Method and system for gradient condensation recovery of hydrochloric acid in waste gas incineration system

Abstract

The application discloses a gradient condensation recovery method and system of hydrochloric acid in a waste gas incineration system, and particularly relates to the field of waste gas purification, and comprises a treatment tank, a treatment tower arranged on the output side of the treatment tank and used for desulfurization and denitrification of waste gas, and a plurality of groups of partitions, wherein the plurality of groups of partitions are vertically arranged at equal intervals in the treatment tank, and a plurality of groups of condensation tanks are assembled on the plurality of groups of partitions. The application constructs a gradient condensation environment by arranging cooling liquids with decreasing temperatures from top to bottom in the plurality of groups of cooling cavities, and rotates the inner sleeve and the elastic scraper to convert the waste gas from laminar flow into turbulent flow to strengthen heat exchange and accelerate the condensation rate of hydrochloric acid vapor. Meanwhile, the elastic scraper is used to scrape off the liquid film and impurities on the inner wall of the condensation tank in real time, the centrifugal force of the inner sleeve is used to realize synchronous self-cleaning of the heat exchange surface, the performance decay is avoided, the efficient, stable and long-term reliable operation of the condensation process is ensured, the hydrochloric acid recovery rate and purity can be effectively improved, and the application is suitable for the treatment of HCl-containing waste gas in the petrochemical industry.

Description

Technical Field

[0001] This invention relates to the field of waste gas purification technology, and more specifically, to a method and system for gradient condensation recovery of hydrochloric acid in a waste gas incineration system. Background Technology

[0002] Petrochemical production generates waste gas containing pollutants such as volatile organic compounds (VOCs) and HCl, which directly harms the environment and human health. Treating waste gas to meet emission standards is an urgent need for petrochemical enterprises. Currently, regenerative thermal oxidizer (RTO) technology is widely used. However, traditional RTO systems have problems such as low hydrochloric acid recovery rate (generally only 25% in China), low purity, and insufficient utilization of flue gas waste heat when treating HCl-containing waste gas, resulting in resource waste and increased carbon emissions.

[0003] In existing waste gas incineration systems, hydrochloric acid recovery mostly adopts a single-temperature condensation method, which has obvious drawbacks: First, the lack of a gradient cooling environment means that the waste gas is in a laminar flow state, resulting in insufficient heat exchange with the condenser wall and further reducing recovery efficiency; Second, the condensate film and impurities easily adhere to the heat exchange surface, affecting the purity of hydrochloric acid, aggravating equipment corrosion and blockage, and lacking an effective self-cleaning mechanism, requiring frequent shutdowns for cleaning, which cannot meet the petrochemical industry's demand for continuous, efficient, and energy-saving hydrochloric acid recovery.

[0004] To address the aforementioned technical shortcomings, a solution is provided. Summary of the Invention

[0005] To overcome the above-mentioned defects of the prior art, the present invention provides a method and system for gradient condensation recovery of hydrochloric acid in a waste gas incineration system.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A gradient condensation and recovery system for hydrochloric acid in a waste gas incineration system includes a treatment tank, a treatment tower for desulfurization and denitrification of the waste gas located at the output side of the treatment tank, and further includes:

[0008] Multiple sets of baffles are equidistantly and vertically arranged inside the processing tank, and multiple sets of condenser tanks are assembled on the baffles. An inner sleeve is rotatably inserted through the middle of the condenser tank, and both ends of the inner sleeve extend to the outside of the condenser tank. An extension pipe is fixedly connected to the top of the condenser tank, and an air inlet pipe is inserted into the top side wall of the condenser tank. Two elastic scrapers are symmetrically installed on the outer wall of the inner sleeve inside the condenser tank. A tapered groove with gradually decreasing diameter is opened on the bottom side wall of the condenser tank, and a drain pipe is fixedly installed at the bottom of the inner sleeve.

[0009] The cooling chamber is formed by two adjacent sets of partitions and the inner wall of the processing tank. The cooling temperature of the multiple sets of cooling chambers decreases sequentially from top to bottom along the height direction of the processing tank.

[0010] A sealed container is fixedly welded to the bottom of the processing container, the bottom of the condensate tank extends into the sealed container, and a discharge container is fixedly provided at the bottom of the sealed container;

[0011] A two-phase tube is fixedly installed on the bottom wall of the condenser and connected to a conical groove. The output end of the two-phase tube passes through the sealed tank and extends into the discharge tank.

[0012] Furthermore, a driven gear is fixedly installed on the outer wall of the extension tube, a reduction motor is fixedly installed on the top of the inner wall of the processing tank, a drive shaft is fixedly connected to the output end of the reduction motor, and a driving gear is fixedly installed at the end of the drive shaft. The driving gear meshes with the driven gear for transmission.

[0013] Furthermore, the extended ends of the multiple sets of two-phase pipes are positioned towards the center of the discharge tank.

[0014] Furthermore, the multiple sets of air intake pipes are connected by a circular ring pipe, and a main intake pipe extending to the outside of the treatment tank is inserted into the side wall of the circular ring pipe.

[0015] Furthermore, the top of the extension tube is rotatably fitted with the inner wall of the top of the treatment tank, the top of the treatment tank is provided with a connecting groove that communicates with the extension tube, a sealing sleeve is provided between the connecting groove and the extension tube, the top wall of the treatment tank is also provided with an annular groove that connects with the connecting groove, and a cold liquid pipe that communicates with the annular groove is inserted into the outer wall of the treatment tank.

[0016] Furthermore, a hydrochloric acid recovery pipe is installed at the bottom of the discharge tank, and a waste gas treatment pipe is inserted into the top side wall of the discharge tank, with the output end of the waste gas treatment pipe connected to the treatment tower.

[0017] Furthermore, the multiple sets of condenser tanks are arranged in a circular array and assembled inside the partition.

[0018] The gradient condensation recovery method for hydrochloric acid in a waste gas incineration system includes the following steps:

[0019] 1. Cooling and drive preparation: Inject coolant into the inner sleeve through the cold liquid pipe until it is full, introduce gradient cooling coolant into the cooling chamber, and turn on the geared motor to drive the extension pipe, inner sleeve and elastic scraper to rotate.

[0020] II. Exhaust gas introduction: The exhaust gas after front-end impurity removal is distributed through the main inlet pipe and the circular ring pipe, and flows into the gap between the condenser and the inner sleeve through the inlet pipe;

[0021] III. Gradient Condensation and Scraping: The exhaust gas flows through the cooling chamber to achieve gradient condensation, and the hydrochloric acid vapor condenses into liquid; the rotating elastic scraper enhances heat exchange and scrapes away impurities from the tank wall, while the centrifugal force of the inner sleeve assists in removing impurities attached to itself.

[0022] Recovery and treatment: Liquid hydrochloric acid flows into the discharge tank through a conical trough and a two-phase pipe for separation, and is then collected by the hydrochloric acid recovery pipe. The waste gas is sent to the treatment tower for desulfurization and denitrification.

[0023] The technical effects and advantages of this invention are as follows:

[0024] 1. This invention creates a stable and controllable gradient condensation environment by setting coolant with a decreasing temperature from top to bottom in multiple cooling chambers. Combined with the low-speed synchronous rotation of the inner sleeve and the elastic scraper, the elastic scraper continuously agitates the exhaust gas during rotation, transforming it from a "laminar flow" to a "turbulent flow" state. This significantly increases the contact probability and heat exchange intensity between the exhaust gas and the cooling wall, thereby accelerating the condensation rate of hydrochloric acid vapor and laying the foundation for efficient recovery of exhaust gas.

[0025] 2. This invention utilizes turbulent enhanced condensation, combined with an elastic scraper to remove hydrochloric acid film and impurities adhering to the inner wall of the condenser in real time. This effectively prevents the heat exchange efficiency from decreasing due to film thickening and avoids the risk of blockage or corrosion caused by impurity accumulation. The centrifugal force generated by the continuous rotation of the inner sleeve can throw the trace impurities and liquid film adhering to its outer wall toward the inner wall of the condenser. Combined with the indirect airflow disturbance of the scraper, it makes it difficult for a stable adhesion layer to form on the outer wall of the inner sleeve, thereby achieving synchronous self-cleaning of the heat exchange surfaces of the inner sleeve outer wall and the inner wall of the condenser. This synergistic mechanism of dynamic scraping and centrifugal self-cleaning ensures that the heat exchange surface remains clean throughout the condensation process, avoiding performance degradation due to contamination accumulation, and thus maintaining the high efficiency, stability, and long-term reliable operation of the condensation process. Attached Figure Description

[0026] Figure 1 This is a perspective view of the overall structure of the present invention.

[0027] Figure 2 This is a front view of the internal structure of the processing tank in this invention.

[0028] Figure 3 This is a three-dimensional view of the internal structure of the processing tank in this invention.

[0029] Figure 4 This is a front view of the internal structure of the condenser in this invention.

[0030] Figure 5 This is a perspective view of the top structure of the processing tank in this invention.

[0031] Figure 6 This is a three-dimensional view of the external structure of the inner sleeve in this invention.

[0032] Figure 7 for Figure 3 Enlarged 3D view of the structure of region A in the middle.

[0033] The attached diagram is labeled as follows: 1. Treatment tank; 2. Baffle plate; 3. Sealed tank; 4. Discharge tank; 5. Condensate tank; 51. Inner sleeve; 52. Extension pipe; 53. Inlet pipe; 54. Circular ring pipe; 55. Elastic scraper; 56. Two-phase pipe; 57. Drain pipe; 58. Annular groove; 59. Connecting groove; 510. Conical groove; 511. Sealed sleeve; 61. Drive gear; 62. Driven gear; 63. Gear motor; 7. Treatment tower; 8. Main inlet pipe; 9. Cold liquid pipe; 10. Waste gas treatment pipe; 11. Hydrochloric acid recovery pipe. Detailed Implementation

[0034] 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.

[0035] Example 1: Please refer to Figure 1 - Figure 7 As shown, the problems of insufficient heat exchange on the condenser wall and lack of an effective self-cleaning mechanism for the heat exchange surface in the existing technology can be solved by the following solutions;

[0036] In this embodiment, the hydrochloric acid gradient condensation and recovery system in the waste gas incineration system includes a treatment tank 1, a treatment tower 7 located on the output side of the treatment tank 1 for desulfurization and denitrification of waste gas, and also includes multiple sets of baffles 2, a sealed tank 3, and a two-phase pipe 56.

[0037] Multiple sets of baffles 2 are equidistantly and vertically arranged inside the processing tank 1. Multiple sets of condensing tanks 5 are arranged on the multiple sets of baffles 2. A cooling chamber is formed between two adjacent sets of baffles 2 and the inner wall of the processing tank 1. The cooling temperature of the multiple sets of cooling chambers decreases sequentially from top to bottom.

[0038] Additional explanation of the cooling chamber: The cooling chamber is used to fill the coolant with gradient cooling. In practical applications, ethylene glycol aqueous solution or industrial chilled water is preferred. Multiple cooling chambers have the coolant temperature decreasing sequentially from top to bottom, forming a gradient condensation environment, which can realize the staged condensation and efficient recovery of hydrochloric acid vapor in the exhaust gas.

[0039] The recycling of the cooling cavities is realized by a closed-loop circulation system, and the specific structural components include a water chiller, graded circulation pumps, temperature sensors, plate heat exchangers, return pipelines and thermal insulation layers, wherein: the temperature sensor is built in each group of cooling cavities to monitor the temperature of the cooling liquid in real time and feed it back to the control system; the cooling liquid in the upper high-temperature cooling cavity is cooled by heat exchange with the water chiller through the plate heat exchanger, and then conveyed by the graded circulation pump to the lower low-temperature cooling cavity; the cooling liquid in the lower low-temperature cooling cavity maintains a constant-temperature circulation, and excess heat is discharged through the water chiller; the return pipeline realizes the circulating conveyance of the cooling liquid, and the thermal insulation layer wraps the outer side of the cooling cavities to reduce heat loss, ensure the temperature stability of each cooling cavity, finally realize the repeated recycling of the cooling liquid, and reduce the operation cost;

[0040] An inner sleeve 51 is rotatably arranged in the middle of the condensation tank 5, both ends of the inner sleeve 51 extend out of the condensation tank 5, an extension pipe 52 is fixedly connected to the top of the condensation tank 5, an air inlet pipe 53 is inserted through the top side wall of the condensation tank 5, two elastic scrapers 55 are symmetrically installed on the outer wall of the inner sleeve 51 located inside the condensation tank 5, a tapered groove 510 with a gradually decreasing pore diameter is opened on the bottom side wall of the condensation tank 5, and a liquid discharge pipe 57 is fixedly installed at the bottom of the inner sleeve 51;

[0041] Supplementary description of the supporting components of the condensation tank 5:

[0042] A PTFE material ball valve is arranged on the outer wall of the extension pipe 52; a PPH material plug valve is arranged on the outer wall of the liquid discharge pipe 57;

[0043] The elastic scraper 55 is made of a composite material consisting of a fluororubber core layer and a carbon fiber reinforced PTFE surface layer. The fluororubber core layer can provide sufficient elasticity to ensure the interference fit effect between the scraper and the inner wall of the condensation tank 5, and the carbon fiber reinforced PTFE surface layer significantly improves the wear resistance, corrosion resistance and structural stability of the scraper, preventing the scraper from aging, wearing out and failing due to long-term scraping and contact with hydrochloric acid;

[0044] In addition, the elastic scraper 55 is in direct elastic interference contact with the inner wall of the condensation tank 5 with a gap-free design. In the free state, the outer diameter of the scraper is 0.1-0.3 mm larger than the inner diameter of the inner wall of the condensation tank 5. After assembly, it clings to the inner wall of the condensation tank 5 by the elastic restoring force of the fluororubber core layer, which not only ensures thorough impurity scraping, but also avoids scraper damage and scratching of the inner wall of the condensation tank 5 caused by rigid contact; the optimal rotation speed of the elastic scraper 55 is 5-10 r / min;

[0045] The taper angle of the tapered groove 510 at the bottom of the condensation tank 5 is designed to be 60°, this angle can ensure that the condensed hydrochloric acid liquid converges rapidly, avoids residue in the groove, and at the same time accelerates the flow of hydrochloric acid into the discharge tank 4 through the two-phase pipe 56, improving the recovery efficiency; the inner wall of the tapered groove 510 is sprayed with a PTFE nano hydrophobic coating to reduce the adhesion of the hydrochloric acid liquid;

[0046] Sealed tank 3 is fixedly welded to the bottom of treatment tank 1. The bottom of condenser tank 5 extends into sealed tank 3. A discharge tank 4 is fixedly provided at the bottom of sealed tank 3 for simultaneously discharging waste gas and hydrochloric acid.

[0047] Two-phase pipe 56 is fixedly installed on the bottom wall of condenser 5 and connected to conical groove 510. The output end of two-phase pipe 56 extends through sealed tank 3 into discharge tank 4.

[0048] Please see Figure 2 - Figure 3 As shown, multiple sets of condenser tubes in a circular array are arranged inside the partition plate 2; this ensures that each set of condenser tanks 5 is in full contact with the coolant in the cooling chamber, with consistent heat exchange efficiency, and guarantees the uniformity of gradient condensation; the connection between the condenser tanks 5 and the partition plate 2 is sealed with PTFE gaskets to prevent coolant leakage from the cooling chamber.

[0049] Please see Figure 2 - Figure 3 , 5 As shown in Figure 6, a driven gear 62 is fixedly installed on the outer wall of the extension tube 52, a reduction motor 63 is fixedly installed on the top of the inner wall of the processing tank 1, a drive shaft is fixedly installed at the output end of the reduction motor 63, and a drive gear 61 is fixedly installed at the end of the drive shaft. The drive gear 61 and the driven gear 62 are in a transmission cooperation.

[0050] Please see Figure 2 - Figure 3 As shown, the extended ends of multiple sets of two-phase pipes 56 are positioned toward the center of the discharge tank 4.

[0051] Please see Figure 2 - Figure 3 As shown, multiple sets of air inlet pipes 53 are connected by a circular ring pipe 54, and a main inlet pipe 8 extending to the outside of the treatment tank 1 is inserted into the side wall of the circular ring pipe 54.

[0052] Please see Figure 5 As shown, the top of the extension tube 52 is rotatably fitted with the inner wall of the top of the treatment tank 1. A connecting groove 59 is provided on the top of the treatment tube to communicate with the extension tube 52. A sealing sleeve 511 is provided between the connecting groove 59 and the extension tube 52. An annular groove 58 connected to the connecting groove 59 is also provided on the top wall of the treatment tank 1. A cold liquid tube 9 connected to the annular groove 58 is inserted into the outer wall of the treatment tank 1.

[0053] To further clarify the above, in order to simultaneously achieve the rotational connection and sealing requirements of the extension tube 52, sealing sleeve 511, and connecting groove 59, a triple-layer synergistic sealing structure of "elastic sealing lip + annular liquid seal + labyrinth seal" is adopted. Specifically, the sealing sleeve 511 is made of carbon fiber reinforced PTFE material, possessing both corrosion resistance and structural rigidity. Two annular sealing grooves are machined on its inner ring, embedding a fluororubber elastic sealing lip. The interference fit between the sealing lip and the outer wall of the extension tube 52 is controlled at 0.1-0.2mm. Relying on elastic recovery force, it tightly adheres to the outer wall of the extension tube 52, forming a radial dynamic seal and blocking... Gas-liquid leakage: An annular liquid seal groove is opened on the inner side of the connecting groove 59, and PTFE-based sealing liquid is injected. When the extension tube 52 rotates, it drives the sealing liquid to form a uniform liquid film, which further blocks the leakage channel and also plays a lubricating role, reducing the wear of the sealing lip; A labyrinth sealing structure is set on the top wall of the treatment tank 1 and the outer side of the sealing sleeve 511 to extend the leakage path and improve the sealing reliability; A PTFE self-lubricating bearing is added at the rotation fit between the top of the extension tube 52 and the inner wall of the top of the treatment tank 1 to ensure the coaxiality of the extension tube 52 rotation, avoid local wear of the sealing lip caused by eccentric rotation, and ensure both smooth rotation and reliable sealing, with no risk of leakage;

[0054] Please see Figure 2-3 As shown, a hydrochloric acid recovery pipe 11 is installed at the bottom of the discharge tank 4, and a waste gas treatment pipe 10 is inserted into the top side wall of the discharge tank 4. A treatment tower 7 is installed at the output end of the waste gas treatment pipe 10. The treatment tower 7 adopts an integrated dry desulfurization and denitrification structure to meet the subsequent deep purification requirements of the waste gas.

[0055] In this embodiment: In practical applications, the cooling substance injected into the inner sleeve 51 is the same as the coolant in the cooling chamber; during gradient condensation, the elastic scraper 55 agitates the exhaust gas to form turbulence, which can accelerate the condensation of the exhaust gas. The turbulence can break the "laminar flow state" of the exhaust gas and enhance the gas-liquid heat exchange efficiency; due to the continuous rotation of the inner sleeve 51, it generates centrifugal force, which can throw the trace impurities and hydrochloric acid liquid film attached to the outer wall of the inner sleeve 51 to the inner wall of the condenser tank 5. Combined with the indirect disturbance of the elastic scraper 55, it is impossible for a stable impurity attachment layer and liquid film to form on the outer wall of the inner sleeve 51. Therefore, there are almost no impurities left on the outer wall of the inner sleeve 51; the continuous movement of the elastic scraper 55 can destroy the stability of the hydrochloric acid liquid film, preventing it from forming a stubborn liquid layer on the inner wall of the condenser tank 5. At the same time, it can push the hydrochloric acid liquid to quickly converge into the conical groove 510, accelerate the discharge of hydrochloric acid through the two-phase pipe 56, and improve the recovery efficiency.

[0056] Working principle:

[0057] I. Pretreatment and Cooling Preparation Stage

[0058] Cooling system preparation: Cooling material is injected into the annular groove 58, the connecting groove 59 and the extension pipe 52 through the cold liquid pipe 9. The cooling material flows into the inner sleeve 51 through the PTFE ball valve on the extension pipe 52. After all the inner sleeves 51 are filled with cooling material, the PTFE ball valve is closed to ensure that the inner sleeves 51 are full of cooling material, laying the foundation for subsequent heat exchange and condensation. At the same time, a gradient cooling coolant is introduced into multiple cooling chambers.

[0059] Drive system startup: Turn on the explosion-proof and corrosion-resistant geared motor 63. The geared motor 63 drives the drive shaft to rotate. The drive gear 61 at the end of the drive shaft meshes with the driven gear 62 on the outer wall of the extension tube 52, thereby driving the extension tube 52 and the inner sleeve 51 to rotate synchronously. The rotation speed of the inner sleeve 51 is stable at 5-10 r / min. When the inner sleeve 51 rotates, the two elastic scrapers 55 symmetrically installed on its outer wall slide close to the inner wall of the condenser tank 5 to scrape off the impurities attached to the inner wall of the condenser tank 5 in advance, preparing for the subsequent condensation operation.

[0060] Exhaust gas pretreatment: After the cooling system and drive system have been running stably, the exhaust gas that has been intercepted by the front end is introduced into the main inlet pipe 8;

[0061] II. Gradient Condensation and Hydrochloric Acid Recovery Stage

[0062] Waste gas introduction and distribution: The pretreated waste gas enters the circular ring pipe 54 through the main inlet pipe 8. The circular ring pipe 54 evenly distributes the waste gas to multiple sets of inlet pipes 53. The waste gas flows into the gap between the condenser tank 5 and the inner sleeve 51 through the inlet pipes 53.

[0063] Graded condensation: The exhaust gas flows from top to bottom within the gap between the condenser tank 5 and the inner sleeve 51, passing through multiple cooling chambers with decreasing temperatures from top to bottom to achieve gradient condensation: the upper cooling chamber has a higher temperature, which first condenses the easily condensable high-concentration hydrochloric acid vapor in the exhaust gas, while the lower cooling chamber has a lower temperature, which further condenses the residual low-concentration hydrochloric acid vapor in the exhaust gas. Compared with single-temperature condensation, gradient condensation can avoid local condensation dead zones and improve hydrochloric acid recovery efficiency. At the same time, the cooling material in the inner sleeve 51 exchanges heat with the exhaust gas, absorbing the heat of the exhaust gas and further accelerating the condensation of hydrochloric acid vapor into liquid hydrochloric acid.

[0064] Dynamic scraping and turbulence enhancement: The inner sleeve 51 rotates continuously, causing the elastic scraper 55 to slide closely against the inner wall of the condenser tank 5. On the one hand, the elastic scraper 55 agitates the waste gas in the gap, causing the waste gas to form turbulence, breaking the laminar flow state of the waste gas, and enhancing the full contact between the waste gas and the cold wall of the inner sleeve 51 and the cold wall of the condenser tank 5, which greatly improves the heat exchange efficiency and accelerates the condensation of hydrochloric acid vapor. On the other hand, the elastic scraper 55 can scrape off the impurities and liquid hydrochloric acid film adhering to the inner wall of the condenser tank 5 in real time, avoiding the thickening of the liquid film from affecting heat exchange, and at the same time preventing the accumulation of impurities. The inner sleeve 51, due to continuous rotation, uses centrifugal force to throw the trace impurities and hydrochloric acid film adhering to the outer wall towards the inner wall of the condenser 5. Combined with the indirect disturbance of the elastic scraper 55, a stable impurity adhesion layer and liquid film cannot be formed on the inner wall of the inner sleeve 51. Therefore, there are almost no impurities remaining on the inner wall of the inner sleeve 51. In addition, the continuous movement of the elastic scraper 55 can disrupt the stability of the hydrochloric acid film, preventing it from forming a stubborn liquid layer on the inner wall of the condenser 5, and pushing the liquid hydrochloric acid to quickly converge to the conical groove 510 at the bottom of the condenser 5.

[0065] Hydrochloric acid discharge and collection: Liquid hydrochloric acid in the conical tank 510 flows into the sealed tank 3 through the two-phase pipe 56. The sealed tank 3 can prevent hydrochloric acid evaporation and exhaust gas leakage. The protruding end of the two-phase pipe 56 faces the middle of the discharge tank 4 and is cut at an angle to reduce the entrainment of hydrochloric acid droplets in the exhaust gas. The hydrochloric acid finally flows into the discharge tank 4 through the two-phase pipe 56. The hydrochloric acid in the discharge tank 4 achieves preliminary gas-liquid separation with the uncondensed exhaust gas. Under the action of gravity, the hydrochloric acid gathers to the bottom of the cone of the discharge tank 4, while the exhaust gas rises to the top of the discharge tank 4.

[0066] III. Equipment Maintenance and Auxiliary Operation

[0067] Coolant draining: When the condensation operation is completed or the equipment needs maintenance, open the PPH stop valve on the drain pipe 57 to quickly and completely drain the coolant in the inner sleeve 51 and discharge it through the sealed tank 3.

[0068] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A gradient condensation and recovery system for hydrochloric acid in a waste gas incineration system, comprising a treatment tank (1) and a treatment tower (7) for desulfurization and denitrification of waste gas located on the output side of the treatment tank (1), characterized in that, Also includes: Multiple sets of partitions (2) are equidistantly and vertically arranged inside the processing tank (1). Multiple sets of condenser tanks (5) are assembled on the multiple sets of partitions (2). An inner sleeve (51) is rotatably inserted in the middle of the condenser tank (5). Both ends of the inner sleeve (51) extend to the outside of the condenser tank (5). An extension pipe (52) is fixedly connected to the top of the condenser tank (5). An air inlet pipe (53) is inserted into the top side wall of the condenser tank (5). Two elastic scrapers (55) are symmetrically installed on the outer wall of the inner sleeve (51) inside the condenser tank (5). A tapered groove (510) with a gradually decreasing diameter is opened on the bottom side wall of the condenser tank (5). A drain pipe (57) is fixedly installed at the bottom of the inner sleeve (51). The cooling chamber is formed by two adjacent sets of partitions (2) and the inner wall of the processing tank (1). The cooling temperature of the multiple sets of cooling chambers decreases sequentially from top to bottom along the height direction of the processing tank (1). A sealed tank (3) is fixedly welded to the bottom of the processing tank (1), the bottom of the condenser (5) extends into the sealed tank (3), and a discharge tank (4) is fixedly provided at the bottom of the sealed tank (3). Two-phase tube (56) is fixedly installed on the bottom wall of the condenser (5) and connected to the conical groove (510). The output end of the two-phase tube (56) passes through the sealed tank (3) and extends into the discharge tank (4).

2. The gradient condensation and recovery system for hydrochloric acid in the waste gas incineration system according to claim 1, characterized in that: A driven gear (62) is fixedly installed on the outer wall of the extension tube (52), and a reduction motor (63) is fixedly installed on the top of the inner wall of the processing tank (1). A drive shaft is fixedly connected to the output end of the reduction motor (63), and a drive gear (61) is fixedly installed at the end of the drive shaft. The drive gear (61) meshes with the driven gear (62) for transmission.

3. The gradient condensation and recovery system for hydrochloric acid in the waste gas incineration system according to claim 1, characterized in that: The extended ends of the multiple sets of two-phase pipes (56) are arranged toward the middle of the discharge tank (4).

4. The gradient condensation and recovery system for hydrochloric acid in the waste gas incineration system according to claim 1, characterized in that: The multiple sets of air inlet pipes (53) are connected by a circular ring pipe (54), and a main inlet pipe (8) extending to the outside of the treatment tank (1) is inserted into the side wall of the circular ring pipe (54).

5. The gradient condensation and recovery system for hydrochloric acid in the waste gas incineration system according to claim 1, characterized in that: The top of the extension tube (52) is rotatably fitted with the inner wall of the top of the treatment tank (1). The top of the treatment tank (1) is provided with a connecting groove (59) that is connected to the extension tube (52). A sealing sleeve (511) is provided between the connecting groove (59) and the extension tube (52). An annular groove (58) connected to the connecting groove (59) is also provided on the top wall of the treatment tank (1). A cold liquid pipe (9) connected to the annular groove (58) is inserted on the outer wall of the treatment tank (1).

6. The gradient condensation and recovery system for hydrochloric acid in the waste gas incineration system according to claim 1, characterized in that: The bottom of the discharge tank (4) is equipped with a hydrochloric acid recovery pipe (11), and a waste gas treatment pipe (10) is inserted on the top side wall of the discharge tank (4). The output end of the waste gas treatment pipe (10) is connected to the treatment tower (7).

7. The gradient condensation and recovery system for hydrochloric acid in the waste gas incineration system according to claim 1, characterized in that: Multiple sets of the condenser tanks (5) are arranged in a circular array and assembled inside the partition (2).

8. A method for gradient condensation recovery of hydrochloric acid in a waste gas incineration system, comprising the gradient condensation recovery system for hydrochloric acid in a waste gas incineration system as described in any one of claims 1-7, characterized in that, Includes the following steps:

1. Cooling and drive preparation: Inject coolant into the inner sleeve (51) through the coolant pipe (9) to fill it, introduce gradient cooling coolant into the cooling chamber, and turn on the geared motor (63) to drive the extension pipe (52), inner sleeve (51) and elastic scraper (55) to rotate.

2. Waste gas inlet: The waste gas after front-end impurity removal is distributed through the main inlet pipe (8) and the circular ring pipe (54), and flows into the gap between the condenser (5) and the inner sleeve pipe (51) through the inlet pipe (53); 3. Gradient condensation and scraping: The waste gas flows through the cooling chamber to achieve gradient condensation, and the hydrochloric acid vapor condenses into liquid; the elastic scraper (55) rotates to enhance heat exchange and scrape off impurities from the tank wall, and the inner sleeve (51) uses centrifugal force to help remove impurities attached to itself. IV. Recovery and treatment: Liquid hydrochloric acid flows into the discharge tank (4) through the conical tank (510) and two-phase pipe (56). After separation, it is collected by the hydrochloric acid recovery pipe (11), and the waste gas is sent to the treatment tower (7) for desulfurization and denitrification.

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