A sulfur-burning sulfur-burning furnace waste heat recovery device

Abstract

The utility model belongs to sulphur sulphuric acid technology field, concretely is a kind of sulphur sulphuric acid sulphur burning furnace waste heat recovery device, including high-temperature flue gas waste heat recovery module, low-temperature tail gas waste heat recovery module, depth purification module and intelligent control module;High-temperature flue gas waste heat recovery module recycles high-temperature flue gas waste heat by honeycomb silicon carbide ceramic heat exchanger and circulating oil circuit;Low-temperature module recycles tail gas waste heat by finned heat exchange unit and jacketed heat exchanger;Depth purification module handles flue gas by SCR denitration, composite filtration and spray absorption;Intelligent control module monitors and regulates each component in real time;The device realizes waste heat cascade recovery and flue gas purification, improves heat utilization rate, avoids pollution.

Description

Technical Field

[0001] This utility model relates to the field of sulfuric acid production equipment, and in particular to a waste heat recovery device for a sulfuric acid incinerator. By efficiently recovering and utilizing the waste heat of the high-temperature flue gas and tail gas generated by the incinerator, energy conservation and emission reduction are achieved, and the overall energy utilization efficiency in the sulfuric acid production process is improved. Background Technology

[0002] In the sulfur-to-acid process, the sulfur incinerator is a key piece of equipment. Sulfur is injected into the furnace through a spray gun, where it comes into full contact with and burns against the air entering through the end inlet under the action of a cyclone device, generating high-temperature flue gas containing sulfur dioxide. Under normal circumstances, the temperature of the flue gas discharged from the sulfur incinerator is as high as 800-1000℃, and even after subsequent purification treatment, the temperature of the tail gas is still between 200-300℃.

[0003] Existing waste heat recovery technologies have several limitations. Some devices focus solely on low-temperature waste heat recovery from exhaust gases, employing simple spiral copper tube structures that can only recover a small amount of waste heat from the exhaust gas, resulting in low heat exchange efficiency. For example, some existing technologies simply heat water in a storage tank by passing exhaust gas through a spiral copper tube. This single-tank heating method has a low waste heat recovery rate and cannot fully utilize the large amount of waste heat generated by the sulfur incinerator. Furthermore, existing technologies often rely on single activated carbon filtration for purification, which is ineffective at removing multiple pollutants such as nitrogen oxides and particulate matter from flue gas, failing to meet increasingly stringent environmental protection requirements. Moreover, existing devices generally lack intelligent control, failing to dynamically adjust the waste heat recovery and purification processes based on real-time operating conditions, leading to low overall operating efficiency and significant energy waste.

[0004] Therefore, developing a waste heat recovery device capable of graded and stepped recovery of high-temperature flue gas and medium- and low-temperature tail gas from sulfur incinerators, with efficient heat exchange structure, deep purification capability, and intelligent control function, is of great practical significance. Summary of the Invention

[0005] To address the aforementioned problems, this utility model provides a waste heat recovery device for sulfuric acid production furnaces, the specific technical solution of which is as follows:

[0006] A waste heat recovery device for sulfuric acid production furnace includes a high-temperature flue gas waste heat recovery module, a medium-low temperature tail gas waste heat recovery module, a deep purification module, and an intelligent control module. The modules are connected in series via pipelines. The specific structure and connection relationships are as follows:

[0007] The high-temperature flue gas waste heat recovery module includes a honeycomb silicon carbide ceramic heat exchanger, which is connected to the flue gas outlet of the sulfur incinerator via a first flange. The heat exchanger has hexagonal honeycomb channels arranged in an array inside. The oil outlet of the honeycomb silicon carbide ceramic heat exchanger is connected to the inlet of the heat transfer oil pump group via a metal bellows. The outlet of the heat transfer oil pump group is connected to the heat medium inlet of the steam generator via an insulated pipe. The heat medium outlet of the steam generator is connected to the oil inlet of the honeycomb silicon carbide ceramic heat exchanger via a return oil pipe, forming a closed-loop oil circuit.

[0008] The medium-low temperature exhaust gas waste heat recovery module includes a finned stainless steel heat exchange unit, the front end of which is connected to the exhaust gas outlet pipe of the high-temperature flue gas waste heat recovery module via a second flange; the finned stainless steel heat exchange unit has longitudinal finned tube bundles welded inside, with the fin spacing increasing along the airflow direction; the exhaust gas outlet of the finned tube bundle is connected to the inner tube inlet of a shell-and-tube dual-channel heat exchanger via a bend, the outer tube inlet of the shell-and-tube dual-channel heat exchanger is connected to the outlet of a steam-water heat exchanger via a pipe, and the steam inlet of the steam-water heat exchanger is connected to the low-pressure steam outlet of the steam generator in the high-temperature flue gas waste heat recovery module via a branch pipe.

[0009] The deep purification module includes a three-stage purification unit: the SCR reactor in the front-end high-temperature denitrification section is connected to the exhaust gas outlet of the medium-low temperature exhaust gas waste heat recovery module via a third flange, and the vanadium-titanium catalyst module is fixed inside the SCR reactor via a slot; the shell of the middle composite filtration section is bolted to the outlet of the SCR reactor, and metal fiber felt filter frames and modified activated carbon filter frames are inserted sequentially from front to back inside the middle composite filtration section; the rear-end spray tower is connected to the outlet of the composite filtration section via a fourth flange; the inlet of the spray tower is equipped with a Venturi tube that extends into the interior of the spray tower cavity, and the liquid outlet at the bottom of the spray tower is connected to the top spray pipe via a circulating pump.

[0010] The intelligent control module includes a gas composition sensor, a PLC controller cabinet, a servo motor, and an electric regulating valve. The gas composition sensor is installed between the outlet pipe of the deep purification module and the spray tower via a three-way connector flange. The signal lines of the gas composition sensor, servo motor, and electric regulating valve are connected to the PLC controller cabinet inside the control cabinet via conduits. The output of the controller is connected to the actuators of each module via signal lines.

[0011] Furthermore, a butterfly valve is installed on the connecting pipe between the high-temperature flue gas waste heat recovery module and the medium-low temperature tail gas waste heat recovery module. The valve stem of the butterfly valve is connected to the servo motor of the intelligent control module through a coupling and to the output terminal of the PLC controller cabinet through a signal line.

[0012] Furthermore, the inner tube of the shell-and-tube dual-channel heat exchanger is connected to the inlet and outlet ends respectively via threaded short pipes, and cold water inlet and outlet pipes are welded to the side wall of the outer tube, with flanges installed at the ends of the pipes.

[0013] Furthermore, rectangular slots are provided on both sides of the housing of the composite filter section, and sealing strips are provided inside the slots. The metal fiber felt filter frame and the modified activated carbon filter frame are slidably connected to the housing through the slots, and a pull handle is welded to the top of the filter frame.

[0014] Furthermore, the top steam outlet of the steam generator is connected to an external steam pipeline and a steam-water heat exchanger via a three-way pipe, and an electric regulating valve with an intelligent control module is installed on the three-way pipe.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The system is equipped with high-temperature and medium-low temperature waste heat recovery modules. Through the structural design of honeycomb ceramic heat exchangers and finned stainless steel heat exchange units, it can fully recover heat from different temperature ranges and improve energy utilization.

[0017] The deep purification module adopts a three-stage purification structure, which sequentially treats exhaust gas through denitrification, filtration and adsorption, and spray absorption, significantly improving the purification effect and meeting environmental emission requirements.

[0018] The intelligent control module works in conjunction with each actuator to monitor and adjust the equipment operating parameters in real time through sensors, ensuring stable operation of the device and reducing the intensity of manual operation.

[0019] Each component adopts standardized connection methods such as flanges and threads, and is equipped with slots and grooves to facilitate installation, disassembly, maintenance and replacement, thereby improving the practicality of the device. Attached Figure Description

[0020] For ease of explanation, this utility model is described in detail below with reference to the specific embodiments and accompanying drawings.

[0021] Figure 1 : Schematic diagram of the overall structure connection of this utility model.

[0022] Figure 2 Schematic diagram of the high-temperature flue gas waste heat recovery module.

[0023] Figure 3 Schematic diagram of a honeycomb silicon carbide ceramic heat exchanger.

[0024] Figure 4 Schematic diagram of the structure and internal structure of the medium and low temperature exhaust gas waste heat recovery module.

[0025] Figure 5 : Schematic diagram of the deep purification module.

[0026] The meanings of the symbols in the attached figures are as follows:

[0027] 101-Honeycomb silicon carbide ceramic heat exchanger; 102-First flange; 103-Hexagonal honeycomb channel; 104-Metal bellows; 105-Heat transfer oil pump unit; 106-Insulated pipe; 107-Steam generator; 108-Return oil pipe;

[0028] 201-Finned stainless steel heat exchange unit; 202-Second flange; 203-Longitudinal finned tube bundle; 204-Bend; 205-Shell-type double-flow-channel heat exchanger; 206-Steam-water heat exchanger.

[0029] 301-SCR reactor; 302-Third flange; 303-Vanadium-titanium catalyst module; 304-Composite filter section; 305-Metal fiber felt filter frame; 306-Modified activated carbon filter frame; 307-Spray tower; 308-Circulating pump; 309-Venturi tube; 310-Spray pipe;

[0030] 401 - Gas composition sensor; 402 - Fourth flange; 403 - T-connector; 404 - PLC controller cabinet; 405 - Signal line; 406 - Butterfly valve; 407 - Servo motor; 408 - Electric regulating valve. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0032] Example 1:

[0033] Reference Figures 1 to 5 A waste heat recovery device for sulfuric acid production furnace includes a high-temperature flue gas waste heat recovery module, a medium-low temperature tail gas waste heat recovery module, a deep purification module, and an intelligent control module, with each module connected in series via pipelines.

[0034] like Figure 2 As shown, in use, the honeycomb silicon carbide ceramic heat exchanger 101 of the high-temperature flue gas waste heat recovery module is connected to the flue gas outlet end of the sulfur incinerator via the first flange 102, and its internal hexagonal honeycomb channels 103 are arrayed (as shown in the image). Figure 3 (As shown); the oil outlet of the honeycomb silicon carbide ceramic heat exchanger 101 is connected to the inlet of the heat transfer oil pump group 105 through the metal bellows 104, the outlet of the heat transfer oil pump group 105 is connected to the heat medium inlet of the steam generator 107 through the heat insulation pipe 106, and the heat medium outlet of the steam generator 107 is connected to the oil inlet of the honeycomb silicon carbide ceramic heat exchanger 101 through the return oil pipe 108, forming a closed-loop oil circuit.

[0035] like Figure 4As shown, the front end of the finned stainless steel heat exchange unit 201 of the medium-low temperature exhaust gas waste heat recovery module is connected to the exhaust gas outlet pipe of the high temperature flue gas waste heat recovery module through the second flange 202. The longitudinal finned tube bundle 203 (the spacing of the fins increases along the airflow direction) is welded inside. The exhaust gas outlet of the longitudinal finned tube bundle 203 is connected to the inner tube inlet of the shell-and-tube dual-channel heat exchanger 205 through the bend 204. The outer tube inlet of the shell-and-tube dual-channel heat exchanger 205 is connected to the outlet of the steam-water heat exchanger 206 through the pipe. The steam inlet of the steam-water heat exchanger 206 is connected to the low-pressure steam outlet of the steam generator 107 in the high temperature flue gas waste heat recovery module through the branch pipe.

[0036] like Figure 5 As shown, the three-stage purification units of the deep purification module are connected in sequence: the SCR reactor 301 of the front-end high-temperature denitrification section is connected to the exhaust gas outlet of the medium-low temperature exhaust gas waste heat recovery module through the third flange 302, and the vanadium-titanium catalyst module 303 is fixed inside by a slot; the shell of the intermediate composite filtration section 304 is bolted to the outlet of the SCR reactor 301, and the metal fiber felt filter frame 305 and the modified activated carbon filter frame 306 are inserted from front to back inside; the gas composition sensor 401 is installed between the outlet pipe of the deep purification module and the spray tower 307 through the interface of the tee connector 403 and the fourth flange 402, and is connected to the outlet of the composite filtration section 304. The inlet of the spray tower 307 is equipped with a venturi tube 309 that extends into the cavity, and the bottom liquid outlet is connected to the top spray pipe 310 through the circulation pump 308.

[0037] like Figure 1 As shown, the gas composition sensor 401 of the intelligent control module is installed between the outlet pipe of the deep purification module and the spray tower 307 through a flange interface. Its signal line 405 is connected to the PLC controller cabinet 404 through a conduit. The controller output is connected to the actuator of each module through the signal line 405.

[0038] During operation, the high-temperature flue gas (800-1000℃) generated by the sulfur incinerator first enters the honeycomb silicon carbide ceramic heat exchanger 101, where it exchanges heat with heat transfer oil through hexagonal honeycomb channels 103. Driven by the heat transfer oil pump group 105, the heat transfer oil transfers heat to the steam generator 107 to generate high-pressure steam. The exhaust gas, cooled to 350-400℃, enters the medium-low temperature module, where it recovers waste heat step by step through the finned stainless steel heat exchange unit 201 and the shell-and-tube dual-channel heat exchanger 205, raising the water temperature to 60-70℃. Subsequently, the exhaust gas enters the deep purification module, where it passes through the SCR reactor 301 for denitrification, the composite filter section 304 for particulate matter removal and adsorption of harmful gases, and the spray tower 307 for absorption and purification before being discharged in compliance with standards. The intelligent control module monitors the parameters of each stage in real time and automatically adjusts the actuators through the PLC controller cabinet 404 to ensure stable operation of the device.

[0039] Example 2:

[0040] A butterfly valve 406 is installed on the connecting pipe between the high-temperature flue gas waste heat recovery module and the medium-low temperature exhaust gas waste heat recovery module. The valve stem is connected to the servo motor 407 of the intelligent control module through a coupling, and is connected to the output terminal of the PLC controller cabinet 404 through a signal line 405. The exhaust gas flow can be controlled by adjusting the opening degree (30%-90%) of the butterfly valve 406.

[0041] The inner tube of the shell-and-tube dual-channel heat exchanger 205 is connected to the inlet and outlet ends by threaded short pipes, respectively. The outer tube sidewall is welded with cold water inlet and outlet pipes, and flanges are installed at the ends of the pipes. During installation, the threaded connection is sealed with PTFE tape, and a high-temperature gasket is installed on the flange connection surface. The inner tube is used for exhaust gas, and the outer tube is used for preheated cold water. Waste heat is recovered through counter-current heat exchange (the cold water inlet pressure is controlled at 0.2-0.3MPa).

[0042] The composite filter section 304 has rectangular slots on both sides of its housing, and sealing strips are installed inside the slots. The metal fiber felt filter frame 305 and the modified activated carbon filter frame 306 are slidably connected to the housing through the slots. A pull handle is welded to the top of the filter frame for easy periodic replacement (operation time can be controlled within 30 minutes).

[0043] The top steam outlet of the steam generator 107 is connected to the external steam supply pipeline and the steam-water heat exchanger 206 via a three-way pipe. An electric regulating valve 408 with an intelligent control module is installed on the three-way pipe, which is connected to the PLC controller cabinet 404 via a signal line 405. When the steam pressure exceeds 1.6MPa, the regulating valve automatically opens to increase the external steam supply, and closes the valve when it is below 1.4MPa to ensure pressure stability.

[0044] Example 3:

[0045] This embodiment focuses on the maintenance and troubleshooting of the device. Before starting the machine each day, check the sealing of the flanges connecting each module to ensure there is no smoke leakage; weekly, remove the metal fiber felt filter frame 305 by pulling out the handle and back-blown the surface dust with 0.6MPa compressed air; monthly, replace the modified activated carbon filter frame 306, ensuring that the filter frame is aligned with the airflow direction during replacement.

[0046] When the intelligent control module displays that the SO2 concentration at the purification outlet exceeds 60 mg / m³ 3 When checking the operation status of the circulating pump 308 of the spray tower 307, if the flow rate is insufficient, the nozzles of the spray pipe 310 that are blocked need to be cleaned; if the denitrification efficiency of the SCR reactor 301 is less than 85%, the activity of the vanadium-titanium catalyst module 303 needs to be checked, and if necessary, nitrogen gas should be introduced at 320-350℃ for 4 hours for regeneration treatment.

[0047] When shutting down, first close the flue gas inlet valve of the sulfur furnace, keep the heat transfer oil pump group 105 running for 30 minutes, and then shut down the oil pump after the temperature of the honeycomb silicon carbide ceramic heat exchanger 101 drops below 100℃ to avoid high temperature damage to the equipment.

[0048] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the design concept of the present invention should fall within the protection scope of the present invention. The technical content for which protection is sought in the present invention has been fully described in the claims.

Claims

1. A waste heat recovery device for sulfuric acid production furnaces, characterized in that: It includes a high-temperature flue gas waste heat recovery module, a medium- and low-temperature exhaust gas waste heat recovery module, a deep purification module, and an intelligent control module. Each module is connected in series via pipelines. The specific structure and connection relationship are as follows: The high-temperature flue gas waste heat recovery module includes a honeycomb silicon carbide ceramic heat exchanger (101), which is connected to the flue gas outlet of the sulfur incinerator via a first flange (102). The heat exchanger has hexagonal honeycomb channels (103) arranged in an array inside. The oil outlet of the honeycomb silicon carbide ceramic heat exchanger (101) is connected to the inlet of the heat transfer oil pump group (105) via a metal bellows pipe (104). The outlet of the heat transfer oil pump group (105) is connected to the heat medium inlet of the steam generator (107) via an insulated pipe (106). The heat medium outlet of the steam generator (107) is connected to the oil inlet of the honeycomb silicon carbide ceramic heat exchanger (101) via a return oil pipe (108), forming a closed-loop oil circuit. The medium-low temperature exhaust gas waste heat recovery module includes a finned stainless steel heat exchange unit (201), the front end of which is connected to the exhaust gas outlet pipe of the high temperature flue gas waste heat recovery module through a second flange (202); the finned stainless steel heat exchange unit (201) has longitudinal finned tube bundles (203) welded inside, and the spacing of the fins increases along the airflow direction; the exhaust gas outlet of the finned tube bundle (203) is connected to the inner tube inlet of the shell-and-tube dual-channel heat exchanger (205) through a bend (204), the outer tube inlet of the shell-and-tube dual-channel heat exchanger (205) is connected to the outlet of the steam-water heat exchanger (206) through a pipe, and the steam inlet of the steam-water heat exchanger (206) is connected to the low-pressure steam outlet of the steam generator (107) in the high temperature flue gas waste heat recovery module through a branch pipe; The deep purification module includes a three-stage purification unit: the SCR reactor (301) of the front-end high-temperature denitrification section is connected to the tail gas outlet of the medium-low temperature tail gas waste heat recovery module through the third flange (302), and the vanadium-titanium catalyst module (303) is fixed inside the SCR reactor (301) through a slot; the shell of the middle composite filtration section (304) is connected to the outlet of the SCR reactor (301) by bolts, and metal fiber felt filter frame (305) and modified activated carbon filter frame (306) are inserted into it from front to back; the rear spray tower (307) is connected to the outlet of the composite filtration section (304) through the fourth flange (402); the inlet of the spray tower (307) is provided with a Venturi tube (309) that extends into the cavity of the spray tower (307), and the liquid outlet at the bottom of the spray tower (307) is connected to the top spray pipe through a circulating pump (308); The intelligent control module includes a gas composition sensor (401), a PLC controller cabinet (404), a servo motor (407), and an electric regulating valve (408). The gas composition sensor (401) is installed between the outlet pipe of the deep purification module and the spray tower (307) through a three-way connector (403) interface flange. The signal lines (405) of the gas composition sensor (401), the servo motor (407), and the electric regulating valve (408) are connected to the PLC controller cabinet (404) in the control cabinet through conduits. The output end of the controller is connected to the actuator of each module through the signal line (405).

2. The waste heat recovery device for sulfuric acid production furnace according to claim 1, characterized in that: A butterfly valve (406) is installed on the connecting pipe between the high-temperature flue gas waste heat recovery module and the medium-low temperature tail gas waste heat recovery module. The valve stem of the butterfly valve (406) is connected to the servo motor (407) of the intelligent control module through a coupling and to the output terminal of the PLC controller cabinet (404) through a signal line (405).

3. The waste heat recovery device for sulfuric acid production furnace according to claim 1, characterized in that: The inner tube of the shell-and-tube dual-channel heat exchanger (205) is connected to the inlet and outlet ends by threaded short tubes, respectively. The outer tube sidewall is welded with cold water inlet and outlet pipes, and flanges are installed at the ends of the pipes.

4. The waste heat recovery device for sulfuric acid production furnace according to claim 1, characterized in that: The composite filter section (304) has rectangular slots on both sides of its housing, and a sealing strip is provided inside the slots. The metal fiber felt filter frame (305) and the modified activated carbon filter frame (306) are slidably connected to the housing through the slots, and a pull handle is welded to the top of the filter frame.

5. The waste heat recovery device for sulfuric acid production furnace according to claim 1, characterized in that: The top steam outlet of the steam generator (107) is connected to an external steam pipeline and a steam-water heat exchanger (206) via a three-way pipe. An electric regulating valve (408) with an intelligent control module is installed on the three-way pipe.

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