Slurry stabilizing mechanism for eliminating pulse by using compressed air cushion

Abstract

The invention relates to the technical field of papermaking equipment, in particular to a pulp stabilizing mechanism utilizing a compressed air cushion to eliminate pulses, which comprises a pulp inlet taper pipe, a pulp stabilizing cover, a sieve plate and a spraying defoaming mechanism, the pulp inlet taper pipe is of a conical cylindrical structure with a wide upper part and a narrow lower part, and the bottom end of the pulp inlet taper pipe is used for being connected with a pulp inlet pipe; the slurry stabilizing cover is of a cylindrical cover structure, the bottom end of the slurry stabilizing cover is connected with the top end of the slurry inlet taper pipe, and a slurry outlet is formed in the side wall. The sieve plate is arranged between the top end of the slurry inlet taper pipe and the bottom end of the slurry stabilizing cover; and the spraying defoaming mechanism is arranged at the inner top of the slurry stabilizing cover and is used for spraying water to the liquid level to eliminate foams on the liquid level. The pulp stabilizing mechanism is arranged on the front side of the pulp flowing box, flowing of paper pulp is hindered through the sieve plate and the pulp inlet taper pipe, and therefore the pulse phenomenon in pulp is weakened.

Description

Technical Field

[0001] This invention relates to the field of papermaking equipment technology, specifically to a stabilizing mechanism that utilizes a compressed air pad to eliminate pulses. Background Technology

[0002] In papermaking, the headbox is a key piece of equipment. Its core function is to uniformly and stably deliver pulp to the lip plate. After flowing out of the lip plate, the pulp enters the wet end of the paper machine to complete subsequent paper web forming and other processes. The stability of the headbox's pulp supply directly determines the quality of the finished paper. However, in actual production, pulp flow pulsation is common, seriously affecting the stability of the pulp supply.

[0003] Specifically, pulp flow pulsations arise from various factors. The impeller rotation of the pump and the periodic rotation of the rotary screen rotor directly cause pulsation within the headbox. Simultaneously, free air accumulated in the pipes and pipe vibrations also trigger pulp flow pulsations, further exacerbating pulp instability. The presence of these pulsations causes irregular fluctuations in pulp velocity and pressure, resulting in uneven pulp distribution at the headbox lip. This leads to increased basis weight variation in the paper web, affecting its uniformity and stability, and potentially causing defects such as pinholes and voids, significantly reducing paper quality. Current pulp stabilization measures are insufficient to effectively eliminate these pulsations. Therefore, we propose a pulp stabilization mechanism that utilizes a compressed air pad to eliminate pulsations, effectively addressing these shortcomings. Summary of the Invention

[0004] The purpose of this invention is to provide a slurry stabilization mechanism that utilizes compressed air pads to eliminate pulses, thereby solving the problems mentioned in the background art.

[0005] This invention is achieved through the following technical solution: a slurry stabilization mechanism that utilizes compressed air pads to eliminate pulses, comprising: The slurry inlet cone is a cone-shaped structure that is wider at the top and narrower at the bottom, and its bottom end is used to connect with the slurry inlet pipe; The slurry stabilizing cover is a cylindrical cover structure, the bottom end of which is connected to the top end of the slurry inlet cone pipe, and the side wall of which has a slurry outlet. A sieve plate is disposed between the top end of the slurry inlet cone and the bottom end of the slurry stabilizing cover; A spray defoaming mechanism is installed at the top inner part of the slurry stabilizer and is used to spray water onto the liquid surface to eliminate foam on the liquid surface. The top of the slurry stabilizing hood is also equipped with an air inlet manifold, which is used to supply air into the slurry stabilizing hood to create a positive pressure environment above the liquid surface.

[0006] Optionally, an inspection hole is provided at the center of the top of the slurry stabilizing cover, and an inspection cover is detachably installed inside the inspection hole. An exhaust pipe is provided on the main air inlet pipe, and an air inlet control valve is also provided on the main air inlet pipe near the end of the slurry stabilizing cover. An exhaust control valve is provided on the exhaust pipe. The screen plate includes an annular positioning part and a perforated plate. The annular positioning part is fixedly connected to the top of the slurry inlet cone pipe. The perforated plate is slidably connected below the annular positioning part in the vertical direction, and an elastic sealing layer is provided circumferentially between the annular positioning part and the perforated plate. An electromagnet and a permanent magnet are respectively provided on the opposite surfaces of the annular positioning part and the perforated plate. When the electromagnet switches between de-energized and energized states, the perforated plate can also move up and down.

[0007] Optionally, the spray defoaming mechanism includes four spray pipes arranged in a rectangular shape. The lower surface of each spray pipe has spray holes spaced apart along its axial direction. A displacement part is fixed to the top of each spray pipe by a pipe clamp. The displacement part slides in contact with the inner top surface of the slurry stabilizing cover. The displacement part and the slurry stabilizing cover slide in contact radially. At the four corners of the inner top surface of the slurry stabilizing cover, a linear drive structure corresponding to each of the four spray pipes is provided. The movable end of the linear drive structure is connected to the corresponding displacement part to control the four spray pipes to converge or diverge.

[0008] Optionally, both ends of the spray pipe are slidably provided with extension pipes, and the extension pipes and the spray pipes are slidably connected along their own axial direction. The extension pipes are closed at the outer end and open at the inner end, and the bottom surface of the pipe wall of the extension pipes is provided with a number of spray holes spaced apart along their own axial direction. The outer end of the extension tube is fitted with a movable sleeve, and the outer surface of the movable sleeve is provided with a sliding post. The inner top surface of the slurry stabilizing cover is provided with a sliding groove for the sliding post to be embedded. When the four spray pipes are in a closed state, the spray holes on the extension tube are all retracted into the spray pipe and aligned with the corresponding spray holes. When the four spray pipes are in a dispersed state, the spray holes are all extended out of the spray pipe.

[0009] Optionally, the top of the slurry stabilizer is also provided with a level transmitter, and the outside of the slurry stabilizer is also provided with a controller. The signal output terminal of the level transmitter is connected to the controller, and the signal output terminal of the controller is connected to an electromagnet and a linear drive structure.

[0010] Optionally, the internal liquid level of the slurry hood has a first height range and a second height range. When the liquid level is in the first height range, the electromagnet is energized and the four spray pipes are dispersed. When the liquid level is in the second height range, the electromagnet is de-energized and the four spray pipes are in a closed state.

[0011] Optionally, the bottom end of the slurry stabilizing cover and the top end of the slurry inlet cone are both flange-shaped, and the two are fixed by bolts.

[0012] Compared with the prior art, the present invention provides a slurry stabilization mechanism that uses a compressed air pad to eliminate pulses, which has the following beneficial effects: 1. The present invention weakens the pulsation phenomenon in the pulp by placing the pulp stabilizing mechanism on the front side of the headbox and hindering the flow of pulp through the screen plate and the pulp feed cone; 2. The present invention provides an air inlet manifold at the top of the slurry stabilization tank, which forms an air cushion at the top of the slurry stabilization tank, thereby maintaining the air pressure above the slurry stabilization tank in a balanced manner and further reducing the slurry pulse phenomenon; 3. The present invention also provides a spray defoaming mechanism at the top of the slurry stabilization tank, which eliminates foam on the liquid surface by spraying water, further helping to improve the slurry quality and the uniformity of slurry output. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the sieve plate structure of the present invention; Figure 3 This is a bottom view of the first state of the slurry stabilizing cover structure of the present invention; Figure 4 This is a bottom view of the second state of the slurry stabilizing cover structure of the present invention; Figure 5 for Figure 1 Enlarged view of point A in the middle; Figure 6 This is a schematic diagram of the extension tube in the contracted state of the present invention; Figure 7 This is a schematic diagram of the extension tube of the present invention in the extended state.

[0014] In the diagram: 100, Inlet cone tube; 200, Slurry stabilizing cover; 201, Slurry outlet; 202, Inspection cover; 203, Sliding groove; 300, Screen plate; 301, Annular positioning part; 302, Perforated plate; 303, Elastic sealing layer; 304, Guide rod; 305, Electromagnet; 306, Permanent magnet; 400, Spray defoaming mechanism; 401, Spray pipe; 402, Spray hole; 403, Displacement part; 404, Linear drive structure; 405, Extension pipe; 406, Moving sleeve; 407, Sliding column; 500, Main air inlet pipe; 501, Exhaust pipe; 502, Air inlet control valve; 503, Exhaust control valve; 600, Level transmitter; 700, Controller. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Please see Figure 1 - Figure 7 This application proposes a pulp stabilizing mechanism that uses a compressed air pad to eliminate pulses. The mechanism includes a pulp inlet cone 100, a pulp stabilizing cover 200, a screen plate 300, and a spray defoaming mechanism 400. The pulp inlet cone 100 is a conical structure, wider at the top and narrower at the bottom, with its bottom end connected to the pulp inlet pipe. The pulp stabilizing cover 200 is a cylindrical cover structure, with its bottom end connected to the top end of the pulp inlet cone 100, and its side wall has a pulp outlet 201. Specifically, both the bottom end of the pulp stabilizing cover 200 and the top end of the pulp inlet cone 100 are flange-shaped and are fixed together by bolts. The pulp flows through the bottom of the bottom pulp inlet cone 100, then into the pulp stabilizing cover 200, and is discharged through the pulp outlet 201.

[0017] Furthermore, the screen plate 300 is positioned between the top of the feed cone 100 and the bottom of the stabilizing cover 200. The screen plate 300 has a porous structure, and when the pulp passes through the screen plate 300, it will be obstructed by the screen plate 300, thus weakening its flow rate. In addition, since the feed cone 100 is a cone shape that is wider at the top and narrower at the bottom, when the pulp enters it, the space at its upper end expands rapidly. The expansion of the space can also slow down the flow rate of the pulp, making it more uniform, and the air contained in the pulp will also be separated from the pulp.

[0018] As one embodiment and not a limitation, the sieve plate 300 includes an annular positioning part 301 and a perforated plate 302. The annular positioning part 301 is fixedly connected to the top of the slurry inlet cone 100. The perforated plate 302 is slidably connected below the annular positioning part 301 in the vertical direction, and an elastic sealing layer 303 is provided circumferentially between the annular positioning part 301 and the perforated plate 302. The elastic sealing layer 303 is made of rubber and its function is to prevent slurry from passing through the gap between the annular positioning part 301 and the perforated plate 302. In addition, a guide rod 304 is vertically provided on the lower surface of the annular positioning part 301. The guide rod 304 movably passes through the perforated plate 302 so that the perforated plate 302 can slide along the guide rod 304. An electromagnet 305 and a permanent magnet block 306 are respectively provided on the opposite surfaces of the annular positioning part 301 and the perforated plate 302. When the electromagnet 305 switches between de-energized and energized states, the perforated plate 302 can also move up and down. In other words, when the electromagnet 305 is de-energized, it is equivalent to an iron block, so the electromagnet 305 and the permanent magnet block 306 can attract each other, and the perforated plate 302 is in a high position at this time; when the electromagnet 305 is energized, its opposite magnetic poles are the same as those of the permanent magnet block 306, and under the action of repulsion, the electromagnet 305 and the permanent magnet block 306 separate from each other, and the perforated plate 302 is in a low position at this time.

[0019] Additionally, it should be noted that the top of the slurry stabilization hood 200 is also equipped with an air inlet manifold 500, which is used to supply air into the slurry stabilization hood 200 to maintain a positive pressure environment above the liquid surface. An exhaust pipe 501 is installed on the air inlet manifold 500, and an air inlet control valve 502 is also installed at one end of the air inlet manifold 500 near the slurry stabilization hood 200. An exhaust control valve 503 is installed on the exhaust pipe 501. Both the air inlet control valve 502 and the exhaust control valve 503 are solenoid valves. By adjusting the flow rate of the two valves, the air inlet rate can be controlled, thereby regulating the gas pressure at the top of the slurry stabilization hood 200.

[0020] like Figure 1 As shown, an inspection hole is provided at the center of the top of the slurry stabilization cover 200, and an inspection cover 202 is detachably installed inside the inspection hole. The inspection cover 202 and the slurry stabilization cover 200 are fixed together by bolts, and the interface is sealed with a sealing ring. When it is necessary to inspect the inside of the slurry stabilization cover 200, the inspection cover is opened, and the personnel can enter the inside of the slurry stabilization cover 200; however, it should be noted that the machine must be stopped during the inspection.

[0021] In this embodiment, a spray defoaming mechanism 400 is disposed on the inner top of the slurry stabilizing cover 200 and is used to spray water onto the liquid surface to eliminate foam on the liquid surface. The spray defoaming mechanism 400 includes four spray pipes 401 arranged in a rectangular shape. Spray holes 402 are spaced apart along the axial direction on the lower surface of each spray pipe 401. A displacement part 403 is fixed to the top of each spray pipe 401 by a pipe clamp. The displacement part 403 slides in contact with the inner top surface of the slurry stabilizing cover 200. The displacement part 403 and the slurry stabilizing cover 200 slide in contact radially. At the four corners of the inner top surface of the slurry stabilizing cover 200, linear drive structures 404 corresponding to the four spray pipes 401 are also provided. The movable end of the linear drive structure 404 is connected to the corresponding displacement part 403 to control the four spray pipes 401 to converge or diverge. Specifically, the linear drive structure 404 can be a linear slide or a cylinder. Figure 3 and Figure 4 As shown, the four spray pipes 401 have two states: closed and open. The sliding direction of each spray pipe 401 is perpendicular to its own axis. It should be added that the outside of the slurry stabilizing cover 200 also has a water supply pipe. One end of this water supply pipe is connected to an external water source, and the other end is connected to the four spray pipes 401 via a flexible hose. When water enters the interior of the spray pipes 401, it can be sprayed downwards through the bottom spray holes 402, primarily to eliminate foam on the liquid surface.

[0022] As one embodiment and not a limitation, both ends of the spray pipe 401 are slidably provided with extension pipes 405. The extension pipes 405 and the spray pipe 401 are slidably connected along their own axial direction, but cannot be twisted relative to each other. The extension pipes 405 are closed at the outer end and open at the inner end. The bottom surface of the pipe wall of the extension pipe 405 is provided with a plurality of spray holes spaced apart along its own axial direction. It should be added that the inner surface of the spray pipe 401 is provided with axially distributed guide ribs, which are slidably engaged with the outer surface of the extension pipe 405. The outer surface of the spray holes has a sealing ring, which is in contact with the inner surface of the spray pipe 401. Furthermore, the spray holes and the liquid spraying holes 402 correspond one-to-one, and the diameter of both does not exceed 2mm.

[0023] As one embodiment and not a limitation, the outer end of the extension pipe 405 is fitted with a movable sleeve 406, and the outer surface of the movable sleeve 406 is provided with a sliding column 407. The inner top surface of the slurry stabilizing cover 200 is provided with a sliding groove 203 for the sliding column 407 to be embedded. When the four spray pipes 401 are in a closed state, the spray holes on the extension pipe 405 are all retracted into the spray pipe 401 and aligned with the corresponding liquid spraying holes. At this time, the water entering the spray pipe 401 will enter the extension pipe 405 and then pass through the spray holes and liquid spraying holes 402 and be sprayed out. The spraying range mainly acts on the center of the liquid surface. When the four spray pipes 401 are in a dispersed state, the spray holes all extend out of the outside of the spray pipe 401. At this time, the water entering the spray pipe 401 can be sprayed out through the spray holes and liquid spraying holes 402 respectively. The spraying range mainly acts on the periphery of the liquid surface.

[0024] A level transmitter 600 is installed at the top of the slurry stabilization hood 200, and a controller 700 is installed outside the slurry stabilization hood 200. The signal output terminal of the level transmitter 600 is connected to the controller 700, and the signal output terminal of the controller 700 is connected to the electromagnet 305 and the linear drive structure 404. The internal liquid level of the slurry stabilization hood 200 has a first height range and a second height range. When the liquid level is in the first height range, the electromagnet 305 is energized, and the four spray pipes 401 are dispersed. When the liquid level is in the second height range, the electromagnet 305 is de-energized, and the four spray pipes 401 are closed. The function of the level transmitter 600 is to monitor the liquid level inside the slurry stabilization hood 200. Specifically, when the liquid level is between the upper and lower surfaces of the slurry outlet 201, it is in the first height range; when the liquid level is higher than the slurry outlet 201, it is in the second height range.

[0025] In summary, in this embodiment, during specific application, the pulp enters from the bottom of the feed cone 100, passes through the screen plate 300, and exits from the discharge port 201. The air inlet manifold 500 is used to blow air onto the top of the stabilizing hood 200, forming an air cushion and maintaining a constant pressure on the air cushion. When the feed pressure increases, the air cushion is compressed, the space occupied by the pulp increases, and the pressure decreases until it balances with the air cushion pressure. When the feed pressure decreases, the air cushion layer expands, the space occupied by the pulp decreases, and the pressure increases until it balances with the air cushion pressure. Therefore, this helps to reduce the impact of pulses on the pulp flow, ensuring that the pulp pressure in the headbox remains constant, resulting in a stable pulp flow.

[0026] Meanwhile, when the liquid level is in the first height range, the electromagnet 305 is de-energized, the perforated plate 302 is at a high position, and the four spray pipes 401 are aligned. At this time, the amount of slurry inside the slurry stabilizer hood 200 is within the normal range, and the generated foam is centrally distributed. Therefore, it is more suitable to centrally distribute the water sprayed by the defoaming spraying mechanism 400, which helps with defoaming. When the liquid level is in the second height range, the electromagnet 305 is energized, the perforated plate 302 is at a low position, and the four spray pipes 401 are dispersed. Since the liquid level is too high at this time, the perforated plate 302 is lowered to a low position, which helps to suppress the continuous rise of the liquid level. At this time, the space between the liquid level and the top wall of the slurry stabilizer hood 200 is limited, so the defoaming spraying mechanism 400 sprays over a wide area, which is more conducive to defoaming.

[0027] It should be further explained that when the slurry inlet pressure is high, the slurry entering the slurry stabilizing hood 200 will impact the liquid surface, entraining air and forming a large amount of fine foam. Furthermore, the slurry at the top flows in a diffused pattern from the center outwards, and the foam will also be blown towards the outer edge of the slurry stabilizing hood 200. Therefore, in this case, it is more appropriate to use the spray defoaming mechanism 400 to spray clean water towards the periphery. Conversely, when the slurry inlet pressure is low, the impact force of the slurry entering the slurry stabilizing hood 200 is also small, resulting in less foam, and the foam formed is more likely to concentrate in the center of the liquid surface. Therefore, in this case, it is more appropriate to use the spray defoaming mechanism 400 to spray clean water towards the center.

[0028] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0029] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A slurry stabilization mechanism that utilizes compressed air pads to eliminate pulses, characterized in that: include: The slurry inlet cone (100) is a cone-shaped structure that is wider at the top and narrower at the bottom, and its bottom end is used to connect with the slurry inlet pipe; The slurry stabilizing cover (200) is a cylindrical cover structure, the bottom end of which is connected to the top end of the slurry inlet cone (100), and its side wall has a slurry outlet (201). A sieve plate (300) is disposed between the top end of the slurry inlet cone (100) and the bottom end of the slurry stabilizing cover (200); A spray defoaming mechanism (400) is provided on the inner top of the slurry stabilizer (200) for spraying water onto the liquid surface to eliminate foam on the liquid surface; The top of the slurry stabilizing cover (200) is also provided with an air inlet manifold (500), which is used to supply air into the slurry stabilizing cover (200) to create a positive pressure environment above the liquid surface.

2. The slurry stabilization mechanism for eliminating pulses using a compressed air pad according to claim 1, characterized in that: An inspection hole is provided at the center of the top of the slurry stabilizing cover (200), and an inspection cover (202) is detachably provided inside the inspection hole.

3. A slurry stabilization mechanism for eliminating pulses using a compressed air pad according to claim 1, characterized in that: An exhaust pipe (501) is provided on the main intake pipe (500), and an intake control valve (502) is also provided on the end of the main intake pipe (500) near the slurry cover (200), and an exhaust control valve (503) is provided on the exhaust pipe (501).

4. A slurry stabilization mechanism for eliminating pulses using a compressed air pad according to claim 1, characterized in that: The sieve plate (300) includes an annular positioning part (301) and a perforated plate (302). The annular positioning part (301) is fixedly connected to the top of the slurry inlet cone (100). The perforated plate (302) is slidably connected below the annular positioning part (301) in the vertical direction. An elastic sealing layer (303) is provided circumferentially between the annular positioning part (301) and the perforated plate (302). The annular positioning part (301) and the perforated plate (302) are respectively provided with an electromagnet (305) and a permanent magnet (306). When the electromagnet (305) switches between the power-off and power-on states, the perforated plate (302) can also move up and down.

5. A slurry stabilization mechanism for eliminating pulses using a compressed air pad according to claim 4, characterized in that: The spray defoaming mechanism (400) includes four spray pipes (401) arranged in a rectangular shape. The lower surface of the spray pipe (401) is provided with spray holes (402) spaced apart along its own axis. The top of the spray pipe (401) is fixed with a displacement part (403) by a pipe clamp. The displacement part (403) and the inner top surface of the slurry stabilizer (200) are in sliding fit.

6. A slurry stabilization mechanism for eliminating pulses using a compressed air pad according to claim 5, characterized in that: The displacement part (403) and the slurry stabilizer (200) slide together radially. The inner top surface of the slurry stabilizer (200) is also provided with linear drive structures (404) corresponding to the four spray pipes (401) at the four corners. The movable end of the linear drive structure (404) is connected to the corresponding displacement part (403) to control the four spray pipes (401) to converge or separate in a divergent manner.

7. A slurry stabilization mechanism for eliminating pulses using a compressed air pad according to claim 6, characterized in that: Both ends of the spray pipe (401) are slidably provided with extension pipes (405). The extension pipes (405) and the spray pipe (401) are slidably connected along their own axial direction. The extension pipes (405) are closed at the outer end and open at the inner end. The bottom surface of the pipe wall of the extension pipes (405) is provided with a number of spray holes spaced apart along its own axial direction. The outer end of the extension tube (405) is fitted with a movable sleeve (406), and the outer surface of the movable sleeve (406) is provided with a sliding column (407). The inner top surface of the slurry stabilizer (200) is provided with a sliding groove (203) for the sliding column (407) to be embedded. When the four spray tubes (401) are in a closed state, the spray holes on the extension tube (405) are all retracted into the spray tube (401) and aligned with the corresponding spray holes. When the four spray tubes (401) are in a dispersed state, the spray holes are all extended out of the outside of the spray tube (401).

8. A slurry stabilization mechanism for eliminating pulses using a compressed air pad according to claim 6, characterized in that: The top of the slurry stabilizer (200) is also provided with a level transmitter (600), and the outside of the slurry stabilizer (200) is also provided with a controller (700). The signal output terminal of the level transmitter (600) is connected to the controller (700), and the signal output terminal of the controller (700) is connected to the electromagnet (305) and the linear drive structure (404).

9. A slurry stabilization mechanism for eliminating pulses using a compressed air pad according to claim 8, characterized in that: The internal liquid level of the slurry stabilizer (200) has a first height range and a second height range. When the liquid level is in the first height range, the electromagnet (305) is energized and the four spray pipes (401) are dispersed. When the liquid level is in the second height range, the electromagnet (305) is de-energized and the four spray pipes (401) are in a closed state.

10. A slurry stabilization mechanism for eliminating pulses using a compressed air pad according to claim 1, characterized in that: The bottom end of the slurry stabilizing cover (200) and the top end of the slurry inlet cone (100) are both flange-shaped and are fixed by bolts.

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