A filtering type potassium nitrate processing tail gas treatment device

Abstract

The application relates to the technical field of industrial tail gas purification treatment, and discloses a filtering type potassium nitrate processing tail gas treatment device, which comprises a treatment tank, a flower plate is fixedly connected to the upper portion in the treatment tank, the flower plate divides the inner cavity of the treatment tank into a gas purification chamber at the upper portion and a dust chamber at the lower portion, a flexible filter bag, a spiral spring framework and a corrugated elastic air bag are coaxially and sequentially arranged in the dust chamber from the outside to the inside, a plurality of duckbill type one-way jet nozzles are arranged in the circumferential array of the upper side wall of the corrugated elastic air bag, the top ends of the flexible filter bag, the spiral spring framework and the corrugated elastic air bag are in close and fixed connection with the flower plate, and the bottom ends are in close and fixed connection with a rigid sealing bottom disc which is suspended. The main shaft is configured as a heat-conducting main shaft with an inner cavity, and the corrugated elastic air bag is coaxially and nested on the outer side of the main shaft, so that the space-time overlap of fluid isochoric heating and forced mechanical compression is constructed, and the extremely heavy degree of potassium nitrate crusting mud cake with high viscous force is easily broken down.

Description

Technical Field

[0001] This invention relates to the field of industrial exhaust gas purification and treatment technology, specifically a filter-type potassium nitrate processing exhaust gas treatment device. Background Technology

[0002] In the industrial crystallization, granulation, and drying processes of potassium nitrate, the exhaust gas inevitably carries a large amount of fine dust. This particular chemical powder has extremely challenging physicochemical properties: it readily absorbs moisture and deliquesces in airflows with high relative humidity, and after undergoing a microscopic temperature phase change, it repeatedly cross-links between dry particles and viscous droplets, eventually forming a dense, hardened, and highly adhesive mud cake shell on the surface of the filter medium.

[0003] Faced with powders exhibiting extreme viscosity, traditional pulse-jet baghouse dust collectors reveal deep-seated thermodynamic and mechanical topological defects. Existing conventional equipment heavily relies on external air compressors for its cleaning logic, attempting to generate a reverse peeling force by instantly injecting room-temperature, high-pressure airflow into the filter bags. However, the rapid expansion of room-temperature compressed gas upon breaking through the blowpipe generates a significant throttling and cooling effect. When this cold airflow abruptly enters the previously hot and humid potassium nitrate tail gas environment, it inevitably triggers "cold bridging and condensation" at the physical interface of the filter bags. This secondary condensation induced by localized temperature differences not only instantly weakens the airflow's kinetic energy but, more critically, the moisture directly acts as a natural binder for the potassium nitrate particles, accelerating deliquescence and phase change, causing deep blockage of the filter media's micropores, ultimately leading to irreversible "bag clogging" failure.

[0004] When purely aerodynamic methods fail, some existing technologies attempt to combat the stubborn mud cake layer by introducing external mechanical vibration, scraping, or deformation devices inside the dust collection chamber, hoping to utilize pure mechanical shear force. However, these designs often underestimate the corrosive force of the harsh environment at the bottom of the dust collection chamber. Directly or partially immersing dynamic transmission components with relatively sliding friction pairs, such as gears, guide rails, and hinges, in a microenvironment filled with a high concentration of highly corrosive potassium nitrate (a solid-liquid mixture), allows deliquescent powder to easily penetrate the tiny mechanical movement gaps. With fluctuations in system operating conditions, these infiltrated materials recrystallize, expand in volume, and harden rapidly, causing severe mechanical jamming or even complete seizure of the bottom moving parts within a very short operating cycle.

[0005] Meanwhile, to alleviate the aforementioned condensation and deliquescence problems, industrial sites are often forced to deploy high-energy-consuming steam tracing networks or high-power electric heating systems outside the dust collector, or even forcibly insert tracing lines inside the filter bags. This rigid physical superposition not only leads to enormous energy consumption and system redundancy, but also, in the dust removal chamber with high-frequency alternating displacement and severe vibration, the rigid tracing lines are extremely prone to stress fatigue and physical fracture, which simply cannot meet the stringent engineering requirements of long-term, maintenance-free operation of environmental protection equipment in modern continuous chemical production. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a filter-type potassium nitrate processing tail gas treatment device, which solves the technical problem of deep bag clogging of filter media micropores caused by "cold bridge condensation" due to the introduction of ambient temperature external airflow in existing reverse-flushing cleaning equipment; at the same time, it solves the engineering problem that conventional bottom-layer mechanical auxiliary cleaning mechanisms are prone to dust entrainment and failure of moving parts when facing highly corrosive and easily deliquescent crystallizing materials; and it also eliminates the structural hazards of traditional external rigid heat tracing pipe networks being prone to fatigue fracture and high energy consumption under alternating vibration conditions.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a filter-type potassium nitrate processing tail gas treatment device, comprising a treatment tank. A perforated plate is fixedly connected to the upper part of the treatment tank, dividing the inner cavity of the treatment tank into an upper clean air chamber and a lower dust chamber. Within the dust chamber, a flexible filter bag, a helical spring frame, and a corrugated elastic airbag are coaxially mounted from the outside in. Several duckbill-shaped unidirectional jet nozzles are arranged circumferentially on the upper sidewall of the corrugated elastic airbag. The top ends of the flexible filter bag, helical spring frame, and corrugated elastic airbag are all sealed and fixedly connected to the perforated plate, and their bottom ends are sealed and fixedly connected to a suspended rigid sealing base. A main shaft is rotatably connected through the center of the perforated plate, and the top end of the main shaft penetrates the clean air chamber and extends to the top of the treatment tank. The top of the treatment tank is equipped with a drive mechanism for driving the main shaft to rotate. The bottom end of the main shaft passes through a corrugated elastic airbag and a rigid sealing chassis in sequence, and is rotatably connected to a bracket. The outer end of the bracket is fixedly connected to the inner wall of the treatment tank. The rigid sealing chassis is slidably connected to the main shaft, and the two are in a circumferentially locked state. When the dust removal program is triggered, the drive mechanism drives the main shaft to rotate the rigid sealing chassis on a fixed axis, forcing the helical spring skeleton to bear torque and undergo axial contraction, causing the flexible filter bag to undergo three-dimensional folds to mechanically crack the external dust. At the same time, the axial contraction pulls the rigid sealing chassis to move upward, forcibly squeezing the corrugated elastic airbag, causing the fluid pressure inside the corrugated elastic airbag to rise and break through the resistance threshold of the duckbill-type unidirectional jet nozzle to spray out transient airflow.

[0008] Preferably, the helical spring skeleton is a variable pitch helical structure. When subjected to torque input transmitted by the main shaft, non-uniform contraction displacement gradient is generated in each coil along the axial direction. Through asynchronous mechanical misalignment between the layers, shearing force is applied to the mud cake shell layer attached to the outer surface of the flexible filter bag.

[0009] Preferably, the perforated plate is provided with a one-way air intake valve. The air intake end of the one-way air intake valve is exposed in the clean air chamber, and the air outlet end penetrates the perforated plate vertically and is in fluid communication with the internal cavity of the corrugated elastic airbag. The one-way air intake valve only allows air in the clean air chamber to flow into the corrugated elastic airbag in one direction.

[0010] Preferably, when the drive mechanism releases the torque lock on the main shaft, the helical spring skeleton releases its elastic potential energy, driving the rigid sealed chassis and flexible filter bag to rotate in the opposite direction and reset downwards. The downward displacement of the rigid sealed chassis elongates the corrugated elastic airbag, creating a negative pressure inside it, and automatically opens the one-way air intake valve to draw in clean air to complete the passive charging of the fluid.

[0011] Preferably, the exhaust gas treatment device further includes a heat exchange circuit system, a heat-conducting jacket is fixedly connected to the inner wall of the treatment tank, a hollow flow channel is opened inside the main shaft, and the heat-conducting jacket and the hollow flow channel are connected through a circulation pipeline and a circulation pump. The heat medium introduced from the heat-conducting jacket provides constant thermodynamic expansion energy to the sealed gas in the corrugated elastic airbag.

[0012] Preferably, a bottom rotary sealing joint is coaxially mounted at the bottom end of the main shaft, and a sealing cover is provided on the outside of the bottom rotary sealing joint. The open edge of the sealing cover is fixedly connected to the surface of the bracket to form a sealed chamber. The circulation pipeline passes through the pipe wall of the sealing cover and is connected to the hollow flow channel through the bottom rotary sealing joint.

[0013] Preferably, a top rotary sealing joint is coaxially provided at the top of the main shaft. Under the drive of the circulating pump, the heat transfer medium is injected into the hollow flow channel from the bottom rotary sealing joint, and forced to flow in a unidirectional direct current from the bottom to the top. Then, it is extracted through the top rotary sealing joint and reinjected into the heat transfer jacket.

[0014] Preferably, the fluid ejection end face of the duckbill-type unidirectional jet nozzle points radially outward toward the inner wall of the flexible filter bag. The duckbill-type unidirectional jet nozzle relies on the elastic restoring force of the material to maintain closure under normal conditions, so as to prevent low-pressure leakage of gas inside the corrugated elastic airbag before reaching the burst critical point.

[0015] Preferably, the three-dimensional folds of the flexible filter bag have the following synergistic features: when the rigid sealed chassis is driven by the rotation of the main shaft, the flexible filter bag follows the spiral spring skeleton to generate spiral folds, and by utilizing the condensation mechanism of geometric surface area, shear stress is generated inside the potassium nitrate dust cake attached to the outer surface of the flexible filter bag and mechanical cracking is forced to occur.

[0016] Preferably, the lower side wall of the dust chamber is provided with a tangential air inlet channel for introducing potassium nitrate tail gas, the top of the clean air chamber is provided with an exhaust channel for discharging purified gas, and the bottom of the dust chamber is connected to an inverted conical dust collection hopper for receiving shed dust.

[0017] This invention provides a filter-type potassium nitrate processing tail gas treatment device. It has the following beneficial effects: 1. This invention constructs a spatiotemporal overlap of fluid isochoric heating and forced mechanical compression by configuring the main shaft as a hollow, heat-conducting main shaft and coaxially nesting a corrugated elastic airbag on its outside. While the sealed airbag is forcibly reduced in physical volume due to being lifted by a rigid, sealed chassis, the fluid expansion potential energy accumulated during the initial heating process simultaneously erupts within this confined space, forcing the internal pressure to surge exponentially and break through the duckbill-shaped unidirectional jet nozzle. This resonance of thermal expansion and mechanical contraction can generate peak jet kinetic energy far exceeding that of room temperature air pressure with extremely low mechanical energy consumption, easily disintegrating highly viscous, extremely dense potassium nitrate cake. Simultaneously, a drive mechanism synchronously drives the underlying rigid-flexible components. The variable-pitch helical spring skeleton generates asynchronous axial contraction under torque, forcing the external flexible filter bag to undergo three-dimensional misalignment and wrinkling, applying purely mechanical pre-shearing damage to the hardened cake shell; at the same instant the cake cracks, internal high-pressure pneumatic pulses precisely bombard the outside along the cracks. This in-situ coordinated action of first mechanical tearing and then pneumatic stripping completely overcomes the industry's pain point that heavily deliquescent dust cannot be blown away by airflow from a physical perspective.

[0018] 2. This invention abandons the conventional dust removal method of spraying room-temperature cold air into a high-temperature and high-humidity exhaust gas environment. Instead, it utilizes a closed heat exchange circuit to impart an extremely high initial enthalpy value to the pneumatic pulse. When the high-temperature transient airflow penetrates the flexible filter bag, it not only eliminates the temperature difference that causes the dust to undergo a secondary phase change and absorb moisture from the thermodynamic boundary, but also generates a transient flash evaporation effect on the trace amounts of deliquescent droplets remaining deep within the porous PTFE fibers. This actively dries the filter bag at the end of each dust removal cycle, continuously maintaining the dryness of the filter material and its core air permeability.

[0019] 3. This invention eliminates the need for an external high-energy-consuming air compressor station and electric heating network. It directly utilizes the circumferential heat-conducting jacket of the outer shell to absorb the waste heat of the exhaust gas without contact, and, in conjunction with a circulating pump, constructs a bottom-in, top-out unidirectional direct current channel for the heat medium within the main shaft. Simultaneously, the physical negative pressure generated by the release of potential energy from the spring frame at the end of the cleaning process and the downward pull of the chassis gravity stretching the corrugated elastic airbag automatically overcomes the resistance of the one-way air intake valve, drawing clean air from the clean air chamber to complete the recharging. This architecture, which combines self-sufficiency in thermal energy with passive mechanical air replenishment, achieves the internalization of the cleaning power source, greatly reducing the overall equipment's footprint and long-term maintenance costs. Attached Figure Description

[0020] Figure 1 This is a perspective view of the present invention; Figure 2 This is a schematic diagram of the internal structure of the processing tank in this invention; Figure 3 This is a schematic diagram of the internal structure of the flexible filter bag in this invention; Figure 4 for Figure 3 Enlarged view of point A in the middle; Figure 5 This is a schematic diagram of the internal structure of the spindle in this invention.

[0021] The components include: 1. Processing tank; 101. Clean air chamber; 102. Dust chamber; 2. Tube sheet; 3. Flexible filter bag; 4. Helical spring frame; 5. Corrugated elastic airbag; 6. Duckbill type one-way jet nozzle; 7. Rigid sealed chassis; 8. Main shaft; 801. Hollow flow channel; 9. Drive mechanism; 10. Support; 11. One-way air inlet valve; 12. Heat-conducting jacket; 13. Bottom rotary sealing joint; 14. Sealing cover; 15. Top rotary sealing joint; 16. Tangential air inlet channel; 17. Exhaust channel; 18. Inverted cone-shaped dust collection hopper. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please see the appendix Figure 1 -Appendix Figure 5This invention provides a filter-type potassium nitrate processing tail gas treatment device, aiming to establish a basic environmental boundary for long-term operation and prevention of mechanical failure from the perspective of physical spatial structure and airflow distribution topology. The tail gas treatment device includes a treatment tank 1, with a perforated plate 2 fixedly connected to the upper part of the treatment tank 1. The perforated plate 2 divides the inner cavity of the treatment tank 1 into an upper clean air chamber 101 and a lower dust chamber 102. Within the dust chamber 102, a flexible filter bag 3, a helical spring frame 4, and a corrugated elastic airbag 5 are coaxially mounted from the outside to the inside. The upper sidewall of the corrugated elastic airbag 5 has a plurality of duckbill-shaped unidirectional jet nozzles 6 arranged circumferentially. The top ends of the flexible filter bag 3, helical spring frame 4, and corrugated elastic airbag 5 are all sealed and fixedly connected to the perforated plate 2, and their bottom ends are sealed and fixedly connected to a suspended rigid sealing chassis 7. A main shaft 8 is rotatably connected through the center of the perforated plate 2. The top end of the main shaft 8 passes through the clean air chamber 101 and extends to the top of the treatment tank 1. A device for driving the main shaft is provided at the top of the treatment tank 1. The drive mechanism 9 rotates, with the bottom end of the main shaft 8 passing through the corrugated elastic airbag 5 and the rigid sealing chassis 7, and is rotatably connected to the bracket 10. The outer end of the bracket 10 is fixedly connected to the inner wall of the treatment tank 1. The rigid sealing chassis 7 is slidably connected to the main shaft 8, and the two are in a circumferentially locked state. When the dust removal program is triggered, the drive mechanism 9 drives the main shaft 8 to rotate the rigid sealing chassis 7 on a fixed axis, forcing the helical spring skeleton 4 to bear torque and undergo axial contraction, causing the flexible filter bag 3 to undergo three-dimensional folds to mechanically crack the external dust. At the same time, the axial contraction pulls the rigid sealing chassis 7 to move upward, forcibly squeezing the corrugated elastic airbag 5, causing the fluid pressure inside the corrugated elastic airbag 5 to rise and break through the resistance threshold of the duckbill-type one-way jet nozzle 6 to spray out transient airflow.

[0024] The three-dimensional folds of the flexible filter bag 3 have the following synergistic characteristics: when the rigid sealing chassis 7 is driven by the rotation of the main shaft 8, the flexible filter bag 3 follows the spiral spring frame 4 to generate spiral folds. By utilizing the condensation mechanism of geometric surface area, shear stress is generated inside the potassium nitrate dust cake attached to the outer surface of the flexible filter bag 3 and mechanical cracking is forced to occur.

[0025] The lower side wall of the dust chamber 102 is provided with a tangential air inlet channel 16 for introducing potassium nitrate tail gas, the top of the clean air chamber 101 is provided with an exhaust channel 17 for discharging purified gas, and the bottom of the dust chamber 102 is connected to an inverted conical dust collection hopper 18 for receiving the shed dust.

[0026] The entire device is based on a vertically placed, sealed treatment tank 1. This treatment tank 1 forms an absolute isolation boundary between the entire exhaust gas treatment system and the external natural environment. The treatment tank 1 has a large cylindrical structure, and its entire material is made of high-strength metal material resistant to chemical corrosion, continuously welded together. The inner wall surface of the treatment tank 1 is mechanically ground and subjected to anti-corrosion passivation treatment to ensure extremely high surface flatness and prevent the disorderly physical adhesion and agglomeration of deliquescent potassium nitrate dust in the non-filtration area.

[0027] Regarding the physical separation of the internal static and dynamic chambers, a rigid perforated plate 2 with high load-bearing capacity is horizontally installed in the upper middle part of the interior of the treatment tank 1. The outer edge of the perforated plate 2 is fully welded to the inner wall of the treatment tank 1 with airtightness throughout its entire circumference. This horizontally arranged heavy perforated plate 2 strictly cuts off the originally continuous space inside the treatment tank 1 vertically into two independent working environments where the upper and lower fluids cannot be directly short-circuited and interconnected.

[0028] Specifically, the enclosed space above the tube sheet 2 is defined as the clean air chamber 101. As the final collection area in the gas-solid separation process, the clean air chamber 101 allows only clean air that has passed through the filter material to circulate within it, and provides a safe operating environment for subsequent fluid control components, free from the corrosive effects of deliquescent dust. The large, deep chamber below the tube sheet 2 is defined as the dust chamber 102. The dust chamber 102 is a high-load, harsh environment where raw chemical exhaust gas containing highly hygroscopic potassium nitrate particles is directly exposed, suspended, and undergoes phase change. It is also the direct area where the core filter components perform their physical interception and pneumatic stripping functions.

[0029] Regarding the layout of the swirl inlet and directional exhaust channels 17, a tangential inlet channel 16 is provided through the cylindrical sidewall at the lower part of the dust chamber 102. The central axis of this tangential inlet channel 16 is horizontally or slightly inclined along the tangent direction of the circular cross-section of the dust chamber 102. When the dust-laden exhaust gas is pumped into the dust chamber 102 through this tangential inlet channel 16, it is constrained by the curved guiding surface of the inner wall of the treatment tank 1, and a wall-adhering, rotating, rising swirling flow field is spontaneously formed in the lower part of the dust chamber 102. This initial swirling flow field utilizes physical centrifugal force to cause some large particles or heavily deliquescent and agglomerated heavy sludge cakes to leave the main airflow channel in advance, significantly reducing the initial oncoming physical load on the core filter components. At the same time, an outwardly extending exhaust channel 17 is provided at the top or high point of the sidewall of the clean air chamber 101 to directionally guide the clean fluid collected in the clean air chamber 101 to the downstream process pipeline network.

[0030] Regarding the bottom settling and ash discharge structure, the bottom of the treatment tank 1 is seamlessly connected to an inverted conical ash collection hopper 18. This inverted conical ash collection hopper 18 has a funnel-shaped geometry, wide at the top and narrowing at the bottom, directly receiving the potassium nitrate solid material that falls freely from the dust chamber 102 due to centrifugal force or the removal of dust from the core components. The inclination angle of the inner wall of the inverted conical ash collection hopper 18 is designed to be greater than the physical angle of repose of the potassium nitrate sludge cake to ensure that the agglomerated material slides smoothly under the action of gravity. An ash discharge port is opened at the bottom of the ash collection hopper, and an airlock unloading device is connected to the flange at the ash discharge port. Under the premise of strictly maintaining the stability of the internal fluid pressure boundary of the system, the collected solid sludge cake material is continuously or intermittently discharged to the outside of the device.

[0031] The spiral spring skeleton 4 is a variable pitch spiral structure. When it is subjected to the torque input transmitted by the main shaft 8, the non-uniform contraction displacement gradient is generated in each coil along the axial direction. Through the asynchronous mechanical misalignment between the layers, a shearing force is applied to the mud cake shell layer attached to the outer surface of the flexible filter bag 3.

[0032] A core multi-dimensional coupled filtration and dust removal assembly is suspended within the dust chamber 102 at the bottom of the treatment tank 1. This assembly features a multi-level coaxial nested structure, with a flexible filter bag 3, a spiral spring frame 4, and a corrugated elastic airbag 5 coaxially nested from the outside in, based on the central axis. The tops of all nested components are connected to the tube sheet 2, forming a stable, static suspension point inside the equipment.

[0033] The outermost flexible filter bag 3 is made of membrane-coated polytetrafluoroethylene porous filter material with self-lubricating properties. This material exhibits extremely low surface tension, directly weakening the initial adhesion force of the potassium nitrate deliquescent cake at the microscopic physical interface. The flexible filter bag 3 as a whole has a slender cylindrical opening shape, with its top opening edge folded upwards and airtightly secured to the edge of the mounting hole in the tube sheet 2 by an expansion ring structure, ensuring that dust-laden fluid cannot bypass and seep into the clean air chamber 101 from the external gaps.

[0034] In this embodiment, a helical spring frame 4 is coaxially sleeved against the inner side of the flexible filter bag 3. This helical spring frame 4 is a cylindrical structure with a variable pitch, made of spring steel wire. It not only serves as the internal radial support frame for the flexible filter bag 3 under conventional gas-solid separation conditions, resisting external fluid pressure differences and preventing the filter bag from collapsing, but also acts as a rigid-flexible coupling medium to transmit axial and circumferential three-dimensional deformation during the dust removal stage. The top of the helical spring frame 4 is firmly anchored to an annular fixing member on the lower surface of the tube sheet 2.

[0035] A corrugated elastic airbag 5 is coaxially disposed inside the helical spring frame 4. This corrugated elastic airbag 5 has continuously folded corrugated sidewalls and is integrally molded from high-temperature resistant and fatigue-resistant polymer composite rubber, forming an independent internal fluid-sealed chamber. The top end face of the corrugated elastic airbag 5 is fully pressed and sealed to the lower surface of the perforated plate 2, completely blocking direct physical communication between the internal chamber fluid and the external dust chamber 102 environment.

[0036] The fluid ejection end face of the duckbill-type unidirectional jet nozzle 6 points radially outward toward the inner wall of the flexible filter bag 3. The duckbill-type unidirectional jet nozzle 6 relies on the elastic restoring force of the material to maintain closure under normal conditions, so as to prevent low-pressure leakage of gas inside the corrugated elastic airbag 5 before reaching the burst critical point.

[0037] On the upper corrugated sidewall of the corrugated elastic airbag 5, several duckbill-type unidirectional jet nozzles 6 are uniformly arrayed along the circumferential direction. The fluid ejection end face of each duckbill-type unidirectional jet nozzle 6 is a flat slit shape, and it faces directly outward along the radial direction to the inner wall surface of the flexible filter bag 3.

[0038] The slit opening structure of the duckbill-type unidirectional jet nozzle 6 relies on the inherent elastic restoring force of the rubber material to maintain a tight physical closure under normal conditions. This normal closure characteristic effectively prevents low-pressure leakage of the fluid inside the corrugated elastic airbag 5 before reaching the ultimate burst critical pressure, ensuring the complete and undamaged accumulation of fluid pressure energy inside the airbag.

[0039] The bottoms of the aforementioned three nested components all converge at a suspended rigid sealing base 7. This rigid sealing base 7 is a solid metal disc with a preset thickness and structural strength, suspended and positioned in the lower middle region of the dust chamber 102. The bottom closed end of the flexible filter bag 3 completely wraps around and tightly secures itself to the outermost circumferential edge of the rigid sealing base 7, forming the outermost layer of physical isolation.

[0040] The bottom end of the helical spring frame 4 is mechanically fixed to a preset node on the inner side of the rigid sealing chassis 7. Simultaneously, the bottom corrugated edge of the corrugated elastic airbag 5 is tightly bonded and pressed against the upper surface of the rigid sealing chassis 7. This rigid sealing chassis 7 forcibly seals and connects the bottom ends of the three nested structures with different mechanical properties—the flexible filter bag 3, the helical spring frame 4, and the corrugated elastic airbag 5—forming a synchronously displaced mechanical reference platform at the bottom of the dust chamber 102.

[0041] The drive mechanism 9 extends downwards to form a main shaft 8. This main shaft 8 penetrates vertically through the center of the perforated plate 2 and coaxially through the internal sealed chamber of the corrugated elastic airbag 5. The bottom end of the main shaft 8 is deeply inserted into and circumferentially locked to the center node of the rigid sealed chassis 7.

[0042] Through the physical convergence design of this coaxial nested structure and rigid sealed chassis 7, all power inputs and fluid pipelines are completely sealed inside the clean air chamber 101 or the pipe fittings. Within the core interception and cleaning exposed chamber directly facing the highly hygroscopic potassium nitrate dust, any mechanical friction pairs such as gears, hinges, or guide rails that could slide relative to each other are completely eliminated, thus blocking the risk of erosion and jamming of moving parts by deliquescent dust from the underlying structural topology.

[0043] A one-way air intake valve 11 is provided on the perforated plate 2. The air intake end of the one-way air intake valve 11 is exposed in the clean air chamber 101, and the air outlet end penetrates vertically through the perforated plate 2 and is in fluid communication with the internal cavity of the corrugated elastic airbag 5. The one-way air intake valve 11 only allows air in the clean air chamber 101 to flow into the corrugated elastic airbag 5 in one direction.

[0044] When the drive mechanism 9 releases the torque lock on the main shaft 8, the helical spring frame 4 releases its elastic potential energy, driving the rigid sealed chassis 7 and the flexible filter bag 3 to rotate in the opposite direction and reset downwards. The downward displacement of the rigid sealed chassis 7 elongates the corrugated elastic airbag 5, creating a negative pressure inside it, and automatically opens the one-way air intake valve 11 to draw in clean air and complete the passive charging of the fluid.

[0045] The exhaust gas treatment device also includes a heat exchange circuit system. A heat-conducting jacket 12 is fixedly connected to the inner wall of the treatment tank 1. A hollow flow channel 801 is opened inside the main shaft 8. The heat-conducting jacket 12 and the hollow flow channel 801 are connected through a circulation pipeline and a circulation pump. The heat medium introduced from the heat-conducting jacket 12 provides constant thermodynamic expansion energy to the sealed gas in the corrugated elastic airbag 5.

[0046] A bottom rotary sealing joint 13 is coaxially installed at the bottom end of the main shaft 8. A sealing cover 14 is provided on the outside of the bottom rotary sealing joint 13. The open edge of the sealing cover 14 is fixedly connected to the surface of the bracket 10 to form a sealed chamber. The circulation pipeline passes through the pipe wall of the sealing cover 14 and is connected to the hollow flow channel 801 through the bottom rotary sealing joint 13.

[0047] A top rotary sealing joint 15 is coaxially provided at the top of the main shaft 8. Under the drive of the circulating pump, the heat transfer medium is injected into the hollow flow channel 801 from the bottom rotary sealing joint 13, and is forced to flow in a unidirectional direct current from the bottom to the top. Then it is extracted through the top rotary sealing joint 15 and reinjected into the heat transfer jacket 12.

[0048] A high-strength support 10 is horizontally spanned in the lower space of the dust chamber 102. The outer end of the support 10 is fully welded to the inner wall of the treatment tank 1, thus constructing a stable bottom support and radial limiting platform in the high-concentration dust settling area.

[0049] The bottom end of the spindle 8 extends vertically downwards. After physically penetrating the solid center node of the rigid sealed chassis 7, the spindle 8 continues to extend downwards and is rotatably connected to the center point of the bracket 10. The bracket 10 provides precise coaxiality guidance and anti-yaw constraint for the suspended rotating spindle 8, ensuring the stability of the rotation trajectory of the core component under severe torque.

[0050] At the lowest point where the main shaft 8 passes through the bracket 10 and extends further, a bottom rotary sealing joint 13 is coaxially installed. This bottom rotary sealing joint 13 serves as a fluid dynamic-static conversion hub between the external static pipeline and the rotating main shaft 8, directly undertaking the function of introducing high-temperature heat transfer medium.

[0051] To completely isolate the dynamic sealing surface from the physical and chemical corrosion of the highly hygroscopic and corrosive solid-liquid mixed phase potassium nitrate dust, a sealing cover 14 is completely installed outside the bottom rotary sealing joint 13. This sealing cover 14 is a hollow solid protective structure with an extremely high level of protection for the mechanical handling tank 1.

[0052] The upper open edge of the sealing cover 14 is fixedly and airtightly to the lower surface of the bracket 10 throughout its circumference. This fixed connection structure completely encloses and seals the bottom rotary sealing joint 13 and all related dynamic and static friction pairs in a separate, bottom-sealed chamber that is free from external dust contamination.

[0053] After penetrating the heat-conducting jacket 12, the circulation pipeline is laid out along the geometric contour of the support 10 and further penetrates the solid pipe wall of the sealing cap 14. After entering the sealed chamber, the circulation pipeline achieves physical and fluid level communication with the hollow flow channel 801 inside the main shaft 8 through the bottom rotary sealing joint 13.

[0054] By constructing a forced physical barrier through the support 10 and the sealing cover 14, the system forcibly creates a clean local microenvironment at the bottom layer, which is full of deliquescent mud cake under extreme working conditions. This bottom isolation mechanism directly blocks the failure path of dust encapsulation, solidification and crystallization, and mechanical jamming between the bottom heat medium pipeline and the rotary joint from the mechanical topology, thus establishing the hardware foundation for the long-term maintenance-free operation of the entire equipment.

[0055] The device is equipped with a heat exchange circulation system to achieve thermodynamic pressurization and fluid kinetic energy amplification during the dust removal process. A heat-conducting jacket 12 is fixed circumferentially on the inner wall of the treatment tank 1. The heat-conducting jacket 12 directly exchanges non-contact wall heat with the dust-laden exhaust gas in the internal tangential swirling flow, continuously absorbing the high enthalpy value carried in the exhaust gas.

[0056] As the central hub for heat transfer and radiation, the main shaft 8 is configured with a hollow flow channel 801 inside. The metal tube wall of the main shaft 8, as a high thermal conductivity interface, directly traverses and is completely exposed to the internal sealed chamber of the corrugated elastic airbag 5, forming the core in-situ heating source.

[0057] The outlet of the heat-conducting jacket 12 is connected to the bottom rotary sealing joint 13 in the bottom sealed chamber through a circulation pipeline. Under the forced power drive of the external circulation pump, the high-temperature heat-conducting medium that has absorbed the sensible heat of the exhaust gas is continuously pumped and directly injected into the internal region of the hollow flow channel 801 through the bottom rotary sealing joint 13.

[0058] Within the hollow flow channel 801, the high-temperature heat-conducting medium is forcibly constrained into a unidirectional direct flow state from bottom to top. During this upward flow process, the heat carried by the heat-conducting medium penetrates the metal tube wall of the main shaft 8, continuously and comprehensively radiating and conducting heat to the fixed mass of sealed gas within the corrugated elastic airbag 5 covering its outer side. This intensifies the thermal motion of gas molecules inside the airbag and generates strong thermodynamic expansion internal pressure.

[0059] The main shaft 8 extends upward and passes through the treatment tank 1, with a top rotary sealing joint 15 coaxially installed at its top. The cooling medium that has completed the heat release along the way is extracted by the circulation pump through the top rotary sealing joint 15 and reinjected back into the heat-conducting jacket 12 through the return pipeline, thereby completing the closed-loop unidirectional heat medium circulation and the heat absorption process of the next cycle.

[0060] To achieve periodic passive charging of the working fluid inside the corrugated elastic airbag 5, a one-way air inlet valve 11 is embedded in the tube sheet 2. The air inlet end of the one-way air inlet valve 11 is exposed to the safe and clean fluid environment of the clean air chamber 101, and its air outlet channel penetrates vertically downward through the thickness of the solid steel plate of the tube sheet 2, and achieves direct physical and fluid communication with the internal sealed chamber of the corrugated elastic airbag 5.

[0061] The one-way air intake valve 11 adopts a mechanical one-way conduction structure driven by pressure difference. This structure only allows clean air in the clean air chamber 101 to flow into the corrugated elastic airbag 5 to replenish its volume when the airbag 5 is stretched to create an internal negative pressure; at the same time, it strictly prevents backflow leakage of the high-pressure fluid inside the airbag into the clean air chamber 101 during the compression and expansion phases. This adaptive one-way fluid replenishment mechanism, combined with the bottom-to-top heating architecture of the closed heat exchange, together construct a complete and rigorous thermo-mechanical coupled energy storage system.

[0062] When the system is in normal gas-solid separation operation, the dust-laden exhaust gas enters the dust chamber 102 through the tangential air inlet channel 16 and is purified by the flexible filter bag 3. During this period, the one-way air inlet valve 11 and the duckbill-type one-way jet nozzle 6 are both in a physically closed state, and a fixed mass of sealed gas chamber is formed inside the corrugated elastic airbag 5.

[0063] During the aforementioned normal filtration cycle, the heat-conducting medium flowing upwards inside the main shaft 8 continuously radiates and conducts heat to the sealed gas inside the airbag. After absorbing enthalpy, the gas molecules undergo intensified thermal motion, accumulating a huge amount of thermodynamic expansion potential energy in advance during this isochoric heating stage.

[0064] When the dust removal process is triggered, the drive mechanism 9 located in the clean air chamber 101 starts, outputs a fixed-axis rotation torque and transmits it directly to the main shaft 8. The main shaft 8 drives the rigid sealed chassis 7 to rotate synchronously on the fixed axis, forcing the bottom end of the helical spring frame 4 fixed on it to rotate as well, thereby bearing a strong torque load.

[0065] While the helical spring skeleton 4 undergoes circumferential torsion under torque, its geometric topology inevitably leads to axial contraction displacement. Due to its non-uniform structure with variable pitch, asynchronous misalignment deformation occurs in each layer along the axial direction, directly forcing the outer flexible filter bag 3 to undergo three-dimensional helical folds. Through pure mechanical shearing force, the hardened potassium nitrate sludge cake attached to the outer surface of the filter material is cracked over a large area.

[0066] The axial contraction of the helical spring frame 4 synchronously forces the rigid sealed chassis 7 upward, causing the chassis to overcome gravity and produce a significant upward displacement. This lifting action of the chassis exerts a violent mechanical axial compression on the flexible filter bag 3 and the corrugated elastic airbag 5 fixed to its upper surface, forcibly reducing the internal physical volume of the airbag.

[0067] The forced mechanical volume compression caused by the chassis lift, combined with the thermodynamic expansion potential energy accumulated by the previous isochoric heating, occurs in the same confined physical space. The pressure of the working fluid inside the airbag soars exponentially. When this pressure exceeds the elastic resistance threshold of the duckbill-type unidirectional jet nozzle 6, the high-temperature and high-pressure fluid instantly breaks through the nozzle slit and violently ejects radially outward in the form of a high-speed pneumatic pulse.

[0068] The transient high-temperature pneumatic pulse directly bombards the inner wall of the flexible filter bag 3, which has been cracked by mechanical torsion. It not only uses macroscopic pneumatic thrust to completely peel off the mud cake, but also uses its high enthalpy value to generate an instantaneous flash evaporation effect on the deliquescent droplets remaining in the micropores of the filter material, thereby achieving in-situ dehydration and air permeability recovery of the filter bag.

[0069] After the dust removal pulse is released, the drive mechanism 9 instantly releases the torque lock on the main shaft 8. The helical spring frame 4 instantly releases the elastic potential energy accumulated in the previous period, driving the rigid sealed chassis 7 and the flexible filter bag 3 to rotate in the opposite direction and rapidly reset downwards.

[0070] The downward reset displacement of the rigid sealed chassis 7 forcibly elongates the corrugated elastic airbag 5, causing its internal volume to increase sharply and forming an extremely strong negative pressure zone. This negative pressure automatically overcomes the opening resistance of the one-way air intake valve 11, drawing clean air from the clean air chamber 101 into the internal cavity of the corrugated elastic airbag 5 in a one-way manner, completing the passive replenishment of fluid and system reset, until seamlessly connecting to enter the next thermo-mechanical coordinated operation cycle.

[0071] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A filter-type potassium nitrate processing tail gas treatment device, comprising a treatment tank (1), characterized in that, The upper part of the treatment tank (1) is fixedly connected to a perforated plate (2). The perforated plate (2) divides the inner cavity of the treatment tank (1) into an upper clean air chamber (101) and a lower dust chamber (102). The dust chamber (102) is coaxially fitted with a flexible filter bag (3), a spiral spring frame (4) and a corrugated elastic airbag (5) from the outside to the inside. The upper side wall of the corrugated elastic airbag (5) is circumferentially arrayed with several duckbill-type unidirectional jet nozzles (6). The top ends of the flexible filter bag (3), the spiral spring frame (4) and the corrugated elastic airbag (5) are all sealed and fixedly connected to the perforated plate (2), and the bottom ends are sealed and fixedly connected to the suspended rigid sealing chassis (7). A main shaft (8) is rotatably connected through the center of the perforated plate (2). The top end of the main shaft (8) passes through the clean air chamber (101) and extends to the top of the treatment tank (1). The top of the treatment tank (1) is provided with a drive mechanism. The drive mechanism (9) for rotating the main shaft (8) has a corrugated elastic airbag (5) and a rigid sealing chassis (7) passing through the bottom end of the main shaft (8) in sequence, and is rotatably connected to a bracket (10). The outer end of the bracket (10) is fixedly connected to the inner wall of the treatment tank (1). The rigid sealing chassis (7) is slidably connected to the main shaft (8), and the two are in a circumferentially locked state. When the dust removal program is triggered, the drive mechanism (9) drives the main shaft (8) to rotate the rigid sealing chassis (7) on a fixed axis, forcing the spiral spring skeleton (4) to bear torque and undergo axial contraction, causing the flexible filter bag (3) to undergo three-dimensional folds to mechanically crack the external dust. At the same time, the axial contraction pulls the rigid sealing chassis (7) to move upward, forcibly squeezing the corrugated elastic airbag (5), causing the fluid pressure inside the corrugated elastic airbag (5) to rise and break through the resistance threshold of the duckbill-type unidirectional jet nozzle (6) to spray out transient airflow.

2. The filter-type potassium nitrate processing tail gas treatment device according to claim 1, characterized in that, The spiral spring skeleton (4) is a variable pitch spiral structure. When it bears the torque input transmitted by the main shaft (8), it generates a non-uniform shrinkage displacement gradient in each ring along the axial direction. Through the asynchronous mechanical misalignment between the layers, it applies a shearing force to the mud cake shell layer attached to the outer surface of the flexible filter bag (3).

3. The filter-type potassium nitrate processing tail gas treatment device according to claim 1, characterized in that, The perforated plate (2) is provided with a one-way air inlet valve (11). The air inlet end of the one-way air inlet valve (11) is exposed in the clean air chamber (101), and the air outlet end penetrates the perforated plate (2) vertically and is in fluid communication with the internal cavity of the corrugated elastic airbag (5). The one-way air inlet valve (11) only allows air in the clean air chamber (101) to flow into the corrugated elastic airbag (5) in one direction.

4. The filter-type potassium nitrate processing tail gas treatment device according to claim 3, characterized in that, When the drive mechanism (9) releases the torque lock on the main shaft (8), the helical spring skeleton (4) releases elastic potential energy, driving the rigid sealed chassis (7) and flexible filter bag (3) to rotate in the opposite direction and reset downward. The downward displacement of the rigid sealed chassis (7) elongates the corrugated elastic airbag (5), causing a negative pressure to be formed inside it, and automatically opening the one-way air intake valve (11) to draw in clean air and complete the passive charging of the fluid.

5. The filter-type potassium nitrate processing tail gas treatment device according to claim 1, characterized in that, The exhaust gas treatment device also includes a heat exchange circuit system. A heat-conducting jacket (12) is fixedly connected to the inner wall of the treatment tank (1). A hollow flow channel (801) is opened inside the main shaft (8). The heat-conducting jacket (12) and the hollow flow channel (801) are connected through a circulation pipeline and a circulation pump. The heat medium introduced from the heat-conducting jacket (12) provides constant thermodynamic expansion energy to the sealed gas in the corrugated elastic airbag (5).

6. The filter-type potassium nitrate processing tail gas treatment device according to claim 5, characterized in that, The bottom of the main shaft (8) is coaxially mounted with a bottom rotary sealing joint (13). The bottom rotary sealing joint (13) is covered with a sealing cover (14). The open edge of the sealing cover (14) is fixedly connected to the surface of the bracket (10) to form a sealed chamber. The circulation pipeline passes through the pipe wall of the sealing cover (14) and is connected to the hollow flow channel (801) through the bottom rotary sealing joint (13).

7. A filter-type potassium nitrate processing tail gas treatment device according to claim 6, characterized in that, The top of the main shaft (8) is coaxially provided with a top rotary sealing joint (15). Under the drive of the circulating pump, the heat transfer medium is injected into the hollow flow channel (801) from the bottom rotary sealing joint (13), and is forced to flow in a unidirectional direct current from the bottom to the top. Then it is extracted through the top rotary sealing joint (15) and reinjected into the heat transfer jacket (12).

8. The filter-type potassium nitrate processing tail gas treatment device according to claim 1, characterized in that, The fluid ejection end face of the duckbill-type unidirectional jet nozzle (6) points radially outward toward the inner wall of the flexible filter bag (3). The duckbill-type unidirectional jet nozzle (6) relies on the elastic restoring force of the material to maintain closure under normal conditions, so as to block the low-pressure leakage of gas inside the corrugated elastic airbag (5) before reaching the burst critical point.

9. A filter-type potassium nitrate processing tail gas treatment device according to claim 2, characterized in that, The three-dimensional folds of the flexible filter bag (3) have the following synergistic features: when the rigid sealing chassis (7) is driven by the rotation of the main shaft (8), the flexible filter bag (3) follows the spiral spring frame (4) to generate spiral folds. By utilizing the condensation mechanism of geometric surface area, shear stress is generated inside the potassium nitrate dust cake attached to the outer surface of the flexible filter bag (3) and mechanical cracking is forced.

10. A filter-type potassium nitrate processing tail gas treatment device according to claim 1, characterized in that, The lower side wall of the dust chamber (102) is provided with a tangential air inlet channel (16) for introducing potassium nitrate tail gas, the top of the clean air chamber (101) is provided with an exhaust channel (17) for discharging purified gas, and the bottom of the dust chamber (102) is connected to an inverted conical dust collection hopper (18) for receiving the peeled dust.

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