the spray, making air removal in the stabilizing section easier and more efficient. However, a problem with the prior art is the low efficiency of air separation, or even the risk of more thorough mixing of air and white water due to the design of the guide section, resulting in lower stabilization efficiency and greater complexity. This is particularly problematic when using a turbine to recover energy from the white water, as the turbine's operation causes a large air stream to follow the white water into the inlet section, increasing the risk of white water contamination in the guide section.

[0006] Therefore, improvements are needed in this area. Summary of the Invention

[0007] The object of the present invention is to eliminate or at least minimize the aforementioned problems. This is achieved by a water and air separation device according to the present invention and a papermaking machine including said water and air separation device.

[0008] A water and air separation device is adapted to remove air from a white water spray ejected from the forming wire in the forming section of a paper machine. The water and air separation device includes an inlet having a receiving inlet for receiving the white water spray comprising white water and air, and a guide portion for guiding the white water from the inlet to a stationary section. The guide portion includes a housing, a separation chamber within the housing, and an inlet in the front side of the housing. Furthermore, the guide portion includes a plurality of guide channels extending from the receiving inlet of the inlet through the inlet of the guide portion into the separation chamber for conveying the white water spray into the separation chamber. Each of the plurality of channels includes a deflecting downstream portion for deflecting the white water spray.

[0009] The guide section also includes a liquid outlet connected to the housing for discharging white water from the separation chamber, and a gas outlet connected to the housing for allowing air to escape from the separation chamber. Furthermore, the guide section includes a first separation plate arranged to extend downwards from the upper end of the separation chamber into the chamber, dividing the chamber into a first section adjacent to the front and a second section adjacent to the rear, the rear side being opposite to the front side. The first separation plate has a first height along a vertical axis that is less than the height of the chamber along the vertical axis, thereby forming a connecting passage to allow white water to enter the second section below the first separation plate, and thereby separating the white water from the air sprayed with white water.

[0010] The main advantage of this invention is that the first separation plate, provided in the manner described above, allows water to enter the second section while largely preventing air from entering the second section and instead retaining it in the first section. Since water has a higher density than air in a water spray, water entering the separation chamber through the guide channel causes it to flow along the lower part of the guide channel, while air flows above the water. The separation plate then largely blocks air from entering the second section, thus preventing air from mixing with water inside the guide section. This allows air to be effectively removed through the gas outlet, while allowing water to exit through the liquid outlet and reach the stabilization section. By thereby reducing the amount of air mixed into the water, the stabilization of the water downstream of the guide section in the stabilization section is made more efficient.

[0011] Suitablely, the first height of the first separation plate is 0.5 to 0.9 times the height of the chamber, preferably 0.6 to 0.7 times the height of the chamber. This achieves a connection passage of appropriate height, allowing the white water sprayed from the white water spray to enter the second section, while preventing most of the air from the white water spray that is not mixed with the white water from entering the second section. This helps ensure the separation of white water and air.

[0012] Furthermore, the first separation plate may have a front surface facing the front of the separation chamber, wherein the front surface extends at a first angle relative to the vertical axis, the first angle being in the range of 5° to 45°, preferably in the range of 10° to 20°. Therefore, wear and damage to the first separation plate due to water impact can be reduced, and a longer lifespan and more reliable operation of the first separation plate can be ensured.

[0013] The separation chamber can also have an average width from front to back, and the second section can have a width of 0.05 to 0.6 times the average width of the separation chamber. This is beneficial in allowing the second section to be appropriately sized so that white water can be contained within it.

[0014] Furthermore, the guiding section may include a second separating plate arranged to extend downward from the upper end of the separating chamber into the first section, and the second separating plate further extends along the front side through the upper part of the outlet of the guiding channel. Therefore, white water can be more effectively guided towards the channel below the first separating plate.

[0015] Appropriately, the second separation plate includes multiple plate openings for allowing air to pass through it. Therefore, by allowing air passing through the upper part of the guide channel to enter through the second separation plate, air can be separated from white water more effectively, and thus the risk of that air mixing into the white water is reduced.

[0016] Furthermore, at least some of the plurality of plate openings can be adjustable. This facilitates adjusting the flow of air inside the guide section by allowing larger or smaller amounts of air to enter the openings of the second separation plate.

[0017] Suitablely, the second separation plate has a second height along the vertical axis, which is less than the first height of the first separation plate. This facilitates the passage of white water beneath the second separation plate and reduces wear on the second separation plate.

[0018] The guide section may also include a sealing plate arranged to extend downward from the upper end of the separation chamber into the first section and combine with a second separation plate to form a third section defined by the second separation plate, the sealing plate, and preferably the upper end of the separation chamber, and the third section may be in fluid communication with a gas outlet. This facilitates allowing air that has entered the third section to exit the guide section through the gas outlet without the risk of further mixing of the air with white water.

[0019] Furthermore, the third section may include a discharge section for draining white water from the third section, the discharge section preferably being arranged at a distance from the inlet of the guide section. This allows any white water that may have ended up in the third section to be discharged in a convenient and reliable manner.

[0020] Appropriately, the sealing plate also includes multiple second plate openings to allow air to enter the third section. This allows air from the first section to also enter the third section, making air removal through the gas outlet more efficient.

[0021] Each guide channel can have a guide channel width in the upstream portion of the inlet section, and the deflection downstream portion of each channel can be formed by a deflection portion of the guide channel wall in the downstream portion, which deflects at least the guide channel width in the lateral direction. Therefore, it is ensured that white water entering the guide channel across its entire width comes into contact with the deflection portion, thus deflecting the white water. This deflection, in turn, facilitates the passage of white water towards the liquid outlet.

[0022] The plurality of guide channels can be formed by multiple plates spaced apart from each other. This is an effective and reliable way to ensure the formation of guide channels for delivering white water spray into the guide section.

[0023] Alternatively, the plurality of guide channels can be formed by a plurality of pipes or fittings. This is an effective and reliable way to provide guide channels and deliver white water spray into the guide section.

[0024] Appropriately, the housing of the guide section also includes at least one additional inlet in the second section of the separation chamber for introducing additional white water from outside the housing into the separation chamber. Thus, white water that fails to enter the receiving inlet of the entry section but ends up on top of the housing of the guide section can be reliably and conveniently introduced into the guide section.

[0025] Appropriately, the turbine can also be arranged to connect to a receiving inlet of the inlet section, so that the white water spray passing through the turbine is received by the receiving inlet. This facilitates the recovery of energy from the white water and keeps the energy consumption for manufacturing paper, tissue paper, or paperboard low.

[0026] Additionally, the first separation plate can be attached to the rear plate, which extends from the lower end of the first separation plate to the upper end of the separation chamber, and the rear plate can be curved. This helps ensure a stable flow of white water that has entered the second section and has been deflected upward by the rear wall of the separation chamber, allowing the white water to be guided downward again to control turbulence without causing excessive wear on the first separation plate.

[0027] Furthermore, the separation chamber may have a first end and a second end, the first end being adjacent to the inlet, and the liquid outlet and gas outlet being closer to the second end rather than closer to the first end. A first separation plate may further extend from the first end toward the second end through the separation chamber, reaching at least to or even beyond the gas outlet. This helps prevent white water from mixing with air in the first or third section, thereby making the separation of white water and air more reliable.

[0028] Suitable, the water and air separation device also includes a stabilizing section connected to the liquid outlet of the guide section, allowing white water discharged through the liquid outlet to enter the stabilizing section. This facilitates stabilization of the white water that has passed through the guide section, thereby allowing any air mixed in the white water to escape as bubbles from the stabilizing section.

[0029] The present invention also relates to a paper machine comprising at least one water and air separation device.

[0030] From the following detailed description, those skilled in the art will readily understand the many additional benefits and advantages of the present invention. Attached Figure Description

[0031] The invention will now be described in detail with reference to the accompanying drawings, in which:

[0032] Figure 1 shows a perspective view of a water and air separation device according to a first embodiment of the present invention;

[0033] Figure 2 shows a plan view of the water and air separation device of Figure 1 as viewed from the first end;

[0034] Figure 3 shows a perspective view of the water and air separation device of Figure 1 viewed from above;

[0035] Figure 4 shows a perspective view of the water and air separation device of Figure 1 viewed from above;

[0036] Figure 5 shows a plan view of the inlet section of the water and air separation device in Figure 1, viewed from above.

[0037] Figure 6 shows a perspective view of the second end of the water and air separation device of Figure 1, viewed from above.

[0038] Figure 7 shows a perspective view of the first end of the water and air separation device of Figure 1, viewed from above.

[0039] Figure 8 shows a perspective view of the water and air separation device of Figure 1 viewed from the second end.

[0040] Figure 9 shows a perspective view of the water and air separation device of Figure 1, viewed from the lower second side, and...

[0041] Figure 10 shows a plan view of the water and air separation device of Figure 1 as viewed from the first end, illustrating the flow of water and air.

[0042] All accompanying drawings are schematic and not necessarily to scale, and generally only show the parts necessary to explain the corresponding embodiments, while other parts may be omitted or are merely suggested. Unless otherwise specified, any reference numerals appearing in multiple drawings indicate the same object or feature in all drawings. Detailed Implementation

[0043] The water and air separation device 100 according to the present invention will now be described with reference to various embodiments.

[0044] The water and air separation device 100 is a treatment device suitable for receiving white water spray from the forming section of a paper machine during the production of paper, paperboard or tissue paper.

[0045] Since the machines and processes used to manufacture paper, paperboard, or tissue paper are well known in the art, they will not be described in detail herein. It will only be described that the headbox typically injects pulp into the press section formed in the forming section of a paper machine, and white water from the pulp, after passing through the press section, is sprayed at high speed through the forming wire along with an airflow formed by the movement of rolls pressing against each other in the press section. The resulting white water spray and airflow, including the air-mixed white water, are captured by a water and air separator 100, as will be described in more detail below, and optionally pass through a turbine just before entering the water and air separator 100 to recover kinetic energy from the white water.

[0046] White water is defined herein as water and particles from the slurry that do not adhere to the formed fabric after the forming press and are therefore ejected from the formed fabric and forming web. Typically, the particles in white water are cellulose, but can also be other particles and fragments from other materials already present in the slurry. The term white water as used herein also includes air mixed with water such that the water and air together form a liquid that holds the bubbles.

[0047] White water spray is defined herein as white water and airflow that are sprayed together from the forming section and / or flow together into the water and air separation device 100. The air in the white water spray is unbound air that forms the airflow, which is transported together with the white water but does not mix sufficiently with the white water to form part of the liquid. Instead, it forms two separate fluids, namely white water and air, which flow together but each maintains its separate properties.

[0048] For the water and air separation device of the present invention, the terms upstream and downstream are defined relative to the flow of white water in the device during use. This means that the component located upstream is the component that the white water passes through before reaching another component located downstream.

[0049] Figure 1 discloses a water and air separation device 100 according to a first embodiment of the present invention, including an inlet portion 10 having an elongated receiving inlet 11, which is typically arranged to connect with the forming section of a paper machine during use. The receiving inlet 11 suitably has a length that is at least the width of the web formed on the forming fabric and forming wire in the paper machine, and therefore the length of the receiving inlet 11 may vary depending on the paper machine used with the water and air separation device 100. However, the primary purpose of the receiving inlet 11 is to be able to receive as much white water spray as possible from the forming section.

[0050] The water and air separation device 10 also includes a guide section 20 connected to the inlet section 10, such that a white water spray entering the receiving inlet 11 is conveyed into a separation chamber 40 inside the guide section 20. For this purpose, the guide section 40 includes an inlet 21 located in the front side 26 of the housing 24, and this inlet 21 is connected to the receiving inlet 11 of the inlet section 10, allowing white water to be conveyed into the separation chamber 40. A plurality of guide channels 12 are provided, extending from the receiving inlet 11 through the inlet 11 of the guide section 20 and into the separation chamber 40, and each guide channel includes a downstream deflection portion 142 for deflecting the white water spray to guide it toward a liquid outlet 22 through which the white water is discharged from the guide section 20. Suitably, as shown in FIG1, the liquid outlet 22 is connected to a static stabilizer 30; however, in some embodiments, the liquid outlet 22 may instead be connected to another component for receiving white water, such as a pipe, conduit, or any other suitable component.

[0051] The guide channel is defined by a guide channel wall 13, which in a first embodiment includes a downstream deflection portion 142, which will be described in further detail below (see Figure 5).

[0052] The guide section 20 also includes a gas outlet 23 for removing air from the guide section 20, which is suitably connected to a chimney 231 or other channel or duct for reliably and conveniently delivering air from the guide section 20.

[0053] Inside the separation chamber 40 of the guide portion 20, a first separation plate 41 extending downward from the upper end 28 within the separation chamber 40 is also provided. In some embodiments, the first separation plate 41 may be attached to the inner wall of the housing 24, but in other embodiments it may be integrally formed with the housing 24, or it may be mounted on another part of the guide portion 20, as long as the first separation plate 41 can extend into the separation chamber 40. The first separation plate 41 is elongated and extends from a first plate end 411 at the first end 201 of the separation chamber 40 toward the second end 202 of the separation chamber 40. In some embodiments, the first separation plate 41 may extend all the way to the second end 202, but in other embodiments the separation plate 41 may alternatively have an end 412 that is a distance away from the second end 202. The first end 201 is the upstream end of the separation chamber 40 located between the front side 26 and the rear side 27. The second end 202 is the downstream end of the separation chamber opposite to the first end 201. Therefore, the first end 201 is closer to the inlet 21 than the second end 202.

[0054] In the first embodiment of FIG1, a second separation plate 44 is also disposed inside the separation chamber 40 and configured to extend from the guide channel 12 along the inlet 21 through the outlet 15. In this embodiment, a sealing plate 45 is also attached to the lower end of the second separation plate 44, and both the second separation plate 44 and the sealing plate 45 are mounted to the upper end 28 of the separation chamber 40 in a manner similar to that of the first separation plate 41.

[0055] The water and air separation device 100 is also provided with at least one, but preferably multiple, additional inlets 25 through which white water spray that is not captured by the receiving inlet 11 but reaches the upper side of the housing 24 can be guided into the separation chamber 40.

[0056] Figure 2 discloses a water and air separation device 100 viewed from the first end 201, and shows a first separation plate 41 extending inside the separation chamber 40 to define a first section A and a second section B. The first section A is adjacent to an inlet 21 in the front side 26, while the second section B is adjacent to a rear side 27 opposite to the front side 26. A connecting passage 46 is formed between the first section A and the second section B below the first separation plate 41 to allow white water to enter the second section B. A gas outlet 23 is operatively connected to at least the first section A in such a way that air can flow from the first section A to the gas outlet 23.

[0057] The first separating plate 41 has a front surface 42 facing the front side 26 of the guide portion 20 and arranged at a first angle α with the vertical axis V. The first angle α is in the range of 5° to 45°, preferably in the range of 10° to 20°. This is to provide sufficient strength to the first separating plate 41 so that damage caused by white water entering the inlet 21 and impacting the front surface 42 can be reduced or even minimized. The first angle α can vary within the range given above and can be adjusted in conjunction with the flow direction of white water leaving the guide channel 12, so that as much white water as possible is allowed to enter the connecting passage 46 and properly does not impact the front surface 42 of the first separating plate 41. For this purpose, it is suitable that the first height h1 of the first separating plate 41 in the vertical direction along the vertical axis V is in the range of 0.5 to 0.9 times the chamber height ch, preferably in the range of 0.6 to 0.7 times the chamber height ch.

[0058] The vertical axis V is the vertical axis when the guide portion 20 is in a position with its lower side 29 facing downwards, that is, the axis that is substantially vertical when the guide portion is arranged to be used in conjunction with a paper machine.

[0059] In a first embodiment, a first separation plate 41 is attached to a rear plate 43, which extends from the lower end 413 of the first separation plate 41 to the upper end 28 of the separation chamber 40. In some embodiments, the first separation plate 41 and the rear plate 43 may be integrally formed, or may comprise a single structure having a front surface and a rear surface, the front surface being shaped as the front surface 42 of the first separation plate 41 of FIG. 1, and the rear surface being shaped as the rear plate 43 of FIG. 1. Other designs of the first separation plate 41 may also fall within the scope of the invention.

[0060] The rear plate 43 is appropriately curved such that white water impacting the rear side 27 of the separation chamber 40 and deflected upward toward the upper end 28 is then guided downward back along the curved rear plate 43 toward the lower side 29. This allows for the treatment of white water, thereby reducing wear on the first separation plate 41. Appropriately, the lower end 413 of the first separation plate 41 is also curved or angled toward the rear side 27, so that white water is further guided downward toward the rear side 27.

[0061] As shown in Figure 2, one or more additional inlets 25 are provided in the upper part of the second section B, allowing additional white water that has not entered the water and air separator 100 through the receiving inlet 11 to be inserted into the second section B. Suitablely, the additional inlets(s) 25 are arranged at an angle to the flow direction of the white water in the second section B, thereby drawing white water into the second section B through the existing white water flow. The additional inlets may have caps to prevent undesirable discharge from the separation chamber 40 through the additional inlets 25. In the first embodiment shown herein, the additional inlets 25 are angled so that their openings open into the separation chamber facing the liquid outlet 22.

[0062] The separation chamber 40 has an average width w from the front side 26 to the rear side 27. a Furthermore, the second segment B has an average second segment width w from the connecting passage 46 to the rear side 27. B The average width of the second segment is the average width w. a 0.05 to 0.6 times. In various embodiments of the invention, the average second segment width w of the second segment B. B The dimensions can be adjusted according to the size of the guide section 20 and the overall size of the water and air separation device 100, and can also be adjusted according to the magnitude of the white water flow to be used by the water and air separation device 100. In some embodiments, the average second segment width w used to determine the second segment B B The main criterion is that the white water flow entering the separation chamber 40 can enter the second section and flow in a suitable manner, as will be explained below with reference to Figure 10.

[0063] In the first embodiment shown in Figure 2, a second separating plate 44 is also provided, and the second separating plate is arranged to protrude from the upper end 28 in the first section A. Suitably, the second separating plate 44 is arranged to connect to the downstream end of the guide channel 12 and cover the upper part of the inlet 21, i.e., the outlet 15 of the guide channel 12, such that the white water spray impacting the second separating plate 44 is deflected downwards in the first section A of the separating chamber 40. This is advantageous in ensuring that the white water flow is guided into the connecting passage 46 to reach the second section B, and it is also advantageous for this purpose that the second separating plate 44 has a second height h2 along the vertical axis V, which is less than the first height h1 of the first separating plate 41. It is also advantageous if the second separating plate 44 forms a second angle β with the vertical axis V, wherein the second angle β is in the range of 10° to 60°, preferably in the range of 30° to 50°. It is also advantageous if the second angle β is greater than the first angle α, so that the white water is effectively deflected downwards toward the connecting passage 46 below the first separating plate 41. By providing the second separation plate 44 at a second angle β, the white water in contact with the second separation plate 44 will be deflected downward into the separation chamber 40, preventing turbulence that would otherwise be caused by the white water flowing upstream toward the inlet portion 10.

[0064] The second separation plate 44 is connected to the sealing plate 45, which extends from the upper end 28 of the separation chamber 40 and engages with the second separation plate 44 at its lower end 442. The second separation plate 44 and the sealing plate 45 may be made of two separation plates joined together by any suitable means, or alternatively may be made of a single structure, integrally formed with the housing 28, or designed in any other suitable manner. A third section C is formed by the second separation plate 44 and the sealing plate 45. In some embodiments, the third section C may also be defined by the upper end 28 of the separation chamber 40, but in other embodiments, the third section C may alternatively be connected at its upper end to an elongated gas outlet or any other space or conduit in which air may be delivered. The third section C is also arranged in fluid communication with the gas outlet 23, such that air in the third section C may be delivered from the guide portion 20 through the gas outlet 23.

[0065] Figures 3 and 4 disclose a water and air separation device 100 viewed from above, to more clearly show the guide channel 12 defined by the channel wall 13, as well as the second separation plate 44 and the sealing plate 45. In this first embodiment, the second separation plate 44 includes a plurality of plate openings 441 through which water spray (particularly the air of the water spray) can be allowed to enter the third section C from the guide channel 12. Furthermore, the sealing plate 45 includes a plurality of second plate openings 451 through which the air of the water spray in the first section A is allowed to enter the third section C. In some embodiments, at least plate opening 441, but optionally a second plate opening 451, is adjustable, for example, by means of a plate section without openings that is movable along the second separating plate 44 and optionally also along the sealing plate 45, or by means of a movable plate section with matching openings. Thus, plate openings 441, 451 can be fully open, fully closed, or partially open by the openings of the plate sections perfectly matching, completely mismatching, or partially matching the openings of the second separating plate 44 and optionally the openings of the sealing plate 45. Furthermore, in some embodiments, all plate openings 441, 451 may be adjustable, while in other embodiments, all plate openings 441, 451 are adjustable. In some embodiments, the second separating plate 44 or the sealing plate 45, or both, may be without openings, allowing airflow to be directed through the second separating plate 44 or the sealing plate 45 into the third section C, or allowing airflow to be retained in the first section A.

[0066] Gas outlet 23 is operatively connected to both first segment A and third segment C to form a fluid connection in which air can flow; however, in some embodiments, gas outlet 23 may alternatively be in fluid communication only with first segment A. In embodiments that include both first segment A and third segment C, first segment A may also be in fluid communication with gas outlet 23 via third segment C.

[0067] Figures 3 and 4 disclose a guide channel 12 with a channel wall 13 and a deflection downstream portion 142 at the downstream end of the guide channel 12, which is disposed within or connected to the separation chamber 40. In a first embodiment, the guide channel 12 is made of a plurality of plates spaced apart to form the channel wall 13. The plurality of plates may be arranged parallel to each other or in any other manner, provided that the guide channel 12 is formed such that a white water spray can enter the separation chamber 40 along the guide channel 12. In some embodiments, the plurality of plates may be arranged substantially vertically, i.e., parallel to the vertical axis V, but in other embodiments, the plurality of plates may alternatively be arranged at an angle to the vertical axis V. Moreover, the plurality of plates may be flat or curved and may form a channel having a rectangular cross-section, a triangular or circular cross-section, or a honeycomb cross-section or any other suitable shape. Moreover, in some embodiments, the guide channel 12 may alternatively be formed of pipes or fittings arranged together to form the plurality of guide channels 12.

[0068] In the first embodiment, it is advantageous that the guide channels 12 are arranged side by side, but not overlapping each other. This has the following benefits: making the guide channels 12 elongated in the vertical direction allows the white water spray to flow along the guide channels 12, wherein, due to the density difference between white water and air, the white water flows near the bottom of the guide channels 12, while the free air from the white water spray flows above the white water. This is particularly advantageous in improving the entry of white water into the connecting passage 46 and preventing air from following into the second section B.

[0069] Figure 5 discloses the entry portion 10 from above, which more clearly shows the guide channel 12 and the channel wall 13 defining the guide channel. Each guide channel 12 has a channel width cw in the upstream portion 131, and in some embodiments, the channel width cw is the same for each guide channel 12, but in other embodiments, the channel width cw can vary, such that some guide channels 12 are wider than others. Additionally, in some embodiments, the channel width cw can be constant along a guide channel 12 from the upstream portion 131 to the downstream portion 141, but in other embodiments, the channel width cw of the guide channel 12 can alternatively vary.

[0070] In the downstream portion 141, a deflecting downstream portion 142 is formed, wherein at least one of the guide channel walls 13 is deflected, i.e., it proceeds in the upstream portion 131 in a direction at an angle to the guide channel wall 13. The purpose of the deflecting downstream portion 142 is to deflect the flow of the white water spray so that it is guided at an angle toward the rear side 27, rather than impacting the rear side 27 in a direction perpendicular to the wall of the rear side 27. This is advantageous in that it stabilizes the white water spray and guides it toward the liquid outlet 22, facilitating the discharge of white water through the liquid outlet 22, and improving the stability of the white water in the subsequent stabilizing portion 30 downstream of the guide portion 20.

[0071] The downstream deflection portion 142 of the guide channel wall is configured to deflect a distance d in a lateral direction, which is perpendicular to the longitudinal direction, which is also the flow direction in the upstream portion 131 of the guide channel 12. It is advantageous if this distance d is equal to or greater than the channel width cw of the guide channel 12. This has the benefit of ensuring the deflection of the entire flow of white water spray, and particularly the white water flow. The downstream deflection portion 142 of the guide channel wall 13 can be integrally formed with the remainder of the guide channel wall 13, or alternatively formed by a separate section 14 fastened to the upstream portion of the guide channel wall 13. This advantageously ensures the strength of the guide channel wall 13 to avoid joints along its length. However, in some embodiments, it is also advantageous to provide the material for the downstream deflection portion 142 with a higher strength than the upstream portion of the guide channel wall 13, thereby enabling it to withstand the forces exerted by white water on the downstream deflection portion 142.

[0072] As can also be seen in Figures 3 to 5, the gas outlet 23 and the first separation plate 41 are arranged relative to each other such that the end 412 of the separation plate 41 is closer to the second end 202 of the guide portion 20 than the gas outlet 23, or at least the end 412 of the separation plate 41 is as close to the second end 202 as the gas outlet 23. This helps to ensure that white water in the second section B is prevented from entering the gas outlet 23. This is also shown more clearly in Figure 6, where the gas outlet 23 is shown specifically relative to the first separation plate 41.

[0073] Figure 7 shows a second separation plate 44 and a sealing plate 45 with a plate opening 441, which together form the third section C. Furthermore, the first section A is shown as being defined by the inlet 21, the second separation plate and the sealing plate, and the lower end 29 of the first separation plate 41 and the separation chamber 40. Additionally, Figure 7 shows a second section B defined by the rear plate 43, the rear side 27, and the lower end 29. As shown in Figures 3 to 5 and Figure 6, each of the first section A, the second section B, and the third section C extends from the first end 201 of the guide portion 20 toward the second end 202 of the guide portion 20, thus forming an elongated section in which the white water spray is delivered to the liquid outlet 22 and the gas outlet 23. During use, the second section B will primarily retain white water mixed with air, while the third section C will primarily retain air, and the first section A will retain both white water and air. When the water spray enters the water and air separation device 100, some air is mixed into the water, but there is also an airflow that forms part of the water spray but does not actually mix into the water in a way that prevents the water from separating from the airflow. By designing the separation chamber 40 to be located inside the guide section 20, the airflow of the water spray is separated from the water and the air mixed into it. This helps remove most of the total amount of air present in the water spray and makes separation in the stabilizing section 30 easier and more efficient, as only the air mixed into the water needs to be separated from the water itself in the stabilizing section 30. Therefore, although many guide sections according to the prior art actually provide a more thorough mixing, resulting in the water containing more air after passing through the guide section, the present invention is able to remove a large amount of air from the water spray that is not mixed into the water itself.

[0074] Figure 8 shows the inlet portion 10 and the guide portion 20 as viewed from the second end 202, specifically illustrating the construction of the first separation plate 41 and the second separation plate 44 having a first section A, a second section B, and a third section C. Furthermore, Figure 8 shows the discharge portion 47 from the third section C, which allows white water that has entered the plate opening 441 or the second plate opening 451 to exit the third section C.

[0075] Figure 9 also discloses the water and air separation device 100 as viewed from the second end 202 of the guide section 20, and shows both the discharge section 47 and the gas outlet 23 more clearly. Advantageously, the discharge section 47 is positioned closer to the second end 202 than the gas outlet 23, or at least at the same distance from the second end 202 as the gas outlet 23, such that fluid is discharged from the third section C, and air is removed from the guide section 20 downstream of the third section.

[0076] Figure 10 illustrates a water and air separation device 100 according to a first embodiment, wherein the flow of water is indicated by arrows, and the flow of air is indicated by dashed arrows. A turbine 60 is also provided, which in some embodiments may be arranged to connect to a receiving inlet 11, allowing white water spray that has passed through the turbine 60 to enter the receiving inlet 11.

[0077] Water will flow at the lower part of each guide channel 12 and enter the separation chamber 40 near its lower end 29. After passing through the connecting passage 46, the water is then deflected upward along the rear wall 27 and guided downward back along the curved side of the first separation plate 41. Simultaneously, the air sprayed with water will pass through the upper part of each guide channel 12, and some air will enter the third section C through the plate opening 441, while some air will instead enter the first section A and be deflected upward along the first separation plate 41 and enter the third section C through the second plate opening 451. A small amount of air may also enter the first section A and remain there, or enter the third section C through the second plate opening 451 closer to the second end 202 of the guide portion 20.

[0078] In some embodiments, air may be propelled by an air delivery device (such as a fan) to exit the guide section 20 through a gas outlet 23, which is connected to or further disposed within a chimney or duct 231. However, in other embodiments, air may not be forced to leave the guide section 20 by an air delivery device, but may instead flow due to the entry of more white water spray into the separation chamber 40 through the inlet section 10.

[0079] It should be noted that the features from the various embodiments described herein can be freely combined unless explicitly stated that such combination is inappropriate.

Claims

1. A water and air separation device for removing air from a white water spray ejected from the forming wire in the forming section of a paper machine, said water and air separation device (100) comprising: - An inlet portion (10) having a receiving inlet (11) for receiving a white water spray including white water and air; - A guide portion (20) for guiding white water from the inlet portion to a stationary portion, the guide portion (20) comprising: - a housing (24); - a separation chamber (40) located within the housing; - an inlet (21) located in the front side (26) of the housing; - a plurality of guide channels (12) extending from the receiving inlet (11) of the inlet portion (10) through the inlet (21) of the guide portion (20) into the separation chamber (40) to deliver the white water spray into the separation chamber, wherein each of the plurality of guide channels (12) includes a downstream deflection portion (142) for deflecting the white water spray; - a liquid outlet (22) connected to the housing (24) to discharge white water from the separation chamber; - a gas outlet (23) connected to the housing (24) to allow air to escape from the separation chamber. Furthermore, the guide portion (20) further includes: a first separation plate (41) arranged to extend downward from the upper end (28) of the separation chamber (40) into the separation chamber (40) and divide the separation chamber (40) into a first section (A) adjacent to the front side (26) and a second section (B) adjacent to the rear side (27), the rear side being opposite to the front side (26), and wherein the first separation plate (41) has a first height (h1) along a vertical axis (V), the first height being less than the chamber height (ch) of the separation chamber (40) along the vertical axis, thereby forming a connecting passage (46) to allow white water to enter the second section (B) below the first separation plate (41) and thereby separate the white water from the air sprayed with the white water, wherein the gas outlet (23) is operatively connected to at least the first section (A) in such a way that air can flow from the first section (A) to the gas outlet (23).

2. The water and air separation device according to claim 1, wherein, The first height (h1) of the first separation plate (41) is 0.5 to 0.9 times the height (ch) of the chamber.

3. The water and air separation device according to claim 1, wherein, The first height (h1) of the first separation plate (41) is 0.6 to 0.7 times the height (ch) of the chamber.

4. The water and air separation device according to any one of claims 1 to 3, wherein, The first separation plate (41) has a front surface (42) facing the front side (26) of the separation chamber (40), and wherein the front surface (42) extends relative to the vertical axis (V) at a first angle (α) in the range of 5° to 45°.

5. The water and air separation device according to claim 4, wherein, The first angle (α) is in the range of 10° to 20°.

6. The water and air separation device according to any one of claims 1 to 3, wherein, The separation chamber (40) has an average width (w) from the front side (26) to the rear side (27). a ), and wherein the second segment (B) has an average second segment width (w B The average width of the second section is the average width (w) of the separation chamber (40). a 0.05 to 0.6 times that of ).

7. The water and air separation device according to any one of claims 1 to 3, wherein, The guide portion (20) also includes a second separation plate (44) arranged to extend downward from the upper end (28) of the separation chamber (40) into the first section (A).

8. The water and air separation device according to claim 7, wherein, The second separation plate (44) extends further along the front side (26) through the upper part of the outlet (15) of the guide channel (12).

9. The water and air separation device according to claim 7, wherein, The second separation plate (44) includes a plurality of plate openings (441) to allow air to pass through the second separation plate (44).

10. The water and air separation device according to claim 9, wherein, At least some of the plurality of plate openings (441) are adjustable.

11. The water and air separation device according to claim 7, wherein, The second separation plate (44) has a second height (h2) along the vertical axis (V), which is less than the first height (h1) of the first separation plate (41).

12. The water and air separation device according to claim 7, wherein, The guide portion (20) further includes a sealing plate (45) arranged to extend downward from the upper end (28) of the separation chamber (40) into the first section (A) and to combine with the second separation plate (44) to form a third section (C), the third section being defined by the second separation plate (44) and the sealing plate (45), and wherein the third section (C) is in fluid communication with the gas outlet (23).

13. The water and air separation device according to claim 12, wherein, The third section is also defined by the upper end (28) of the separation chamber (40).

14. The water and air separation device according to claim 12, wherein, The third section (C) includes a discharge section (47) for discharging white water from the third section (C).

15. The water and air separation device according to claim 14, wherein, The discharge section (47) is located at a distance from the inlet (21) of the guide section (20).

16. The water and air separation device according to claim 14, wherein, The sealing plate (45) also includes a plurality of second plate openings (451) to allow air to enter the third section (C).

17. The water and air separation device according to any one of claims 1 to 3, wherein, Each of the plurality of guide channels (12) has a guide channel width (cw) in the upstream portion (131) of the receiving inlet (11), and wherein the deflected downstream portion (142) of each channel (12) is formed by a deflected portion (14) of the guide channel wall (13) in the downstream portion (141), the deflected portion being deflected in the lateral direction by at least the guide channel width (cw).

18. The water and air separation device according to any one of claims 1 to 3, wherein, The plurality of guide channels (12) are formed by a plurality of plates spaced apart from each other.

19. The water and air separation device according to any one of claims 1 to 3, wherein, The plurality of guide channels (12) are formed by a plurality of pipes or fittings.

20. The water and air separation device according to any one of claims 1 to 3, wherein, The housing (24) of the guide portion (20) further includes at least one additional inlet (25) located in the second section (B) of the separation chamber (40) for introducing additional white water from outside the housing (24) into the separation chamber (40).

21. The water and air separation device according to any one of claims 1 to 3, further comprising a turbine (60) arranged to be connected to the receiving inlet (11) of the inlet portion (10) such that a white water spray through the turbine (60) is received by the receiving inlet (11).

22. The water and air separation device according to any one of claims 1 to 3, wherein, The first separation plate (41) is attached to the rear plate (43), which extends from the lower end (413) of the first separation plate (41) to the upper end (28) of the separation chamber (40), and wherein the rear plate (43) is curved.

23. The water and air separation device according to any one of claims 1 to 3, wherein, The separation chamber (40) has a first end (201) and a second end (202), the first end (201) being adjacent to the inlet (21) between the front side (26) and the rear side (27) and located upstream of the second end (202), and wherein the liquid outlet (22) and the gas outlet (23) are closer to the second end (202) than to the first end (201), and wherein the first separation plate (41) further extends from the first end (201) toward the second end (202) through the separation chamber (40) to at least the gas outlet (23).

24. The water and air separation device according to claim 23, wherein, The first separation plate (41) extends beyond the gas outlet (23).

25. The water and air separation device according to any one of claims 1 to 3, further comprising a static stabilizer (30) connected to the liquid outlet (22) of the guide portion (20) such that white water discharged through the liquid outlet (22) enters the static stabilizer (30).

26. A paper machine, comprising at least one water and air separation device (100) according to any one of claims 1 to 25.

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