Slurry conveying device for eliminating bubbles in sizing pipeline

Abstract

The utility model discloses a slurry conveying device for eliminating bubbles in a slurry feeding pipeline. The slurry conveying device comprises a pre-papermaking slurry pump, the slurry feeding pipeline, an exhaust valve, a slurry feeding flow valve and a slurry feeding pump, the sizing pipeline is used for conveying sizing agent and comprises a first sizing channel, a U-shaped channel and a second sizing channel; the first sizing channel, the U-shaped channel and the second sizing channel are sequentially connected into a whole; an outlet of the pre-papermaking pulp pump is connected with an inlet of the first sizing channel; the exhaust valve and the sizing flow valve are arranged on the second sizing channel; an outlet of the second sizing channel is connected with an inlet of the sizing pump; when the sizing agent passes through the U-shaped channel, bubbles in the sizing agent gradually float on the surface of the sizing agent and are discharged through the exhaust valve on the second sizing channel, so that the bubbles in the sizing agent are eliminated, and no bubbles exist. According to the slurry conveying device, bubbles mixed in the slurry feeding pipeline can be reduced, the stability of the slurry feeding flow is enhanced, the paper breaking frequency is reduced, the production efficiency is improved, and slurry waste and environmental pollution are reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to pulp conveying and control technical field, concretely relates to a kind of pulp conveying device for eliminating bubble in sizing pipeline. BACKGROUND

[0002] In the broad field of paper production, every technical detail is related to the quality and production efficiency of the final product. Papermaking tobacco sheet is an advanced tobacco production process that uses tobacco leaf reconstruction technology to process tobacco stems, tobacco fines and part of tobacco leaves in the tobacco production process according to the principle of papermaking to produce a sheet close to natural tobacco leaf, which is then used for cigarette production. Papermaking tobacco sheet is more conducive to reducing tar and harm and improving the internal quality of cigarettes compared to tobacco sheet produced by other processes. Among them, the sizing process as a key link, its stability directly affects the uniformity, strength and a series of physical and chemical properties of paper. However, in the actual production process, the stability of sizing flow cannot always be guaranteed as desired, especially when bubbles are unfortunately mixed in the sizing pipeline. This seemingly small flaw may cause a series of production problems.

[0003] The sizing process, in brief, is to deliver the well-prepared pulp to the headbox uniformly, and then form the preliminary structure of the paper. In this process, the accurate control of the sizing flow is of great importance. It not only requires the flow velocity of the pulp in the pipeline to remain constant to ensure the consistency of the basis weight of the paper (i.e. the weight of the paper per square meter), but also requires the parameters such as the moisture content of the pulp to remain stable to ensure the physical properties and chemical stability of the paper. However, in actual operation, the bubbles in the sizing pipeline become an important factor that cannot be ignored to affect the stability of the flow. The generation of the bubbles is caused by two aspects. On the one hand, the pulp itself may contain a certain amount of air, which is entrained into the pulp in the process of stirring, pumping, etc., forming small bubbles. On the other hand, the design, installation and maintenance status of the pipeline may also cause the generation and accumulation of the bubbles. For example, the loose connection of the pipeline joints, the high roughness of the inner wall of the pipeline, and the unreasonable layout of the pipeline, etc. may become a breeding ground for the bubbles. In addition, the running state of the sizing pump is also an important factor affecting the generation of the bubbles. The excessive fast or slow speed of the pump, the poor sealing performance of the pump, etc. may cause air to be sucked into the pump, and then enter the pipeline with the pulp. The existence of the bubbles will change the flow characteristics of the pulp, making the flow of the pulp in the pipeline no longer uniform, causing the frequent fluctuation of the sizing flow valve, and making it difficult to maintain the stability of the delivery amount of the pulp. The fluctuation of the flow will directly lead to the instability of the basis weight of the paper, affecting the uniformity and strength of the paper. More seriously, when the bubbles accumulate to a certain extent in the pipeline, they may form air resistance, hinder the normal flow of the pulp, cause the flow to be interrupted, and then cause the paper to be broken. The broken paper not only means the temporary stop of the production line, but also means the waste of a large amount of human and material resources. Because after each broken paper, the operator needs to clean up and rethread the paper quickly, which not only increases the labor intensity, prolongs the production cycle, reduces the production efficiency, causes the waste of pulp and environmental pollution, but also seriously affects the quality of the product.

[0004] Therefore, it is necessary to design a pulp delivery device capable of eliminating bubbles, so as to reduce the bubbles mixed in the sizing pipeline, enhance the stability of the sizing flow, reduce the number of broken papers, improve the production efficiency, and reduce the waste of pulp and environmental pollution. The utility model discloses a pulp delivery device capable of eliminating bubbles in a sizing pipeline, which can reduce the bubbles mixed in the sizing pipeline, enhance the stability of the sizing flow, reduce the number of broken papers, improve the production efficiency, and reduce the waste of pulp and environmental pollution.

[0005] The utility model discloses a pulp delivery device capable of eliminating bubbles in a sizing pipeline, which can reduce the bubbles mixed in the sizing pipeline, enhance the stability of the sizing flow, reduce the number of broken papers, improve the production efficiency, and reduce the waste of pulp and environmental pollution.

[0006] To solve the above technical problems, the utility model adopts the following technical scheme:

[0007] The patent provides a sizing material conveying device for eliminating bubbles in a sizing pipeline, comprising a pre-drafting sizing pump, a sizing pipeline, an exhaust valve, a sizing flow valve and a sizing pump; the sizing pipeline is used for conveying sizing material, comprising a first sizing channel, a U-shaped channel and a second sizing channel; the first sizing channel, the U-shaped channel and the second sizing channel are sequentially connected to form an integrated design; the outlet of the pre-drafting sizing pump is connected with the inlet of the first sizing channel; the exhaust valve and the sizing flow valve are arranged on the second sizing channel; the outlet of the second sizing channel is connected with the inlet of the sizing pump; when the sizing material passes through the U-shaped channel, the bubbles in the sizing material will float on the surface of the sizing material and be discharged through the exhaust valve on the second sizing channel, so that the bubbles are eliminated.

[0008] Further, the U-shaped channel comprises a downhill pipeline, a horizontal pipeline and an uphill pipeline; the downhill pipeline, the horizontal pipeline and the uphill pipeline are sequentially connected to form an integrated design.

[0009] Further, the horizontal span of the inlet of the downhill pipeline and the outlet of the uphill pipeline is 3-4 meters, 4-5 meters or 5-6 meters; the vertical height difference of the inlet of the downhill pipeline and the horizontal pipeline is 0.8-1.0 meters, 1.0-1.2 meters or 1.2-1.5 meters.

[0010] Further, the first sizing channel comprises a first vertical channel and a first horizontal channel; the first vertical channel and the first horizontal channel are sequentially connected to form an integrated design.

[0011] Further, the second sizing channel comprises a second horizontal channel, a second vertical channel and a third horizontal channel; the second horizontal channel, the second vertical channel and the third horizontal channel are sequentially connected to form an integrated design.

[0012] Further, the outlet of the pre-drafting sizing pump is connected with the inlet of the first vertical channel; the outlet of the first horizontal channel is connected with the inlet of the downhill pipeline; the outlet of the uphill pipeline is connected with the inlet of the second horizontal channel.

[0013] Further, the downhill pipeline has a downward inclination angle compared with the first horizontal channel, and the downward inclination angle is 15-30 degrees, 30-45 degrees or 45-60 degrees; the uphill pipeline has an upward inclination angle compared with the horizontal pipeline, and the upward inclination angle is 15-30 degrees, 30-45 degrees or 45-60 degrees.

[0014] Further, the exhaust valve is arranged on the second horizontal channel close to one end of the inlet of the second horizontal channel; when the sizing material passes through the uphill pipeline of the U-shaped channel, the bubbles in the sizing material gradually float on the surface of the sizing material; when the sizing material passes through the outlet of the uphill pipeline and enters the second horizontal channel of the second sizing channel, the exhaust valve is opened, so that the bubbles in the sizing material are eliminated.

[0015] Further, the sizing flow valve is located on the second vertical channel for flow control of the bubble-eliminated sizing material.

[0016] Further, the inlet of the sizing pump is connected with the outlet of the third horizontal channel for receiving the bubble-eliminated sizing material flow-controlled by the sizing flow valve and pumping into the downstream pulp box.

[0017] Compared with the prior art, the patent has the following beneficial effects:

[0018] Therefore, it can be concluded that the pulp conveying device for eliminating bubbles in a sizing pipeline provided by the utility model has the following beneficial effects on the prior art:

[0019] 1. The pulp conveying device for eliminating bubbles in a sizing pipeline provided by the utility model is provided with a U-shaped channel in the sizing channel, the U-shaped channel comprises a downhill pipeline, a horizontal pipeline and an uphill pipeline, the horizontal span H of the U-shaped channel is 3-6 meters, and the vertical height difference L is 0.8-1.5 meters, so that the bubbles in the pulp float on the surface of the pulp by the action of buoyancy when flowing through the uphill pipeline.

[0020] 2. The utility model is further provided with an exhaust valve downstream of the U-shaped channel, the exhaust valve is located on the second horizontal channel, the bubbles have floated to the surface after the pulp passes through the uphill pipeline, then the bubbles are exhausted by the exhaust valve after passing through the second horizontal channel, and the flow of the pulp is not affected, and the pulp is not produced, so that the efficiency is higher. BRIEF DESCRIPTION OF DRAWINGS

[0021] The above contents of the utility model and the following specific implementation mode can be better understood when being read in combination with the drawings. It should be noted that the drawings are only used as examples of the claimed technical scheme.

[0022] Fig. 1 It is a structural schematic view of the pulp conveying device in the patent;

[0023] Fig. 2 It is a structural schematic view of the sizing pipeline in the patent;

[0024] Fig. 3 It is a structural schematic view of the U-shaped channel in the patent.

[0025] Among them, the sign explanation is as follows:

[0026] Pre-sizing pump: 1;

[0027] First sizing channel: 2;

[0028] First vertical channel: 21;

[0029] First horizontal channel: 22;

[0030] U-shaped channel: 3;

[0031] Downhill pipe: 31;

[0032] Horizontal pipe: 32;

[0033] Uphill pipe: 33;

[0034] Second sizing channel: 4;

[0035] Second horizontal channel: 41;

[0036] Second vertical channel: 42;

[0037] Third horizontal channel: 43;

[0038] Exhaust valve: 5;

[0039] Sizing flow valve: 6;

[0040] Sizing pump: 7. DETAILED DESCRIPTION

[0041] The detailed features and advantages of the present patent are described in detail in the following detailed description, which is sufficient to enable any person skilled in the art to understand the technical content of the present patent and to implement it, and according to the description, claims and drawings disclosed in the specification, those skilled in the art can easily understand the purposes and advantages related to the present patent.

[0042] It should be noted that in the present specification, similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0043] It should be understood that although the terms "first", "second", "third", "horizontal", "vertical" and the like are used to describe various information in the present patent, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. The first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information, without departing from the scope of the present patent. Therefore, the features defined with "first", "second", "third", "horizontal", "vertical" can explicitly or implicitly include one or more of the features, unless otherwise specifically limited.

[0044] In order to make the purposes, technical solutions and advantages of the present patent more clear, the embodiments of the present patent will be further described in detail below in combination with the drawings. The experimental methods described in the embodiments of the present patent are all conventional methods, and the materials, reagents and the like used in the following examples can be obtained from commercial channels, unless otherwise specified.

[0045] As Figs. 1-3 As shown in a specific embodiment of the utility model, the patent provides a sizing pipeline bubble eliminating pulp conveying device, which comprises a pre-drafting pulp pump 1, a sizing pipeline, an exhaust valve 5, a sizing flow valve 6, and a sizing pump 7. The sizing pipeline is used for conveying pulp and comprises a first sizing channel 2, a U-shaped channel 3, and a second sizing channel 4. The first sizing channel 2, the U-shaped channel 3, and the second sizing channel 4 are sequentially connected to form an integrated design. The outlet of the pre-drafting pulp pump 1 is connected to the inlet of the first sizing channel 2. The exhaust valve 5 and the sizing flow valve 6 are arranged on the second sizing channel 4. The outlet of the second sizing channel 4 is connected to the inlet of the sizing pump 7. When the pulp passes through the U-shaped channel 3, the bubbles in the pulp float to the surface of the pulp and are discharged through the exhaust valve 5 on the second sizing channel 4, so that the bubbles are eliminated.

[0046] Specifically, one end of the pre-drafting pulp pump 1 is connected to a pre-drafting pool, which refers to a pulp pool in front of a paper machine, also known as a pulp pool. The pulp fiber ratio and concentration in the pre-drafting pool are quite stable and meet the requirements of papermaking. The pulp in the pre-drafting pool flows through the sizing pipeline by the pre-drafting pulp pump 1 and is pumped to the headbox by the sizing pump.

[0047] Specifically, the pre-drafting pulp pump 1 comprises a pump body, an impeller, a bearing, a sealing device, a motor and a transmission device, a control valve, etc.

[0048] Specifically, the sizing pipeline comprises the first sizing channel 2, the U-shaped channel 3, and the first sizing channel 4, and the sizing pipeline is integrally connected.

[0049] Specifically, the first sizing channel 2 is in the shape of an inverted L. It can be understood that the first sizing channel 2 first vertically upwardly conveys the pulp (forming a first vertical channel 21) after being connected to the pre-drafting pulp pump 1, and then extends horizontally for a certain distance (forming a first horizontal channel 22), forming an inverted L-shaped pipeline layout. This pipeline layout structure is to adapt to the space environment on site or to ensure that the bubbles are located at the pulp liquid surface in the first sizing channel 2 to some extent, thereby reducing the mixed bubbles inside the pulp. At the same time, it also helps to reduce the pressure fluctuation of the first sizing channel 2 during the conveying of the pulp, improves the stability of the conveying, and is more conducive to the subsequent pulp processing and distribution process.

[0050] It can be understood that the inclination of the output port of the pre-drafting pulp pump 1 and the inlet of the starting section of the first sizing channel 2 can be adjusted according to actual needs to ensure smooth conveying of the pulp.

[0051] Specifically, the pipe diameter of the first sizing channel 2 is determined according to the flow rate and flow velocity of the slurry. The flow rate can be calculated by material or heat balance, and the flow velocity can be selected according to the characteristics of the slurry and process requirements. Generally, the diameter of the first sizing channel 2 is appropriately increased to reduce the risk of blockage. Preferably, the pipe diameter of the first sizing channel 2 is 15-120 mm.

[0052] It can be understood that the material and specifications of the first sizing channel 2 should be adjusted according to the actual characteristics of the slurry and the conveying pressure to ensure that the first sizing channel 2 can withstand the flow and pressure of the slurry, while reducing wear and corrosion.

[0053] Specifically, the U-shaped channel 3 includes a downward pipe 31, a horizontal pipe 32, and an upward pipe 33; specifically, the downward pipe 31, the horizontal pipe 32, and the upward pipe 33 are designed as an integrated connection. Specifically, the U-shaped channel 3 is made of the same material as the first sizing channel 2.

[0054] Specifically, the outlet of the slurry outlet pipe 2 is connected to the inlet of the downward pipe 31 of the U-shaped channel 3, i.e., the outlet of the first horizontal channel 22 of the slurry outlet pipe 2 is connected to the inlet of the downward pipe 31, and the downward pipe 31 has a certain downward inclination angle compared to the first horizontal channel 22 of the first sizing channel 2. Specifically, the downward inclination angle of the downward pipe 31 is 15-30 degrees, 30-45 degrees, or 45-60 degrees.

[0055] Specifically, the horizontal pipe 32 is parallel to the first horizontal channel 22 of the first sizing channel 2, the outlet of the downward pipe 31 is connected to the inlet of the horizontal pipe 32, and the outlet of the horizontal pipe 32 is connected to the inlet of the upward pipe 33.

[0056] Specifically, the outlet of the upward pipe 33 is connected to the inlet of the second sizing channel 4; the upward pipe 33 has a certain upward inclination angle compared to the horizontal pipe 32, and specifically, the upward inclination angle of the upward pipe 33 is 15-30 degrees, 30-45 degrees, or 45-60 degrees.

[0057] Specifically, the highest point of the downward pipe 31 and the highest point of the upward pipe 33 are on the same horizontal line, and it can be understood that the inlet height of the downward pipe 31 and the outlet height of the upward pipe 33 are consistent.

[0058] Specifically, the horizontal span H between the inlet of the downward pipe 31 and the outlet of the upward pipe 33 is 3-4 meters, 4-5 meters, or 5-6 meters.

[0059] Specifically, the vertical height difference L between the inlet of the downward pipeline 31 and the outlet of the downward pipeline 31 is 0.8-1.0 meters, 1.0-1.2 meters, or 1.2-1.5 meters. Preferably, the vertical height difference between the inlet of the downward pipeline 31 and the outlet of the downward pipeline 31 is 1.2 meters. Specifically, the vertical height difference between the inlet of the upward pipeline 33 and the outlet of the upward pipeline 33 is 0.8-1.0 meters, 1.0-1.2 meters, or 1.2-1.5 meters. Preferably, the vertical height difference between the inlet of the upward pipeline 33 and the outlet of the upward pipeline 33 is 1.2 meters.

[0060] It can be understood that, in the process of rising, the bubbles in the slurry need to overcome the action of gravity, and the vertical height difference between the highest point and the lowest point of the U-shaped channel 3 is 0.8-1.0 meters, 1.0-1.2 meters, or 1.2-1.5 meters.

[0061] When the vertical height difference between the highest point and the lowest point of the U-shaped channel 3 is less than 0.8 meters, the height difference of the U-shaped channel is small, the power of the bubble rising is insufficient, the bubbles are difficult to float to the surface of the slurry, and the bubbles may be accumulated at the bottom or the elbow of the U-shaped channel, forming a large bubble group, which has an adverse effect on the flowability of the slurry and the quality of papermaking. The retention of bubbles increases the flow resistance of the slurry, slows down the flow speed of the slurry in the pipeline, and reduces the production efficiency. At the same time, the accumulation and uneven distribution of bubbles make the flow of the slurry unstable, which may cause local vortex or turbulent flow, affects the normal operation of the equipment, and cannot remove the bubbles through subsequent processes, thereby affecting the quality of the product.

[0062] When the vertical height difference between the highest point and the lowest point of the U-shaped channel 3 is greater than 1.5 meters, the power requirement for lifting is significantly increased, resulting in an increase in energy consumption. The increase in energy consumption directly increases the operating cost of the papermaking equipment and reduces the economic benefit of the enterprise. At the same time, the high-speed flow of the slurry in the pipeline and the impact of the bubbles intensify the wear of the pipeline, shorten the service life of the pipeline, and increase the risk of equipment failure in long-term high-load operation, affecting the continuity and stability of production. Although the increase in the height difference helps the bubbles to float out, the long rising time may cause the bubbles to break or merge during the rising process, forming larger bubbles, which reduces the removal effect, and the bubbles may be unevenly distributed in the pipeline, causing excessive bubbles in some areas and affecting the overall quality of the slurry.

[0063] It can be understood that the U-shaped channel 3 is a positive “U” shape. If it is set as an inverted “U” shape, the slurry will rapidly descend when it reaches the highest point of the inverted “U” shaped channel, additional bubbles will be generated during the descending process, and the bubbles cannot be removed through the exhaust valve 5, so a vacuum pump needs to be added to remove the bubbles.

[0064] Specifically, the second sizing channel 4 is designed in one piece, and extends horizontally for a distance along the outlet of the upward pipe 33 (forming a second horizontal channel 41), then vertically downward (forming a second vertical channel 42), and finally extends horizontally for a distance again (forming a third horizontal channel 43).

[0065] Specifically, the second sizing channel 4 is designed in one piece, and extends horizontally for a distance along the outlet of the upward pipe 33 (forming a second horizontal channel 41), then vertically downward (forming a second vertical channel 42), and finally extends horizontally for a distance again (forming a third horizontal channel 43).

[0066] Specifically, when the sizing material is transported to the outlet of the upward pipe 33, the gas bubbles will gather upward due to the buoyancy effect, at this time the exhaust valve 5 is quickly opened to discharge the gas bubbles to the outside of the pipe, preventing the gas bubbles from entering the subsequent process link. By timely removing the gas bubbles, the exhaust valve 5 can maintain the stability of the sizing material, avoid problems such as poor flow of sizing material, reduction of device efficiency, etc. caused by excessive gas bubbles, reduce the impact and damage of gas bubbles on the equipment, help to optimize the entire process flow, improve product quality and production efficiency, prolong the service life of the equipment, and reduce maintenance and replacement costs.

[0067] It can be understood that the exhaust valve 5 can adapt to the sizing material transportation requirements under different working conditions, whether it is the change of sizing material flow, viscosity or gas bubble content, the exhaust valve 5 can effectively play its role.

[0068] Specifically, the sizing flow valve 6 is arranged on the second vertical channel 42. Specifically, the sizing flow valve 6 comprises a valve body, a valve inner member and a sealing structure, and further, the valve inner member comprises a valve core, a valve seat and a valve rod.

[0069] Specifically, the sizing flow valve 6 can accurately control the flow of sizing material after the gas bubbles are removed by adjusting the opening of the valve, and has good sealing function to effectively prevent sizing material leakage and ensure production safety and environmental hygiene. Specifically, the sizing flow valve 6 has certain corrosion resistance and wear resistance.

[0070] Specifically, the pressure of the sizing flow valve 6 is 0.25-1.6 MPa; the working temperature of the sizing flow valve 6 is less than or equal to 120℃.

[0071] Specifically, the sizing pump 7 is arranged at the outlet of the third horizontal channel 43, i.e. the end of the third horizontal channel 43 away from the second vertical channel 42.

[0072] Specifically, the sizing pump 7 is used to receive the sizing material after the gas bubbles are removed, and transport the sizing material after the gas bubbles are removed to the headbox of the subsequent processing equipment.

[0073] Specifically, the path of the slurry in the slurry conveying device is as follows: the slurry enters the first vertical channel 21 of the first sizing channel 2 by using the pre-sizing pump 1, enters the first horizontal channel 22 under the action of pressure, and passes through the downhill pipeline 31, the horizontal pipeline 32 and the uphill pipeline 33 of the U-shaped channel 3 at one time. When the slurry passes through the uphill pipeline 33, the air bubbles in the slurry float on the surface of the slurry due to their buoyancy. When the slurry enters the second horizontal channel 41 on the second sizing channel 4, the exhaust valve 5 is opened, and the air bubbles are discharged through the exhaust valve 5. At this time, the slurry no longer contains air bubbles, so the slurry after the air bubbles are removed passes through the second vertical channel 42 and the third horizontal channel 43 again, and the flow of the slurry is controlled by the sizing flow valve 6 on the third sizing channel 43. After the sizing pump pumps the slurry to the subsequent headbox for subsequent processing.

[0074] Specifically, the pump body of the pre-sizing pump 1 is generally of a horizontal structure, which is convenient for installation and maintenance. The pump body can adopt a rear-opening door structure, so that the inlet and outlet pipelines do not need to be disassembled for maintenance. The pump body is provided with inlet and outlet flanges, which are convenient for connecting with the pipelines. Specifically, the material of the pump body can be cast steel or cast iron. The interior of the pump body is treated specially, so that the pump body has good corrosion resistance and wear resistance.

[0075] Specifically, the impeller of the pre-sizing pump 1 is generally of a double-suction type or a semi-open type, which has a large inlet and outlet diameter. The blades on the impeller adopt a curved or inclined structure, which helps to reduce the rotation and turbulence of the paper slurry, so that the efficiency and service life of the pump body are improved. Specifically, the material of the impeller can be high-chromium alloy, silica gel or rubber, etc., which has certain wear resistance and can resist the wear and corrosion of the slurry.

[0076] Specifically, the bearing of the pre-sizing pump 1 is generally a heavy load type bearing, which has strong carrying capacity and impact resistance. The bearing is supported by a high-precision rolling bearing seat and is lubricated by thin oil, so as to ensure the stable operation of the pre-sizing pump 1.

[0077] Specifically, the pre-sizing pump 1 adopts advanced sealing technology, such as packing seal or mechanical seal, to ensure the stability and reliability of the pre-sizing pump 1, and to reduce the risk of leakage and failure. Specifically, the sealing device of the pre-sizing pump 1 generally adopts hard alloy or ceramic material as the sealing surface, which has high wear resistance.

[0078] Specifically, the pre-sizing pump 1 is driven by a motor and is connected with the pump shaft through a coupling on the transmission device for transmission. Specifically, the pre-sizing pump 1 is provided with a control valve. When the pulp outlet fails or all the exhaust valves are closed, the pressure stabilizing valve will automatically open to discharge the high-pressure liquid back to the low-pressure chamber, thereby protecting the stable operation of the pre-sizing pump 1.

[0079] Specifically, the other end of the pre-draft pulp pump 1 is connected with a pulp outlet pipeline 2; the pulp outlet pipeline 2 is led out from the output end of the pre-draft pulp pump 1 and is used for conveying pulp.

[0080] Specifically, the pre-draft pulp pump 1 is a variable frequency pump, the conveying amount of the pre-draft pulp pump 1 is changed by adjusting the frequency of the pre-draft pulp pump 1, which is easy to implement, stable and reliable to adjust, and has high implementability.

[0081] Specifically, the first sizing channel 2 is made of a steel pipe or other materials; specifically, the steel pipe is a carbon steel rubber-lined pipe, a plastic-lined steel pipe, a glass steel pipe (FRP) or a stainless steel pipe; other materials are, for example, polypropylene (PPR, PPH) pipes and the like, which have the characteristics of light weight, corrosion resistance and difficulty in scaling. However, compared with metal pipes, the strength is lower and the rigidity is poor, and long-term exposure to ultraviolet radiation can cause aging. In papermaking or tobacco sheet production, the specific actual needs can be selected for use.

[0082] Specifically, the carbon steel rubber-lined pipe takes ordinary carbon steel pipe or high-quality steel pipe as a base body, and rubber (such as butyl rubber) as an anti-wear and anticorrosion layer, which has the properties of wear resistance, anti-permeability, corrosion resistance and heat resistance (usually up to 120 DEG C), and is suitable for conveying slurry containing solid particles, such as limestone-gypsum wet flue gas desulfurization slurry pipeline, and is also suitable for conveying slurry containing fiber particles in the paper industry; the plastic-lined steel pipe takes ordinary carbon steel pipe or high-quality steel pipe as a base body, and plastic (such as polypropylene PP, polyethylene PE, polyvinyl chloride PVC, polytetrafluoroethylene PTFE, etc.) as a lining, which has the characteristics of corrosion resistance, light weight and easy installation, and is suitable for conveying slurry with strong corrosion or occasions with high hygiene requirements, and can be used for conveying some special formula slurry in papermaking or tobacco sheet production; the glass steel pipe is composed of base material (such as resin) and reinforcing material (such as carbon fiber, glass fiber, etc.). It has the characteristics of corrosion resistance, heat resistance, light weight, high strength and the like, and is suitable for conveying corrosive slurry or occasions with weight requirements, and can also be used in papermaking or tobacco sheet production; the stainless steel pipe has the characteristics of corrosion resistance, heat resistance, high strength and beauty. Commonly used stainless steel materials include 304 and 316, which are suitable for conveying highly corrosive slurry or occasions with extremely high hygiene requirements, and can also be used in papermaking or tobacco sheet production.

[0083] Therefore, it can be concluded that the pulp conveying device for eliminating air bubbles in the sizing pipeline has the following beneficial effects on the prior art:

[0084] 1. The pulp conveying device for eliminating bubbles in the sizing pipeline, which is characterized in that a U-shaped channel 3 is arranged in the sizing channel, the U-shaped channel 3 comprises a downhill pipeline 31, a horizontal pipeline 32 and an uphill pipeline 33; the horizontal span H of the U-shaped channel 3 is 3-6 meters, and the vertical height difference L is 0.8-1.5 meters, so that the bubbles in the pulp float on the surface of the pulp by the action of buoyancy when flowing through the uphill pipeline 33.

[0085] 2. The utility model discloses a gas exhaust valve 5 is further arranged downstream of the U-shaped channel, the gas exhaust valve 5 is located on the second horizontal channel 41, the bubbles have floated to the surface after the pulp passes through the uphill pipeline 33, then the bubbles are exhausted by the gas exhaust valve 5 after passing through the second horizontal channel 41, and the pulp flow is not affected, and the pulp does not overflow, and the efficiency is higher.

[0086] Here, the terms and expressions used are only for description, and the utility model should not be limited to these terms and expressions. Using these terms and expressions does not mean excluding any equivalent features of the description (or part thereof). It should be recognized that various modifications can exist and should be included in the scope of the claims. Other modifications, changes and replacements can also exist. Accordingly, the claims should be considered to cover all these equivalents.

[0087] Similarly, it should be pointed out that although the utility model has been described with reference to the current specific embodiments, those skilled in the art should recognize that the above embodiments are only used to illustrate the utility model, and various equivalent changes or replacements can be made without departing from the spirit of the utility model, therefore, as long as the changes and modifications of the above embodiments are within the scope of the utility model, they will fall within the scope of the claims of the utility model.

Claims

1. A slurry delivery device for eliminating air bubbles in a sizing pipe, characterized by, The pulp conveying device comprises a pre-dressing pulp pump, a sizing pipe, an exhaust valve, a sizing flow valve and a sizing pump; The sizing pipe is used for conveying pulp and comprises a first sizing channel, a U-shaped channel and a second sizing channel; the first sizing channel, the U-shaped channel and the second sizing channel are sequentially connected to form an integrated design; The outlet of the pre-dressing pulp pump is connected to the inlet of the first sizing channel; the exhaust valve and the sizing flow valve are arranged on the second sizing channel; the outlet of the second sizing channel is connected to the inlet of the sizing pump; When the pulp passes through the U-shaped channel, the bubbles in the pulp float on the surface of the pulp and are discharged through the exhaust valve on the second sizing channel, so that the bubbles are eliminated.

2. The slurry delivery device to eliminate air bubbles in a sizing pipe according to claim 1, wherein, The U-shaped channel comprises a downhill pipe, a horizontal pipe and an uphill pipe; the downhill pipe, the horizontal pipe and the uphill pipe are sequentially connected to form an integrated design.

3. The pulp conveying device for eliminating bubbles in a sizing pipe according to claim 2, wherein The horizontal span between the inlet of the downhill pipe and the outlet of the uphill pipe is 3-4 meters, 4-5 meters or 5-6 meters; The vertical height difference between the inlet of the downhill pipe and the horizontal pipe is 0.8-1.0 meters, 1.0-1.2 meters or 1.2-1.5 meters.

4. The pulp conveying device for eliminating bubbles in a sizing pipe according to claim 3, wherein The first sizing channel comprises a first vertical channel and a first horizontal channel; the first vertical channel and the first horizontal channel are sequentially connected to form an integrated design.

5. The slurry delivery device to eliminate air bubbles in a sizing pipe according to claim 4, wherein, The second sizing channel comprises a second horizontal channel, a second vertical channel and a third horizontal channel; the second horizontal channel, the second vertical channel and the third horizontal channel are sequentially connected to form an integrated design.

6. The pulp conveying device for eliminating bubbles in a sizing pipe according to claim 5, wherein The outlet of the pre-dressing pulp pump is connected to the inlet of the first vertical channel; The outlet of the first horizontal channel is connected to the inlet of the downhill pipe; The outlet of the uphill pipe is connected to the inlet of the second horizontal channel.

7. The pulp conveying device for eliminating bubbles in a sizing pipe according to claim 6, wherein The downhill pipe has a downward inclination angle compared to the first horizontal channel, and the downward inclination angle is 15-30 degrees, 30-45 degrees or 45-60 degrees; The uphill pipe has an upward inclination angle compared to the horizontal pipe, and the upward inclination angle is 15-30 degrees, 30-45 degrees or 45-60 degrees.

8. The slurry delivery device to eliminate air bubbles in a sizing pipe according to claim 6, wherein, The exhaust valve is arranged on the second horizontal channel close to one end of the inlet of the second horizontal channel; When the pulp passes through the uphill pipe of the U-shaped channel, the bubbles in the pulp gradually float on the surface of the pulp, and when the pulp passes through the outlet of the uphill pipe and enters the second horizontal channel of the second sizing channel, the exhaust valve is opened, so that the bubbles are eliminated.

9. The slurry delivery device to eliminate air bubbles in a sizing pipe according to claim 6, wherein, The sizing flow valve is located on the second vertical channel for flow control of the bubble-eliminated slurry.

10. The slurry delivery device to eliminate air bubbles in a sizing pipe according to claim 6, wherein, The inlet of the sizing pump is connected with the outlet of the third horizontal channel for receiving the bubble-eliminated slurry flow controlled by the sizing flow valve and pumping to the downstream pulp box.

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