A low-temperature waste heat driven dilute acid concentration device

Abstract

This invention discloses a low-temperature waste heat-driven dilute acid concentration device, relating to the technical field of waste heat recovery and concentration. It includes a preheating box with preheating pipes inside, and temporary storage tanks at both ends. This invention preheats the dilute acid using a grid-plate heat exchange structure within the preheating box, and then uses mechanical compression in a pressurized tank to increase the temperature and grade of steam for secondary heating. This achieves efficient cascade utilization of low-grade industrial waste heat, significantly reducing the overall energy consumption of the concentration process. Furthermore, the pressurized component compresses the steam, significantly increasing the temperature threshold of the heated dilute acid and effectively improving concentration efficiency. The pressurized component is equipped with a linkage shaft and bevel gear transmission structure, allowing adjustment of the eccentricity of the support shaft, thereby flexibly changing the piston plate stroke and compression intensity. This enables precise matching of heating power according to the initial concentration of the dilute acid and the concentration target, avoiding energy waste caused by overheating.

Description

Technical Field

[0001] This invention relates to the technical field of waste heat recovery and concentration, and in particular to a low-temperature waste heat-driven dilute acid concentration device. Background Technology

[0002] In the production processes of industries such as chemical, metallurgical, and pharmaceutical, a large amount of low-grade low-temperature waste heat steam and dilute acid waste liquid that needs to be concentrated are usually generated. How to efficiently utilize these low-temperature waste heat resources to concentrate and purify dilute acid is an important issue for achieving energy conservation, emission reduction and resource recycling.

[0003] Currently, existing dilute acid concentration devices have the following main problems in the process of using low-grade waste heat to drive concentration: traditional heat exchange structures have low thermal energy utilization efficiency of low-temperature waste heat, the waste heat steam flows at a high velocity in the heat exchange pipes, and the heat is often discharged before it is fully transferred, resulting in insufficient preheating of dilute acid, high energy consumption in subsequent concentration stages, and overall heat recovery efficiency that is difficult to meet the needs of industrial production. Furthermore, the temperature of the low-temperature waste heat steam itself is limited, and the temperature further decreases after the initial heat exchange, making it difficult to directly provide enough heat for dilute acid to drive efficient evaporation and concentration, resulting in low concentration efficiency and long processing cycle. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the above and / or existing low-temperature waste heat driven dilute acid concentration devices, the present invention is proposed.

[0006] Therefore, the problem to be solved by the present invention is how to solve the problem that the temperature of existing low-temperature waste heat steam is limited and further decreases after preliminary heat exchange, making it difficult to directly provide enough heat to drive the efficient evaporation and concentration of dilute acid, resulting in low concentration efficiency and long processing cycle.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a low-temperature waste heat driven dilute acid concentration device, comprising: a preheating box, which is provided with a preheating pipe inside, and temporary storage boxes at both ends of the preheating box, the temporary storage boxes being provided with a plurality of insert plates inserted into the preheating box; a pressure tank, which is located on one side of the preheating box and connected to the preheating pipe; a heating tank, which is connected to both ends of the pressure tank and connected to the preheating box, and a heat-conducting cover is fixedly installed inside the heating tank; a pressurizing component, which is located inside the pressure tank and is used to compress the steam entering the pressure tank to increase the steam temperature; a filtration component, which includes a support and a filter box set on the support, the filter box being provided with an Md distillation membrane to divide the interior into two chambers respectively connected to the heating tank and circulating cold water; waste heat steam enters the preheating pipe to preheat the dilute acid in the temporary storage box, and then enters the pressure tank where it is compressed and heated by the pressurizing component to perform secondary heating of the dilute acid.

[0008] As a preferred embodiment of the low-temperature waste heat driven dilute acid concentration device of the present invention, the pressurizing component includes: a rotating disk rotatably disposed inside the pressurizing tank, the rotating disk having a connecting groove inside; a support shaft slidably disposed at both ends of the connecting groove; a cam disk disposed at the end of the support shaft away from the rotating disk, the two cam disks being disposed opposite each other, a sliding groove being provided on one side of the cam disk; a threaded rod rotatably disposed inside the sliding groove, the end of the support shaft being slidably disposed in the sliding groove and threadedly engaged with the threaded rod; and a rotating shaft disposed on the other side of the cam disk and passing through the pressurizing tank, and being rotatably connected to the pressurizing tank through a flange.

[0009] As a preferred embodiment of the low-temperature waste heat driven dilute acid concentration device of the present invention, the pressurizing component further includes: a linkage shaft, which is rotatably disposed inside the rotating shaft. One end of the linkage shaft is driven by a bevel gear set and a threaded rod, which is used to drive the threaded rod to rotate to adjust the position of the support shaft in the sliding groove.

[0010] As a preferred embodiment of the low-temperature waste heat driven dilute acid concentration device of the present invention, wherein: a connecting rod is rotatably provided on the outer periphery of the support shaft via a bearing, and a piston plate is rotatably connected to the other end of the connecting rod, and the piston plate is in sliding sealing cooperation with the pressure tank.

[0011] As a preferred embodiment of the low-temperature waste heat driven dilute acid concentration device of the present invention, the pressurizing component further includes a synchronization component, which includes: a gear shaft, rotatably disposed at the center of the rotating disk; two synchronization gears, respectively rotatably disposed at both ends of the gear shaft; and toothed plates, disposed at one end of the two support shafts inserted into the connecting groove, and the two toothed plates respectively meshing with the opposite sides of the synchronization gears to realize the synchronous opposite movement of the two support shafts.

[0012] As a preferred embodiment of the low-temperature waste heat driven dilute acid concentration device of the present invention, wherein: the two side walls of the connecting groove are provided with limiting grooves, and the toothed plate is slidably disposed inside the limiting grooves.

[0013] As a preferred embodiment of the low-temperature waste heat driven dilute acid concentration device of the present invention, the heat-conducting cover is cylindrical and its top end is fixedly connected to the inner wall of the heating tank, and a flowable gap is formed between the outer peripheral wall of the heat-conducting cover and the inner wall of the heating tank.

[0014] As a preferred embodiment of the low-temperature waste heat driven dilute acid concentration device of the present invention, wherein: the insert plate forms a grid structure inside the preheating box, and a heat-conducting plate is filled between the inner wall of the grid holes and the outer wall of the preheating pipe, for uniformly transferring the steam heat in the preheating pipe to the dilute acid liquid inside the temporary storage box.

[0015] As a preferred embodiment of the low-temperature waste heat driven dilute acid concentration device of the present invention, it further includes a recovery mechanism comprising: a dilute acid collection tank, which is connected to a side cavity of the filter box and a heating tank, for collecting dilute acid concentrated by the Md distillation membrane; and a circulating water collection tank, which is connected to a side cavity of the filter box and a circulating water tank, for recovering the circulating water after heat exchange.

[0016] As a preferred embodiment of the low-temperature waste heat driven dilute acid concentration device of the present invention, it further includes a drainage component, which includes a collection chamber disposed on one side of the support, with pipes provided at both ends of the collection chamber, and the other end of the pipes connected to both ends of the pressure tank for collecting the discharged steam.

[0017] The beneficial effects of this invention are as follows: the dilute acid is preheated once by the grid-plate heat exchange structure in the preheating box, and then the dilute acid is reheated by the mechanical compression in the pressurization tank to increase the temperature and grade of the steam. This achieves efficient cascade utilization of low-grade industrial waste heat, significantly reducing the overall energy consumption of the concentration process. Furthermore, the steam compression by the pressurization component can significantly increase the temperature threshold of the dilute acid after heating, effectively improving the concentration efficiency. The pressurization component is equipped with a linkage shaft and bevel gear transmission structure, which can adjust the eccentricity of the support shaft, thereby flexibly changing the piston plate stroke and compression intensity. It can accurately match the heating power according to the initial concentration of the dilute acid and the concentration target, avoiding energy waste caused by overheating. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a scene diagram of a low-temperature waste heat-driven dilute acid concentration device.

[0020] Figure 2 This is a structural diagram of the filter assembly for a low-temperature waste heat-driven dilute acid concentration device.

[0021] Figure 3 A scene diagram of the preheating box and pressurizing tank of a low-temperature waste heat-driven dilute acid concentration unit.

[0022] Figure 4 This is a structural diagram of the preheating box for a low-temperature waste heat-driven dilute acid concentration device.

[0023] Figure 5 This is a diagram of the internal structure of the pressurization tank for a low-temperature waste heat-driven dilute acid concentration device.

[0024] Figure 6 This is a diagram of the internal structure of the heating tank in a low-temperature waste heat-driven dilute acid concentration device.

[0025] Figure 7 This is a structural diagram of the pressurization component of a low-temperature waste heat-driven dilute acid concentration device.

[0026] Figure 8 This is a structural diagram of a cam disk used in a low-temperature waste heat-driven dilute acid concentration device.

[0027] Figure 9 This is a structural diagram of the synchronous component of a low-temperature waste heat driven dilute acid concentration device.

[0028] Figure 10 This is a structural diagram of a bevel gear assembly used in a low-temperature waste heat-driven dilute acid concentration device.

[0029] In the diagram: 1. Preheating box; 2. Preheating pipe; 3. Temporary storage box; 4. Insert plate; 5. Pressurizing tank; 6. Heating tank; 7. Heat conduction cover; 8. Pressurizing assembly; 81. Rotating disc; 82. Connecting groove; 83. Support shaft; 84. Cam disc; 85. Sliding groove; 86. Threaded rod; 87. Rotating shaft; 88. Linkage shaft; 89. Bevel gear set; 810. Connecting rod; 811. Piston plate; 812. Synchronization assembly; 8121. Gear shaft; 8122. Synchronization gear; 8123. Gear plate; 813. Limiting groove; 9. Filter assembly; 91. Filter box; 92. Distillation membrane; 10. Recovery mechanism; 101. Dilute acid collection tank; 102. Circulating water collection tank; 11. Drainage assembly; 111. Gathering chamber; 112. Through pipe. Detailed Implementation

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0033] Example 1, referring to Figures 1-10 This is the first embodiment of the present invention. This embodiment provides a low-temperature waste heat driven dilute acid concentration device. The low-temperature waste heat driven dilute acid concentration device includes a preheating of dilute acid through a heat exchange structure of mesh plate 4 in a preheating box 1, and a secondary heating of dilute acid by mechanically compressing and increasing the temperature and grade of steam in a pressurizing tank 5. At the same time, the steam is compressed by a pressurizing component 8 to increase its temperature. During the secondary heating, the temperature threshold of the dilute acid after heating can be significantly increased.

[0034] Specifically, it includes a preheating box 1, which is equipped with a preheating pipe 2 inside. Both ends of the preheating box 1 are equipped with temporary storage boxes 3, and the temporary storage boxes 3 are equipped with several insert plates 4 that are inserted into the preheating box 1. A pressure tank 5 is located on one side of the preheating box 1 and is connected to the preheating pipe 2. A one-way valve is installed at the connection point so that steam can only flow into the interior of the pressure tank 5 from the preheating pipe 2. The valve automatically closes during the compression stroke of the pressure assembly 8 to prevent high-temperature steam from flowing back into the preheating pipe 2, ensuring that the compression heat is not lost and ensuring the compression heating efficiency and the stability of the airflow in the preheating section.

[0035] Heating tank 6 is connected to both ends of pressurizing tank 5 and communicates with preheating box 1. Heat conduction cover 7 is fixedly installed inside heating tank 6. Low temperature waste heat steam from the external industrial environment first enters the preheating pipe 2 inside the preheating box 1 through the inlet flange. At this time, the dilute acid liquid to be purified is injected into the temporary storage tank 3 located at both ends of the preheating box 1 through the pipeline.

[0036] Since one end of the insert plate 4 is inserted into the preheating box 1 and is in close contact with the outer wall of the preheating pipe 2 or connected through a heat transfer medium, while the other end is inserted into the liquid in the temporary storage box 3, the heat carried by the steam in the preheating pipe 2 will be efficiently conducted to the dilute acid liquid in the temporary storage box 3 through the insert plate 4. By utilizing the extended heat exchange surface formed by the insert plate 4, uniform and rapid heat transfer is achieved in a limited space, thereby completing the first preheating treatment of the dilute acid, effectively reducing the energy consumption of subsequent heating stages, and improving the overall waste heat recovery efficiency.

[0037] The preheated dilute acid flows from the temporary storage tank 3 into the heating tank 6 under pressure or gravity. The steam, which has completed the initial heat exchange and whose temperature has decreased, flows along the outlet direction of the preheating pipe 2 and enters the pressure tank 5 located on one side of the preheating box 1. The left and right ends of the pressure tank 5 are respectively connected to the cavities of the two heating tanks 6. After the steam is further compressed and heated in the pressure tank 5, the high temperature heat it carries is transferred to the dilute acid flowing through it through the heat-conducting cover 7 that is slidably set inside the heating tank 6, thereby achieving secondary enhanced heating of the dilute acid. By heating the dilute acid multiple times, the temperature rise threshold of the dilute acid and the heating efficiency of the dilute acid can be significantly improved, so as to improve the concentration efficiency.

[0038] Specifically, the pressurizing component 8 is located inside the pressurizing tank 5 and is used to compress the steam entering the pressurizing tank 5 to increase the steam temperature. The pressurizing component 8 is used to change the volume and pressure of the steam entering the pressurizing tank 5. During operation, the external drive motor drives the pressurizing component 8 through the transmission shaft to perform periodic compression work on the preheated steam flowing into the pressurizing tank 5. According to thermodynamic principles, the internal energy of a gas increases and its temperature rises significantly during adiabatic or near-adiabatic compression. Therefore, through the mechanical compression of this component, the preheated steam, whose temperature had already decreased, is raised to a higher temperature level, so that the heat can be effectively used for the secondary heating stage. This overcomes the defect of insufficient heat transfer temperature difference in the single heat exchange process and ensures that the dilute acid can reach the expected temperature rise target in the heating tank 6 to promote the subsequent membrane distillation process.

[0039] Specifically, the filter assembly 9 includes a support frame and a filter box 91 mounted on the support frame. The filter box 91 is equipped with an Md distillation membrane 92 to divide the interior into two chambers that are respectively connected to the heating tank 6 and the circulating cold water. Waste heat steam enters the preheating pipe 2 to preheat the dilute acid in the temporary storage tank 3, and then enters the pressurizing tank 5 where it is compressed and heated by the pressurizing assembly 8 to reheat the dilute acid. The support frame is made of channel steel welded together to stably support the filter box 91 located above it. The interior of the filter box 91 is strictly divided into a hot side chamber and a cold side chamber by one or more Md distillation membranes 92.

[0040] Specifically, the inlet of the hot side cavity is connected to the dilute acid outlet of the heating tank 6 through a corrosion-resistant pipe, which is used to receive the high-temperature dilute acid after two heating cycles; the inlet of the cold side cavity is connected to an external cooling tower or chiller unit through a circulating water pipeline, which introduces low-temperature circulating water.

[0041] Because the hot-side dilute acid has a high temperature and high saturated vapor pressure, while the cold-side water has a low temperature and low vapor pressure, a significant water vapor partial pressure difference is formed across the micropores of the Md distillation membrane 92. Driven by this pressure difference, water molecules in the dilute acid continuously pass through the pores of the Md distillation membrane 92 in gaseous form and condense on the cold side, while the solute and other non-volatile components in the acid solution are retained on the hot side, thus achieving the dehydration and concentration of the dilute acid.

[0042] Example 2, refer to Figures 2 to 10 This is the second embodiment of the present invention, which is based on the previous embodiment.

[0043] Specifically, the pressurization assembly 8 includes: a rotating disk 81, rotatably disposed inside the pressurization tank 5, with a connecting groove 82 inside the rotating disk 81; a support shaft 83, slidably disposed at both ends of the connecting groove 82; a cam disk 84, disposed at the end of the support shaft 83 away from the rotating disk 81, with two cam disks 84 arranged opposite each other, and a sliding groove 85 on one side of the cam disk 84; a threaded rod 86, rotatably disposed inside the sliding groove 85, with the end of the support shaft 83 slidably disposed in the sliding groove 85 and threadedly engaged with the threaded rod 86; and a rotating shaft 87, disposed on the other side of the cam disk 84 and passing through the pressurization tank 5, and rotatably connected to the pressurization tank 5 via a flange. During operation, external driving force is input through the rotating shaft 87, causing the cam disk 84 to rotate synchronously.

[0044] Since one end of the support shaft 83 is inserted into the sliding groove 85 on the side of the cam disk 84 and forms a threaded engagement with the threaded rod 86 therein, while the other end is slidably connected to the connecting groove 82 of the rotating disk 81, the support shaft 83 will move along the rotation trajectory of the cam disk 84 when the cam disk 84 rotates. The radial sliding freedom of the support shaft 83 in the connecting groove 82 allows the rotating disk 81 to rotate smoothly without motion interference, converting the rotational motion into piston reciprocating motion. The rotating shaft 87 is connected to the shell of the pressure tank 5 by a flange with a seal, which not only ensures smooth rotation but also effectively prevents steam leakage from the inside of the pressure tank 5 along the rotational gap, maintaining the sealing performance of the compression chamber.

[0045] Specifically, the pressurizing assembly 8 also includes: a linkage shaft 88, which is rotatably disposed inside the rotating shaft 87. One end of the linkage shaft 88 is driven by a bevel gear set 89 to drive the threaded rod 86 to rotate in order to adjust the position of the support shaft 83 in the sliding groove 85. In order to realize the online adjustment of the compression stroke, a linkage shaft 88 is coaxially inserted inside the hollow rotating shaft 87. One end of the linkage shaft 88 extends to the end of the sliding groove 85 and is connected to the threaded rod 86 through a pair of meshing bevel gear sets 89.

[0046] When the operator drives the linkage shaft 88 to rotate via an external micro motor, the micro motor and linkage shaft 88 are connected by a reduction gearbox. The torque is redirected by the bevel gear set 89 and drives the threaded rod 86 to rotate. Since the support shaft 83 and the threaded rod 86 form a threaded pair, and the circumferential rotation of the support shaft 83 is restricted by the connecting groove 82, the rotation of the threaded rod 86 forces the support shaft 83 to move along the length of the sliding groove 85. This changes the eccentricity of the end of the support shaft 83 relative to the rotation center of the cam disk 84, allowing the operator to flexibly adjust the compression intensity according to the dilute acid concentration without disassembling the pressure tank 5, thus avoiding energy waste or over-concentration caused by overheating.

[0047] Specifically, a connecting rod 810 is rotatably mounted on the outer periphery of the support shaft 83 via a bearing. The other end of the connecting rod 810 is rotatably connected to a piston plate 811. The piston plate 811 is in sliding and sealing fit with the pressure tank 5. When the support shaft 83 moves with the cam disc 84, a rolling bearing is sleeved on its journal. The large end of the connecting rod 810 is mounted on the outer ring of the bearing, forming a rotating pair. The small end of the connecting rod 810 is hinged to the back of the piston plate 811 via a pin. When the support shaft 83 moves along an eccentric trajectory, the piston plate 811 is driven to slide linearly back and forth on the smooth inner wall of the pressure tank 5 by the swing of the connecting rod 810.

[0048] Multiple high-temperature resistant elastic sealing rings are nested on the outer circumference of the piston plate 811, which fit tightly against the inner wall of the tank to form a sliding seal. When the piston plate 811 moves toward the heating tank 6, the volume of the corresponding side chamber in the pressurization tank 5 is compressed, and the steam pressure and temperature inside rise sharply. The compressed steam can be quickly introduced into the interior of the heat conduction shroud 7. At this time, the high temperature heat of the compressed steam is transferred to the dilute acid in the heating tank 6 through the heat conduction shroud 7. When the piston plate 811 returns, the chamber volume expands, and the steam flowing out of the preheating pipe 2 is drawn in to prepare for the next round of compression. This mechanical structure that transmits motion through the connecting rod 810 has the beneficial effects of strong load-bearing capacity and stable operation, and can withstand the high temperature steam environment for a long time.

[0049] Specifically, the pressurizing assembly 8 also includes a synchronization assembly 812, which includes: a gear shaft 8121, rotatably disposed at the center of the rotating disk 81; two synchronization gears 8122, respectively rotatably disposed at both ends of the gear shaft 8121; and toothed plates 8123, disposed at one end of the two support shafts 83 inserted into the connecting groove 82, with the two toothed plates 8123 respectively meshing with the opposite sides of the synchronization gear 8122 to achieve synchronous opposite movement of the two support shafts 83. To ensure the symmetry of the piston movement on both sides and the balance of pressure in the compression chamber, the synchronization assembly 812 is disposed at the center of the rotating disk 81. The gear shaft 8121 is vertically installed in the central hole of the rotating disk 81 and can rotate freely. Each end of the gear shaft 8121 is fixed with a synchronization gear 8122 of the same size. The ends of the two support shafts 83 are each fixed with a toothed plate 8123, which are located on the upper and lower sides of the synchronization gear 8122 and mesh with the gear.

[0050] When the support shaft 83 on one side undergoes radial displacement under the drive of the threaded rod 86, the toothed plate 8123 on that side will drive the synchronous gear 8122 to rotate. The synchronous gear 8122, in turn, drives the toothed plate 8123 on the other side to move the corresponding support shaft 83 in the opposite direction by the same distance through meshing. This ensures that the stroke change of the compression chambers on both sides is always equal when adjusting the eccentricity, maintaining the dynamic balance during equipment operation, effectively suppressing vibration and noise caused by uneven force, and extending the service life of the equipment.

[0051] Specifically, limiting grooves 813 are provided on both sides of the connecting groove 82. The toothed plate 8123 is slidably disposed inside the limiting groove 813. In order to further improve the guiding accuracy and structural rigidity of the support shaft 83 during reciprocating sliding, two parallel limiting grooves 813 are machined on the inner side wall of the connecting groove 82 on the rotating disk 81. The two sides of the toothed plate 8123 are embedded in the limiting groove 813 to form a clearance fit.

[0052] When the support shaft 83 is subjected to force and slides, the toothed plate 8123 can only move within the straight trajectory defined by the limiting groove 813, thereby strictly constraining the degree of freedom of the support shaft 83 in the non-movement direction. This not only avoids jamming or shaking of the support shaft 83 due to uneven force, but also protects the meshing relationship between the synchronous gear 8122 and the toothed plate 8123 from interference by the radial component force.

[0053] Specifically, the heat-conducting cover 7 is cylindrical, and its top end is fixedly connected to the inner wall of the heating tank 6. A flowable gap is formed between the outer peripheral wall of the heat-conducting cover 7 and the inner wall of the heating tank 6 to facilitate the flow of dilute acid inside the heating tank 6 and to ensure sufficient contact with the heat-conducting cover 7. The heat-conducting cover 7 adopts a metal cylindrical structure with excellent thermal conductivity. Its top edge flange is fixed to the inner wall interface at the top of the heating tank 6 and is suspended in the center of the cavity of the heating tank 6. The inner cavity of the heat-conducting cover 7 is connected to the compression heat chamber of the pressure tank 5 and directly contacts the high-temperature steam that is compressed and heated. A certain width of annular flow gap is maintained between the outer wall of the heat-conducting cover 7 and the inner wall of the heating tank 6 shell.

[0054] During use, the dilute acid liquid flows in from the inlet of the heating tank 6 and flows along the annular gap, fully scouring the outer surface of the heat-conducting cover 7. This annular gap flow channel design forces the dilute acid to form a thin layer of turbulence, which greatly increases the contact time and contact area between the fluid and the heat exchange wall, and enhances the convective heat transfer effect. Compared with simple immersion heat exchange, this flow heat exchange pattern enables the dilute acid to quickly absorb heat and heat up to the required temperature in a shorter path, significantly improving the heat exchange efficiency per unit volume of equipment.

[0055] Specifically, the insert plate 4 forms a grid structure inside the preheating box 1, and a heat-conducting plate is filled between the inner wall of the grid holes and the outer wall of the preheating pipe 2 to uniformly transfer the steam heat in the preheating pipe 2 to the dilute acid liquid inside the temporary storage box 3. In the internal chamber of the preheating box 1, multiple parallel or cross-arranged preheating pipes 2 pass through the grid holes formed by the insert plate 4. In order to eliminate the air gap between the outer wall of the pipe and the inner wall of the insert plate 4 to reduce the contact thermal resistance, a heat-conducting plate material with a high thermal conductivity is tightly filled in the gaps of the grid holes.

[0056] When hot steam passes through the preheating pipe 2, the heat is first conducted to the pipe wall, and then quickly transferred to the root of the insert plate 4 through the filled heat-conducting plate. The insert plate 4, as an extended fin, evenly distributes the heat to every corner inside the temporary storage box 3. The grid-like structure with heat-conducting filling not only solves the problem of insufficient heat exchange area relying solely on the pipe wall, but also effectively absorbs the natural heat loss of the hot steam in the pipe. This effectively makes the temperature distribution of the dilute acid in the temporary storage box 3 more uniform, avoiding low energy utilization efficiency caused by local overheating or underheating, and providing preheated materials with stable temperature conditions for subsequent processes.

[0057] Specifically, the recycling mechanism 10 includes: a dilute acid collection tank 101, which is connected to the side cavity of the filter box 91 and connected to the heating tank 6, for collecting the dilute acid concentrated by the Md distillation membrane 92; and a circulating water collection tank 102, which is connected to the side cavity of the filter box 91 and connected to the circulating water, for recovering the circulating water after heat exchange. After passing through the Md distillation membrane 92, the concentration of the dilute acid in the hot side cavity of the filter box 91 gradually increases due to the continuous evaporation of water. It is discharged to the dilute acid collection tank 101 for storage or to enter the next process through a pipeline connected to a control valve. At the same time, the temperature of the circulating water in the cold side cavity of the filter box 91 will rise after absorbing the latent heat of condensation of water vapor passing through the membrane pores. This part of the water with residual heat flows into the circulating water collection tank 102 through a pipeline. The outlet of the circulating water collection tank 102 can be connected to a cooling tower or waste heat recovery equipment to cool down the heated cooling water for reuse, or to use the low-grade heat energy in it for factory heating and other occasions.

[0058] Specifically, it also includes a drainage component 11, which comprises: a collection chamber 111, located on one side of the support, with pipes 112 at both ends of the collection chamber 111. The other end of the pipes 112 is connected to both ends of the pressure tank 5 to collect the discharged steam. After the pressure tank 5 completes compression and heat exchange, the steam inside releases heat, resulting in a decrease in temperature and pressure. Direct discharge would cause heat loss and condensate accumulation. Therefore, the drainage component 11 is provided. The collection chamber 111 is a buffer tank with a large volume. The pipes 112 at both ends are connected to the exhaust ports of the two working chambers of the pressure tank 5 through flange interfaces. When the piston plate 811 returns, the low-temperature steam that has completed heat exchange in the chamber is pushed into the pipes 112 by the hot steam flowing in from above and flows into the collection chamber 111. In the collection chamber 111, the steam flow rate slows down, and the carried droplets are allowed to settle and separate. The steam can then be discharged uniformly to the subsequent condensation recovery system.

[0059] On the connecting pipes between the through pipe 112 and the steam vents of the chambers on both sides of the pressurized tank 5, a one-way valve is installed. The one-way valve is configured to allow fluid to flow from the inside of the pressurized tank 5 to the through pipe 112 and the subsequent collection chamber 111, while it is in a tightly closed state in the opposite direction. When the pressurizing assembly 8 completes its compression stroke and the piston plate 811 is about to start its return stroke, the steam in the corresponding chamber of the pressurized tank 5 has been compressed to a higher temperature and the pressure is significantly higher than the back pressure in the through pipe 112. At this time, the one-way valve opens under the action of the positive pressure difference, and the cooled and pressurized steam that has completed its heat exchange mission in the chamber begins to be discharged through the one-way valve to the through pipe 112. The one-way valve has a small rated flow cross section. When the steam flows through the valve, the narrow throttling channel inside the valve core restricts the instantaneous discharge flow of the steam, prolongs the effective heat exchange time, and improves the heat conduction depth.

[0060] Furthermore, the position where the pressure tank 5 is connected to the preheating box 1 is closer to the piston plate 811 than the position where the pressure tank 5 is connected to the through pipe 112. Therefore, when the compressed steam is discharged, it can effectively avoid the intake of steam in the preheating pipe 2. Therefore, during use, the piston plate 811 is pushed from the side away from the heating tank 6 toward the heating tank 6. During this process, the steam in the chamber is compressed and the pressure increases. Since the exhaust port is located at the front end of the piston movement direction, the compressed high-temperature steam enters the heat conduction cover 7 for heat exchange. At the same time, the exhaust check valve in the through pipe 112 is opened to achieve the purpose of discharging the heat exchanged gas.

[0061] After the heat exchanged gas is discharged, when the piston plate 811 just begins to return, the volume of the chamber increases, and the exhaust check valve in the through pipe 112 closes. During the return process of the piston plate 811, the volume of the chamber gradually increases. Therefore, the intake check valve at the connection position with the preheating pipe 2 draws in the gas inside the preheating pipe 2, so as to achieve the purpose of fresh preheating steam being drawn into the chamber from the intake port.

[0062] In operation, low-temperature waste heat steam is first introduced into the preheating pipe 2 inside the preheating box 1. The heat in the pipe is evenly transferred to the dilute acid to be purified in the temporary storage box 3 through the mesh-like insert plate 4 and the filled heat-conducting plate, completing the first preheating treatment. The preheated dilute acid flows into the heating tank 6 and flows from bottom to top along the annular flow gap on the outer wall of the heat-conducting cover 7. At the same time, the steam, whose temperature has decreased after the initial heat exchange, is drawn into the chamber of the pressurization tank 5 through the one-way valve at the outlet of the preheating pipe 2.

[0063] An external drive motor drives the cam disk 84 to rotate via the rotating shaft 87. Under the action of eccentricity, the support shaft 83 drives the piston plate 811 to reciprocate linearly within the pressure tank 5 via the connecting rod 810. When the piston plate 811 moves towards the heating tank 6, the steam in the chamber is compressed, and the pressure and temperature rise sharply. The high-temperature compressed steam enters the inner cavity of the heat-conducting cover 7, and the heat is transferred to the dilute acid in the flow gap through the wall of the heat-conducting cover 7, realizing secondary enhanced heating of the dilute acid. After the compression heat exchange is completed, when the piston plate 811 moves to the maximum stroke, the outlet check valve slowly opens under the action of pressure difference. The exhaust steam that has completed heat exchange is discharged into the collection chamber 111 through the through pipe 112 for buffering and settling before being discharged uniformly. At the same time, the pressure in the chamber drops, the inlet check valve opens, and fresh preheated steam is drawn into the chamber to prepare for the next compression cycle.

[0064] The dilute acid, heated twice to the preset temperature, enters the hot side chamber of the filter box 91. Driven by the water vapor partial pressure difference on both sides of the Md distillation membrane 92, the water in the dilute acid passes through the membrane pores in gaseous form and enters the cold side chamber, where it is condensed and carried away by the circulating cold water, thus increasing the concentration of the dilute acid. The concentrated dilute acid is collected in the dilute acid collection tank 101, and the heated circulating water is recycled to the circulating water collection tank 102. During operation, the eccentricity of the support shaft 83 can be adjusted by the linkage shaft 88 and the bevel gear set 89 according to the concentration of the dilute acid, thereby flexibly adjusting the compression stroke and intensity.

[0065] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A low-temperature waste heat driven dilute acid concentration device, characterized in that: include, The preheating box (1) is equipped with a preheating pipe (2) inside. Both ends of the preheating box (1) are equipped with temporary storage boxes (3). The temporary storage boxes (3) are equipped with several insert plates (4) that are inserted into the preheating box (1). The pressurization tank (5) is located on one side of the preheating box (1) and connected to the preheating pipe (2); Heating tank (6) is connected to both ends of pressurized tank (5) and communicates with preheating box (1). A heat conduction cover (7) is fixedly installed inside heating tank (6). The pressurization component (8) is located inside the pressurization tank (5) and is used to compress the steam entering the pressurization tank (5) to increase the steam temperature; The filter assembly (9) includes a support and a filter box (91) mounted on the support. The filter box (91) is provided with an Md distillation membrane (92) to divide the interior into two chambers that are respectively connected to the heating tank (6) and the circulating cold water. Waste heat steam enters the preheating pipe (2) to preheat the dilute acid in the temporary storage tank (3), and then enters the pressurizing tank (5) where it is compressed and heated by the pressurizing component (8) to reheat the dilute acid.

2. The low-temperature waste heat driven dilute acid concentration device as described in claim 1, characterized in that: The pressurization assembly (8) includes: A rotating disk (81) is rotatably disposed inside the pressure tank (5), and a connecting groove (82) is provided inside the rotating disk (81). Support shaft (83) is slidably disposed at both ends of connecting groove (82); Cam disk (84) is located at one end of the support shaft (83) away from the rotating disk (81). Two cam disks (84) are arranged opposite to each other. A sliding groove (85) is provided on one side of the cam disk (84). The threaded rod (86) is rotatably disposed inside the sliding groove (85), and the end of the support shaft (83) is slidably disposed inside the sliding groove (85) and threadedly engaged with the threaded rod (86); A rotating shaft (87) is located on the other side of the cam plate (84) and passes through the pressure tank (5), and is rotatably connected to the pressure tank (5) via a flange.

3. The low-temperature waste heat driven dilute acid concentration device as described in claim 1 or 2, characterized in that: The pressurization assembly (8) also includes: The linkage shaft (88) is rotatably set inside the rotating shaft (87). One end of the linkage shaft (88) is driven by the threaded rod (86) through the bevel gear set (89) to drive the threaded rod (86) to rotate in order to adjust the position of the support shaft (83) in the sliding groove (85).

4. The low-temperature waste heat driven dilute acid concentration device as described in claim 3, characterized in that: The outer periphery of the support shaft (83) is provided with a connecting rod (810) rotatably mounted on a bearing. The other end of the connecting rod (810) is rotatably connected to a piston plate (811), which is in sliding sealing fit with the pressure tank (5).

5. The low-temperature waste heat driven dilute acid concentration device as described in claim 1 or 2, characterized in that: The pressurization assembly (8) also includes a synchronization assembly (812), which comprises: The gear shaft (8121) is rotatably located at the center of the rotating disk (81); There are two synchronizing gears (8122), which are rotatably mounted at both ends of the gear shaft (8121); The toothed plate (8123) is disposed at one end of the connecting groove (82) into which the two support shafts (83) are inserted, and the two toothed plates (8123) are respectively meshed on opposite sides of the synchronous gear (8122) to realize the synchronous opposite movement of the two support shafts (83).

6. The low-temperature waste heat driven dilute acid concentration device as described in claim 1 or 4, characterized in that: Limiting grooves (813) are provided on both sides of the connecting groove (82), and the toothed plate (8123) is slidably disposed inside the limiting groove (813).

7. The low-temperature waste heat driven dilute acid concentration device as described in claim 1, characterized in that: The heat-conducting cover (7) is cylindrical and its top end is fixedly connected to the inner wall of the heating tank (6). A flowable gap is formed between the outer peripheral wall of the heat-conducting cover (7) and the inner wall of the heating tank (6).

8. The low-temperature waste heat driven dilute acid concentration device as described in claim 1, characterized in that: The insert plate (4) forms a grid structure inside the preheating box (1), and a heat-conducting plate is filled between the inner wall of the grid holes and the outer wall of the preheating pipe (2) to uniformly conduct the steam heat in the preheating pipe (2) to the dilute acid liquid inside the temporary storage box (3).

9. The low-temperature waste heat driven dilute acid concentration device as described in claim 1, characterized in that: It also includes recycling facilities (10), including: The dilute acid collection tank (101) is connected to the side cavity of the filter box (91) which is connected to the heating tank (6), and is used to collect the dilute acid concentrated by the Md distillation membrane (92); The circulating water collection tank (102) is connected to the side cavity of the filter box (91) that is connected to the circulating water, and is used to recover the circulating water after heat exchange.

10. The low-temperature waste heat driven dilute acid concentration device as described in claim 1, characterized in that: It also includes a drainage assembly (11), which includes: The collecting chamber (111) is located on one side of the support. Both ends of the collecting chamber (111) are provided with connecting pipes (112). The other end of the connecting pipes (112) is connected to both ends of the pressurized tank (5) to collect the steam after discharge.

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