A sulfide removal device and method in a waste oil regeneration process

Abstract

The application provides a sulfide removal device and method in a waste oil regeneration process, relates to the technical field of vacuum distillation, and comprises a reaction tank, a cover is detachably and fixedly installed at the upper end of the reaction tank, a feeding valve is installed on the side of the reaction tank, oil can be input into a storage tank in the reaction tank through the feeding valve, an electric heating wire is embedded in the storage tank, the oil in the storage tank can be distilled by using the electric heating wire, a flow guide unit is arranged in the reaction tank, the distilled steam can be condensed and collected by the flow guide unit, and the steam condensate is discharged by opening a discharge valve, and a discharge unit is arranged on the side of the reaction tank. The cleaning unit is driven by steam, the rising steam generated in the distillation process or an electric heating plate is used to drive the rotation of the fan blade, and then the scraper slides along the circumference of the storage tank, so that the automatic online cleaning of the residues and coking substances in the storage tank can be realized without additional power elements such as motors.

Description

Technical Field

[0001] This invention relates to the field of vacuum distillation technology, and in particular to a device and method for removing sulfides during waste oil regeneration. Background Technology

[0002] Waste mineral oil is classified as hazardous waste under the national hazardous waste list. It is also a petroleum resource with extremely high recycling value. Through regeneration processes, it can yield base oil that meets usage standards, achieving the circular utilization of petroleum resources. This is a key development direction in the current field of solid waste resource utilization and environmental protection. Sulfides are the most critical harmful impurities in waste mineral oil. They not only severely degrade the core properties of the recycled base oil, such as oxidation stability and anti-wear properties, but also cause equipment corrosion and the emission of toxic and harmful exhaust gases during oil use. Therefore, efficient removal of sulfides is an indispensable core step in waste oil regeneration processes.

[0003] Currently, the mainstream desulfurization process for waste oil regeneration in the industrial sector adopts vacuum distillation. This process utilizes the boiling point difference between sulfide fractions and base oil fractions in waste oil, lowering the vaporization temperature of each fraction under negative pressure to separate sulfides from base oil. It is characterized by mature technology and stable separation effect, making it a core pretreatment step in waste oil regeneration. However, in existing waste oil distillation desulfurization units, high-boiling-point sulfides, gums, asphaltenes, and other components in the waste oil cannot be vaporized and distilled, continuously accumulating in the storage tank at the bottom of the distillation vessel. Under prolonged high-temperature operation, these components are prone to coking and hardening, firmly adhering to the inner wall of the tank. Most existing equipment lacks suitable online cleaning structures, requiring manual cleaning by personnel entering the vessel after shutdown and cooling. This not only results in extremely low efficiency and high labor intensity but also poses significant safety risks due to confined space operations and contact with flammable and explosive media. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a device and method for removing sulfides during waste oil regeneration.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a sulfide removal device for waste oil regeneration, comprising a reaction tank arranged vertically, a detachably sealed cap connected to the top opening of the reaction tank, a feed valve provided on the lower part of the side wall of the reaction tank, through which oil enters a storage tank inside the reaction tank, an electric heating wire for heating the oil is embedded inside the storage tank, a flow guiding unit for condensing and collecting distillation vapor is provided above the storage tank, the condensate outlet of the flow guiding unit is connected to a discharge valve, a discharge unit for discharging distillation residue is provided on the side wall of the reaction tank corresponding to the storage tank, a vertical pipe is inserted vertically at the center of the bottom of the reaction tank, the vertical pipe extends upward to a position close to the cap, a one-way valve that only allows gas to flow out is provided at the bottom end of the vertical pipe, and a vacuum pump is connected to the vertical pipe to create a reduced pressure distillation environment inside the reaction tank.

[0006] Preferably, a fixing frame is fixedly fitted on the outer wall of the reaction vessel, and multiple support frames are evenly provided along the circumference at the bottom of the fixing frame, which vertically supports and fixes the reaction vessel to the ground.

[0007] Preferably, a conical collecting hopper, wider at the top and narrower at the bottom, is fixed inside the reaction vessel and above the storage tank. The lower end of the collecting hopper is open, and after the steam rises, it condenses into droplets on the bottom surface of the cover and the outer wall of the collecting hopper. The condensate flows down the outer wall of the collecting hopper into a collecting frame. The collecting frame is fixed circumferentially to the inner wall of the reaction vessel and is connected to the discharge valve.

[0008] Preferably, the flow guiding unit includes a flow guiding rod that extends through the collecting hopper in an inclined direction, with the lower end outlet of the flow guiding rod facing the upper opening of the collecting frame.

[0009] Preferably, multiple condensing rods are evenly distributed radially at the upper end of the guide rod. The condensing rods are spread outward to increase the contact area with the steam. Each condensing rod is fitted with multiple cones of progressively larger diameter from top to bottom. A flow hole is provided between the cone and the condensing rod to allow the condensate to flow down. The condensate flows into the collection frame through the flow hole and the guide rod.

[0010] Preferably, the reaction vessel is equipped with a cleaning unit for automatically cleaning residue. The cleaning unit includes an annular storage tank with a vertically penetrating groove in the center. A rotating unit driven by steam is installed in the groove. The output end of the rotating unit is connected to a scraper. The scraper slides against the inner wall of the storage tank and scrapes the residue to the discharge position. The bottom of the reaction vessel is equipped with a heating plate with a temperature higher than that of the electric heating wire. Steam flows upward from the groove and drives the rotating unit to rotate.

[0011] Preferably, the rotating unit includes a rotating cylinder rotatably fitted onto the outer wall of the vertical pipe. The outer wall of the rotating cylinder is uniformly provided with multiple fan blades along the circumference. The fan blades are located in the through groove and are driven to rotate by upward-flowing steam. An installation ring is fixed at the upper end of the rotating cylinder. The installation ring is fixedly connected to the scraper through a radially extending connecting arm. A reinforcing ring is provided at the bottom of the storage tank. The reinforcing ring is fixedly connected to the inner wall of the reaction vessel to support the storage tank.

[0012] Preferably, the discharge unit is arranged horizontally on the side wall of the reaction vessel, corresponding to the height position of the storage tank, and is used to discharge the residue in the storage tank out of the vessel.

[0013] Preferably, the discharge unit includes a square tube that horizontally penetrates the side wall of the reaction vessel. A baffle plate is detachably connected to the outer end of the square tube by fastening bolts. A guide rod is slidably inserted through the baffle plate in a horizontal direction. A plug plate that can slide horizontally inside the square tube is fixed to the inner end of the guide rod. A sealing gasket is provided between the plug plate and the inner wall of the square tube. A tightening screw is rotatably connected to the outer side of the plug plate. The tightening screw is threadedly engaged with the baffle plate. A handwheel is provided at the outer end of the tightening screw. A discharge groove is opened at the bottom of the square tube. The plug plate moves horizontally to open or close the discharge groove, realizing the sealed storage and directional discharge of residue.

[0014] Preferably, a method for removing sulfides during waste oil regeneration, using the aforementioned sulfide removal device for waste oil regeneration, includes the following steps:

[0015] S1. Open the feed valve on the side wall of the reaction tank and input the waste oil to be treated into the annular storage tank inside the reaction tank. After the waste oil is filled to the preset liquid level, close the feed valve and seal the cover at the top opening of the reaction tank to ensure that a closed cavity is formed inside the reaction tank.

[0016] S2. Start the vacuum pump connected to the bottom of the vertical pipe to extract the air from the sealed cavity of the reaction vessel through the vertical pipe. After the vacuum level in the cavity reaches the preset vacuum level for depressurization distillation, turn off the vacuum pump and use the one-way valve at the bottom of the vertical pipe to maintain the negative pressure state in the cavity to prevent the outside air from flowing back in.

[0017] S3. Start the electric heating wire in the storage tank to heat the waste oil in the storage tank in stages with controlled temperature. This causes the low-boiling-point sulfides and base oil fractions in the waste oil to evaporate in sequence to form distilled steam. The distilled steam flows upward along the vertical channel inside the reaction tank. High-boiling-point sulfides, gums and asphaltenes remain in the storage tank, achieving initial separation from the distillate oil.

[0018] S4. The upward-flowing distilled steam comes into full contact with the condenser rod and cone of the guide unit for heat exchange. The steam condenses to form condensate. The condensate of the pre-distillate containing low-boiling-point sulfides flows into the guide rod through the flow hole between the cone and the condenser rod. It is then guided by the inclined guide rod to drip into the collection frame. The discharge valve on the side wall of the reaction tank is opened to discharge the sulfur-containing pre-distillate in a directional manner, thus completing the removal and separation of sulfides. The condensate of the subsequent base oil fraction is collected separately to obtain desulfurized regenerated base oil.

[0019] S5. After the distillation operation is completed, start the electric heating plate at the bottom of the reaction tank. The high-temperature steam generated by the electric heating plate flows upward along the through groove in the center of the storage tank. The steam impacts the fan blades of the rotating unit and drives the rotating drum to rotate around the vertical pipe. The rotating drum drives the scraper to slide circumferentially against the inner wall of the storage tank through the mounting ring and connecting arm at the upper end. This scrapes off the sulfur-containing residue and coking material attached to the inner wall of the storage tank and collects them at the interface of the discharge unit.

[0020] S6. Rotate the handwheel of the discharge unit, and tighten the screw to drive the stopper plate to slide horizontally outward along the guide rod, so that the discharge trough at the bottom of the square tube is connected to the inside of the reaction tank. The collected sulfur-containing residue is discharged through the square tube and the discharge trough in a sealed manner. After the residue is discharged, rotate the handwheel in the opposite direction to drive the stopper plate to reset and reseal the discharge trough to prevent leakage of the medium inside the tank.

[0021] S7. Remove the negative pressure environment inside the reaction tank, take out the remaining desulfurization regeneration base oil in the storage tank, clean the inside of the reaction tank, the flow guiding unit and the cleaning unit, close all valves, and the device enters standby mode to complete this waste oil regeneration sulfide removal operation.

[0022] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0023] 1. In this invention, a closed vacuum distillation environment is constructed by using a vertical pipe in conjunction with a one-way valve and an external vacuum pump, which significantly reduces the vaporization boiling point of sulfide fractions and base oil fractions in waste oil.

[0024] 2. In this invention, the radially expanding multiple sets of condensing rods combined with a progressively variable diameter conical structure significantly increase the contact heat exchange area with distilled steam, enhance the condensation effect, and prevent the escape of uncondensed sulfur-containing steam. At the same time, the inclined guide rods and flow holes work together to achieve directional flow and collection of condensate, enabling the separate collection of sulfur-containing pre-distillate and regenerated base oil fractions, further improving the sulfide removal efficiency.

[0025] 3. In this invention, a steam-driven cleaning unit is used. The rising steam generated by the distillation process or the electric heating plate drives the fan blades to rotate, which in turn drives the scraper to slide along the circumference of the storage tank. The fully automatic online cleaning of residues and coking materials in the storage tank can be achieved without the need for additional power components such as motors. Attached Figure Description

[0026] Figure 1 This invention provides a three-dimensional structural schematic diagram of a sulfide removal device and method for waste oil regeneration.

[0027] Figure 2 This is another structural schematic diagram of a sulfide removal device and method in the waste oil regeneration process proposed by the present invention;

[0028] Figure 3 This is a partial disassembly diagram of a sulfide removal device and method in the waste oil regeneration process proposed by the present invention;

[0029] Figure 4 This invention proposes a device and method for removing sulfides during waste oil regeneration. Figure 3 Vertical cross-sectional view;

[0030] Figure 5 This is a partial schematic diagram of the collection hopper in a sulfide removal device and method for waste oil regeneration proposed in this invention;

[0031] Figure 6 This is a partial schematic diagram of the flow guiding unit in a sulfide removal device and method for waste oil regeneration proposed in this invention;

[0032] Figure 7 This invention proposes a device and method for removing sulfides during waste oil regeneration. Figure 6 Enlarged view of point A;

[0033] Figure 8 This is a partial schematic diagram of the cleaning unit in a sulfide removal device and method for waste oil regeneration proposed in this invention;

[0034] Figure 9 This is a partial schematic diagram of the discharge unit in a sulfide removal device and method for waste oil regeneration proposed in this invention.

[0035] Legend: 1. Support frame; 2. Fixing frame; 3. Reaction vessel; 4. Cover; 5. Feed valve; 6. Discharge unit; 61. Square tube; 62. Baffle plate; 63. Fastening bolt; 64. Guide rod; 65. Tightening screw; 66. Plug plate; 67. Handwheel; 68. Discharge trough; 7. Collection hopper; 8. Vertical pipe; 81. Guide rod; 82. Conical hopper; 83. Flow hole; 84. Condensing rod; 85. Collection frame; 9. Cleaning unit; 91. Storage tank; 92. Rotary drum; 93. Fan blade; 94. Through groove; 95. Mounting ring; 96. Connecting arm; 97. Scraper; 98. Reinforcing ring. Detailed Implementation

[0036] Example 1, as Figure 1-9As shown, a sulfide removal device and method for waste oil regeneration includes a reaction tank 3 arranged vertically. A cover 4 is detachably and sealed at the top opening of the reaction tank 3 via a flange and bolts. An oil-resistant and high-temperature-resistant sealing element is placed between the cover 4 and the contact surface of the reaction tank 3 to ensure the airtightness of the tank interior. A fixing frame 2 is fixedly fitted onto the outer wall of the reaction tank 3. Multiple sets of support frames 1 are evenly distributed circumferentially at the bottom of the fixing frame 2. The bottom of the support frames 1 can be fixedly installed on the working ground, thereby stably supporting the reaction tank 3 in a preset working position. A feed inlet is opened at the lower part of the side wall of the reaction tank 3, and a feed valve 5 is installed at the feed inlet. The waste oil to be treated can be stably input into the reaction tank 3 through the open feed valve 5. Inside the storage tank 91, which has a ring-shaped structure, an electric heating wire is embedded. The output power of the heating wire can be adjusted by an external temperature control system to uniformly heat the waste oil contained in the storage tank 91 for distillation. A vertical pipe 8 is inserted vertically at the center of the bottom of the reaction vessel 3. The upper end of the vertical pipe 8 extends upward to near the lower end face of the cover 4, and the lower end of the vertical pipe 8 extends to the outside of the reaction vessel 3 and is equipped with a one-way valve. The one-way valve only allows gas to flow from the inside of the reaction vessel 3 to the outside. A vacuum pump can be connected to the bottom of the vertical pipe 8. The vacuum pump can extract the air inside the reaction vessel 3 through the vertical pipe 8 to create the negative pressure environment required for reduced pressure distillation. The inside of the reaction vessel 3 is located above the storage tank 91. A collecting hopper 7 is fixedly installed. The collecting hopper 7 adopts a conical structure that is larger at the top and smaller at the bottom. The lower end of the collecting hopper 7 has a through opening. As the steam generated by heating flows upward, it can condense into droplets on the lower end face of the cover 4 and the outer wall of the collecting hopper 7. The condensed liquid can flow downward along the outer wall of the collecting hopper 7 and drip into the collecting frame 85 below. The collecting frame 85 is fixedly arranged circumferentially along the inner wall of the reaction tank 3. The liquid outlet of the collecting frame 85 is connected to the discharge valve installed at the corresponding position on the side wall of the reaction tank 3, thereby realizing the directional discharge of the condensate. A flow guiding unit is set in the area above the storage tank 91 inside the reaction tank 3. The flow guiding unit can fully condense and collect the distilled steam generated by heating. The condensed liquid can flow downward through the side wall of the reaction tank 3. The discharge valve directs the liquid outwards. The guiding unit includes a guide rod 81 that penetrates the side wall of the collecting hopper 7 along an inclined direction. The guide rod 81 has an internal guiding channel for liquid flow. The bottom outlet of the inclined guide rod 81 faces the upper opening of the collecting frame 85. Multiple condensing rods 84 are evenly arranged radially at the upper end of the guide rod 81, spreading outwards from the upper end to increase the contact area with the upward-flowing distilled steam and improve the condensation effect. Multiple conical hoppers 82 are sequentially fitted onto the outer wall of each condensing rod 84 from top to bottom. The diameter of the conical hoppers 82 gradually increases from bottom to top along the direction of the guide rod 81. The hoppers 82 further increase the contact area with the steam, achieving efficient condensation.A flow hole 83 is provided in the gap between the cone 82 and the outer wall of the condenser rod 84. The liquid formed by steam condensation can flow down the surface of the condenser rod 84 along the flow hole 83, and finally drip into the collection frame 85 after being guided by the guide rod 81. The interior of the reaction tank 3 is provided with a cleaning unit 9. The core supporting structure of the cleaning unit 9 is an annular storage tank 91. A through groove 94 is provided in the center of the storage tank 91 in the vertical direction. A rotating unit that can be driven by steam is provided inside the through groove 94. A scraper 97 is fixedly connected to the power output end of the rotating unit. The lower end face of the scraper 97 is closely attached to the bottom surface of the storage tank 91. The rotating unit can drive the scraper 97 along the inner circumference of the storage tank 91. The tank slides upwards to scrape off debris adhering to it and collect it at a preset discharge position. A heating plate is installed at the bottom of the reaction tank 3, below the storage tank 91. The heating temperature of the heating plate can be set higher than the heating temperature of the heating wire. Oil added to the reaction tank 3 is heated by the heating plate to generate steam. The generated steam flows upwards along the through-slot 94 and drives the rotating unit to rotate. The rotating unit includes a rotating cylinder 92 rotatably mounted on the outer wall of the vertical pipe 8 via a bearing structure. Multiple fan blades 93 are evenly installed circumferentially on the outer wall of the rotating cylinder 92. All fan blades 93 are located within the internal space of the through-slot 94. The steam flowing upwards along the through-slot 94 impacts the fan blades 93, thereby driving the rotating cylinder 92 to rotate around the axis of the vertical pipe 8. During rotation, a mounting ring 95 is fixedly connected to the upper end of the rotating drum 92. A connecting arm 96 is fixedly connected radially to the outer wall of the mounting ring 95. The end of the connecting arm 96 is fixedly connected to the side wall of the scraper 97. When the rotating drum 92 rotates, the mounting ring 95 and the connecting arm 96 can drive the scraper 97 to complete a circumferential sliding action along the tank of the storage tank 91. A reinforcing ring 98 is fixedly connected to the bottom of the storage tank 91. The outer ring surface of the reinforcing ring 98 is fixedly connected to the inner wall of the reaction vessel 3, thereby providing stable support and reinforcement for the bottom of the storage tank 91. A discharge unit 6 is provided on the side wall of the reaction vessel 3 at a position corresponding to the height of the storage tank 91. The discharge unit 6 can seal and discharge the solid and semi-solid impurities remaining in the storage tank 91 after distillation. Unit 6 includes a square tube 61 that runs horizontally through the side wall of the reaction vessel 3. The internal channel of the square tube 61 is connected to the internal cavity of the reaction vessel 3 and the interior of the storage tank 91. A baffle plate 62 is provided at the outer end of the square tube 61. The baffle plate 62 and the outer end face of the square tube 61 are detachably fixedly connected by multiple sets of fastening bolts 63. Multiple guide rods 64 are slidably inserted into the baffle plate 62 along the horizontal direction. A stopper plate 66 is slidably connected in the internal channel of the square tube 61. A sealing gasket is placed between the outer wall of the stopper plate 66 and the inner wall of the square tube 61. The outer end face of the stopper plate 66 is fixedly connected to the inner end of the guide rods 64. A tightening screw 65 is rotatably mounted at the center of the outer end face of the stopper plate 66 through a bearing structure.A tightening screw 65 passes horizontally through the baffle plate 62 and forms a threaded fit with it. A handwheel 67 is fixedly connected to the outer end of the tightening screw 65. The operator can rotate the handwheel 67 to drive the tightening screw 65 to rotate, thereby causing the stopper plate 66 to slide horizontally along the internal channel of the square tube 61. A through discharge groove 68 is provided on the bottom wall of the square tube 61. When the stopper plate 66 slides to the position between the discharge groove 68 and the reaction vessel 3, it can completely seal the discharge groove 68. When the stopper plate 66 slides away from the reaction vessel 3 to a preset position, it connects the discharge groove 68 with the internal cavity of the reaction vessel 3, thereby allowing the residue in the storage tank 91 to be discharged outwards.

[0037] The working principle utilizes the boiling point differences between different sulfide and base oil fractions to significantly reduce the vaporization temperature of each fraction under negative pressure, achieving precise separation of sulfides and base oil under mild operating conditions. It is equipped with a steam-driven self-driving residue cleaning structure and a fully enclosed slag discharge structure to prevent coking, blockage, and media leakage during distillation, ensuring continuous and stable operation of the unit. During formal operation, the waste oil to be treated is first fed into the storage tank 91 inside the reaction tank 3 through the open feed valve 5. After the waste oil reaches the preset level, the feed valve 5 is closed, and the cap 4 is sealed tightly to the reaction tank 3, forming a completely sealed cavity inside the tank. Then, the process is started. A vacuum pump connected to the bottom of the vertical pipe 8 continuously extracts air from the tank through the vertical pipe 8. Once the vacuum level inside the tank reaches the preset pressure reduction distillation requirement, the vacuum pump is turned off. The one-way valve at the bottom of the vertical pipe 8 prevents backflow of external air, maintaining a stable negative pressure environment inside the tank. Subsequently, the electric heating wire in the storage tank 91 is activated, and the waste oil is heated in stages through an external temperature control system. This causes the low-boiling-point sulfide components in the waste oil to vaporize first, forming distillation steam. The steam flows upward along the vertical channel inside the tank, and after sufficient contact and heat exchange with the open condenser rods 84 and the multi-stage conical hoppers 82, it condenses to form sulfur-containing condensate. The sulfur-containing condensate flows along the flow holes 8 between the conical hoppers 82 and the condenser rods 84. 3. The distillate flows into the guide rod 81, and after being guided by the inclined guide rod 81, it drips into the collection frame 85. Finally, it is discharged through the discharge valve to complete the removal and separation of sulfides. The base oil fraction that is subsequently heated and vaporized is collected separately after condensation to obtain the desulfurized regenerated base oil. After the distillation operation is completed, high-boiling-point sulfur-containing residues, gums and coke will adhere to the inner wall of the storage tank 91. At this time, the electric heating plate at the bottom of the tank is activated to generate high-temperature steam. When the steam flows upward along the through groove 94 in the center of the storage tank 91, it will continuously impact the fan blade 93, thereby driving the rotating drum 92 to rotate stably around the axis of the vertical pipe 8. The rotating drum 92 drives the scraper 9 through the mounting ring 95 at the upper end and the connecting arm 96. 7. Slide the circumferentially of the storage tank 91 to scrape away all the residue and coking material attached to the tank and collect it at the interface of the discharge unit 6. When performing the residue discharge operation, the operator turns the handwheel 67 to tighten the screw 65 and drive the plug plate 66 to slide horizontally outward along the square tube 61, so that the discharge trough 68 at the bottom of the square tube 61 is connected to the inside of the tank. The collected sulfur-containing residue can be discharged in a sealed manner through the square tube 61 and the discharge trough 68 to avoid leakage of harmful media and pollution of the working environment. After the residue is discharged, turn the handwheel 67 in the opposite direction to drive the plug plate 66 to reset, so that the discharge trough 68 can be resealed to restore the airtightness of the tank and complete the entire process of waste oil regeneration and sulfide removal.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may utilize the disclosed technical content to make changes or modifications to create equivalent embodiments applicable to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, still fall within the protection scope of the present invention. In the description of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood through specific circumstances.

Claims

1. A sulfide removal device for waste oil regeneration, comprising a reaction tank (3) arranged vertically, characterized in that: The top opening of the reaction vessel (3) is detachably sealed with a cover (4). The lower side wall of the reaction vessel (3) is provided with a feed valve (5). The oil enters the storage tank (91) inside the reaction vessel (3) through the feed valve (5). The storage tank (91) is equipped with an electric heating wire for heating the oil. The storage tank (91) is provided with a flow guiding unit for condensing and collecting distilled vapor above the storage tank (91). The condensate outlet of the flow guiding unit is connected to a discharge valve. The side wall of the reaction vessel (3) is provided with a discharge unit (6) for discharging distilled residue corresponding to the storage tank (91). A vertical pipe (8) is inserted vertically at the bottom center of the reaction vessel (3). The vertical pipe (8) extends upward to a position close to the cover (4). The bottom end of the vertical pipe (8) is provided with a one-way valve that only allows gas to flow out. The vertical pipe (8) is connected to a vacuum pump to form a reduced pressure distillation environment inside the reaction vessel (3).

2. The sulfide removal device in the waste oil regeneration process according to claim 1, characterized in that: The outer wall of the reaction vessel (3) is fixedly fitted with a fixed frame (2), and a plurality of support frames (1) are evenly provided around the bottom of the fixed frame (2) in the circumferential direction. The support frames (1) vertically support and fix the reaction vessel (3) to the ground.

3. The sulfide removal device in the waste oil regeneration process according to claim 1, characterized in that: Inside the reaction vessel (3) and above the storage tank (91), there is a conical collecting hopper (7) that is larger at the top and smaller at the bottom. The lower end of the collecting hopper (7) is open. After the steam rises, it condenses into droplets on the bottom surface of the cover (4) and the outer wall of the collecting hopper (7). The condensate flows down the outer wall of the collecting hopper (7) into the collecting frame (85). The collecting frame (85) is fixed circumferentially to the inner wall of the reaction vessel (3). The collecting frame (85) is connected to the discharge valve.

4. The sulfide removal device in the waste oil regeneration process according to claim 3, characterized in that: The flow guiding unit includes a flow guiding rod (81) that extends through the collecting hopper (7) in an inclined direction, with the lower end outlet of the flow guiding rod (81) facing the upper opening of the collecting frame (85).

5. The sulfide removal device in the waste oil regeneration process according to claim 4, characterized in that: The upper end of the guide rod (81) is provided with multiple condensing rods (84) evenly arranged radially. The condensing rods (84) are spread outward to increase the contact area with the steam. Each condensing rod (84) is fitted with multiple cones (82) with progressively larger diameters from top to bottom. A flow hole (83) is provided between the cone (82) and the condensing rod (84) for the condensate to flow down. The condensate flows into the collection frame (85) through the flow hole (83) and the guide rod (81).

6. The sulfide removal device in the waste oil regeneration process according to claim 1, characterized in that: The reaction vessel (3) is equipped with a cleaning unit (9) for automatically cleaning residues. The cleaning unit (9) includes an annular storage tank (91). A through groove (94) is opened in the center of the storage tank (91) and runs vertically through it. A rotating unit driven by steam is provided in the through groove (94). A scraper (97) is connected to the output end of the rotating unit. The scraper (97) slides close to the inner wall of the storage tank (91) and scrapes the residues to the discharge position. A heating plate with a temperature higher than that of the electric heating wire is provided at the bottom of the reaction vessel (3). Steam flows upward from the through groove (94) and drives the rotating unit to rotate.

7. The sulfide removal device in the waste oil regeneration process according to claim 6, characterized in that: The rotating unit includes a rotating cylinder (92) rotatably fitted onto the outer wall of the vertical pipe (8). The outer wall of the rotating cylinder (92) is uniformly provided with a plurality of fan blades (93) along the circumference. The fan blades (93) are located in the through groove (94) and are driven to rotate by the upward flowing steam. An installation ring (95) is fixed at the upper end of the rotating cylinder (92). The installation ring (95) is fixedly connected to the scraper (97) through a radially extending connecting arm (96). A reinforcing ring (98) is provided at the bottom of the storage tank (91). The reinforcing ring (98) is fixedly connected to the inner wall of the reaction vessel (3) to support the storage tank (91).

8. The sulfide removal device in the waste oil regeneration process according to claim 1, characterized in that: The discharge unit (6) is arranged horizontally on the side wall of the reaction vessel (3) and corresponds to the height position of the storage tank (91) to discharge the residue in the storage tank (91) out of the vessel.

9. The sulfide removal device in the waste oil regeneration process according to claim 8, characterized in that: The discharge unit (6) includes a square tube (61) that runs horizontally through the side wall of the reaction vessel (3). A baffle plate (62) is detachably connected to the outer end of the square tube (61) by a fastening bolt (63). A guide rod (64) slides horizontally through the baffle plate (62). A plug plate (66) that can slide horizontally inside the square tube (61) is fixed to the inner end of the guide rod (64). A sealing gasket is provided between the plug plate (66) and the inner wall of the square tube (61). A tightening screw (65) is rotatably connected to the outer side of the plug plate (66). The tightening screw (65) is threadedly engaged with the baffle plate (62). A handwheel (67) is provided at the outer end of the tightening screw (65). A discharge groove (68) is opened at the bottom of the square tube (61). The plug plate (66) moves horizontally to open or close the discharge groove (68) to achieve sealed storage and directional discharge of residue.

10. A method for removing sulfides during waste oil regeneration, characterized in that: The sulfide removal device used in the waste oil regeneration process according to claim 9 includes the following steps: S1. Open the feed valve (5) on the side wall of the reaction tank (3) and input the waste oil to be treated into the annular storage tank (91) inside the reaction tank (3). After the waste oil is added to the preset liquid level, close the feed valve (5) and seal the cap (4) at the top opening of the reaction tank (3) to ensure that a closed cavity is formed inside the reaction tank (3). S2. Start the vacuum pump connected to the bottom of the vertical pipe (8) to extract the air in the sealed cavity of the reaction vessel (3) through the vertical pipe (8). After the vacuum degree in the cavity reaches the preset vacuum degree of depressurization distillation, turn off the vacuum pump and use the one-way valve at the bottom of the vertical pipe (8) to maintain the negative pressure state in the cavity and prevent the outside air from flowing back in. S3. Start the electric heating wire in the storage tank (91) to heat the waste oil in the storage tank (91) in stages with controlled temperature, so that the low boiling point sulfides and base oil fractions in the waste oil are heated and evaporated in sequence to form distilled steam. The distilled steam flows upward along the vertical channel inside the reaction tank (3). The high boiling point sulfides, gums and asphalt remain in the storage tank (91) to achieve the initial separation from the distilled oil. S4. The upward-flowing distilled steam comes into full contact with the condenser rod (84) and cone (82) of the guide unit for heat exchange. The steam condenses to form condensate. The condensate of the pre-distillate containing low-boiling-point sulfides flows into the guide rod (81) through the flow hole (83) between the cone (82) and the condenser rod (84). It is guided by the inclined guide rod (81) and drips into the collection frame (85). The discharge valve on the side wall of the reaction tank (3) is opened to discharge the sulfur-containing pre-distillate in a directional manner, thus completing the removal and separation of sulfides. The subsequent base oil distillate condensate is collected separately to obtain desulfurized regenerated base oil. S5. After the distillation operation is completed, start the electric heating plate at the bottom of the reaction tank (3). The high-temperature steam generated by the electric heating plate flows upward along the through groove (94) in the center of the storage tank (91). The steam impacts the fan blades (93) of the rotating unit, driving the rotating drum (92) to rotate around the vertical pipe (8). The rotating drum (92) drives the scraper (97) to slide circumferentially against the inner wall of the storage tank (91) through the mounting ring (95) and connecting arm (96) at the upper end, scraping off the sulfur-containing residue and coking material attached to the inner wall of the storage tank (91) and collecting them at the interface position of the discharge unit (6). S6. Rotate the handwheel (67) of the discharge unit (6) and tighten the screw (65) to drive the stopper plate (66) to slide horizontally outward along the guide rod (64) so ​​that the discharge groove (68) at the bottom of the square tube (61) is connected to the inside of the reaction tank (3). The collected sulfur-containing residue is discharged through the square tube (61) and the discharge groove (68) in a sealed manner. After the residue is discharged, rotate the handwheel (67) in the opposite direction to drive the stopper plate (66) to reset and reseal the discharge groove (68) to avoid leakage of the medium inside the tank. S7. Break the negative pressure environment inside the reaction tank (3), take out the remaining desulfurization regeneration base oil in the storage tank (91), clean the inside of the reaction tank (3), the flow guiding unit and the cleaning unit (9), close all valves, and the device enters the standby state to complete this waste oil regeneration sulfide removal operation.

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