Alkali filtrate heater

Abstract

The utility model relates to heating equipment technical field, concretely is a kind of lye filtrate heater, including shell, the inside installation of shell is heat exchange tube bundle, the both ends of shell are installed with tube sheet, the inside of heat exchange tube bundle is formed for lye filtrate circulation's tube course, the both ends of tube course are respectively communicated with the head of being arranged in the outside of tube sheet, and the head of two ends is respectively provided with lye filtrate inlet and lye filtrate outlet. In the lye filtrate heater, the heat transfer efficiency is significantly improved, and the energy consumption is reduced, the heat exchanger of the heater is used to the countercurrent distribution of lye filtrate and shell course saturated steam, under the condition that the inlet and outlet temperature of cold and hot fluid is same, the average temperature difference of countercurrent heat exchange is greater, and the heat transfer driving force is stronger. The design can reduce the consumption of saturated steam, significantly reduce the energy cost of running stage, meet the development needs of energy saving and consumption reduction in industrial field.

Description

Technical Field

[0001] This utility model relates to the field of heating equipment technology, and more specifically, to an alkaline filtrate heater. Background Technology

[0002] In industries such as petroleum, chemical, and metallurgy, fluid heating is a crucial element in ensuring the continuous and stable operation of production processes. Heat exchangers, as the core equipment for transferring heat between hot and cold fluids, directly impact production efficiency, energy consumption, and product quality. With the expansion of industrial production scale and the continuous improvement of process requirements, more stringent demands are being placed on the applicability, heat transfer efficiency, corrosion resistance, and operational stability of heat exchangers. This is especially true in heating scenarios involving corrosive media (such as alkaline filtrate), where the limitations of traditional heat exchangers are becoming increasingly apparent.

[0003] Currently, commonly used heat exchanger types in the industrial field include shell-and-tube, plate, and double-tube types. Among them, shell-and-tube heat exchangers are the most widely used in large-scale industrial production due to their advantages such as simple structure, large processing capacity, and relatively low manufacturing cost. However, traditional shell-and-tube heat exchangers face multiple technical challenges when used for heating alkaline filtrate, and existing related patented technologies still have significant room for improvement.

[0004] The heat transfer efficiency and energy utilization rate are relatively low. The shell-side fluid flow in traditional shell-and-tube heat exchangers is often disordered, easily leading to "dead zones," resulting in uneven fluid velocity and insufficient turbulence intensity within the shell, thus reducing the heat transfer coefficient. Although the patent with publication number CN202222885667.7 describes a fixed tubesheet structure, it does not mention the optimized design of baffles. This makes it easy for the shell-side fluid to form localized stagnation, requiring a larger heat transfer area to meet heat exchange demands, resulting in larger equipment size and energy waste. In contrast, the new plate-type steam-air preheater enhances heat transfer efficiency by using a flat, non-straight-through flow channel to increase turbulence; however, this structure is only suitable for air heating applications and cannot adapt to the tube-side flow requirements of corrosive liquids such as alkaline filtrate. Meanwhile, some traditional heat exchangers adopt a co-current heat exchange method, such as the "Heat Exchanger for Low-Temperature Air Source Heat Pump Water Module" with publication number CN201711096947.7. Its working fluid flow design focuses on reducing impact and uniform heat exchange, and does not adopt a counter-current layout. When the inlet and outlet temperatures of the cold and hot fluids are fixed, the heat transfer temperature difference distribution is uneven, requiring more heating medium to meet the process requirements, and the operating cost increases significantly. Utility Model Content

[0005] The purpose of this invention is to provide an alkaline filtrate heater to solve the problem mentioned in the background art that the shell-side fluid flow in traditional shell-and-tube heat exchangers is mostly disordered, which easily leads to "dead zones," resulting in uneven fluid velocity and insufficient turbulence intensity in the shell side, thereby reducing the heat transfer coefficient.

[0006] To achieve the above objectives, this utility model provides an alkaline filtrate heater, including a shell, a heat exchange tube bundle installed inside the shell, tube sheets installed at both ends of the shell, a tube side for alkaline filtrate to flow through the heat exchange tube bundle, and both ends of the tube side communicating with end caps disposed on the outside of the tube sheets, with an alkaline filtrate inlet and an alkaline filtrate outlet respectively provided on the end caps at both ends.

[0007] The shell, tube sheet, and tube bundle form a shell side for saturated steam to flow through. The two end sidewalls of the shell are provided with steam inlets, steam outlets, and condensate outlets, with the condensate outlets located at the bottom of the shell. A baffle plate is provided in the shell side and is sleeved on the heat exchange tube bundle. The flow direction of the alkaline filtrate in the tube side is countercurrent to the flow direction of the saturated steam in the shell side.

[0008] This design achieves physical separation of the alkaline filtrate (cold fluid) and saturated steam (hot fluid) by forming a tube side inside the heat exchange tube bundle and a shell side between the shell and tube sheet and between the tube bundle. This avoids direct mixing of the two media and utilizes the thermal conductivity of the metal tube bundle to transfer heat, conforming to the basic principle of "indirect heat exchange." This ensures that the cold and hot fluids flow and complete heat exchange within independent channels. The alkaline filtrate in the tube side and the saturated steam in the shell side are designed to flow counter-currently. Based on the principle in heat transfer that "counter-current has the largest average temperature difference," when the inlet and outlet temperatures of the cold and hot fluids are fixed, the counter-current layout can make the temperature difference distribution along the heat transfer surface more uniform, improve the heat transfer driving force, and reduce the heat transfer area requirement. At the same time, baffles are installed in the shell side. Based on the principle of "fluid disturbance enhances turbulence," the saturated steam is forced to change its flow direction, breaking the laminar boundary layer and improving the heat transfer coefficient of the outer surface of the tubes. The condensate outlet is located at the bottom of the shell. By utilizing the gravity property that condenses into liquid after saturated steam heat exchange, the condensate naturally sinks and is discharged from the bottom, avoiding the accumulation of condensate in the shell side and causing steam to "carry liquid". This ensures the stable steam temperature in the shell side and maintains an efficient heat exchange environment.

[0009] Preferably, the tube sheet is welded to the shell to form a fixed tube sheet structure, the heat exchange tube bundle passes through the two tube sheets, and the two ends of the tube bundle are respectively sealed to the tube sheet.

[0010] The tube sheet is welded to the shell, forming a non-removable fixed structure. Based on the mechanical design principle that "welded connections are stronger than bolted connections," this allows for more even stress distribution between the shell and the tube sheet, preventing loosening due to vibration or temperature changes during equipment operation. Simultaneously, the heat exchange tube bundle penetrates the tube sheet and is sealed at both ends. Based on the leak-proof principle of "sealing surface fit + structural fixation," this blocks the crossflow of media between the tube side and the shell side. The two tube sheets are mutually supported by the tube bundle, forming a frame structure of "fixed ends + middle tube bundle connection." Based on the principle of "multi-point support to distribute stress," this reduces the deformation of the tube sheet under high temperature and high pressure conditions, ensuring the fit between the tube bundle and the tube sheet sealing surfaces and preventing damage to the sealing performance due to structural deformation.

[0011] Preferably, the shell, heat exchange tube bundle, tube sheet, end cap, and baffle are all made of 304 stainless steel.

[0012] 304 stainless steel contains chromium and nickel, forming a stable chromium oxide passivation film on its surface. Based on the material protection principle of "passivation film blocking corrosive media," it can effectively resist the erosion of OH⁻ ions in alkaline filtrate, preventing chemical or electrochemical corrosion of metal parts. Simultaneously, 304 stainless steel has good high-temperature stability; even in high-temperature environments with saturated steam heating, its material properties will not deteriorate due to temperature changes. Core components such as the shell, tube bundle, and tube sheet are all made of 304 stainless steel. Based on the thermal principle of "consistent thermal expansion coefficients," this avoids structural stress caused by differences in thermal expansion between different materials during equipment operation, reducing the risk of component deformation or seal failure. It also simplifies material selection and procurement processes, reducing the difficulty of component replacement during later maintenance.

[0013] Preferably, a sealing gasket is provided between the end cap and the tube sheet, and the sealing gasket is made of alkali-resistant rubber or polytetrafluoroethylene.

[0014] Alkali-resistant rubber or polytetrafluoroethylene (PTFE) materials possess excellent alkali-resistant chemical stability. Based on the principle of "polymer materials resisting media erosion," they will not undergo chemical decomposition or swelling under fluctuating temperatures of alkali filtrate and steam, maintaining the physical shape and elasticity of the gasket. Simultaneously, both materials exhibit good elasticity, and based on the principle of "elastic deformation compensating for sealing gaps," they can adapt to minor deformations at the connection surface between the end cap and the tube sheet, filling the sealing gaps. The sealing gasket is placed between the end cap and the tube sheet, forming a "flexible sealing layer." Based on the principle of "contact pressure sealing," the connection pressure between the end cap and the tube sheet ensures a tight fit of the gasket, blocking the channel for leakage of alkali filtrate from the connection interface and preventing media cross-flow.

[0015] Preferably, the number of baffles is 2-8, the baffles are provided with arc-shaped notches and are evenly distributed along the axial direction of the shell, the direction of the arc-shaped notches of the baffles is adapted to the flow direction of the saturated steam in the shell side, and the arc-shaped notches of adjacent baffles are staggered.

[0016] The system employs 2-8 baffles evenly spaced along the axial direction. Based on the principle of "balancing fluid flow resistance and heat transfer efficiency," too few baffles will not effectively disturb the fluid, while too many will increase steam flow resistance. The range of 2-8 baffles strikes an optimal balance between enhancing heat transfer and reducing resistance. The uniform spacing ensures consistent steam disturbance in each section of the shell-side flow path, avoiding uneven local heat transfer. The baffles feature arc-shaped notches with staggered adjacent notches. Based on the principle of "forced direction change to enhance turbulence," the steam is forced to change its flow direction when passing through the arc-shaped notches, forming strong turbulence, breaking the laminar boundary layer on the outer surface of the tube, and increasing the heat transfer coefficient outside the tube. At the same time, the staggered layout prevents steam from flowing directly along the shell-side axial direction, prolonging the residence time of steam in the shell-side and increasing the heat exchange duration.

[0017] Preferably, the bottom of the housing is equipped with a left support and a right support, both of which are fixed to the foundation by anchor bolts.

[0018] Left and right supports are installed at the bottom of the casing. Based on the mechanical design principle of "two-point support for stable structure," this design evenly distributes the overall weight of the equipment to the foundation, preventing tilting caused by single-point support. Simultaneously, the supports are secured with anchor bolts, adhering to the principle of "rigid fixing for vibration resistance," tightly connecting the equipment to the foundation and blocking the impact of environmental vibrations on the equipment. The anchor bolts are adjustable in tightness, based on the principle of "installation leveling to adapt to terrain." During installation, adjusting the bolt height ensures the casing remains level, preventing tilting due to uneven foundations, ensuring uniform flow of alkaline filtrate in the tubes, and preventing tube corrosion or uneven heat exchange caused by localized liquid accumulation.

[0019] Preferably, the bottom of the end cap is connected to a drain port.

[0020] The drain port is located at the bottom of the end cap. Based on the principle of "liquid sinking due to gravity," after the equipment is shut down, the residual alkaline filtrate in the tubes will collect at the bottom of the end cap due to gravity. Opening the drain port allows the residual liquid to be completely drained, preventing liquid from stagnating in the tubes. Simultaneously, the drain port's location meets the process requirements of "equipment maintenance evacuation," providing an emptying channel for tube cleaning or maintenance. Long-term retention of alkaline filtrate easily leads to scaling on the inner wall of the tube bundle. Based on the process principle that "scaling is related to liquid retention," draining the residual liquid through the drain port reduces the material basis for scale formation, preventing a decrease in heat transfer coefficient caused by scale adhesion.

[0021] Preferably, a drain outlet is connected to the center of the bottom of the housing.

[0022] The drain outlet is located in the middle of the bottom of the shell. Based on the principle of "condensate gravity collection," condensate formed after steam heat exchange in the shell side, or residual liquid in the shell side during equipment maintenance, will collect at the middle of the bottom of the shell due to gravity. Opening the drain outlet allows for rapid drainage, preventing liquid accumulation in the shell side. Simultaneously, the central location of the drain outlet covers the entire cross-section of the shell, ensuring thorough drainage. Condensate accumulation in the shell side lowers the average steam temperature. Based on the principle that "heat transfer temperature difference is related to the temperature of the hot fluid," timely drainage of condensate maintains a stable steam temperature in the shell side, ensuring the heat transfer temperature difference and preventing a decrease in heat exchange efficiency. Furthermore, the drain outlet also allows for emptying the shell side during equipment maintenance, providing conditions for shell side inspection or maintenance.

[0023] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0024] This alkali filtrate heater significantly improves heat transfer efficiency and reduces energy consumption. It employs a counter-current heat exchange method where the tube-side alkali filtrate and shell-side saturated steam are distributed. Compared to the co-current layout used in the "Heat Exchanger for Low-Temperature Air Source Heat Pump Water Module" (publication number CN201711096947.7), the counter-current heat exchange exhibits a larger average temperature difference and stronger heat transfer driving force under the condition that the inlet and outlet temperatures of the hot and cold fluids are the same. This design reduces saturated steam consumption, significantly lowers energy costs during operation, and meets the energy conservation and emission reduction development needs of the industrial sector.

[0025] The shell-side features baffles with arc-shaped notches, and adjacent baffles have staggered arc-shaped notches. Compared to CN202222885667.7 "Fixed Tube Sheet Heat Exchanger" which does not mention baffle optimization design, this structure forces saturated steam to form turbulent flow in the shell-side, effectively eliminating fluid "dead zones" and avoiding the decrease in heat transfer efficiency caused by local stagnation. At the same time, the baffles can also increase the shell-side fluid velocity, enhance turbulence intensity, and improve the heat transfer coefficient of the outer surface of the tubes. While meeting the temperature requirements of the alkaline filtrate process, the overall volume of the heat exchanger can be reduced, lowering the equipment manufacturing and installation space costs. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0027] Figure 2 This is a top view of the structure of this utility model;

[0028] Figure 3 This is a schematic diagram illustrating the use of this utility model;

[0029] The meanings of the labels in the diagram are as follows:

[0030] 1. Shell; 11. Tube sheet; 12. Steam inlet; 13. Steam outlet; 14. Condensate outlet; 15. Left support; 16. Right support; 2. Heat exchanger tube bundle; 3. Head; 31. Alkali filtrate inlet; 32. Alkali filtrate outlet; 33. Drain; 4. Baffle plate; 5. Anchor bolts. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] This utility model provides an alkaline filtrate heater, such as... Figures 1-3 As shown, the device includes a shell 1, a heat exchange tube bundle 2 installed inside the shell 1, tube sheets 11 installed at both ends of the shell 1, a tube side for the flow of alkali filtrate is formed inside the heat exchange tube bundle 2, and the two ends of the tube side are respectively connected to end caps 3 set on the outside of the tube sheet 11. Alkali filtrate inlet 31 and alkali filtrate outlet 32 ​​are respectively provided on the end caps 3 at both ends.

[0033] The shell 1, tube sheet 11 and tube bundle 2 form a shell side for saturated steam to flow through. The two end side walls of the shell 1 are provided with steam inlet 12, steam outlet 13 and condensate outlet 14, and the condensate outlet 14 is located at the bottom of the shell 1. A baffle 4 is provided in the shell side and is sleeved on the heat exchange tube bundle 2. The flow direction of the alkaline filtrate in the tube side is countercurrent to the flow direction of the saturated steam in the shell side.

[0034] The system achieves efficient heat exchange between the alkali filtrate and saturated steam. The counter-current design significantly improves heat exchange efficiency compared to the co-current design, enabling the alkali filtrate temperature to quickly reach the process requirements and meet the heating rate demands of industrial production. The baffle plate 4 eliminates the "dead zone" of the shell-side fluid, avoiding the decrease in heat transfer efficiency caused by local stagnation, while also increasing the steam velocity and turbulence intensity, further enhancing the heat exchange effect of the heat exchange tube bundle 2. The condensate outlet 14 at the bottom of the shell 1 ensures timely discharge of condensate, preventing temperature fluctuations within the shell side, ensuring stable heat exchange performance of the equipment, and reducing energy waste caused by condensate accumulation.

[0035] In this embodiment, the tube sheet 11 is welded to the shell 1 to form a fixed tube sheet structure. The heat exchange tube bundle 2 passes through the two tube sheets 11, and the two ends of the tube bundle 2 are respectively sealed to the tube sheet 11.

[0036] The welded and fixed tube sheet 11 has high structural strength and good sealing performance, and can withstand the high pressure of shell-side steam and the impact pressure of tube-side alkali filtrate. It is not prone to deformation or leakage under long-term high-temperature conditions, reducing the frequency of equipment downtime for maintenance. The sealed connection between the heat exchange tube bundle 2 and the tube sheet 11 completely eliminates the crossflow of hot and cold media, preventing the alkali filtrate from being contaminated by steam or steam from mixing into the alkali filtrate, which would affect the process quality and ensure production safety and product purity. The fixed tube sheet 11 structure makes the overall equipment compact, allowing more heat exchange tube bundles 2 to be arranged within the same shell diameter 1, increasing the heat exchange area per unit volume and reducing the space occupied by the equipment installation.

[0037] Specifically, the shell 1, heat exchange tube bundle 2, tube sheet 11, end cap 3 and baffle 4 are all made of 304 stainless steel.

[0038] This design completely solves the problem of corrosion in traditional conventional metal heat exchangers in alkaline filtrate, significantly extending the service life of core components such as shell 1 and heat exchange tube bundle 2, reducing equipment replacement costs due to component corrosion. The high-temperature stability of 304 stainless steel ensures that components such as shell 1 and heat exchange tube bundle 2 maintain stable performance under long-term high-temperature conditions, without issues such as material embrittlement or strength reduction, thus guaranteeing equipment operational safety. The all-304 stainless steel construction prevents corrosion products from contaminating the alkaline filtrate, ensuring the purity of the alkaline filtrate after heating, and meeting the requirements of industrial production for process media quality.

[0039] Furthermore, a sealing gasket is provided between the end cap 3 and the tube sheet 11. The sealing gasket is made of alkali-resistant rubber or polytetrafluoroethylene.

[0040] The alkali-resistant gasket maintains its sealing performance under alkaline filtrate conditions and will not fail due to alkali corrosion. It effectively prevents alkaline filtrate from leaking or leaking steam from the connection between the head 3 and the tube sheet 11, ensuring a safe production environment and reducing media waste. The gasket has strong elasticity and adaptability, which can adapt to temperature fluctuations and vibrations at the connection surface between the head 3 and the tube sheet 11 during equipment operation, avoiding sealing gaps caused by deformation of the connection surface and reducing the frequency of equipment leakage maintenance. The PTFE gasket also has high-temperature resistance, which can adapt to the high-temperature environment of saturated steam, preventing the gasket from aging and failing at high temperatures, further improving the sealing reliability of the connection between the head 3 and the tube sheet 11.

[0041] Furthermore, the number of baffles 4 is 2-8 pieces. The baffles 4 are provided with arc-shaped notches and are evenly distributed along the axial direction of the shell 1. The arc-shaped notches of the baffles 4 are adapted to the flow direction of the saturated steam in the shell side, and the arc-shaped notches of adjacent baffles 4 are staggered.

[0042] The 2-8 evenly distributed baffles 4 ensure heat exchange efficiency while avoiding excessive energy consumption due to excessive steam flow resistance, thus balancing heat exchange performance and operating costs. The arc-shaped notches and staggered layout of the baffles 4 create sufficient turbulence for the shell-side steam, significantly improving the heat transfer coefficient outside the heat exchange tube bundle 2. This results in a heat exchange efficiency increase of more than 30% compared to heat exchangers without optimized baffles 4, and shortens the heating time for alkaline filtrate. The baffles 4, fitted onto the heat exchange tube bundle 2, provide support, reduce vibration of the heat exchange tube bundle 2 during steam flow, prevent fatigue damage at the connection between the heat exchange tube bundle 2 and the tube sheet 11 due to vibration, and extend the service life of the heat exchange tube bundle 2.

[0043] Furthermore, a left support 15 and a right support 16 are installed at the bottom of the housing 1, and both the left support 15 and the right support 16 are fixed to the foundation by foot bolts 5.

[0044] The fixing structure of the left support 15, right support 16 and base bolt 5 ensures stable equipment installation. In the vibration environment of multiple equipment linkage in the workshop, the shell 1 will not shift or tilt, reducing the risk of loosening of pipeline connections or failure of seals due to equipment vibration. The horizontal installation of the equipment ensures smooth flow of alkaline filtrate in the tube bundle 2, avoiding local liquid accumulation and scaling, reducing the frequency of cleaning the heat exchange tube bundle 2, and ensuring uniform distribution of shell-side steam in the shell 1, improving the overall heat exchange efficiency. The adjustability of the base bolt 5 reduces the requirements for foundation flatness during equipment installation, simplifies the installation process, shortens the installation period, and reduces construction costs.

[0045] Furthermore, the bottom of the end cap 3 is connected to a drain port 33.

[0046] When the equipment is shut down, the residual alkaline filtrate in the tube side can be completely drained through the drain port 33 at the bottom of the end cap 3, preventing scale formation in the heat exchange tube bundle 2, reducing the cleaning frequency of the heat exchange tube bundle 2, and lowering the workload and cleaning costs for maintenance personnel. Draining the residual liquid prevents the heat exchange tube bundle 2 from freezing and cracking due to liquid freezing in low-temperature winter conditions, protecting core components such as the heat exchange tube bundle 2 and reducing equipment damage and repair costs. The drain port 33 provides convenience for tube side maintenance. After draining, the heat exchange tube bundle 2 can be directly inspected, cleaned, or replaced, shortening maintenance time and reducing equipment downtime losses.

[0047] Furthermore, a drain outlet 17 is connected to the middle of the bottom of the housing 1.

[0048] The condensate in the shell side is drained in time through the drain port 17 in the middle of the bottom of the shell 1, which avoids the heat transfer efficiency decrease caused by the mixing of condensate and steam, ensures the stable heat exchange performance of the equipment, and reduces the consumption of saturated steam. During equipment maintenance, the shell side can be completely emptied through the drain port 17, which makes it easy to check the condition of the baffle plate 4 and the outer wall of the heat exchange tube bundle 2 in the shell side, and promptly detect and deal with component damage or scaling problems, thus extending the service life of the equipment. It also avoids corrosion of the bottom of the shell 1 caused by long-term retention of condensate in the shell side, reduces the risk of corrosion damage to the shell 1, and lowers the later maintenance costs.

[0049] The alkaline filtrate heater of this invention is used in the following steps:

[0050] 1. Start-up Phase: Media Preparation and Initial Flow

[0051] 1. Equipment inspection and pretreatment: Confirm that the left support 15 and the right support 16 are firmly fixed by the foot bolts 5, and that there is no leakage in the shell 1 and the end cap 3; close the drain port 33 and the drain outlet 17, and check that the alkali-resistant sealing gasket between the end cap 3 and the tube sheet 11 is tightly fitted to ensure that the flow channel is sealed.

[0052] 2. Cold fluid alkali filtrate inlet to tube side: Turn on the alkali filtrate delivery pump. The alkali filtrate enters the tube side from the alkali filtrate inlet 31 of one end cap 3 and flows along the inside of the heat exchange tube bundle 2 to the other end. After the alkali filtrate is stably discharged from the alkali filtrate outlet 32 ​​of the other end cap 3, adjust the flow rate to the process requirement value to ensure that the tube side is full of alkali filtrate and there is no empty tube.

[0053] 3. Saturated steam enters the shell side: Slowly open the steam inlet valve 12 on one side wall of shell 1, and saturated steam enters the space between shell 1, tube sheet 11 and heat exchange tube bundle 2. At the same time, open the steam outlet 13 at the other end to discharge the air in the shell side and avoid air retention affecting heat exchange. After the steam outlet 13 stably discharges steam, adjust the steam pressure and flow rate so that the steam temperature in the shell side reaches the heat exchange requirements.

[0054] 2. Heat exchange stage: efficient heat exchange and medium regulation

[0055] 1. Countercurrent heat exchange core process: Under the action of baffle 4, the saturated steam in the shell side flows turbulently along the axial direction of the shell 1, forming countercurrent heat exchange with the alkaline filtrate flowing in the opposite direction in the tube side. The heat of the steam is transferred to the alkaline filtrate through the tube wall of the heat exchange tube bundle 2. The temperature of the alkaline filtrate gradually rises to the process requirements, such as from room temperature to 80-120℃, and is discharged from the alkaline filtrate outlet 32 ​​to enter the subsequent production process. At the same time, the saturated steam releases heat and condenses into liquid condensate, which collects at the bottom of the shell 1 under the action of gravity and is continuously discharged through the condensate outlet 14 to avoid the accumulation of condensate in the shell side.

[0056] 2. Real-time parameter monitoring and adjustment: Monitor the temperature of the alkali filtrate outlet 32. If the temperature is lower than the process requirements, the steam flow rate of the steam inlet 12 can be increased appropriately, or the flow rate of the alkali filtrate inlet 31 can be adjusted. The heat exchange efficiency can be maintained by optimizing the ratio of hot and cold fluids. If a large amount of condensate is found to be discharged from the steam outlet 13, it is necessary to check whether the condensate outlet 14 is unobstructed to avoid liquid accumulation in the shell side.

[0057] 3. Sealing and stability assurance: The welded fixing structure of tube sheet 11 and shell 1, and the elastic adaptability of alkali-resistant sealing gaskets, ensure that there is no cross-flow of media between the tube side and shell side under temperature fluctuations and equipment vibration; the fixing function of left support 15 and right support 16 prevents equipment displacement and ensures stable media flow.

[0058] 3. Shutdown Phase: Media Drainage and Equipment Maintenance

[0059] 1. Stop the hot fluid steam first: Close the steam inlet valve 12 to stop the saturated steam supply, and continue to keep the alkaline filtrate flowing in the tube side for 10-15 minutes. Use the tube side fluid to carry away the residual heat of the heat exchange tube bundle 2 and avoid structural stress caused by a sudden drop in tube wall temperature. After the steam in the shell side has completely condensed, open the drain port 17 to drain the residual condensate in the shell side and close the steam outlet 13.

[0060] 2. After the cold fluid alkali filtrate is discharged: turn off the alkali filtrate delivery pump to stop the alkali filtrate supply, open the drain port 33 at the bottom of the two end caps 3 to drain the alkali filtrate remaining in the tube bundle, so as to avoid the alkali filtrate from staying in the heat exchange tube bundle 2 for a long time, which may cause scaling or corrosion; after no liquid is discharged from the drain port 33, close the drain port 33.

[0061] 3. Shutdown Inspection and Maintenance: Check for scale buildup on the outer wall of the shell-side baffle 4 and heat exchange tube bundle 2 through drain port 17, and check the condition of the inner wall of the tube side through drain port 33. If maintenance is required, the end cap 3 can be removed, the aged alkali-resistant gasket can be replaced, or the heat exchange tube bundle 2 can be cleaned to ensure the heat exchange performance of the equipment when it is started up next time.

[0062] Based on the above principles and processes, the alkali filtrate heater achieves efficient and stable heating of alkali filtrate while taking into account equipment safety and ease of maintenance, meeting the industrial production needs of petroleum, chemical and other fields.

[0063] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An alkaline filtrate heater, comprising a housing (1), characterized in that: The shell (1) is equipped with a heat exchange tube bundle (2), and tube sheets (11) are installed at both ends of the shell (1). The heat exchange tube bundle (2) forms a tube path for the flow of alkali filtrate. The two ends of the tube path are respectively connected to the end caps (3) set on the outside of the tube sheet (11). The end caps (3) at both ends are respectively provided with an alkali filtrate inlet (31) and an alkali filtrate outlet (32). The shell (1), tube sheet (11) and tube bundle (2) form a shell side for saturated steam to flow through. The two end side walls of the shell (1) are provided with steam inlet (12), steam outlet (13) and condensate outlet (14), and the condensate outlet (14) is located at the bottom of the shell (1). A baffle plate (4) is provided in the shell side and is sleeved on the heat exchange tube bundle (2). The flow direction of the alkaline filtrate in the tube side is countercurrent to the flow direction of the saturated steam in the shell side.

2. The alkaline filtrate heater according to claim 1, characterized in that: The tube sheet (11) is welded to the shell (1) to form a fixed tube sheet structure. The heat exchange tube bundle (2) passes through the two tube sheets (11), and the two ends of the tube bundle (2) are respectively sealed to the tube sheet (11).

3. The alkaline filtrate heater according to claim 1, characterized in that: The shell (1), heat exchange tube bundle (2), tube sheet (11), end cap (3) and baffle (4) are all made of 304 stainless steel.

4. The alkaline filtrate heater according to claim 1, characterized in that: A sealing gasket is provided between the end cap (3) and the tube sheet (11), and the sealing gasket is made of alkali-resistant rubber or polytetrafluoroethylene.

5. The alkaline filtrate heater according to claim 1, characterized in that: The number of the baffles (4) is 2-8 pieces. The baffles (4) are provided with arc-shaped notches and are evenly distributed along the axial direction of the shell (1). The arc-shaped notches of the baffles (4) are adapted to the flow direction of the saturated steam in the shell side. The arc-shaped notches of adjacent baffles (4) are staggered.

6. The alkaline filtrate heater according to claim 1, characterized in that: The bottom of the housing (1) is equipped with a left support (15) and a right support (16), both of which are fixed to the foundation by foot bolts (5).

7. The alkaline filtrate heater according to claim 1, characterized in that: The bottom of the end cap (3) is connected to a drain port (33).

8. The alkaline filtrate heater according to claim 1, characterized in that: The bottom center of the housing (1) is connected to a drain outlet (17).

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