A drying section heating system for a paper machine

Abstract

This invention discloses a heating system for the drying section of a paper machine, comprising a shell, an air distributor, a hollow shaft, a steam connector, a condensate connector, and bearings. The hollow shaft is rotatably connected to the bearings. The ends of the hollow shaft are respectively provided with steam connectors and condensate connectors. The air distributor is housed in a cavity between the shell and the hollow shaft. The sidewall of the air distributor has several first through holes and second through holes, which are staggered. The inner sidewall of the second through hole is provided with an inner sleeve, forming a 0.2–1.5 mm channel with the inner wall of the second through hole. The air distributor and the inner sleeve are made of a hydrophilic material. The inner sleeve has a strip-shaped through hole penetrating its sidewall. A steam distribution pipe and a condensate collection pipe are provided inside the air distributor. The steam distribution pipe connects the first through hole and the steam connector, and the condensate collection pipe connects the second through hole and the condensate connector. This invention prevents condensate from clogging the through holes, promotes steam flow, and improves heat transfer efficiency.

Description

Technical Field

[0001] This invention relates to the field of paper drying technology, and in particular to a heating system for the drying section of a paper machine. Background Technology

[0002] The drying section of a paper machine is a mechanical component used in papermaking machinery to continuously dry the paper blanks after the pulp has been formed. It is a hollow cylinder made of cast iron with lids at both ends, also known as a drying cylinder. Steam is introduced into the cylinder, and the heat of the steam evaporates the moisture in the paper, thus drying the paper. To ensure uniform steam distribution within the drying cylinder, multiple small channels are provided inside. Steam flows through these channels, releasing heat and condensing, making the steam flow within the drying cylinder more uniform. However, these small channels are easily blocked by condensate. Although the condensate can be discharged from the channels under air pressure, the increased flow resistance in the blocked channels causes steam to pass through the channels with less resistance, resulting in uneven steam distribution within the drying cylinder and affecting steam flow and heat transfer efficiency. Summary of the Invention

[0003] In view of the above-mentioned prior art, the present invention provides a heating system for the drying section of a paper machine, which prevents condensate from clogging the through holes, makes the steam more evenly distributed inside the drying cylinder, promotes the flow of steam, and improves the heat transfer effect.

[0004] To achieve the above objectives, the technical solution of this invention is implemented as follows:

[0005] A heating system for the drying section of a paper machine includes a steam connector, a hollow shaft, a housing, a siphon pipe, a condensate connector, and a bearing. The hollow shaft is rotatably connected to the bearing. The ends of the hollow shaft are respectively provided with the steam connector and the condensate connector. The condensate connector is connected to the siphon pipe. A gas distribution cylinder is provided in the cavity between the housing and the hollow shaft. The side wall of the gas distribution cylinder is provided with a plurality of first through holes and second through holes, which are staggered. The diameter of the first through holes and the second through holes is 2-8 mm. An inner sleeve is provided on the inner side wall of the second through hole. The inner sleeve and the inner wall of the second through hole form a channel of 0.2-1.5 mm. The gas distribution cylinder and the inner sleeve are made of hydrophilic material. The inner sleeve is provided with a strip-shaped through hole penetrating its side wall. A steam distribution pipe and a condensate collection pipe are provided inside the gas distribution cylinder. The steam distribution pipe connects the first through hole and the steam connector. The condensate collection pipe connects the second through hole and the condensate connector.

[0006] Furthermore, the second through hole has an isolation groove at one end near the side wall of the housing, and the isolation groove communicates with the strip-shaped through hole.

[0007] Furthermore, a mesh cylinder is fitted onto the outside of the inner sleeve, and the side wall of the mesh cylinder forms several flow guiding channels. The flow guiding channels are composed of several flow guiding units connected in series. Each flow guiding unit includes a branching channel and a meandering channel. The meandering channel connects the upper end of the branching channel, with the upper end referring to the end near the outer shell and the lower end referring to the end near the hollow shaft. The branching channels of adjacent flow guiding units are connected in series in sequence.

[0008] Furthermore, the outer wall of the hollow shaft is provided with a support rod, which is connected to the air distribution cylinder.

[0009] Furthermore, the support rods are spaced apart circumferentially along the hollow shaft.

[0010] Furthermore, the end of the housing is provided with a slot, and the end of the air distribution cylinder is embedded in the slot.

[0011] Furthermore, the steam connector is connected to the inner cavity of the hollow shaft, and the steam distribution pipe is also connected to the inner cavity of the hollow shaft.

[0012] Furthermore, a connecting rod is provided inside the air distribution cylinder, and the connecting rod is connected to the support rod.

[0013] The beneficial effects of this invention are as follows:

[0014] 1. Several first through holes and second through holes are provided on the gas distribution cylinder. Steam enters through the first through holes and contacts the inner wall of the outer shell, heating the outer shell with high-temperature steam. After heat exchange, the steam exits through the second through holes. The first and second through holes are staggered, thus ensuring uniform distribution of high-temperature steam within the outer shell. The diameters of the first and second through holes are 2~8mm. Smaller diameters allow for a larger number of first and second through holes, resulting in more uniform distribution of high-temperature steam.

[0015] 2. An inner sleeve is installed inside the second through hole, forming a 0.2~1.5mm channel with the inner wall of the second through hole. Both the air distribution tube and the inner sleeve are made of hydrophilic material. The inner sleeve has a strip-shaped through-hole penetrating its sidewall. The attraction between the liquid molecules condensing inside the second through hole and the solid wall molecules allows the condensate to enter the 0.2~1.5mm channel along the strip-shaped through-hole and diffuse along it, preventing liquid accumulation that could block the second through hole. The liquid flowing along the 0.2~1.5mm channel eventually enters the condensate collection pipe. Because the second through hole is not easily blocked by condensate, steam can effectively pass through at different locations, resulting in uniform steam distribution, promoting steam flow, and improving heat transfer. Attached Figure Description

[0016] Figure 1 This is a cross-sectional structural schematic diagram of a heating system for the drying section of a paper machine according to an embodiment of this application;

[0017] Figure 2 For this application Figure 1 Enlarged structural diagram of region A in the middle;

[0018] Figure 3 This is a schematic diagram of the heating system of the drying section of a paper machine according to an embodiment of this application;

[0019] Figure 4 This is a schematic diagram of the structure of the mesh cylinder in the embodiments of this application;

[0020] Figure 5 This is a schematic diagram of the flow of condensate in the guide channel in an embodiment of this application;

[0021] Figure 6 This is a schematic diagram of the flow of condensate in the guide channel in an embodiment of this application;

[0022] Explanation of icon numbers:

[0023] 1. Shell; 2. Air distributor; 3. Hollow shaft; 4. Steam connector; 5. Condensate connector; 6. Bearing; 7. First through hole; 8. Second through hole; 9. Inner sleeve; 10. Strip through hole; 11. Steam distributor pipe; 12. Condensate collection pipe; 13. Isolation groove; 14. Mesh cylinder; 15. Branching channel; 16. Detour channel; 17. Support rod; 18. Slot; 19. Connecting rod. Detailed Implementation

[0024] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0025] It should also be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "inner," "outer," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0026] Example 1

[0027] Please refer to the attached document. Figures 1-2This application provides a heating system for the drying section of a paper machine, including a steam connector 4, a hollow shaft 3, a housing 1, a siphon pipe, a condensate connector 5, and a bearing 6. The hollow shaft 3 is rotatably connected to the bearing 6. The ends of the hollow shaft 3 are respectively provided with the steam connector 4 and the condensate connector 5. The steam connector 4 communicates with the inner cavity of the hollow shaft 3, and the condensate connector 5 communicates with the siphon pipe. The cavity between the housing 1 and the hollow shaft 3 is provided with an air distribution cylinder 2. The side wall of the air distribution cylinder 2 is provided with a plurality of first through holes 7 and second through holes 8, which are staggered. The first through hole 7 and the second through hole 8 have diameters of 2-8 mm. The inner wall of the second through hole 8 is provided with an inner sleeve 9, which forms a channel of 0.2-1.5 mm with the inner wall of the second through hole 8. The air distribution cylinder 2 and the inner sleeve 9 are made of hydrophilic material. The inner sleeve 9 is provided with a strip-shaped through hole 10 penetrating its side wall. The air distribution cylinder 2 is provided with a steam distribution pipe 11 and a condensate collection pipe 12. The steam distribution pipe 11 connects the first through hole 7 and the steam connector 4, and the condensate collection pipe 12 connects the second through hole 8 and the condensate connector 5.

[0028] High-temperature steam enters through the steam connector and flows along the steam distribution pipe into the first through hole 7. As it enters the area between the steam distribution cylinder 2 and the outer shell 1 through the first through hole 7, it heats the outer shell 1, and dries the raw paper as the shell contacts it. The steam then flows along the second through hole 8 into the condensate collection pipe 12, and flows through the condensate collection pipe 12 to the condensate connector 5, thus discharging the condensate. After heat exchange, the high-temperature steam temperature decreases, and some of the water vapor condenses to form cooling water. This cooling water flows to the condensate collection pipe 12, which is connected to an external drain pipe via the condensate connector 5. When the drain pipe is full of condensate, a siphon effect is created, thereby siphoning out the condensate in the condensate collection pipe 12. Several first through holes 7 and second through holes 8 are provided on the air distribution cylinder 2. Steam enters through the first through holes 7 and contacts the inner wall of the outer shell, using high-temperature steam to heat the outer shell. After heat exchange, the steam exits through the second through holes 8. The first through holes 7 and second through holes 8 are arranged alternately, so the high-temperature steam is evenly distributed in the outer shell 1. The diameter of the first through holes 7 and second through holes 8 is 2~8mm. Smaller diameters allow for a larger number of first through holes 7 and second through holes 8, resulting in a more uniform distribution of high-temperature steam. An inner sleeve 9 is installed inside the second through hole 8, forming a 0.2-1.5 mm channel with the inner wall of the second through hole 8. Both the air distributor 2 and the inner sleeve 9 are made of hydrophilic material. The inner sleeve 9 has a strip-shaped through hole 10 penetrating its sidewall. The attraction between the liquid molecules condensing inside the second through hole and the solid wall molecules allows the condensate to enter the 0.2-1.5 mm channel along the strip-shaped through hole 10 and diffuse along it, preventing liquid accumulation that could block the second through hole 8. The liquid flowing along the 0.2-1.5 mm channel eventually enters the condensate collection pipe 12 and is finally discharged. Because the second through hole is not easily blocked by condensate, steam can effectively pass through at different locations, resulting in uniform steam distribution, promoting steam flow, and improving heat transfer. The steam connector 4 ensures a stable supply of high-temperature steam when the outer casing rotates, and the condensate connector 5 ensures the discharge of condensate when the outer casing rotates.

[0029] Specifically, the second through hole 8 has an isolation groove 13 at one end near the side wall of the housing 1, and the isolation groove 13 communicates with the strip-shaped through hole 10. When condensate diffuses along the strip-shaped through hole 10 and the 0.2~1.5mm channel to the isolation groove 13, it is intercepted, preventing condensate from flowing back into the air distributor 2 and the area of ​​the housing diameter. As the housing rotates, even if condensate accumulates in the second through hole 8 at the bottom, the accumulated condensate gathers at the isolation groove 13, blocking the channel in the second through hole 8 at the bottom, allowing more airflow to pass through the first through hole 7 and the second through hole 8 above, drying the upper paper.

[0030] Example 2

[0031] Please refer to the attached document. Figures 1-6 The difference between this embodiment and Embodiment 1 is that a mesh cylinder 14 is fitted around the outer side of the inner sleeve 9. The sidewall of the mesh cylinder 14 forms several flow guiding channels, which are formed by several flow guiding units connected in series. Each flow guiding unit includes a branching channel 15 and a meandering channel 16. The meandering channel 16 connects the upper ends of the branching channels 15 (the upper end refers to the end near the outer shell, and the lower end refers to the end near the hollow shaft 3). The branching channels 15 of adjacent flow guiding units are connected in series. The upper end of the branching channel 15 is an arc-shaped channel with a slight bend. At the lower end of the arc-shaped channel, it branches into two channels, which are connected by the meandering channel 16. The middle part of the meandering channel 16 bends upwards into an arc shape. When condensate flows from the upper end to the lower end, the water flow gathers from the two branching channels towards the arc-shaped channel, resulting in low resistance to the water flow. As the condensate flows from the bottom to the top, it branches into two channels from the arc-shaped channel. Part of the condensate passes through a detour before converging with the other branch channel 15. The direction of the water flowing back from the detour is different from the original flow direction of the branch channel 15, obstructing the flow of condensate at the convergence point and preventing it from flowing upwards. This prevents excessive condensate from flowing into the isolation tank 13, which could cause overflow into the area between the air distributor 2 and the outer shell.

[0032] Example 3

[0033] Please refer to the attached document. Figures 1-6 The difference between this embodiment and Embodiment 1 is that a support rod 17 is provided on the outer wall of the hollow shaft 3, and the support rod 17 is connected to the air distribution cylinder 2. One end of the support rod 17 is fixed to the outside of the hollow shaft 3 by bolts, and the other end is fixed to the inner wall of the air distribution cylinder 2 by bolts. The air distribution cylinder 2 is fixed by the support rod 17, which improves the stability of the air distribution cylinder 2.

[0034] Specifically, the support rods 17 are spaced apart circumferentially along the hollow shaft 3. By arranging the support rods 17 at equal intervals circumferentially, the air distribution cylinder 2 can be stabilized from multiple angles, improving stability.

[0035] Specifically, the end of the housing 1 is provided with a slot 18, and the end of the air distributor 2 is embedded in the slot 18. The slot 18 is used to fix the air distributor 2, thereby improving the stability of the air distributor 2.

[0036] Specifically, the steam connector 4 is connected to the inner cavity of the hollow shaft 3, and the steam distribution pipe 11 is also connected to the inner cavity of the hollow shaft 3, thus achieving communication between the steam distribution pipe 11 and the steam connector 4. During operation, high-temperature steam enters the inner cavity of the hollow shaft 3 and then flows from the inner cavity of the hollow shaft 3 into each steam distribution pipe 11. The inner diameter of the hollow shaft 3 is much larger than the inner diameter of the steam distribution pipe 11, allowing the steam to enter each steam distribution pipe 11 more evenly.

[0037] Specifically, a connecting rod 19 is provided on the inner side of the air distribution cylinder 2, and the connecting rod 19 is connected to the support rod 17. The connection of the support rod 17 through the connecting rod 19 improves the stability of the support rod 17.

[0038] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A heat supply system for a drying section of a paper machine, characterized in that The device includes a housing, a gas distribution cylinder, a hollow shaft, a steam connector, a condensate connector, and a bearing. The hollow shaft is rotatably connected to the bearing. The ends of the hollow shaft are respectively provided with the steam connector and the condensate connector. The cavity between the housing and the hollow shaft is provided with the gas distribution cylinder. The side wall of the gas distribution cylinder is provided with several first through holes and second through holes, which are staggered. The diameter of the first through holes and the second through holes is 2~8mm. The inner side wall of the second through hole is provided with an inner sleeve, which forms a 0.2~1.5mm channel with the inner wall of the second through hole. The gas distribution cylinder and the inner sleeve are made of hydrophilic material. The inner sleeve is provided with a strip-shaped through hole penetrating its side wall. The inside of the gas distribution cylinder is provided with a steam distribution pipe and a condensate collection pipe. The steam distribution pipe connects the first through hole and the steam connector, and the condensate collection pipe connects the second through hole and the condensate connector.

2. A drying section heat supply system for a base paper machine according to claim 1, characterized in that The second through hole has an isolation groove at one end near the side wall of the housing, and the isolation groove communicates with the strip-shaped through hole.

3. A drying section heat supply system for a base paper machine according to claim 1, characterized in that, The inner sleeve is fitted with a mesh cylinder, and the side wall of the mesh cylinder forms several flow guiding channels. The flow guiding channels are composed of several flow guiding units connected in series. Each flow guiding unit includes a branching channel and a meandering channel. The meandering channel connects the upper end of the branching channel, and the branching channels of adjacent flow guiding units are connected in series in sequence.

4. A drying section heat supply system of a base paper machine according to claim 1, characterized in that, The outer wall of the hollow shaft is provided with a support rod, which is connected to the air distribution cylinder.

5. A drying section heat supply system of a base paper machine according to claim 4, characterized in that, The support rods are spaced apart circumferentially along the hollow shaft.

6. A heat supply system for a drying section of a base paper machine according to claim 1, characterized in that The end of the housing is provided with a slot, and the end of the air distribution cylinder is embedded in the slot.

7. A heat supply system for a drying section of a paper machine according to claim 1, characterized in that The steam connector is connected to the inner cavity of the hollow shaft, and the steam distribution pipe is also connected to the inner cavity of the hollow shaft.

8. A heat supply system for a drying section of a base paper machine according to claim 4, characterized in that The air distribution cylinder is provided with a connecting rod on its inner side, and the connecting rod is connected to the support rod.

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