Treatment system suitable for multi-stage Claus sulfur recovery

Abstract

The utility model discloses a treatment system suitable for multistage Claus sulfur recovery, which comprises a conventional Claus sulfur recovery device and a steam injection device, and the conventional Claus sulfur recovery device comprises a waste heat boiler for generating high-pressure steam and a four-stage sulfur condensation cooler for generating low-pressure steam, the first input end of the steam injection device is connected with the output end of the waste heat boiler, the second input end of the steam injection device is connected with the output end of the four-stage sulfur condensation cooler, and the output end of the steam injection device is connected with a low-pressure saturated steam system; according to the utility model, high-pressure steam generated by the waste heat boiler is utilized to eject low-pressure steam of the four-stage sulfur condensation cooler through the steam ejection device, so that the temperature and the pressure of a process gas outlet of the four-stage sulfur condensation cooler are effectively reduced, more sulfur in the process gas is condensed and separated out, the sulfur mist entrainment amount is greatly reduced, and the production efficiency is improved. The burden of a tail gas treatment device is reduced, the starting times of the APU are reduced, and the solution loss and the sewage treatment cost are reduced.

Description

Technical Field

[0001] This utility model relates to the field of natural gas purification technology, specifically to a treatment system suitable for multi-stage Claus sulfur recovery. Background Technology

[0002] During processing, sulfides in crude oil or natural gas are converted into hydrogen sulfide (H2S). Hydrogen sulfide is a highly toxic substance that is extremely harmful to humans and the environment, and must be rendered harmless. The most suitable process for this is sulfur recovery. Sulfur recovery refers to the chemical process of converting sulfides in toxic sulfur-containing gases such as hydrogen sulfide into elemental sulfur, thereby turning waste into treasure and protecting the environment.

[0003] Sulfur recovery is typically achieved using the Claus sulfur recovery process, a method for recovering sulfur from acidic gases containing hydrogen sulfide. First, the acidic gas is burned with air or oxygen in a device called a combustion furnace. Part of the hydrogen sulfide is oxidized to sulfur dioxide (SO2). The amount of air or oxygen is strictly controlled to ensure that the volume ratio of hydrogen sulfide to sulfur dioxide in the combustion products is 2:1. The combustion gases are then cooled, and the sulfur in the gases is condensed and recovered. The remaining gas is heated and then fed into a Claus reactor for further reaction. The reaction mainly involves the reaction of hydrogen sulfide and sulfur dioxide to produce sulfur and water. This reaction requires a catalyst. After the reaction, the gas is also cooled to recover sulfur. The remaining gas then undergoes secondary and tertiary reactions. Typically, sulfur recovery units can achieve a sulfur recovery rate of 95%–98%. This method for purifying sulfides in tail gas and recovering sulfur has been widely used in industry.

[0004] Please refer to Figure 1As shown, the existing three-stage conventional Claus sulfur recovery process flow is as follows: The high-temperature process gas from the main combustion furnace is mixed with the acid gas entering the rear of the main combustion furnace. After being cooled by the waste heat boiler (E-1403), most of it enters the first-stage sulfur condenser (E-1404) at 330°C and is cooled to 170°C, separating most of the condensed liquid sulfur. The process gas, after which most of the condensed liquid sulfur is separated, is mixed with a small portion of the 550°C high-temperature process gas from the waste heat boiler through a high-temperature blending valve and enters the first-stage reactor (R-1401). H2S and SO2 in the gas flow continue to react on the catalyst bed to generate elemental sulfur, while most of the organic sulfur undergoes hydrolysis. The process gas from the first-stage reactor enters the second-stage sulfur condenser (E-1405) and is cooled to 170°C, separating the liquid sulfur. The process gas exiting the secondary sulfur condenser enters the primary reheat furnace (H-1404), where it is heated by fuel gas combustion before entering the secondary reactor (R-1402). H2S and SO2 in the gas flow continue to react on the catalyst bed to generate elemental sulfur. The gas is then cooled to 170°C in the tertiary sulfur condenser (E-1406), where the condensed liquid sulfur is separated. The process gas from the tertiary sulfur condenser then enters the secondary reheat furnace (H-1406), where it is heated by fuel gas combustion before entering the tertiary reactor (R-1403). H2S and SO2 in the gas flow continue to react on the catalyst bed to generate elemental sulfur. The gas is then cooled to 170°C in the quaternary sulfur condenser (E-1407). The tail gas is further condensed and separated by the liquid sulfur trap (D-1405) before entering the tail gas treatment unit.

[0005] Currently, the designed sulfur mist content of the tail gas from the liquid sulfur trap (D-1405) in the three-stage conventional Claus sulfur recovery unit is 5.8 g / m3. Analysis shows that the average value in the second stage is 15.1 g / m3, exceeding the design value. The high sulfur mist content in the tail gas results in an SO2 flow rate of 370-390 m3 / h in the regeneration section, exceeding the design value by 284.56 m3 / h. This leads to an increase in the number of APU (auxiliary power unit) start-ups, which not only increases the loss of solution in the tail gas treatment system but also increases the wastewater treatment load. Utility Model Content

[0006] The purpose of this invention is to provide a treatment system suitable for multi-stage Claus sulfur recovery. This system uses a steam ejector to eject high-pressure steam generated by a waste heat boiler to a low-pressure steam system, thereby reducing the outlet temperature and pressure of the process gas in the four-stage sulfur condenser. This allows more sulfur in the process gas to be condensed and separated, reducing the amount of sulfur mist entrained and effectively solving the problem of high sulfur mist content in the tail gas of the liquid sulfur trap.

[0007] This utility model is achieved through the following technical solution:

[0008] A processing system suitable for multi-stage Claus sulfur recovery includes:

[0009] A conventional Claus sulfur recovery unit, comprising a waste heat boiler that generates high-pressure steam and a four-stage sulfur condenser that generates low-pressure steam.

[0010] A steam ejector device is provided, with its first input end connected to the output end of the waste heat boiler, its second input end connected to the output end of the four-stage sulfur condenser, and its output end connected to low-pressure saturated steam to the system.

[0011] In this scheme, the waste heat boiler and the four-stage sulfur condenser in the conventional Claus sulfur recovery unit generate high-pressure and low-pressure steam respectively, providing steam sources of different pressures for the system. The steam ejector is connected to the waste heat boiler and the four-stage sulfur condenser. This connection method can utilize the energy of the high-pressure steam generated by the waste heat boiler to eject the low-pressure steam generated by the four-stage sulfur condenser. Through this ejection action, steam mixing and energy distribution are achieved, and finally, the mixed low-pressure saturated steam is delivered to the system. This process not only optimizes the steam utilization efficiency but also has a positive impact on the entire sulfur recovery process. In actual operation, it can reduce the pressure and temperature of the four-stage sulfur condenser, promote the condensation of more sulfur vapor, reduce the sulfur mist content in the tail gas, and thus improve the efficiency and quality of sulfur recovery. At the same time, it also helps to solve the tail gas treatment problem in the existing process, reduce tail gas treatment costs and environmental pressure.

[0012] As an optimized solution for the processing system, the steam ejector device is a steam ejector.

[0013] In this solution, the steam ejector utilizes the negative pressure effect generated by a high-speed steam flow to draw in and mix with other media, achieving heat energy transfer and conversion through heat exchange. This working principle gives the steam ejector significant advantages in heat recovery and energy-saving retrofitting. The steam ejector is stable and reliable, operates efficiently, and employs energy-saving technologies, significantly reducing energy consumption, saving operating costs for enterprises, and achieving sustainable development.

[0014] As an optimization scheme for the processing system, a three-way switch valve is installed on the pipeline connecting the steam ejector and the waste heat boiler. One passage of the three-way switch valve connects the waste heat boiler and the steam ejector, and the other passage forms a bypass.

[0015] In this scheme, the three-way switch valve allows the high-pressure steam generated by the waste heat boiler to flow smoothly to the steam ejector device, ensuring the stable operation of the steam ejection process. This enables the system to efficiently reduce the pressure and temperature of the four-stage sulfur condenser and reduce the sulfur mist content in the tail gas. When the steam ejector device malfunctions and needs maintenance, the three-way switch valve can be switched to allow the high-pressure steam to be transported via a bypass, avoiding the impact of steam ejector device malfunction on the normal operation of the waste heat boiler and the entire sulfur recovery system, ensuring production continuity and reducing downtime losses caused by equipment failure.

[0016] As an optimized solution for the processing system, another passage of the three-way switch valve is connected to the output end of the steam ejector device via a pipeline.

[0017] In this scheme, by adjusting the three-way switch valve, some steam can flow directly from the bypass to the output end of the steam ejector, thereby maintaining the stability of the low-pressure saturated steam parameters output by the steam ejector and ensuring the stability of the entire processing system. During the maintenance phase of the steam ejector, on the one hand, it ensures that the high-pressure steam generated by the waste heat boiler has a reasonable destination during maintenance, preventing problems such as system pressure buildup due to the steam ejector's malfunction; on the other hand, the steam flowing to the output end through this path can maintain some functions of the system, reducing the impact of equipment maintenance on the entire sulfur recovery process, ensuring production continuity, and reducing economic losses caused by shutdowns.

[0018] As an optimization of the processing system, a first regulating valve is also connected between the three-way switch valve and the output end of the steam ejector device.

[0019] In this solution, by adjusting the first regulating valve, the steam delivery volume and pressure can be precisely controlled, ensuring a stable steam supply to meet the needs of the production process and thus guaranteeing the efficient and stable operation of the sulfur recovery process. In case of system malfunction or steam ejector failure, if bypass steam directly enters the output end, it may cause abnormal pressure fluctuations. In this situation, the first regulating valve can limit the steam flow to prevent sudden pressure increases from damaging other equipment in the system, effectively protecting the safety of the entire processing system.

[0020] As an optimization of the processing system, a second regulating valve is also connected between the three-way switch valve and the input end of the steam ejector device.

[0021] In this design, the second regulating valve is used to precisely control the flow rate and pressure of high-pressure steam entering the steam ejector, thereby optimizing the steam ejection process. During normal system operation, the amount of high-pressure steam entering the steam ejector can be adjusted by regulating the second regulating valve according to different production loads and process requirements. When the steam ejector malfunctions and needs to switch to bypass operation mode, the second regulating valve can control the amount of steam entering the faulty steam ejector, preventing further damage to the device due to steam backflow or abnormal pressure. It also ensures a stable steam supply for the entire system, reducing the impact on the sulfur recovery production process.

[0022] As an optimized solution for the processing system, the conventional Claus sulfur recovery unit also includes a multi-stage Claus reactor, and the output of all Claus reactors is connected to the output of the steam ejector.

[0023] In this scheme, the gas output from the multi-stage Claus reactor still contains a certain amount of sulfur vapor and unreacted components. Introducing these gases into the output end of the steam ejector device allows the steam ejector device to perform secondary treatment on the gas after the reaction while delivering low-pressure saturated steam. The steam ejector device's effect of reducing temperature and pressure can further condense and separate the sulfur vapor in these gases, thereby improving the sulfur recovery rate.

[0024] As an optimization of the processing system, a fourth regulating valve is also connected between the output end of the Claus reactor and the output end of the steam ejector.

[0025] In this design, the gas composition and flow rate output from the Claus reactor fluctuate due to changes in production conditions. The fourth regulating valve precisely controls the post-reaction gas entering the steam ejector's output. When the sulfur vapor content in the reaction-generated gas is high, adjusting the fourth regulating valve to reduce its opening appropriately lowers the gas flow rate entering the steam ejector's output, preventing excessive sulfur vapor from affecting the normal operation of the steam ejector and the quality of subsequent steam. This ensures the steam ejector stably delivers low-pressure saturated steam to the system. Conversely, when system load changes or sulfur recovery efficiency needs adjustment, the fourth regulating valve can flexibly change its opening to optimize gas flow distribution, allowing the steam ejector and Claus reactor to work together better, further improving sulfur recovery efficiency and reducing sulfur mist content in the exhaust gas.

[0026] As an optimized solution for the treatment system, the conventional Claus sulfur recovery unit also includes a condensate tank, the input end of which is connected to the output end of the waste heat boiler and the output end of the steam ejector device.

[0027] In this scheme, the condensate generated during the operation of the waste heat boiler and steam ejector contains a certain amount of heat. The condensate tank collects this condensate, creating conditions for waste heat recovery. It can be reused in other parts of the system, such as being returned to the boiler as feedwater, reducing energy consumption, improving the overall thermal efficiency of the system, and lowering production costs. Furthermore, the condensate tank effectively buffers the flow fluctuations of the condensate generated by the waste heat boiler and steam ejector, preventing sudden flow changes from affecting the normal operation of the equipment.

[0028] As an optimized solution for the treatment system, an air preheater and an acid gas preheater are also connected between the input end of the condensate tank and the output end of the waste heat boiler, and the air preheater and the acid gas preheater are connected in parallel.

[0029] In this scheme, the high-temperature condensate output from the waste heat boiler contains a large amount of heat energy, which can be fully recovered through parallel air preheaters and acid gas preheaters. Preheated air entering the combustion stage improves combustion efficiency, resulting in more complete combustion, releasing more energy, and reducing fuel consumption. Preheating the acid gas helps enhance its reactivity in the Claus reaction, accelerating the reaction rate and thus improving sulfur recovery efficiency.

[0030] As an optimization scheme for the processing system, a three-way safety valve is installed on the pipeline connecting the steam ejector and the four-stage sulfur condenser. One passage of the three-way safety valve connects the four-stage sulfur condenser and the steam ejector, while the other passage forms a bypass.

[0031] In this design, the main passage of the three-way safety valve ensures that the low-pressure steam generated by the four-stage sulfur condenser smoothly enters the steam ejector, ensuring the stable operation of the entire system's steam ejection process and maintaining the pressure and temperature reduction effect of the four-stage sulfur condenser, thereby continuously reducing the sulfur mist content in the exhaust gas. If the steam ejector malfunctions, such as internal blockage or component damage leading to an abnormal pressure increase, the bypass passage of the three-way safety valve activates, allowing the low-pressure steam to be directly discharged through the bypass. This prevents a sharp rise in pressure within the four-stage sulfur condenser due to the steam's inability to be properly ejected, thus preventing equipment damage due to overpressure and ensuring equipment safety.

[0032] As an optimized solution for the treatment system, another passage of the three-way safety valve is connected to the four-stage sulfur condenser via a pipeline to form an exhaust pipeline.

[0033] In this solution, when the steam ejector malfunctions, such as becoming blocked or having internal components damaged, preventing the normal ejection of low-pressure steam, the pressure inside the four-stage sulfur condenser will rise rapidly, potentially causing serious safety accidents such as equipment rupture. In this case, the discharge pipeline can promptly discharge excess low-pressure steam back to the four-stage sulfur condenser, preventing the pressure from continuing to rise and effectively protecting equipment safety. During system maintenance, technicians can controllably discharge steam through the discharge pipeline, facilitating the inspection, repair, and maintenance of the steam ejector and related pipelines, and preventing residual steam from affecting operational safety.

[0034] As an optimization of the processing system, a third regulating valve is also connected between the three-way safety valve and the steam ejector.

[0035] In this solution, the third regulating valve can precisely adjust the steam flow and pressure entering the steam ejector based on the real-time operating conditions of the system, ensuring that the steam ejector is always in optimal operating condition and guaranteeing the stability and continuity of the sulfur recovery process. When the system pressure is abnormal, it can respond and adjust quickly to avoid excessive steam impact that could damage the equipment and reduce the probability of safety accidents. The third regulating valve can reasonably control the steam flow to improve steam utilization, reduce energy waste, and lower production costs. During equipment maintenance and repair, it can cut off the steam path, providing a safe working environment for maintenance personnel and reducing maintenance difficulty and risks.

[0036] As an optimized solution for the processing system, both the three-way switching valve and the three-way safety valve are electrically connected to an external control system.

[0037] In this solution, through electrical connection with an external control system, the three-way switching valve and the three-way safety valve can automatically adjust their working status according to the system's preset program and real-time monitoring data. When the system detects a malfunction in the steam ejector device, the external control system can quickly control the three-way switching valve to switch the path, allowing steam to be transported through a bypass. At the same time, it controls the three-way safety valve to open the discharge pipeline to ensure stable system pressure and prevent equipment damage due to abnormal pressure, thereby achieving automation and intelligence in system operation.

[0038] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0039] 1. This utility model utilizes a steam ejector device to inject high-pressure steam generated by a waste heat boiler into a four-stage sulfur condenser, effectively reducing the process gas outlet temperature and pressure of the four-stage sulfur condenser. This allows more sulfur in the process gas to condense and separate, significantly reducing the amount of sulfur mist entrained, alleviating the burden on the tail gas treatment device, reducing the number of APU start-ups, and lowering solution loss and wastewater treatment costs.

[0040] 2. This utility model is equipped with a three-way switch valve and a three-way safety valve on the pipeline connecting the steam ejector device to the waste heat boiler and the four-stage sulfur condenser, respectively. When the system malfunctions, it can respond quickly, switch the path, ensure stable system operation, and reduce the risk of production stoppage caused by equipment failure or parameter fluctuations. Attached Figure Description

[0041] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0042] Figure 1 This is a schematic diagram of the existing three-stage conventional Claus sulfur recovery process.

[0043] Figure 2 This is a schematic diagram of the three-stage conventional Claus sulfur recovery process of this utility model.

[0044] The attached diagram shows the markings and corresponding component names:

[0045] 1-Condensate tank, 2-Waste heat boiler, 3-Main combustion furnace, 4-Main combustion furnace burner, 5-Air preheater, 6-Acid gas preheater, 7-Three-way switch valve, 8-First regulating valve, 9-Second regulating valve, 10-Steam ejector device, 11-Third regulating valve, 12-Fourth-stage sulfur condenser, 13-Third-stage sulfur condenser, 14-Second-stage sulfur condenser, 15-Fourth regulating valve, 16-First-stage sulfur condenser. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0047] Example 1

[0048] This embodiment 1 provides a processing system suitable for multi-stage Claus sulfur recovery, such as... Figure 2 As shown, it includes the existing three-stage conventional Claus sulfur recovery unit and steam ejector unit 10;

[0049] The three-stage conventional Claus sulfur recovery unit includes a waste heat boiler 2 that generates high-pressure steam (typically around 2.8 MPa after mixing high-temperature process gas from the main combustion furnace 3 and its burner 4 with acid gas entering the rear of the main combustion furnace and then cooling it via the waste heat boiler 2), and a four-stage sulfur condenser 12 that generates low-pressure steam. The steam ejector device 10 is a steam ejector that utilizes the negative pressure effect generated by a high-speed steam flow to draw in and mix other media, achieving heat transfer and conversion through heat exchange. This working principle gives the steam ejector significant advantages in heat recovery and energy-saving retrofitting. The steam ejector is stable, reliable, and highly efficient, and employs energy-saving technologies to significantly reduce energy consumption, saving operating costs for enterprises and achieving sustainable development. Of course, those skilled in the art can also use other pressure-reducing and cooling devices based on the steam ejector to achieve the same result.

[0050] Specifically, the first input end of the steam ejector device 10 is connected to the output end of the waste heat boiler 2, the second input end of the steam ejector device 10 is connected to the output end of the four-stage sulfur condenser 12, and the output end of the steam ejector device 10 is connected to low-pressure saturated steam to the system. The steam ejector device 10 uses the high-pressure steam generated by the waste heat boiler 2 to eject the low-pressure steam of the four-stage sulfur condenser 12, reducing the outlet pressure of the four-stage sulfur condenser 12 from 0.17MPa to 0.1MPa and the temperature from 145℃ to 125℃, thereby reducing the amount of sulfur mist entrained in the process gas by condensing more sulfur. Since the four-stage sulfur condenser 12 (E-1407) is modified to produce 0.1MPa steam, most of the sulfur vapor is condensed and separated. The produced steam is injected into the low-pressure steam network using high-pressure steam, effectively solving the problem of high sulfur mist content in the tail gas of the liquid sulfur trap. In practical use, the sulfur mist content in the tail gas of the device modified by this utility model has decreased from 7.4g / m³ before the modification. 3 ~19.0g / m 3 It dropped to less than 3g / m 3 The flue gas load SO2 flow rate of the exhaust gas treatment device was reduced from 403 m³ / h before the retrofit. 3 / h dropped to 305m 3 / h, which can reduce the load on the exhaust gas treatment device by 1 / 4.

[0051] In summary, this treatment system utilizes high-pressure steam generated by a waste heat boiler to eject low-pressure steam from a four-stage sulfur condenser via a steam ejector device. This effectively reduces the process gas outlet temperature and pressure of the four-stage sulfur condenser, allowing more sulfur in the process gas to condense and separate, significantly reducing sulfur mist entrainment, alleviating the burden on the tail gas treatment unit, reducing the number of APU start-ups, and lowering solution loss and wastewater treatment costs.

[0052] Example 2

[0053] This embodiment 1 provides a processing system suitable for multi-stage Claus sulfur recovery based on the technical solution of embodiment 1, such as... Figure 2 As shown, the difference is that a three-way switch valve 7 is installed on the pipeline connecting the steam ejector device 10 and the waste heat boiler 2, and a three-way safety valve is installed on the pipeline connecting the steam ejector device 10 and the four-stage sulfur condenser 12.

[0054] In this embodiment, one passage of the three-way switch valve 7 connects the waste heat boiler 2 and the steam ejector device 10, while the other passage forms a bypass. In this embodiment, the other passage of the three-way switch valve 7 is connected to the output end of the steam ejector device 10 via a pipeline. During the maintenance phase of the steam ejector device 10, on the one hand, it ensures that the high-pressure steam generated by the waste heat boiler 2 has a reasonable destination during the maintenance period, and will not cause problems such as system pressure buildup due to the steam ejector device's inability to work properly; on the other hand, the steam flowing to the output end through this passage can maintain the operation of some functions of the system, reduce the impact of equipment maintenance on the entire sulfur recovery process, ensure production continuity, and reduce economic losses caused by shutdown.

[0055] Meanwhile, another passage of the three-way safety valve is connected to the four-stage sulfur condenser 12 via a pipeline to form a discharge pipeline. During system maintenance, technicians can controllably discharge steam through the discharge pipeline, which facilitates the inspection, repair and maintenance of the steam ejector device 10 and related pipelines, and avoids the impact of residual steam on operational safety.

[0056] Example 3

[0057] This embodiment 3 provides a processing system suitable for multi-stage Claus sulfur recovery based on the technical solution of embodiment 2. The difference is that a first regulating valve 8 is also connected between the three-way switch valve 7 and the output end of the steam ejector device 10. The first regulating valve 8 can limit the steam flow to prevent sudden pressure rise from damaging other equipment in the system. A second regulating valve 9 is also connected between the three-way switch valve 7 and the input end of the steam ejector device 10. The second regulating valve 9 can control the amount of steam entering the faulty steam ejector device 10 to avoid further damage to the device due to steam backflow or abnormal pressure. Furthermore, a third regulating valve 11 is also connected between the three-way safety valve and the steam ejector device 10. The third regulating valve 11 can reasonably control the steam flow to improve steam utilization, reduce energy waste, and lower production costs. During equipment maintenance and repair, it can cut off the steam passage to provide a safe working environment for maintenance personnel.

[0058] Meanwhile, the aforementioned three-stage conventional Claus sulfur recovery unit also includes a three-stage sulfur condenser 13, a two-stage sulfur condenser 14, and a one-stage sulfur condenser 16. The output ends of the three-stage sulfur condenser 13, the two-stage sulfur condenser 14, and the one-stage sulfur condenser 16 are all connected to the output end of the steam ejector 10. Furthermore, a fourth regulating valve 15 is connected between the output end of the three-stage conventional Claus sulfur recovery unit and the output end of the steam ejector 10. By adjusting the opening of the fourth regulating valve 15, the gas flow rate entering the output end of the steam ejector 10 can be appropriately reduced, avoiding excessive sulfur vapor from affecting the normal operation of the steam ejector 10 and the quality of subsequent steam, and ensuring that the steam ejector 10 stably delivers low-pressure saturated steam to the system.

[0059] In some embodiments, both the three-way switch valve 7 and the three-way safety valve are electrically connected to the external control system. When the system detects a malfunction in the steam ejector device 10, the external control system can quickly control the three-way switch valve 7 to switch the passage, allowing steam to be transported through the bypass. At the same time, it controls the three-way safety valve to open the discharge pipeline to ensure stable system pressure, prevent equipment damage due to abnormal pressure, and realize the automation and intelligence of system operation.

[0060] Example 4

[0061] This embodiment 4 provides a treatment system suitable for multi-stage Claus sulfur recovery based on the technical solution of embodiment 3. In this embodiment, the conventional Claus sulfur recovery device also includes a condensate tank 1. The input end of the condensate tank 1 is connected to the output end of the waste heat boiler 2 and the output end of the steam ejector device 10, respectively. The condensate tank 1 can effectively buffer the flow fluctuation of condensate generated by the waste heat boiler 2 and the steam ejector device 10, and avoid the normal operation of the equipment due to sudden flow changes.

[0062] Meanwhile, an air preheater 5 and an acid gas preheater 6 are connected between the input end of the condensate tank 1 and the output end of the waste heat boiler 2. The air preheater 5 and the acid gas preheater 6 are connected in parallel. Through the parallel connection of the air preheater 5 and the acid gas preheater 6, this part of the heat energy can be fully recovered. After the air is preheated, it enters the combustion stage, which can improve the combustion efficiency, make the combustion more complete, release more energy, and reduce fuel consumption. The acid gas preheating helps to improve the reactivity of the acid gas in the Claus reaction, accelerate the reaction rate, and thus improve the sulfur recovery efficiency.

[0063] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A treatment system suitable for multi-stage Claus sulfur recovery, characterized in that, include: A conventional Claus sulfur recovery unit, comprising a waste heat boiler (2) that generates high-pressure steam and a four-stage sulfur condenser (12) that generates low-pressure steam; A steam ejector device (10) is provided, with its first input end connected to the output end of the waste heat boiler (2), its second input end connected to the output end of the four-stage sulfur condenser (12), and its output end connected to low-pressure saturated steam to the system.

2. The processing system for multi-stage Claus sulfur recovery according to claim 1, characterized in that, The steam ejector device (10) is a steam ejector.

3. The processing system for multi-stage Claus sulfur recovery according to claim 1, characterized in that, A three-way switch valve (7) is provided on the pipeline connecting the steam ejector device (10) and the waste heat boiler (2). One passage of the three-way switch valve (7) connects the waste heat boiler (2) and the steam ejector device (10), and the other passage forms a bypass.

4. The processing system for multi-stage Claus sulfur recovery according to claim 3, characterized in that, The other passage of the three-way switch valve (7) is connected to the output end of the steam ejector device (10) via a pipeline.

5. A treatment system for multi-stage Claus sulfur recovery according to claim 4, characterized in that, A first regulating valve (8) is also connected between the three-way switch valve (7) and the output end of the steam ejector device (10).

6. The processing system for multi-stage Claus sulfur recovery according to claim 4, characterized in that, A second regulating valve (9) is also connected between the three-way switch valve (7) and the input end of the steam ejector device (10).

7. A treatment system for multi-stage Claus sulfur recovery according to claim 4, characterized in that, The conventional Claus sulfur recovery unit also includes a multi-stage Claus reaction unit, and the output of all the Claus reaction units is connected to the output of the steam ejector (10).

8. A treatment system for multi-stage Claus sulfur recovery according to claim 7, characterized in that, A fourth regulating valve (15) is also connected between the output end of the Claus reactor and the output end of the steam ejector (10).

9. A treatment system for multi-stage Claus sulfur recovery according to claim 7, characterized in that, The conventional Claus sulfur recovery unit also includes a condensate tank (1), the input end of which is connected to the output end of the waste heat boiler (2) and the output end of the steam ejector device (10).

10. A treatment system for multi-stage Claus sulfur recovery according to claim 9, characterized in that, An air preheater (5) and an acid gas preheater (6) are connected between the input end of the condensate tank (1) and the output end of the waste heat boiler (2), and the air preheater (5) and the acid gas preheater (6) are connected in parallel.

11. A treatment system suitable for multi-stage Claus sulfur recovery according to any one of claims 3-10, characterized in that, A three-way safety valve is provided on the pipeline connecting the steam ejector (10) and the four-stage sulfur condenser (12). One passage of the three-way safety valve connects the four-stage sulfur condenser (12) and the steam ejector (10), and the other passage forms a bypass.

12. A treatment system for multi-stage Claus sulfur recovery according to claim 11, characterized in that, The other passage of the three-way safety valve is connected to the four-stage sulfur condenser (12) via a pipeline to form a discharge pipeline.

13. A treatment system for multi-stage Claus sulfur recovery according to claim 11, characterized in that, A third regulating valve (11) is also connected between the three-way safety valve and the steam ejector (10).

14. A treatment system for multi-stage Claus sulfur recovery according to claim 11, characterized in that, Both the three-way switch valve (7) and the three-way safety valve are electrically connected to the external control system.

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