Steam down-flow type medium-concentration paper pulp pipeline heater
By designing a steam downstream medium-tonized pulp pipeline heater, the water hammer phenomenon and low heat exchange efficiency during traditional steam jet heating medium-tonized pulp are solved, and efficient mixing and stable heating of steam and pulp are achieved, ensuring the smooth operation of the production line and product quality.
Patent Information
- Application Number
- CN202510689575.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-27
- Publication Date
- 2025-08-01
AI Technical Summary
When traditional steam directly sprays and heats medium-toned pulp, there are problems such as water hammering, low heat exchange efficiency, low energy utilization rate and pipeline blockage, which affects the stable operation of the production line and product quality.
A steam downstream medium-tonized pulp pipeline heater is designed. By setting a steam mixing tube and annular steam introduction tube in the outer tube body, the steam flow direction is consistent with the pulp, avoiding severe impact, and using a multiple inner cavity structure to improve mixing efficiency and heat exchange effect.
It effectively eliminates the water hammer phenomenon, improves the mixing and heat exchange efficiency between steam and pulp, reduces energy consumption, and ensures the stable operation of the pipeline system and the stability of product quality.
Smart Images
Figure CN120401259A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of pulp conveying pipelines, and in particular to a steam downstream medium-consistency pulp pipeline heater. Background Art
[0002] In the papermaking industry, the processing of medium-consistency pulp is a crucial step in the pulping and papermaking process. Medium-consistency pulp typically refers to pulp with a concentration between 8% and 15%. Prior to oxygen delignification and bleaching, it must be heated to an optimal temperature range of 95°C to 11°C to ensure smooth processing and maximize treatment effectiveness.
[0003] Currently, the most common and simple method for heating medium-consistency pulp is direct steam heating. In traditional steam heating systems, steam is typically injected directly into the pulp pipe through a steam nozzle connected vertically to the pipe, mixing the steam and pulp to heat the pulp. This method is simple to operate and has high thermal efficiency, making it widely used in the pulp and paper industry.
[0004] However, the traditional direct steam injection heating method has several technical drawbacks: First, since the flow directions of steam and medium-consistency pulp are inconsistent, that is, the steam flow direction is perpendicular or inverse to the pulp flow direction, when high-pressure steam is sprayed into the pipeline at high speed, it will form a violent impact with the pulp flow, resulting in severe water hammer inside the pipeline. This water hammer phenomenon will not only cause violent vibration and noise in the pipeline system, but also produce huge impact force on the pipeline system and its connectors. It will also interfere with the normal operation of various instruments and valves installed on the pipeline, reduce measurement accuracy, and even cause damage to the measuring equipment, thereby affecting the stable operation of the entire production line and product quality control.
[0005] Secondly, due to insufficient mixing of steam and pulp, the heat exchange efficiency is low and the steam energy utilization rate is not high. In actual production, more steam is needed to achieve the required heating effect, which undoubtedly increases production energy consumption and operating costs.
[0006] Moreover, medium-consistency pulp has certain viscosity and rheological properties. Under the traditional direct steam injection method, it is easy for local accumulation of pulp or unstable flow areas to form near the steam injection point, which will not only affect the heating effect, but may also cause local blockage of the pipeline or uneven pulp quality.
[0007] Therefore, how to design a steam heating device that can avoid or significantly alleviate the above-mentioned problems, achieve smooth mixing of steam and medium-consistency pulp, avoid water hammer, improve energy utilization efficiency, and ensure the safe and stable operation of the pipeline system is a technical problem that needs to be urgently solved in the current pulp and paper industry. Summary of the Invention
[0008] To solve the above problems, the present application provides a steam co-current medium consistency pulp pipeline heater that effectively eliminates water hammer and improves the mixed heat exchange efficiency.
[0009] To achieve the above object, the steam co-current medium consistency pulp pipeline heater designed in the present application includes: An outer pipe body having a pulp inlet and a pulp outlet disposed opposite to each other; A steam mixing pipe disposed inside the outer pipe body, one end of the steam mixing pipe facing the pulp inlet being a closed end, and the other end being provided with an opening communicating with the outer pipe body; A plurality of steam introduction pipes circumferentially and equidistantly arranged on the outer wall surface of the steam mixing pipe, and a plurality of the steam introduction pipes are all located in an annular flow channel formed between the outer pipe body and the steam mixing pipe; Steam inlets, a plurality of which are provided on the outer wall surface of the outer pipe body corresponding to the positions of the respective steam introduction pipes, and each of the steam inlets is communicated to the steam mixing pipe through a corresponding steam introduction pipe; Wherein, each of the steam introduction pipes has an opposite first side and second side, the inner diameter of the steam introduction pipe gradually decreases in the direction from the first side to the second side, the first side is located between the second side and the pulp inlet, and a steam outlet extending along the axial direction of the steam introduction pipe is provided on the second side of the steam introduction pipe; the steam outlet is flush and communicated with the opening of the steam mixing pipe, and the total outlet area of the steam outlet and the opening of the steam mixing pipe is equal to the total inlet area of the plurality of steam inlets.
[0010] Preferably, the closed end is conical.
[0011] Preferably, it further includes an inner pipe body disposed inside the outer pipe body, the inner pipe body having a first end and a second end disposed opposite to each other, the first end of the inner pipe body and the outer edge of the port of the steam mixing pipe facing the pulp inlet integrally form the closed end, and the second end of the inner pipe body and the outer edge of the port of the steam mixing pipe facing the pulp outlet are spaced apart to form the opening; wherein, the inner pipe body communicates the pulp inlet and the pulp outlet.
[0012] Preferably, the closed end is a hollow frustum shape.
[0013] Preferably, the inner pipe body includes a contraction section and a straight section smoothly connected to the contraction section, and the inner diameter of the contraction section gradually increases in the direction from the straight section to the first end.
[0014] Preferably, a guiding portion is convexly provided on the first side of the steam inlet pipe, and the guiding portion has two guiding inclined surfaces arranged at an acute angle; the guiding inclined surfaces are located on both sides of the axis of the steam inlet pipe and are respectively connected to the inner wall surface of the outer pipe body and the outer wall surface of the steam mixing pipe.
[0015] Preferably, the guiding portion is a hollow structure integrally formed with the steam inlet pipe.
[0016] Preferably, the outer pipe body, the steam mixing pipe and the inner pipe body are coaxially arranged; the axis of the steam inlet pipe is perpendicular to the axis of the outer pipe body.
[0017] Preferably, the number of the steam inlet pipes is 3 - 8.
[0018] In the steam co - current medium - consistency pulp pipeline heater designed in the present application, by making the introduced steam flow in the same direction as the main flow of the pulp, not only the water hammer phenomenon, vibration and noise are effectively avoided, the stable operation of the pipeline system is ensured, the interference to the instrument valves is reduced, and the service life of the equipment is prolonged; the multiple inner cavity structure inside it also significantly improves the mixing efficiency of the steam and the pulp and the heat exchange effect, reduces the energy consumption, and maximally maintains the stable flow state of the pulp, thereby ensuring the stable operation of the production line and the stability of the product quality. Description of the Drawings
[0019] Figure 1 is a schematic plan view of a steam co - current medium - consistency pulp pipeline heater provided by an embodiment of the present application.
[0020] Figure 2 is Figure 1 the cross - sectional view taken along A - A in
[0021] Figure 3 is a schematic perspective view of a steam co - current medium - consistency pulp pipeline heater provided by another embodiment of the present application Figure 1 .
[0022] Figure 4 is a schematic perspective view of a steam co - current medium - consistency pulp pipeline heater provided by another embodiment of the present application Figure 2 .
[0023] Figure 5 is a schematic plan view of a steam co - current medium - consistency pulp pipeline heater provided by another embodiment of the present application.
[0024] Figure 6 is Figure 5 the cross - sectional view taken along B - B in
[0025] Figure 7 is Figure 5 the cross - sectional view taken along C - C in
[0026] Figure 8 is Figure 5 The sectional view taken along the D-D line in the figure.
[0027] Among them: outer pipe body 10, pulp inlet 11, pulp outlet 12, steam mixing pipe 20, closed end 21, open end 22, steam introduction pipe 30, first side 31, second side 32, steam outlet 33, steam inlet 40, inner pipe body 50, contraction section 51, straight section 52, flow guiding part 60, flow guiding inclined surface 61. Specific embodiments
[0028] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.
[0029] As Figures 1 to 8 shown, the steam co-current medium consistency pulp pipeline heater described in this embodiment mainly consists of an outer pipe body 10, a steam mixing pipe 20 arranged inside the outer pipe body 10, a plurality of steam introduction pipes 30 arranged circumferentially, and a corresponding plurality of steam inlets 40.
[0030] Specifically, the outer pipe body 10 is a tubular shell, and a pulp inlet 11 for the medium consistency pulp to flow in and a pulp outlet 12 for the medium consistency pulp to flow out are respectively provided at both ends thereof. In this embodiment, the material of the outer pipe body 10 is preferably stainless steel to meet the corrosion resistance requirements of the pulp industry; the diameter of the outer pipe body 10 can be determined according to actual process requirements, and is usually 300 mm - 800 mm.
[0031] The steam mixing pipe 20 is coaxially arranged inside the outer pipe body 10. Specifically, the outer diameter of the steam mixing pipe 20 is smaller than the inner diameter of the outer pipe body 10, so as to form an annular main flow channel therebetween for the medium consistency pulp to flow from the pulp inlet 11 to the pulp outlet 12. One end of the steam mixing pipe 20 facing the pulp inlet 11 is a closed end 21 for preventing the pulp from entering the internal cavity of the steam mixing pipe 20.
[0032] As Figure 2 shown, in a possible implementation manner, the closed end 21 is conical, and the tip of the cone points to the pulp inlet 11 direction, so as to effectively reduce the flow resistance when the medium consistency pulp flows through here, and help prevent the pulp from accumulating or staying near the closed end 21. For example, the cone angle of the conical closed end 21 can be designed to be 30° to 60° to achieve a balance between the flow guiding effect and the structural compactness.
[0033] A plurality of steam inlet pipes 30 are circumferentially and equidistantly arranged on the outer wall surface of the steam mixing pipe 20. A plurality of the steam inlet pipes 30 are all located in the annular flow channel formed between the outer pipe body 10 and the steam mixing pipe 20, and the axis of the steam inlet pipe 30 is perpendicular to the axis of the outer pipe body 10. In this embodiment, the number of the steam inlet pipes 30 is 3 - ⑧. Preferably, the number of the steam inlet pipes 30 is 4, that is, the 4 steam inlet pipes 30 are arranged at intervals of 90° along the circumferential direction of the steam mixing pipe 20.
[0034] A plurality of steam inlets 40 are provided on the outer wall surface of the outer pipe body 10 at positions corresponding to the respective steam inlet pipes 30. Each of the steam inlets 40 is communicated with the steam mixing pipe 20 through the corresponding steam inlet pipe 30. The high-temperature steam supplied externally enters through these steam inlets 40, and is respectively introduced into the corresponding steam inlet pipes 30, and finally converges into the inner cavity of the steam mixing pipe 20. In a specific embodiment, a steam supply pipeline can be connected to each steam inlet 40, and a steam control valve (not shown in the figure) can be installed to control and adjust the steam flow rate entering each steam inlet pipe 30.
[0035] Wherein, each of the steam inlet pipes 30 has an opposite first side 31 and second side 32. The inner diameter of the steam inlet pipe 30 gradually decreases along the direction from the first side 31 to the second side 32, thereby forming a contraction channel inside it; the first side 31 is located between the second side 32 and the pulp inlet 11, and a steam outlet 33 extending along the axial direction of the steam inlet pipe 30 is provided on the second side 32 of the steam inlet pipe 30; the steam outlet 33 is flush and communicated with the open end 22 of the steam mixing pipe 20, which means that the steam ejected from each steam outlet 33 converges with the steam ejected from the open end 22 to form a total steam flow. In order to ensure the continuity and stability of the steam flow and avoid local pressure fluctuations or energy losses that may be caused by a sharp change in the flow cross-sectional area, the total outlet area of the steam outlets 33 and the open end 22 of the steam mixing pipe 20 is equal to the total inlet area of the plurality of steam inlets 40.
[0036] During operation, by way of example: the medium consistency pulp stably flows in from the pulp inlet 11 of the outer pipe body 10, and is conveyed in the annular main flow channel formed between the outer pipe body 10 and the steam mixing pipe 20 in the direction of the pulp outlet 12; at the same time, the high-temperature and high-pressure steam enters from an external steam source through each steam inlet 40 and respectively flows through the corresponding steam inlet pipes 30; since the inside of the steam inlet pipe 30 is a gradually contracting channel, the steam is accelerated when flowing through this contraction channel, its kinetic energy increases, and the pressure energy decreases accordingly; finally, the high-speed steam flow is ejected from each steam outlet 33 and the open end 22 of the steam mixing pipe 20 at a high speed in a manner consistent with the flow direction of the medium consistency pulp in the annular main flow channel.
[0037] Since the steam injection direction is consistent with the main pulp flow direction, and the steam flow rate is usually much greater than the pulp flow rate, this avoids the severe impact and shearing effects caused by the velocity difference and direction difference between the steam and the pulp during traditional radial or reverse steam injection. Thus, the water hammer phenomenon and the resulting pipeline vibration and noise are fundamentally eliminated or greatly reduced, ensuring the stable operation and service life of the pipeline system and the connected instrument valves. Moreover, the high-speed ejected steam can more effectively penetrate and disperse into the medium-consistency pulp, forming finer steam bubbles and quickly condensing, greatly increasing the vapor-liquid contact area, thereby significantly improving the mixing efficiency and heat exchange efficiency between the steam and the pulp, making the pulp heated more evenly and quickly, and at the same time reducing the energy waste caused by the unutilized steam. Furthermore, the co-current mixing method has less damage to the original laminar or near-laminar state of the pulp, which helps to maintain the stability of the pulp flow and reduce unnecessary turbulence and energy consumption.
[0038] In another embodiment of the present application, as Figures 3 to 8 shown, it further includes an inner pipe body 50 disposed inside the outer pipe body 10. The inner pipe body 50 is coaxially arranged with the outer pipe body 10 and has a first end and a second end arranged oppositely. Specifically, its first end faces the pulp inlet 11, and the second end faces the pulp outlet 12. In this way, the inner pipe body 50 and the outer pipe body 10 together form two parallel medium-consistency pulp conveying channels: one is the internal channel of the inner pipe body 50, and the other is the annular flow channel between the outer wall of the inner pipe body 50 and the inner wall of the outer pipe body 10. After the medium-consistency pulp enters from the pulp inlet 11 of the outer pipe body 10, a part of the pulp flows into the first end of the inner pipe body 50 and flows forward inside it, and the other part of the pulp enters the above annular flow channel and flows forward.
[0039] Wherein: the first end of the inner pipe body 50 and the outer edge of the port of the steam mixing pipe 20 facing the pulp inlet 11 integrally form the closed end 21. In specific implementation, the first end of the inner pipe body 50 and the outer edge of the port of the steam mixing pipe 20 facing the pulp inlet 11 can be combined by welding or integral forming connection method to jointly form a closed and shunt-functioning closed end 21, so as to effectively distribute the pulp flow supplied from the pulp inlet 11 to the internal channel of the inner pipe body 50 and the annular flow channel between the inner pipe body 50 and the outer pipe body 10. In a preferred embodiment, as Figure 4 、 Figure 7 shown, the closed end 21 is a hollow frustum shape to reduce the pulp flow resistance and improve the smoothness of the flow.
[0040] The second end of the inner tube body 50 and the outer edge of the port of the steam mixing tube 20 facing the pulp outlet 12 are spaced apart to form the open end 22. In this way, the second end of the inner tube body 50 and the outer edge of the port of the steam mixing tube 20 facing the pulp outlet 12 are not directly connected, but maintain a preset, usually annular gap. This annular gap constitutes the open end 22.
[0041] In this way, when the medium consistency pulp from the pulp inlet 11 flows in the internal channel of the inner tube body 50 and the annular flow channel between the inner tube body 50 and the outer tube body 10 towards the pulp outlet 12, in the outlet area close to or just leaving these channels, the two pulp flows will simultaneously encounter the high-temperature steam ejected at high speed in a downstream direction from the annular open end 22 and the steam outlets 33 of a plurality of steam introduction tubes 30, enabling the steam to come into full contact and mixing heating with the pulp flowing out from the inner tube and the outer ring simultaneously and evenly. It is particularly suitable for occasions where rapid and deep heating of pulp with a large cross-section or specific stratified flow is required.
[0042] In some embodiments, as Figure 6 、 Figure 7 shown, the inner tube body 50 includes a contraction section 51 and a straight section 52 smoothly connected to the contraction section 51. The inner diameter of the contraction section 51 gradually increases from the straight section 52 to the direction of the first end. Specifically, the contraction section 51 is located at the inlet part of the inner tube body 50, that is, adjacent to its first end. The inner diameter of this contraction section 51 gradually decreases along the flow direction of the medium consistency pulp to form a gradually contracting channel configuration. When the pulp flows through the contraction section 51, due to the reduction of the flow cross-sectional area, the flow rate of the pulp will increase accordingly and then flow into the straight section 52. This can accelerate and stabilize the flow of the pulp to a certain extent before the pulp enters the heating and mixing area of the outer tube body 10 with a relatively large inner diameter subsequently, which helps the subsequent penetration and mixing of the steam.
[0043] In some embodiments, as Figure 4 、 Figure 6 、 Figure 8 shown, a guiding portion 60 protrudes from the first side 31 of the steam introduction tube 30. The guiding portion 60 has two guiding inclined surfaces 61 arranged at an acute angle; the guiding inclined surfaces 61 are located on both sides of the axis of the steam introduction tube 30 and are respectively connected to the inner wall surface of the outer tube body 10 and the outer wall surface of the steam mixing tube 20. That is, the two smooth inclined surfaces 61 of the guiding portion 60 can gently divert the oncoming pulp flow to both sides of the steam introduction tube 30, enabling it to bypass the steam introduction tube 30 more smoothly, reducing the form drag when the pulp flows through here, thereby reducing the overall flow energy consumption, and avoiding damage to the pulp fibers caused by local violent disturbance or affecting the uniformity of subsequent mixing.
[0044] In this embodiment, as Figure 6 , Figure 7 , Figure 8 shown, the diversion part 60 is a hollow structure integrally formed with the steam inlet pipe 30. Integral forming avoids the possible weak links in welding or mechanical connection, making the combination of the diversion part 60 and the steam inlet pipe 30 more firm and reliable, capable of withstanding fluid impact and vibration for a long time, and having a long service life.
[0045] The steam co-current medium consistency pulp pipeline heater provided by the embodiment of the present application, by making the introduced steam flow in the same direction as the main flow of the pulp, not only effectively avoids water hammer phenomenon, vibration and noise, ensures the stable operation of the pipeline system, reduces the interference to the instrument valves, and prolongs the service life of the equipment; its internal multiple cavity structure also significantly improves the mixing efficiency and heat exchange effect of the steam and the pulp, reduces energy consumption, and maximally maintains the stable flow state of the pulp, thereby ensuring the stable operation of the production line and the stability of the product quality.
[0046] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "vertical", "upper", "lower", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.
[0047] In the description of the present application, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.
[0048] Finally, it should be noted that the above are only the preferred embodiments of the present application and are not used to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A steam co-current medium consistency pulp pipeline heater, characterized in that, Comprising: An outer tube body having a pulp inlet and a pulp outlet disposed opposite to each other; A steam mixing tube disposed inside the outer tube body, one end of the steam mixing tube facing the pulp inlet being a closed end, and the other end being provided with an opening communicating with the outer tube body; A plurality of steam introduction tubes circumferentially and equidistantly arranged on the outer wall surface of the steam mixing tube, and a plurality of the steam introduction tubes are all located in an annular flow channel formed between the outer tube body and the steam mixing tube; Steam inlets, a plurality of which are provided on the outer wall surface of the outer tube body corresponding to the positions of the respective steam introduction tubes, and each of the steam inlets is communicated to the steam mixing tube through a corresponding steam introduction tube; Wherein, each of the steam introduction tubes has an opposite first side and a second side, the inner diameter of the steam introduction tube gradually decreases in the direction from the first side to the second side, the first side is located between the second side and the pulp inlet, and a steam outlet extending along the axial direction of the steam introduction tube is formed on the second side of the steam introduction tube; the steam outlet is flush and communicated with the opening of the steam mixing tube, and the total outlet area of the steam outlet and the opening of the steam mixing tube is equal to the total inlet area of the plurality of steam inlets.
2. The steam co-current medium consistency pulp pipeline heater according to claim 1, wherein The closed end is conical.
3. The steam co-current medium consistency pulp pipeline heater according to claim 1, characterized in that, It further includes an inner tube body disposed inside the outer tube body, the inner tube body having a first end and a second end disposed opposite to each other, the first end of the inner tube body and the outer edge of the port of the steam mixing tube facing the pulp inlet integrally form the closed end, and the second end of the inner tube body and the outer edge of the port of the steam mixing tube facing the pulp outlet are spaced apart to form the opening; wherein, the inner tube body communicates the pulp inlet and the pulp outlet.
4. The steam co-current medium consistency pulp pipeline heater according to claim 3, characterized in that, The closed end is a hollow frustum shape.
5. The steam co-current medium consistency pulp pipeline heater according to claim 3, characterized in that, The inner tube body includes a contraction section and a straight section smoothly connected to the contraction section, and the inner diameter of the contraction section gradually increases in the direction from the straight section to the first end.
6. The steam co-current medium consistency pulp pipeline heater according to claim 1, characterized in that, A flow guiding portion is convexly provided on the first side of the steam introduction tube, and the flow guiding portion has two flow guiding inclined surfaces disposed at an acute angle; the flow guiding inclined surfaces are located on both sides of the axial direction of the steam introduction tube and are respectively connected to the inner wall surface of the outer tube body and the outer wall surface of the steam mixing tube.
7. The steam co-current medium consistency pulp pipeline heater according to claim 6, characterized in that, The flow guiding portion is a hollow structure integrally formed with the steam introduction tube.
8. The steam co-current medium consistency pulp pipeline heater according to claim 3, characterized in that, The outer tube body, the steam mixing tube and the inner tube body are coaxially arranged; the axis of the steam introduction tube is perpendicular to the axis of the outer tube body.
9. The steam co-current medium consistency pulp pipeline heater according to claim 1, characterized in that, The number of the steam introduction tubes is 3 - 8.